Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Grumblebuns on Sunday,May 06, 2018, 09:05:03 AM
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I'm almost done with the M/C swap out on my S2, just need to reinstall the linkage box assembly. What a pain in the ass this turning out to be, struggling the past week trying to get it in one last time. I've had it on and off several times during the M/C change out with little issue. For some reason I'm having some difficulty this time.
I'm thinking if using studs to secure the linkage box to the inside backing plate. Are studs as strong as bolts and should they used for this application?
If the studs can keep the holes in the backing plate aligned, I will probably use the studs to support the linkage box and swap out the studs one by one with bolts. The next time I do this, I'll get the right length studs for permanent use.
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My linkage box was frozen and rotten underneath. I was thinking that I would rebuild without a linkage box. It doesn't seem like a good solution to introduce an extra linkage. Have you considered this option?
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My linkage box is in good shape so I'm going to keep the box in place. Without the box, you will probably have to use a M/C with a remote reservoir due to the steering rack interfering with the reservoir. You can use a spacer, similar to the one that the twinks use but then it may intrude into the space for the spare tire.
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Spare tire? Are you still using a spare tire?! :)
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I'm thinking if using studs to secure the linkage box to the inside backing plate. Are studs as strong as bolts and should they used for this application?
Most of the studs I've come across on cars are plain mild steel (exhaust studs & engine block items mainly) whereas bolts come in different flavours and strengths. So as a universal "can I use a stud ?" I think the answer "maybe" but it's down to the type of bolt you're replacing.
Bearing in mind I don't have a car with this sort of arrangement and I'm in pure guesswork mode, then I think you'd be ok in this situation.
The bolts are taking the weight of the assembly (not much) and the tensile load from you pressing the pedal as hard as you can. That's usually taken as somewhere between 100-150lbs, factor in the 4.3 ratio of the standard Europa pedal arrangement and we're looking at what, 650lbs tensile load over 2 bolts ? That's pretty low in the grand scheme of things so I'd be surprised to see HT bolts specified for there.
Having said that, is there enough metal to hold a stud securely in place there ? What I tend to do in similar situations where I'm just making life easier for myself is to tack the bolt head onto on oversize washer with a flat on one side that jams in place to prevent it turning or a custom plate which links two bolts together. I don't know if that would work here but if there's not enough metal thickness to take a stud then it's an option.
Brian
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It's 16g sheet metal. You could spot weld in a bolt to make a stud. What I would do is braze/weld a length of steel to link the two bolts. That will make them more likely to stay in place, and easier to tighten the nuts as well.
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Spare tire? Are you still using a spare tire?! :)
Good question for a poll but yes, my S2 came with a spare Dunlop 155HR13, probably the same vintage as the car. No cracking in the sidewalls. If it holds pressure, I'll put it back in as a spare.
Thanks Brian for your input. The S2 linkage system uses four bolts to secure the linkage box to the chassis with an approx. 1/4" steel backing plate. The tensile load will be distributed over four studs and the relatively thin steel back flange of the linkage box. From your estimate of the load on the bolts, substituting same quality studs seems to be acceptable.
What I'm probably going to do is use studs long enough to have enough threads sticking out the rear of the backing plate to locktite a nut. I've attached a photo of the backing plate the studs will thread into.
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Looking at that backing plate I think you'll have no problems, and more to the point you'll have a much easier job should you need to pull it apart again. I didn't realise there was such a substantial backing plate, I bet Chapman didn't realise that was in there, he'd have thrown a fit ! ;)
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I did what John C. suggested. Spot welded bolts into the backing plate. Have had that for over 20 years with no problem.
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At this point it will be easier for me to use studs. I have four Gr 8 studs on order, overkill I'm sure for this application.
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Hi Grumblebuns, please double check that lower control arm nut. I don't like how the threads aren't getting into the locking part of the lock nut. Maybe it's nothing but...
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Hi Grumblebuns, please double check that lower control arm nut. I don't like how the threads aren't getting into the locking part of the lock nut. Maybe it's nothing but...
I had the same problem with the 3/4" nut that holds the anti-roll bar drop links on the top front wishbone studs.
I drilled the nut through the stud and out the other side, and fitted a split pin.
The washers I used were thicker than the originals, the nut was wider, there were still enough turns left on the thread, but the Nylock was doing nothing.
The first nut/stud took ages to drill, the second took about a minute.
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Since the A-arm pivot shafts are in shear, half height lock nuts are a good solution when there isn't enough length to fully engage a full height lock nut.
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I did notice the nut being fully threaded while doing the M/C change out. The opposite side is in the same condition. It looks like the PO may have used shorter pivot pins in the past. I'm thinking of drilling and safety wiring the nut but I like the idea of using half height lock nuts as BDA suggests. Thanks for the reminder.
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The nut in pic also appears to be a flanged nut. Wouldn’t be surprised if that explains some of the extra thickness.
Perhaps consider an “all metal” lock nut which is shorter than a standard Nylock?
Like this:
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Those would work. Nylon lock nuts can also be found in half height. I thought I had seen them at Lowes but I can't find them online. You can get them at Aircraft Spruce (https://www.aircraftspruce.com/), probably ebay, or some racing supply stores. Another trick half height nut is a "jet nut" which is an all metal lock nut. You can get them on ebay.
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The nut in pic also appears to be a flanged nut. Wouldn’t be surprised if that explains some of the extra thickness.
Perhaps consider an “all metal” lock nut which is shorter than a standard Nylock?
Like this:
I thought I read somewhere that the all metal style locknuts were one time use only due to the damage to the threads when used. I'll measure the thickness of my current nut versus a regular nylon locknut.
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Unfortunately you cannot thin down a normal Nylock on a grinder, as the heat melts the plastic.
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You're SUPPOSED to replace all lock nuts every time. I think you can be perfectly safe replacing them every third time or so as long as I need a wrench to turn it in the lock zone. I use the same rule for metal lock nuts except in high heat applications were I'll replace them every time or two.
Edit:
I forgot to say that using nylon lock nuts on threads created by a die means it almost has to be changed every time because those threads cut the nylon whereas the rolled threads of a bolt push the nylon aside.
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I thought I read somewhere that the all metal style locknuts were one time use only due to the damage to the threads when used. I'll measure the thickness of my current nut versus a regular nylon locknut.
Yes, and that's the recommendation for most lock nuts as far as I can tell.
But as BDA says, you can get away with stuff . . just have to ensure there's "sufficient" drag caused by whatever locking mechanism is employed.
The 'all metal' lock nuts have a triangular deformed area on the exit side but don't seem to be detrimental to the threads from my experience. They are commonly used in high heat applications where a Nyloc would melt.
Anyway, if you like, measure your lower pin length.
I can measure my Type 54 (in bits) which I assume is the same, and compare.
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OK, I've measured the lower pin length - the available length.
51 mm (2.0”)
Does that help?
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OK, I've measured the lower pin length - the available length.
51 mm (2.0”)
Does that help?
Gavin, my overall lower pin extension from the end of the nut to the beginning of the pivot pin tube on the chassis is 2". My nut is not flush with the end of the pin by about 1/8".
I've attached a picture of a locknut similar to what is now on my S2, a used locknut from my TCS and a half height locknut. What would be optimal is to locate a locknut similar in height to the TCS nut. All of the 1/2"-20 nylon insert locknuts that I've checked out have the same approx. height as the tall locknut shown. I haven't checked out the all metal locknut yet. IF I can't find a shorter full height locknut, there may be room to use two of the half height locknuts back to back.
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If room is tight, how about a regular nut and split lock washer? Myself, I would not use half height nylocks as suspension fasteners. I used to do OPI (out-of-province) inspections and I would fail any car so equipped.
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I use jet nuts on some of my A-arm pivots (I might use them on all. I don't remember). They are about the same height as the half height nyloc nut but I think they are stronger.
Half height nuts are designed and intended for bolts that are stressed in double shear (i.e. there is essentially no load on the nut other than what is imparted by tightening and the torque specified is on the order of 1/2 that specified for a full height nut) which makes them appropriate for most of the suspension. However, I would not use them for the radius arm pivot, for example, because it is only in single shear and if the bolt bends, that could put a tensile load on the nut.
Having said all that, JB got me thinking. The front A-arms are in double shear except possibly in an accident. Because the A-arms are not held captive by anything other than a big washer and a nut, an A-arm that is being bent could impart a tensile load on the nut. If the A-arm halves were inside the frame rather than outside, this would not be an issue but they're not so it is. During an accident, it is much better to have even a bent suspension piece remain attached to the car rather than come off the car because of a failure of the nut. I did a bit of digging and found that jet nuts (MS21042) are rated at 160kpsi and the full height aircraft nylon lock nut (AN 365) is rated at 125kpsi. So I feel comfortable using jet nuts on the A-arm pivots. I would note that AN and MS standards are much more rigorous than SAE standards which govern nuts and bolts we normally put cars together with (for example, grade 5 and grade 8 are SAE designations).
Auto safety regulations are another matter and should be followed regardless.
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G’day Grumbles,
I’ve attached a pic of my pin with an A-arm installed. The bush in the A-arm is a stock OEM item.
I’ve measured all four of the lower pin lengths and they’re all the same - 51 mm (2.0”).
The nut in my pic is a thick one and pretty much the same as the left hand one in your pic.
As you can see, it’ll fit OK.
Nut height: 15.02 mm (± 0.05)
A-arm bush inner steel sleeve: 35.05 mm (± 0.02)
So, the math seems to add up.
By process of elimination, I wonder if your inner bush sleeve is a bit too long?
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I'd be ok with jet nuts as there is a lot more thread length than with the nylock half nuts.
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The front A-arms are in double shear except possibly in an accident.
Nah, the A-arms are in single shear.
The lower damper mounting and the trunnion are in double shear, however.
(https://upload.wikimedia.org/wikipedia/commons/b/b7/Bolt-in-shear.PNG)
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Myself, I would not use half height nylocks as suspension fasteners. I used to do OPI (out-of-province) inspections and I would fail any car so equipped.
I've got to agree with John here, looking at those half height nuts they don't inspire me for this application. I'd want a bit more thread and the ability to get the full torque setting to clamp the inner sleeve securely because if it starts rotating then I've no idea what would happen. Probably nothing, but I wouldn't want to find out the hard way.
While the conversation is about nut height, I did start to wonder about the overall pin length and whether it's been set centrally in the past. It would be very handy if there were 1/4" of thread sticking out on the rear nut.... :)
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Let me first say that while I do have a degree in mechanical engineering, I only worked as one for a few years and it was a LONG time ago so I don't really consider myself an engineer anymore. I have to make some modifications to what I've posted here.
Gavin:
I was going to disagree with you but the more I thought about it. I have to agree - BUT I think for our purposes we can consider the A-arms to be in double shear and here's why: If the A-arm halfs were welded together at the outboard end and the 'T' section of the frame was solid - no place for the shock - that would look like the double shear picture you posted. Now, that's not exactly the situation we have so in analyzing the stresses, it probably makes sense to consider the pivot to be in single shear for safety but I think for the purposes of what nuts we might use on the pivot, double shear rules work here.
JB & Brian:
In my previous post I didn't consider the number of threads engaged in a half height nyloc nut. I was taught that if you had four threads engaged, you had essentially full strength of the nut. A half height nyloc nut only has 2-3 so I think they should be used only in unambiguous double shear applications so I think JB and Brian are correct about using either a full height nut or a jet nut on the front suspension. A half height nyloc nut is not appropriate there.
While I was researching this I found a couple of interesting points. Jet nuts are infinitely reusable (says Carroll Smith, author of Prepare to Win, Tune to Win, and Nuts, Bolts, Fasteners and Plumbing Handbook
). Also that even though I believe the manual says not to reuse nyloc nuts (and I've heard others say they only use them once), it is perfectly acceptable to reuse them if they can't be turned by hand. This is a practice I've used but at least partially to save money. It was nice to see that stated authoritatively!
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Also that even though I believe the manual says not to reuse nyloc nuts (and I've heard others say they only use them once), it is perfectly acceptable to reuse them if they can't be turned by hand. This is a practice I've used but at least partially to save money. It was nice to see that stated authoritatively!
:) me too !
If a nut stops when the nylon meets thread and I need a spanner to get it to turn, then I also re-use it although I do tend to chuck any nut away that looks a bit on the rusty or "used" side with marks on the flats. I'm in two minds about nylocs if I'm honest, I feel that the biggest thing stopping a nut coming loose is getting the correct loading and not the bit of nylon in the end. Having said that, I'm not about to experiment with replacing all nylocs with plain nuts !
BUT..... I'm definitely not a mech. eng. guy so it was interesting to hear the "4 threads" theory. My dad used to be a fitter and I remember him saying something about having the same depth of thread engaged as the bolt diameter which I've generally followed when doing stuff. Logically though the number of threads engaged probably makes more sense and is easier to apply.
Yet again a topic on here has been another school day !
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I think the nylon really keeps vibrations from loosening the nut rather than acting as resistance to loosening (which could be a distinction without a difference!).
On a similar subject, Carroll Smith does not believe in split lock washers. I don't use them unless I have no other choice. I suspect the spring action is intended to perform a similar function as the nylon but a friend of mine who was an engineering classmate and became a REAL engineer and recently retired from Shell Oil as one of their best rotating equipment men told me an interesting story from early in his career. They had a machine that was literally shaking itself apart. They used regular nuts with spring lock washers and the vibrations were so severe that the ends of the spring washers actually gouged grooves in the metal as it loosened!
So what does that mean? Maybe the way they really work is that the sharp ends of the lock washer dig into the nut and the part - at least in part. If that's true, that means that it's probably not a good idea to put a flat washer under the spring washer because it will just rotate as it loosens defeating what could be part of the purpose of the lock washer.
Incidentally, my buddy figured out and cured what was causing all the vibration and was one of his early successes. I don't remember if he changed the nuts to lock nuts though.
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I was taught by a meticulous rally mechanic to lock wire any nuts that could vibrate loose, and when going under a car, take spanners with you to check all the nuts and bolts are tight.
He also argued with the head of Austin-Rover motorsport on the Tour de Course International Rally that no-one should be asked to go under a rally car held up only by a jack, i.e. no axle stand.
On this basis, to drill and split pin a nut which is 6 full turns on the thread, but too short for a Nylock, gets my seal of approval.
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I agree that lock-wiring is an excellent idea. I run a Ducati single that vibrates quite a bit. Everything essential is lock wired. Lock wiring requires a hole through a single "ear" of the nut. The strength of the bolt is only compromised a very small amount.
Drilling right through the centre of the nut and using a split pin? Not so much. You are weakening both the nut and the stud/bolt. Split pins are always at the very end of the castellated nut, not in the middle. You also can't check the nut, or tighten it if things settle. If you want to use split pins, then use a proper castellated nut as well.
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G’day BDA,
About your hypothetical re the A-arm halves being welded together at the outboard end, that makes sense, too - no mechanical engineer here though.
I was thinking through my reply when I read your phrase, “in unambiguous double shear applications”.
That’s it in a nutshell, for me.
If we were talking about a crane lifting 100 tons, then we’d be perfectly justified in wanting the hook to be attached in double shear. But I agree, our front A-arms aren’t primarily looking to perform that same discreet function.
In fact, if we were to consider function, then the existing A-arm mounting system is reasonable IMHO.
If there were another chassis plate with a through hole on the outside of the A-arm, that would complete the double shear picture.
But is that what we want?
I say, no.
If we hit a curb, it’s likely either the A-arm or the pin will bend. That’s a much better outcome than the chassis taking the full force. The same argument applies to folk who consider changing fasteners to Grade 8 to be an upgrade.
On the non-reusability of Nyloc nuts, I strongly suspect this recommendation originates from the Nyloc manufacturer and likely relates to liability issues.
The Nyloc OEM has no control over the broad range of intended applications and therefor is in no position to sanction a second or third time usage.
The other thing to consider with the half height Nyloc nut is this; if we can’t apply full torque to it, then the assembly can’t function correctly. I somehow doubt clamping the inner steel sleeve of the rubber bush is achievable with 2 - 3 threads.
I’m glad you mentioned Carroll Smith’s books. I think I’ve got the same ones and everyone with a Lotus should have them on the shelf, I reckon . . even if it’s only to figure out exactly how sneaky Colin was. :))
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I managed to remove the offending nut to get a slightly more accurate length of the exposed threads. The picture of the measuring scale is washed out by the flash but it measures about 0.5" from the end of the bushing inner sleeve. The removed nut and washer measures 0.663"/16.84mm. At the rear attachment point, the pivot pin appears to e flush with the end of the nut. From Gavin's picture of his nut next to the pivot shaft threads, appears that I'm about three threads short of minimum acceptability for thread reach.
So for me the question is what is safer, having a thinner locknut with fewer threads engaged on the shaft or my current situation, a wider nut with maximum threads engaged but can be safety wired to prevent loosening assuming same material grade. Right now I'm leaning towards safety wiring the nut as the safest option with wicking blue locktite as backup.
I can't figure out where the difference in pivot pin thread length between Gavin's and mine is.
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Gavin, I agree that the standard A-arm arrangement is certainly reasonable. Except for the use of trunnions, it's not different from older race car suspensions. As you mentioned, the frame is important to protect (thus the driver and passenger on either side to protect it in the event of an accident!) and that's why the A-arms are designed the way they are - so that in the event of an accident, the A-arms will absorb a lot of the energy of the crash. I would think that the pivot pin would survive almost any accident. Of course, now that those arms are becoming scarce, we have to go to tubular replacements which puts the frame at risk.
I always used either Grade 5 bolts or AN bolts because they are less brittle than Grade 8. I've known people who use Grade 8 without problem and I know someone who used a Grade 8 bolt and it broke in an accident. I don't think Grade 8 is the wrong choice but I think Grade 5 or AN are preferable. AN is more preferable because of the reduced length of threads but are a lot more trouble because it requires you to keep a large inventory of lengths and you must measure the thickness of the clamped parts.
Smith's books are excellent. They are invaluable if you're building race cars and while a lot of the information he gives out is pretty esoteric with regard to street cars, it's always nice to understand things at a different level.
Re: "unambiguous double shear" - I'll be asking my REAL engineer friend what he thinks about parameters for double/single shear.
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Joji, It seems to me that when I took my car apart, it had full height nuts on the pivot pins and everything fit but for some reason, when I put my car together, I needed half height nuts. I offer no explanation, nor do I trust my memory, but I don't think there were half height nuts anywhere on the car originally.
There should be a two or three threads past the nut when it's tightened but if all the nylon grips the threads, that should be sufficient. I put a big washer on the outside of the A-arm half (under the nut) to help retain the A-arm in the unlikely event that the bushing delaminates. That's probably overkill but maybe that's why my pivot shafts seem shorter.
It maybe time for jet nuts.
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I can't figure out where the difference in pivot pin thread length between Gavin's and mine is.
G’day Joji,
Did you measure the inner steel sleeve of the rubber bush?
My current thinking is that it’s a bit too long.
My bush inner steel sleeve: 35.05 mm (± 0.02)
I wouldn't consider using a half height Nylock for this situation, because I doubt you could apply the required torque loading.
Safety wiring and Loktite would be a PIA in my book.
According to the Pegasus Racing site, a 1/2” Jetnut is 0.410" high . . and at $4.99 each, sounds like a quick and easy remedy.
https://www.pegasusautoracing.com/productselection.asp?Product=MS21042
BDA,
Since you also experienced the need for shorter nuts, I wonder if you’d also replaced the A-arm bushes at the time of rebuild?
If yes, perhaps there’s some replacements out there that are a little longer than the OEM items and that’s also what Joji is dealing with?
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perhaps there’s some replacements out there that are a little longer than the OEM items and that’s also what Joji is dealing with ?
When I fitted poly bushes the stainless inserts were fractionally longer than the OEM ones and stuck out too much IMO. From hazy memory I think I ground them down a touch so they were only just proud of the bush. When I fitted new wishbones to the Elan later on I bought conventional bushes from SJS and they were correct.
It wouldn't surprise me at all to find replacement bushes not quite to the same dimensions. But realistically we shouldn't have to worry about one or two mm on this sort of thing, I'd be tempted to replace the pin for a longer one instead.
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BDA,
Since you also experienced the need for shorter nuts, I wonder if you’d also replaced the A-arm bushes at the time of rebuild?
If yes, perhaps there’s some replacements out there that are a little longer than the OEM items and that’s also what Joji is dealing with?
I did replace my bushes but they didn't seem unusually long to me. I would say with all this talk about it, I should take a wheel off and make sure I'm being accurate.
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G’day Joji,
Did you measure the inner steel sleeve of the rubber bush?
My current thinking is that it’s a bit too long.
My bush inner steel sleeve: 35.05 mm (± 0.02)
BDA,
Since you also experienced the need for shorter nuts, I wonder if you’d also replaced the A-arm bushes at the time of rebuild?
If yes, perhaps there’s some replacements out there that are a little longer than the OEM items and that’s also what Joji is dealing with?
I can't really measure the inner sleeve without removing the A arm. The Europa manual doesn't even address the bushings so no specs or how they should be pressed in. The parts manual for the S2 shows a washer only on the outside ends of the bush, no washer on the inside, mine has a washer on the front inside bush. Looking at the picture of my bush area, there is only about 1/8" protruding from the A arm sleeve, zero from the rear due to the washer I mentioned earlier.
With the thickness spec Gavin mentioned for the jetnut, I'm leaning towards going that route, its simpler than drilling a nut for safety wire.
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I'd be tempted to replace the pin for a longer one instead.
I recall this was discussed some time ago but I don't remember the outcome.
My foggy memory says that the TC lower pin is removable but the S2 pin isn't. :confused:
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A very interesting discussion about locking nuts.
As shown, not all applications can use nylocks, or sometimes locking nuts are just not at hand.
For many years, we made our own lock nuts using a common hex nut and never experienced premature loosening.
(1) A common hex nut of the appropriate thread size is placed on a hard, immovable surface.
(2) The rounded end of a ballpein hammer (larger than the i.d. of the nut) is placed on top of the nut.
(3) The other end of the ballpein hammer is struck by a larger, heavier hammer, thus deforming the top few threads of the nut. (Yes, I am aware of the risks of striking a hammer with another hammer, so common sense needs to prevail.)
(4) The deformed threads are the "outer" portion of the nut and are the last to contact the male threads. ....The amount of deformation needed can be gauged by the force needed to thread the nut onto male threads.
(5) The nut can be re-used if deformation is re-done, but why bother? ...It's a common hex nut!
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It is fun to watch the metamorphosis of a topic.
From my part box new Dave Bean bush (old style)inner length 1.365 on my dial caliper.
Gary
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The parts manual for the S2 shows a washer only on the outside ends of the bush, no washer on the inside, mine has a washer on the front inside bush...
With the thickness spec Gavin mentioned for the jetnut, I'm leaning towards going that route, its simpler than drilling a nut for safety wire.
I also put a washer between the frame and the A-arm bush in addition to one on the outside because I experienced delamination in one or two bushings that I recently said was unlikely (I think I've already apologized for my geezer memory). Perhaps that's why yours also has one.
I agree with your not wanting to safety wire the nut. It's a bigger job than it looks as you need to get a jig for drilling the hole in the nut for the wire. I had one once and it was pretty hit or miss so I take that to mean that I needed to spend more money on one.
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I'd be tempted to replace the pin for a longer one instead.
I recall this was discussed some time ago but I don't remember the outcome.
My foggy memory says that the TC lower pin is removable but the S2 pin isn't. :confused:
Delving into the cobwebs of my memory, I am pretty sure I put red Loktite on my lower pivot pin. I had a jet nut welded on the end of my upper pivot pins. I don't remember if the TC lower pivot pin was originally locked similarly but I suspect it was since it makes taking it apart much easier.
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Good lock-wire jigs work very well as long as you remember to clear the drill bit and hole as you drill. The swarf build-up can jam the small bit and break it.
You only need washers on the outside as one, or the other, will prevent sideways movement.
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Yes, you need a good one. Probably one with a hardened drill guide and using cobalt drill bits is probably a really good idea. Because you're drilling on an angle, it's really easy to break bits. I thought I got mine from a trusted source but it wasn't a good one and I gave up after breaking a few bits. I would expect that my technique probably left a lot to be desired too.
We discussed the issue of the bushings coming apart before. I was very lucky to have found the thread and guess who started it? You, JB! http://www.lotuseuropa.org/LotusForum/index.php?topic=1709.0
I am certain that I had a washer on the outside of all of my bushings but still got delamination (see attached picture). You brought up that there seem to be two styles of bushing and that those whose ends are rolled over a bit work best. It's very possible that the bushings that failed on my car were the "unrolled" (i.e. straight outer tube) and that was my problem but I decided to put a large diameter but thin washer between my bushing and the frame (I posted a picture on the aforementioned thread of the washer installed on my suspension but you have to look VERY carefully to see it) and the problem went away. It could also be that the replacement bushings were of the "rolled" type.
Since it was on the lower A-arm, I figure that either one arm was warped a bit or more likely, the bushing for the bottom of my SPAX shock was a bit smaller than stock and tightening it tended to try to squeeze the inboard end closer together. When I found it, I posted to the yahoo group about it and I had several people say they had the same problem. Thinking about it more now, When assembling the front suspension, I think it make sense to build the lower A-arms with shock and trunnion and put it up to the frame first to see if you should shim around the lower shock mount in case that is a cause.
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. . . I think it make sense to build the lower A-arms with shock and trunnion and put it up to the frame first to see if you should shim around the lower shock mount in case that is a cause.
Excellent point.
Given the different types of bushes available and, I suspect, different lengths, this idea certainly has some merit.
EDIT to add:
Also, Joji provided a pic of the Nyloc nut from a TCS.
That nut is shorter than the ~15 mm nut we’ve been discussing, so perhaps that's the Goldilocks solution.
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I finally got the jet nuts in from Pegasus and doing a trial fit, it looks like they will do the trick. With a washer between the nut and the inner spacer, I have about two threads showing. Looing at the TCS nut, I'm wondering if Lotus had special lock nut made for the Europas. Anyway, I'm calling this problem fixed. Time to move on to finishing up the master cylinder installation
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I'd call it done too, Joji,
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Looks good Joji.
I kinda like those flanged Jetnuts for this situation.
I agree the TCS nut looks fine.
I didn't mention it previously, but when I was checking some nuts for a reply, I accidentally picked up a 12 mm Nyloc.
It's about the same size as your TCS nut.
Anyway, it's done as you say.