Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Dilkris on Tuesday,February 02, 2021, 09:43:54 AM
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During the disassembly/inspection/reassembly process on the 365 Gearbox you will recall that I went on a journey regarding the sourcing of the 2 taper roller bearings for the differential; the "journey" is on this forum.
The transaxle is now back together, (I do not like to have things disassembled for long periods of time as I "forget stuff"), but there are 2 issues with the unit which I am uncomfortable about - I address just one of them here.
Upon removing the 5th gear housing I noticed that the detent plunger for the 5th Gear was not there, (the external plug was, but there was no spring or plunger, items 23 and 24) - please refer photo and parts page. Neither was it floating around in the gearbox. :)) :))
My question is, (and perhaps a stupid one), should it be there and if so, what does the Lotus external 'Heath Robinson' indent arrangement do? (item 26) - or does the latter make the original Renault indent redundant?
Finally, the million dollar question, if the plunger and spring, (items 23 and 24), should be there, where can I get them? (Anybody got a redundant/destroyed 365 in pieces? :help:)
Obviously they can be fitted with the box assembled, which is why I pressed ahead and put the whole unit together.
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I've not worked on a 365 but the parts diagram shows that the 5th gear detent should be in place. Why they need another one as well, I have no idea. I'm running a 395 and the stock, internal detent works well albeit I have a low-inertia cable shifter. Wait for someone who has worked on a 365 to comment before getting too worried.
There are a number of 365s out there bad 5th gears that may be able to supply parts.
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I purchased a complete 365 from Grumblebuns on this forum. In the transaction was a return of my detonated 365. You should contact him if you need diagnostic or parts.
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The 365 didn't come with the internal 5th gear detent ball and spring. But a member here, from Denmark I think, has a few he sourced and is selling.
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The 365 didn't come with the internal 5th gear detent ball and spring.
So the spring and plunger are not missing - they are just not fitted on this application?
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As far as I can remember it is not there and relies on the external reverse 5th gear cam and ball set up. If it there engaging 5th might be rather difficult
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It seems the consensus of opinion is that it is removed and effectively replaced by the "Lotus" external cam plate arrangement; in conjunction with comments received from members I also contacted Steve at SJSports (UK) who feels that the above conclusion is in all probability correct. So I am missing nothing it seems - which is good news (I think).
However, it begs the question, "Why is it removed and why do Lotus modify the selector shaft into the gearbox to allow for the fitting of their external cam plate which locates 5th gear and reverse?"
In my earlier ignorance I was of the impression that the 5th gear on the 365 gearbox was a 100% "Lotus" addition - which explained the "crude" adapter plate on the rear of the gearbox which permitted the installation of the 5th gear casing and internals. This however is not the case as Renault made the 365 gearbox (with 5th gear) and fitted it to their Renault 15 and 17 cars (1972-1979). I know this as I managed to find a copy of the Renault 15 & 17 Haynes manual on ebay. The adapter plate for the 5th gear casing prevails.
What Lotus did to this box, (please correct me if I am mistaken here) was change some of the gear ratios with Hewland manufactured components AND added their external cam plate for reverse and 5th gear.
So now we are back to square one. As the 365 box existed in original 5 speed form, why was the original 5th speed internal plunger and spring removed and replaced with the Lotus external cam plate.??? :confused: :confused:
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The original 5th gear ratio was 0.93 (or 0.91, would have to look it up). Using it as supplied would mean that the 5spd equipped cars (3.78 final drive) would be slower than the 4spd equipped cars (3.56 final drive). So Lotus had Hewland make up a 0.86 5th. In the Renault application, the 365 has 5 nice spaced gears. The Lotus 365 is a 4spd with an OD 5th. That explains the ratio change.
I can only speculate on why the 5th gear detent was dropped. If they had to make a detent for reverse, why not make it for 5th as well?
Myself? I would refit the Renault detent spring and plunger and make up a reverse lock out at the shifter. Side to side gives you either the 1-2 rail or the 3-4 rail. Push through the detent to 5th. Work through the lock out for reverse. I did this with my 395 and shifting is problem free and intuitive.
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I can only speculate on why the 5th gear detent was dropped. If they had to make a detent for reverse, why not make it for 5th as well?
Myself? I would refit the Renault detent spring and plunger and make up a reverse lock out at the shifter. Side to side gives you either the 1-2 rail or the 3-4 rail. Push through the detent to 5th. Work through the lock out for reverse. I did this with my 395 and shifting is problem free and intuitive.
I agree John - fortunately as the Renault detent plunger and spring can be fitted without disassembling the 5th gear casing I can try it "in or out" - I just have to locate the 2 parts first.... (spring and plunger):help:.
I like the reverse lock out idea but for me I see this as a stand alone project for when the car is back together.
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It is a good idea to use the location for a reverse lock. I also tried with an electrical system on an NG3. But the lifespan was very limited. Electromagnet problem
https://www.youtube.com/watch?v=A5_IgWX299g
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Here's a short video of the mock up of my reverse lock out:
https://jbcollier.smugmug.com/Lotus-Europa/i-4qr8BZx/A
Here's the finished piece:
(https://photos.smugmug.com/Lotus-Europa/i-nc9PsWm/0/2f94ad0c/X2/IMG_1408-X2.jpg)
Very simple to make. The shift boot is the "spring" to lift the lock out tube up:
(https://photos.smugmug.com/Lotus-Europa/i-7cfKc95/0/5a1cb9aa/X2/60764478355__71CD8718-B89D-4491-A28B-F07B77A2E96A-X2.jpg)
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Yes it is a good solution.
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I looked through my old messages. I got the reverse detent ball and spring from member Peter Boedker (pboedker). I also got his reverse lockout kit. At the time he said he had a few left. So you might contact him.
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I looked through my old messages. I got the reverse detent ball and spring from member Peter Boedker (pboedker). I also got his reverse lockout kit. At the time he said he had a few left. So you might contact him.
Thankyou Kendo - just to be clear I am looking for the 5th gear indent INSIDE the 5th gear housing and it consists of a plunger and spring. (The external Lotus indent system is the one with the ball and spring - I have that assembly.)
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I think your best bet is to find someone with a Renault 365 and get them to measure up the plunger and spring. Should be simple to have a plunger made if you have the dimensions.
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I looked through my old messages. I got the reverse detent ball and spring from member Peter Boedker (pboedker). I also got his reverse lockout kit. At the time he said he had a few left. So you might contact him.
Thankyou Kendo - just to be clear I am looking for the 5th gear indent INSIDE the 5th gear housing and it consists of a plunger and spring. (The external Lotus indent system is the one with the ball and spring - I have that assembly.)
If I recall the post correctly Peter Boedker was offering the Reverse Lockout kit AND the internal spring/ ball bearing for the 5th gear detent so the external reverse solution for both could be completely removed (cam, housing, spring and bearing).
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Yup, S-Beast is correct:
http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg706#msg706
Specifically:
http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg5746#msg5746
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Here is the link for pboeker's solution/kits http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg8263#msg8263 (http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg8263#msg8263)
Edit: Mr Collier beat me to it!
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Thanks so much everyone!! - I now have sufficient leads to pursue this to a conclusion. (It is also now clear that Lotus remove the Renault 5th gear internal indent system on the 365 and replace this function with their own external indent set up- but it still remains a mystery as to why !!. :confused:)
jb - I was fascinated with your pictures of the reverse lock out system and was wondering why you went for this approach as opposed to the Ferrari system of visible gates - was the decision made on visual reasons or is there a technical reason for not going "Ferrari" - or maybe you just don't like Ferrari's ;)
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In the LOTUS EUROPA MASTER DOCUMENTATION MENU found at http://lotus-europa.com/manuals/
A series of 5 pictures and a drawing are available from Tom Rollins, the previous owner of my current Europa, of a 5 Speed Reverse Lockout.
Thought this should be added to this discussion.
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Gates are great at protecting expensive trannies, not so great for shifting quickly. You can find Ferraris with the gates removed, or, long ago, cut away (yikes). An open shifter with proper delineated rail selection via internal spring loading and reverse lock outs is much nicer to use and quicker to shift. I go from 3rd to 2nd with nary a second's thought. As it sits naturally in the 3-4 slot, 5th to 4th is equally easy.
I think the Lotus shifter mech has a lot of inertia and this may mask the internal selector guide springs of the stock Renault transaxle. Mine is a cable shifter so I can't fairly comment on that. Mine shifts like butter.
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It appears we have just reinvented the wheel - why I never search the Master Documentation Data is beyond me. :headbanger: As jpane points out, within another post (by Aaron Hines) quotes - "The external 5th gear/reverse detent is a poorly designed factory addition to the 365-07 transaxle. I installed Renault's internal 5th gear detent"
Within the Transmission & Final Drive section, information extends to include 5th gear lock out methods (Tom Rollins) as advised.
Once again, many thanks to all.
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Coming in a little late to the discussion for various reasons, I have a few comments to the Lotus detent system, as I see it. ;D
My theory is that Lotus needed to do something about a reverse gear lockout when switching from the 336 box to the 352 box (4 speed). So they added their own detent plate with one cam to the backside of the transmission. When the 365 (5 speed) was introduced the detent plate got another cam, and the internal Renault plunger was removed. And now all the trouble began, because the detent cover had to be adjusted very delicately to even have a small chance of getting it right. "That is the theory that I have and which is mine and what it is, too." ;) ;)
For my part I never succeeded in adjusting it properly which led me to removing mine and fabricating my own reverse liftup handle and a copy of the Renault-style internal plunger for 5th gear. Using those instead of the Lotus detent cam has given me now 15+ years of trouble free gear changes in my Europa. 8)
I still have a couple of the 'plunger+spring' available for sale and might look into having another batch produced if necessary. I also have some liftup handles which can be used on cars with either the 352 or 365 box.
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Just to close the thread, I PM'd Peter Boedker, who replied as a PM, (Meanwhile he'd posted on the main Forum :FUNNY:), All now in motion to close this query. Once again, big thanks to all.:beerchug:
Now onto the next problem... :))
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If I understand your modification correctly you have completely removed the external reverse/5th gear cam and now rely on your gear lever device to prevent accidental selection of reverse. I seems you also have no problem selecting 5th gear without the external cam and relying on your own version of the internal Renault style spring plunger. If you still have your plunger/spring units available I would like one. Also a drawing or photo of your reverse protection device would be appreciated; unless of course you have a spare device!
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My car has Peters kit, slightly modified I believe, the car has no springs,plungers indents etc. A rubber 3/4” chair leg protector fits on the gearbox covering the shaft. This way there is no strains anywhere on the shift linkage which should last longer? The tab on the gearstick lifts to select reverse.
Tunnel as present off for winter dash refinishing,boot surround cut from an old road sign.
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Hi: At the risk of revving up even more dialogue on a topic that's received plenty of coverage already, I thought I'd share this photo and info since it seems to apply to the original question and may be helpful in the future.
I've been working on my '74 TCS for 6 months after rescuing it from 25+ years of "storage." Have not been able drive it yet due to nagging brake system issues, but I finally decided to go through the shifting mechanism. Turns out I have TONS of play at the front shift rod clevis connection, so new bushings are in store. However, when giving things the once over, I found that the 5th gear tang on the external detent setup had apparently been ground off.
At first I thought it was another DAPO "fix," but reading this thread helped me realize (I think) what the deal is with my car. It definitely has strong 5th detent action, so the internal spring and ball are in place. Looking at some other articles, I believe what I may have is a factory expedient used in the very early 5 speeds. My car, 3826, is an early build '74, built in July, '73. Or perhaps they just kept using the 4 speed detent plate until they ran out?
But of course, this still doesn't answer the question of why/when Lotus stopped using the internal setup. As an aside, I found photos of the same setup on a Renault forum where posters were scratching their heads as to why a used "Renault" box had grown some sort of homemade looking mutation. https://www.aussiefrogs.com/forum/index.php?threads/365-box-mod-from-a-lotus-europa.148492/
Ron
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That did not come from the factory. My car is 3635 and it did not have one that looked like that. I believe the DPO modified (or made his own) "Cam Reverse Indent" (from the parts manual (http://lotus-europa.com/manuals/tcparts/f/tcfl.pdf), I always called it the R/5 detent cam). It used to have two ears. The one on the "R" side of the cam was obviously to keep you from going into R without meaning to. The one on the "5" side of the cam is apparently to keep you from going into 5 without meaning to. This makes going into 5 much more difficult than it should be and that's why the DPO either ground off the 5 ear of the cam or made his own - it looks like he made his own.
On 5-speed trannies, there is usually a spring and/or detent mechanism to "center" the gear shift (I don't remember a similar situation in the Hewland of my old race car - the only 4 speed transmission I've been in which is admittedly a poor example in this discussion). The R/5 detent cam apparently provides that function. When I had my 365, I considered shaving down the 5 ear to make it easier to get into 5 but I think cutting it off is a bit extreme. I don't know because I never tried it as I ended up replacing my 365 with an NG3.
I believe that r.d. enterprises has replacement cams (DBE probably also has them). My advice would be to get two replacement cams and "massage" one of them in hopes of getting a better change into 5 without detrimental uncertainness about where the gear shift is or is going and then use that one. The second one is in case your efforts with the first one fail.
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I have no idea why Lotos felt the need to come up with such a Rube Goldberg solution. I can only speculate that built in inertia and friction masked the original Renault set up. FourLoti is indeed lucky to have found their car has a modified set-up. Myself, I’d leave well enough alone and enjoy shifting with pleasure.
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Thanks JB: Yes; it seems I am lucky and I take back the aspersions I cast on the former owner. Hidden in the Lotus Ltd. Technical Manual, I found this very relevant write up by Glenn Davis from the October 1984 issue of Lotus ReMarque - see photo.
I do indeed have the internal spring and plunger. so apparently that Definitely Astute Prior Owner followed this plan, or one similar. Unfortunately, a quick search for those Renault parts comes up empty, but perhaps they are still out there somewhere. (BTW, I can't imagine who would want to try his first suggestion of finding and adding a larger ball!)
Back to the question as to why Lotus did this, don't rule out the possibility it was due to being cheap/frugal. If you're contracting for a thousand or so gearboxes at a time, you might be able to shave a few pence off of the unit cost by deleting those parts. Especially when you can (theoretically) accomplish the task with a virtually free mod to the existing cam. Or maybe it was just "adding lightness"? ;)
Ron