steering rack

[BDA]

I know, D'man. The thing I really NEEDED was the rack rod itself which is not available by itself. I could have gotten one of their rebuilt racks for almost $200 and then added the Europa bits to make it work for my Europa but I also could have gotten a rebuilt one from Richard for about $150 (exchange) plus shipping but that seemed like a lot when all I really needed was that one part and as I said, the one I bought was very nice and very economical.

After starting this discussion many moons ago, it was assumed that any Spitfire (and GT6, but those were phased out long before Spitfires so their racks were probably less available and with more miles. Those on the other side of the pond have more options.) rack but it wasn't known for sure. At least that's what I took away from the thread. I just wanted everybody to know that if they needed to repair their rack, they could get one from the latest model Spitfire they could find which would hopefully have fewer miles and that the swapping of parts was very straightforward. Others who read the thread might have come to that conclusion but I wasn't absolutely sure. Now I am! 

There is an uprated/aftermarket rack ("quick rack") for Spitfires but I understand they are not at all appropriate for our use.

Update: I tried to install the rack on the car and found an incomparability in the rack tube. On the casting that houses the pinion, there is an ear that gets in the way of the master cylinder. When I looked at the original rack tube, sure enough, it was cut off. Depending on the master cylinder you use, it may not be a problem but I am using the original one.

[Bodzer]

Hi BDA,

I’ve got Brian Buckland’s book on maintaining and restoring the Elan. He had interviewed Ron Hickman several times to get some background on the Elan and the source of its parts. He says that the steering rack was case hardened in the area of the pinion by lotus. I’ll have check it again later as I’m getting the kids ready for school!

Also, if you’re looking for the rod end, Kelvedon Lotus are selling them. https://kelvedonlotus.co.uk/product/tie-rod/


I hope it helps.

Regards

[BDA]

Thanks Bodzer, it's all back together. My tie rods were still good and I think they are available on my side of the pond.

As for case hardening on the rack, there is definitely signs of heat on the Europa rack. I supposed it could have come from machining or heat treatment - or both. I would have noticed if the Spitfire rack didn't have the same coloration. I would be very surprised if the racks were not hardened before they ended up at Lotus since gears are normally hardened. I would expect that if there was anything different about the Lotus racks, it might be because they specified a different heat treatment than British Leyland specified. Obviously, this is all supposition. It would be interesting to learn what Hickman had to say.

I didn't look really closely at the Spitfire rack teeth, as with a magnifying glass, but there was no discernible wear on them. I looked at the pinion much closer and it did show a little wear which isn't surprising really. I'm collecting all the good parts of those racks for spares. Who knows, they may come in handy, but then I'll probably end up as some eccentric octogenarian with a garage full of antique Europa parts.

[4129R]

Who knows, they may come in handy, but then I'll probably end up as some eccentric octogenarian with a garage full of antique Europa parts.

I was thinking just that last weekend when I was tidying up my collection of bits.

I have nearly finished rebuilding chassis #7, so anything not used that I have is surplus.

Having swapped 7 racks LHD to RHD, I have heaps of Triumph Herald bits lying around, as I used the RHD casings only when swapping over.

[BDA]

By the time you're an octogenarian, you'll be a hero to a small collection of owners of super antique Europas and other cars that share those parts!

[Grumblebuns]

This is another source for vintage British car parts:

http://www.britishmasters.net/

I've dealt with them before and I've had not issues. I live only about 45 minutes from them but parts are mail order only, I can't pick them up even though I live about 40 minutes from the business.

[BDA]

Nice source, Joji! I assume all communication is via phone or email since they didn't have any parts or price information on their website.

[Grumblebuns]

Phone is probably the best way; they have a 800 number and had no problems with some one answering.

[chrisbeck]

I realise I'm replying to an old thread, hopefully someone out there will pick this up.
I'm converting a '73 TC/Special to RHD, can anyone out there confirm that I need to swap out the pinion as well as the rack housing? It looks like it because the rack has straight cut teeth and the pinion is angled so must have angled teeth. I'm asking because I don't want to change the ratio with a 'quicker' 7-tooth pinion.
Thanks

[BDA]

I was about to suggest that it didn't matter. I thought I had a spare pinion to confirm my idea but I didn't. I do have a spare rack and housing and because the pinion is at a slight angle to the rack, it probably does make a difference which end of the rack you put the pinion - the angle of the pinion to the rack would be reversed. That is probably what you were thinking, wasn't it?

My suggestion is to get a good used RHD Spitfire steering rack (I found one on ebay that was supposed to be only 40,000 miles old). Replace the "cup nuts" that hold in the tie-rods and the tie-rods themselves from your Europa steering rack while adding the spacer to the passenger side as it was on the Europa rack. That will obviously require you to re-shim the tie-rods in the cup nuts and and the pinion so save all your shims and get new lock tabs for the cup nuts.

I think those are all the differences but if I missed something, it should be pretty obvious.

[Richard H]

This is a heads-up on something that isn't generally known about the Spitfire rack.  It has a central section, the bit of the rack that comes into action in straight ahead driving where the teeth have been cut fractionally shallower, that is more metal is left on the rack leading to a high point in the teeth.  The shims to minimise pinion backlash are adjusted [in the Spitfire] at this point. That's all fine so far because when the car is steering a corner the rack is under load, but has a fraction more backlash where the teeth have been cut deeper.

Lotus took a standard rack and moved the effective centre point, the straight ahead position off-centre.  This means that if the rack is adjusted for minimum backlash at the straight ahead position it will jam when it reaches the high point in the rack.  This only applies to types 54, 65 and standard TC.  The TCS had a different arrangement where the rack is properly centred.

[Richard H]

The addendum to my comment, which I seem to have accidentally posted before it was finished, is that you can check this by measuring over a pin.  Take a needle roller of a diameter that fits into the rack tooth gaps whilst contacting both flanks.  Into each tooth gap place the roller in turn measuring the distance across the roller to the other side of the rack rod.  You will discover that there is a hump where the Spitfire is at straight ahead.. It's only a few thou, but it makes a difference to precision in the straight ahead position when the rack is used in all but the TCS Europa.

[Roger]

Richard H, are you sure about the difference between TC and TCS?
I ask because to my knowledge there are only 2 part numbers for TC(S) racks, LHD and RHD. There are differences is switch gear and columns etc., but I think at the chassis mounting they are the same.
The S1 and S2 racks are a different part number though.

[BDA]

Very interesting, Richard!!

I think years ago, Richard told me (I'm sorry I don't remember all the specifics) that when you rebuild the rack (presumably using used Spitfire parts) that the the center (straight ahead) would be a bit looser than either side. When I rebuilt my rack - actually I added the Lotus rack parts to a "lightly" used Spitfire rack because it was nicer than mine - I noticed that even though my Spitfire rack was only 40,000 miles old, it exhibited that same pattern. I assumed that it was because of wear but I didn't expect it because the Spitfire rack wasn't much over 20,000 miles older than mine and that didn't seem like enough mileage to cause that much wear (?). When it came to shimming the cap nut, I sort of split the difference between being too tight and too loose, I basically shimmed it so that if I added one more thin shim (0.004), I could feel the teeth on the rack when turning the pinion.

As far as any differences between the Spitfire rack and my TCS rack, I didn't see any. To my eye, they both used the same rack, pinion, rack tube, etc. (but the Spitfire rack had extended sleeve nuts, longer tie rods, and included a tube to go over the rack to reduce the total turning action). So I'm surprised that the TCS racks would be any different from other Europa or Spitfire racks. I don't see the reason for making a small change to a small number of racks when the older Europa racks and Spitfire racks (without Lotus mods) work fine. Can you tell us some more about how you found this out?

[Richard H]

Richard H, are you sure about the difference between TC and TCS?
I ask because to my knowledge there are only 2 part numbers for TC(S) racks, LHD and RHD. There are differences is switch gear and columns etc., but I think at the chassis mounting they are the same.
The S1 and S2 racks are a different part number though.

Actually Roger, I can't now find the source from which I got the idea that the TC and TCS were different.  My recollection is that there is a tiny amount of bump steer coming from the steering control arm length being slightly too long in the S2 installation.  The TCS at the very least has extension pieces at the end of the rack such that the track control arms can be shorter eliminating that source of bump steer. 

Having failed to find definitive information I resorted to looking at pictures which indicate the TC and TCS are very likely the same because neither have the external steering control arm extender pieces fitted.

Sorry for the confusion, as an S2 owner  !