Jump to content

TR4 early and late chassis


Recommended Posts

Hi all, I am replacing the chassis on my new TR4 project, the old one was shot to s--t and so I purchased a good used one, the old one had the steering rack mounted vertically and the new one has the rack mounted horizontally. I know I will have to change the rack but is there anything else I need to change ? the wishbone  arms are the earlier type and would appear to fit but should I use this opportunity to change to the later wishbone and ball joint assembly assuming this was deemed an improvement ? and if so would this necessitate further changes @

Regards

Ron Hatch

Link to post
Share on other sites

Steering levers connected to the vertical post changed during the time that the early rack mount was used.  You would need to check you comm no. against the parts book to find out what was fitted originally and decide if what you have will do.

see here. https://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/steering-suspension

I do not know what the change involved.

Peter W

Link to post
Share on other sites

Ron,

Why not swap the steering rack platform mounts off your old chassis onto your replacement chassis ? that's what the chassis remanufacturers do.

It's likely your old platforms are in decent condition unless accident damaged. Just compare the front of the chassis... measure up the mounting points positions, even make a small jig up in timber or steel to present the rack platforms to the replacement chassis...then weld them on. 

Your old chassis is vastly superior on steering rack positioning against the replacement chassis with the old "rabbits tabs" rack mounts, which you could probably move by hand twisting them. When driving the feel of the new rack platforms is much more substantial...thats why the factory went onto them. Saves all the messing with racks and steering arm changes etc.

Mick Richards 

Link to post
Share on other sites

To make the original, vertical, rack mountings strong enough for rally work, Ray Henderson, Graham's Chief mechanic in the Comps. Department. devised a very clever reinforcement mechanism. 

From the cross tube, a pair of downward facing brackets mated with the existing brackets at the rack mountings, with each U bolt clamping the rack to its pair of upward and downward brackets - see photo.

This is the arrangement on 4VC - but I believe that the other 3 cars have the later arrangement.  I can say that, with engine and radiator installed, getting the bolts into position and the nuts clamped tight is not easy, even with my small hands.

All four of the original VC Works' cars should be on display at Malvern in August.

Ian Cornish

Tulip '62 - Prep - New 11.doc

Link to post
Share on other sites

Here's another shot of the brackets devised by Ray Henderson.

As with the uocoming brackets, the downcomers are a C shape - in other words, not just a flat piece of steel, but with ears either side, making them very strong. 

And because the downcomers fit snugly inside the upcomers, fitting the nyloc nuts onto the U bolts is very fiddly.  With the rack in place and held by solid ally blocks (no rubber), I think that this is as strong and as rigid as the later rack mounting.

Ian Cornish

1992 Chassis prep at CTM 6-1280.jpg

Link to post
Share on other sites

Thanks for the photo Ian, I did keep the old stanchions from the original chassis with the intention of using them but it seemed more trouble to hack off the original mountings and bracing from the replacement chassis rather than change the rack, any thoughts on the pros and cons ?

Regards

Ron 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Link to post
Share on other sites

Ron - I had no choice as the new chassis for 4VC had to be built as it was in 1962/3.   I think you need the advice of suspension/steering experts on this - as you can see from the photo of 4VC's chassis, there is quite a lot to do if you cut off the later mountings and implement Ray Henderson's strengthening of the rack mountings.

Why "new" chassis?  When the car was re-built in the late 1990s, Neil sent the original chassis to Colin Matthews, who pronounced it to be scrap!  Fortunately, in 1971/2 I had bought a new chassis from Lankester's, Triumph agent in Kingston on Thames.  This was sent to Colin, who then implemented every one of the Works' mods on the new chassis - it was only later that I twigged that Triumph had changed the rack mountings, so Colin had chopped them off, as can be seen.  Incidentally, rallying caused a lot of damage to chassis, and the Works' TR4s used a considerable number in 2 years - 5VC consumed about 8, I believe!  Easier to put the body on a newly fettled chassis than try to straighten a bent one - same applied to wire wheels.

Ian Cornish

 

Link to post
Share on other sites
3 hours ago, ianc said:

Here's another shot of the brackets devised by Ray Henderson.

As with the uocoming brackets, the downcomers are a C shape - in other words, not just a flat piece of steel, but with ears either side, making them very strong. 

And because the downcomers fit snugly inside the upcomers, fitting the nyloc nuts onto the U bolts is very fiddly.  With the rack in place and held by solid ally blocks (no rubber), I think that this is as strong and as rigid as the later rack mounting.

Ian Cornish

1992 Chassis prep at CTM 6-1280.jpg

Yep,

Pro.

1) By using your old steering rack platforms there is no cost implications ( as long as you can weld and get it in the correct position). Even if you weld it too low or high on the chassis by a couple of mm either way ( unlikely) you can adjust it by adding a Packer underneath,  ( normally a scrap piece of steel) and if you follow my instructions on how to minimise bump steer you’ll get a bump free TR4 which is more than Triumph was able to do.

2) You can get on with it now, you have all the bit’s to hand,

3) the finished chassis will look identical to your original and be much stronger than the   “ modified” added on bracing bits needed to support the flexing “ rabbit tabs” steering rack mounts Triumph decided needed supporting to give merely acceptable performance.

4) In the event of your car needing a rebuild to conform with DVLA rules for registration, the chassis would be indistinguishable from it’s original iteration. Nobody could tell it was not the correct chassis because of a different rack mounting point used than the regional... it would score maximum points towards it’ originality factor.

Cons... if you can’t weld you’ll have to pay somebody £50-100 to weld it for you, but still much less than a new rack and bits a likely cost for you £ 150-£200.

Mick Richards

Link to post
Share on other sites

Cheers Mick, As I said this was the way I originally intended to proceed and I think I will stick to the plan, it will look as made and the original rack is in good nick. Time to dust off the welder. Cheers all for the replies

Ron

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.