Rear 'A' Frame Replacement
Rear 'A' Frame Replacement
Author
Discussion

ian8542

Original Poster:

615 posts

274 months

Thursday 15th July 2004
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Has anybody had new parts made up lately by TVR Engineering.
The reason for the post is that i ordered a diff carrier and 'A' frames to do a conversion from the earlier trailing arms set-up.
Having got the parts, all shiny in new powdercoating, i inspected them.
The diff carrier was mis-shapen and was longer at one side than the other. It had also been cut up once fabricated and then re-welded. Unsightly grind marks can be seen where this cut and shut has taken place.
There's more;
The 'U' section channel has been drilled to take the bolts for the lower wishbone/ 'A' frame. One side has a reasonable amount of metal between the hole and the edge of the 'U' channel but the other side as only 3mm. A recipe for disaster.
The 'A' frames are little better.
On trying to fit them to the diff carrier you have to force them into place, bending the bracket in the process.
On coming to fit the upright nothing lines up, the bushes are not in line and when you try to fit the damper it ends up at 25 degrees to the vertical.
I know i am not the only person having problems as i recently spoke to a guy at Bell Hill Garage who told me he fitted some to a customers car and found there was 5 Degrees of negative camber amoungst other things.
I have been unable to speak to anybody with any know how at TVR and have just been told to send them back via my dealer to be made again.
I was even prepared to bring them back and show them what the problem was but they would rather bury their heads in the sand and carry on regardless.
Apart from it wasting my time and money and obviously theirs surely you would think they could get it right despite being told about the problems on numerous occasions.

Graham

16,378 posts

306 months

Thursday 15th July 2004
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when you get a set that fit can i erm borrow them for a day to erm measure... for research only obviously.


What did you do about the hub carriers?

wedg1e

27,003 posts

287 months

Thursday 15th July 2004
quotequote all
This sounds like a similar saga to the window frames for the FHC cars. Almost as if someone shows a picture of what needs to be made, to a monkey, and sits back and waits for the results.
Graham; I have long planned on overhauling my rear suspension and I was thinking of making those same measurements myself!

Ian

suffolkfoxy

39 posts

261 months

Thursday 15th July 2004
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Not that I would think of doing what your not thinking of doing, but could you include anyone include pictures (of what you're not doing)

ian8542

Original Poster:

615 posts

274 months

Friday 16th July 2004
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suffolkfoxy said:
Not that I would think of doing what your not thinking of doing, but could you include anyone include pictures (of what you're not doing)


Sounds like you've just got back from the pub.
What pictures would you like, but first i need detailed info on how to upload pictures onto the post.
Graham; I have a s/h diff carrier, 1 s/h wishbone and a pair of s/h diff brackets.
I intend to find somebody to fabricate some copies so i will need to prepare them first i.e remove old bushes and rust etc. I will also take some measurements and forward them to you.
The ones i had made by TVR went back this morning for them to have another go.
Must dash, i have some CV joints to source for a Griff 500.

suffolkfox

458 posts

275 months

Friday 16th July 2004
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Hi
Wasn't aware there was a conversion option to A frame, so would be interested in the dimensions etc, or the details of any engineer able to fabricate the components (as TVR seems to be having a problem). I am guessing you are doing this for the racers but would assume this would also work with the early 350i(as in ours) with the trailing suspension setup.

As far as pictures are concerned, as many as possible of the components and the fitting. If you create an account at www.webshots.com, then upload photos to your area, make your area a public area then add the URL(web addresses) of the photos to a message they magically appear. Contact me offline if you need a hand.

As a relative newbie to the Wedges, and not knowing all the etiquette so sorry if I am saying something obvious but, could I nevertheless suggest that any conversion be photographed and passed to Mike at The Wedge Pages. This seems to be a superb resource and this exercise one that would be worth inclusion for a number of early car owners, not just racers.
SF

Graham

16,378 posts

306 months

Friday 16th July 2004
quotequote all
I'M Fairly sure that RT Racing have done an A-frame conversion on Steve HAlls racer.... i'll try and get some pics this weekend.

I THink Steve is intending to go to BBWF on the way back from Lydden same as us


G

ian8542

Original Poster:

615 posts

274 months

Friday 16th July 2004
quotequote all
Converting the earlier chassis (trailing arm) to the 'A' frame spec isn't just a case of buying the parts and bolting them on. The rear of the chassis needs altering and captive nuts fitting into the altered rear chassis tubes.
The bottom tube at the rear of the transmission tunnel needs drilling to accept crush tubes, welded in, to mount the front of the diff carrier.
If you want to use the link rods from the hub/upright to the chassis, then the rearmost chassis rails below the fuel tank area will need removing and new tubing welded into a different position.
I decided not to use these as i was told that they do not really do anything.
A lot of work and only recommended if you intend to work on a bare chassis.
The early type trailing arms are still available, so anybody needing replacements should still be able to get them.
Other than what i have just mentioned, i have also modified the spring/damper turrets to make them stronger and be able to accept a coil over damper unit.
The front suspension is totally different from standard. I will send Graham some pictures of the assembled fabricated parts.

tasmania

782 posts

285 months

Saturday 17th July 2004
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Ian,
Apologies for not getting back to you with a photo as promised - been a bit pre-occupied of late.
Interesting thoughts ref: Factory stuff - It'd be good to talk at Wedge fest about this and others in the game who supply bits for our machines to see if there is a better way!
TaS

ian8542

Original Poster:

615 posts

274 months

Saturday 17th July 2004
quotequote all
[quote=tasmania]Ian,
Apologies for not getting back to you with a photo as promised - been a bit pre-occupied of late.

No problem Gary, i've got some s/h parts to look at now but i am busy with other cars at the moment.
Hopefully by the end of next week i might have some useful proposals for fabricating some uprated stuff with sealed spherical bearings.

Graham

16,378 posts

306 months

Monday 19th July 2004
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Ians Front Suspension arms











and the current setup on mine, showing different damper mounts.

Where the top wishbone goes through the chassis, whe whole turret has started to pull out of the chassis



the brackets on the inside of the chassi the otherside of the damper mounts are for a strut brace.