Wedge Trailer Arm Wahers/Spacers.

[John042]

Good Morning all. I'm in the process of changing my 2.8i rear wheel bearings. Contray to my initial worrys the process of dismantling has been surprisingly easy. However I've noticed that the mounting arm to chassis bolts have washers/spacers between the chassis and trailing arm. Are these used to adjust camber etc at the rear wheels? If so should they be the same each side? The reason I ask is a cursory inspection looks as if each side has a different collection of washers, one being a external star locking washer! Doesn't look right to me? Thanks for any advice. J C.

[v8s4me]

The washers are used to adjust the toe in/out of the rear wheels. If you strip yours down make a note of the order they come off in. Be careful when you pull the pivot out or all the washers will end up on the floor. (You don't need to know how I know this!).

If you want the settings see this thread. Although, unless you notice any scrubbing on the shoulders of the tyres I'd suggest you put every thing back exactly as you find it and then leave well alone.

Take care when bolting it all up and use no more then 40ft/lbs on the torque wrench. You don't want to strip that smaller thread.

When you get your pivot bolt off can you post up the measurements please? One side of mine needs to go out a bit more (ideal world) but the pivot bolt isn't long enough to fit more than one more spacer. I'd be interested to know if longer versions of this pivot are available.

[mrzigazaga]

John042 said:

inspection looks as if each side has a different collection of washers

Hi John.

The washers are to set up the geo of the suspension so paying particular attention to how many are on one side is important and how they are placed, This is why when getting the 4 wheel geo done it needs to be with someone who understands the setup...Its the only way of adjusting it.

v8s4me said:

When you get your pivot bolt off can you post up the measurements please? One side of mine needs to go out a bit more (ideal world) but the pivot bolt isn't long enough to fit more than one more spacer. I'd be interested to know if longer versions of this pivot are available.

Hi Joe.

The pivot bolts should be long enough..Have you spoken to RT?....


Cheers


Ziga

[v8s4me]

mrzigazaga said:

Hi Joe. The pivot bolts should be long enough..Have you spoken to RT?....Cheers Ziga

Hi Mark - not yet. It's not too far out. Not enough the scrub a tyre so if it can't be spot on I'll ignore it. This is the problem with modern alignment equipment; it is just too accurate for a a car built in a shed in the late 1970's/early 80's by blokes using chalk marks on the floor and bit of string

[mrzigazaga]

v8s4me said:

Hi Mark - not yet. It's not too far out. Not enough the scrub a tyre so if it can't be spot on I'll ignore it. This is the problem with modern alignment equipment; it is just too accurate for a a car built in a shed in the late 1970's/early 80's by blokes using chalk marks on the floor and bit of string

True....Well as true as a piece of calk and string can be...

[John042]

Hi Joe. My rear arm mounting pin measures from the chassis to the end 90mm. With approximately 30mm attachment. Each side has washers/spacers totalling 17mm each side. Both bushes on the chassis are not in bad condition but are they still available? Thanks J C.

[mrzigazaga]

As said John...Give Richard a call at RT racing.

https://www.google.co.uk/url?sa=t&rct=j&q=...



Or Neil at ML Performance...
https://www.google.co.uk/url?sa=t&rct=j&q=...

Or you can call Superflex and ask to speak to Chris.
https://www.google.co.uk/url?sa=t&rct=j&q=...

[John042]

Thanks Mark. Don't know what the spring washers were doing in the spacer pack? Needless to say replaced maintaining the same measurements. Cheers J C.

[mrzigazaga]

No worries mate..Im sure the washers should be much bigger than that though?

Here are some nice links...
https://www.google.co.uk/url?sa=t&rct=j&q=...

[John042]

Thanks Mark. Work tomorrow should supply.:cool J C

[Wedg1e]

John042 said:

Both bushes on the chassis are not in bad condition but are they still available? Thanks J C.

The original Metalastik (17/404?) have been unobtainable for years but reproductions are available. I used a pair in the late 90s and they were cr4p then so I hope they've been improved.
As it happens it's the same bush as used on the Lotus Esprit although that car had a top link added to the suspension setup which means the trailing arm bushes last years. Even so they will work on the TVR; S.J. Sportscars in Devon sell them.

[v8s4me]

John042 said:

Hi Joe. My rear arm mounting pin measures from the chassis to the end 90mm. With approximately 30mm attachment.

Hi John. Thanks but I'm not quite sure I follow that. This is how my pivot bolt measures up...



The washers/spacers fit in section 'C'. I have this arrangement of spacers/washers...



If you still have your trailing arm off the car can you tell me the distance between the centre of the pivot hole and the center line of the outside edge of the wheel bearing carrier please?

Like this...



I'm hoping that with some simple maths I can get a rough idea what size spacer will give a 2 1 degree increase in toe-out.

Thanks again

Edited by v8s4me on Sunday 13th November 17:39

[John042]

Hi Joe. My trailing arm measures 755mm from pivot centre to centre outer side of bearing carrier. My pivot bolt measures 155mm in length. Hope this helps. Incidentally I'll post up a photo of the pivot mounting bush I removed. Interesting mod' I think. J C.

[v8s4me]

Thanks John.
My 'O' Level maths implies that to move the hub 1 degree needs spacers totaling 13mm. Would anyone like to check that?

[John042]

Thanks Joe. Interesting calculation. I've posted these photos' of one of the trailing arm bushes I removed. Examination shows they have spot welded centres leading to my conclusion that perhaps they were fabricated? Two now on order from RT. J C.

[Wedg1e]

v8s4me said:

Thanks John.
My 'O' Level maths implies that to move the hub 1 degree needs spacers totaling 13mm. Would anyone like to check that?

Get me some better dimensions of the trailing arm and I'll model it in CAD for you, 13mm seems a hell of a lot of packing required. ISTR my Tasmin just had a couple of washers either side.

[John042]

Thanks Ian, my trailing arm spacers measured 17mm each side?? I guess will have to be re-assembled with the same? Seems a lot though unless anyone knows different? Cheers J C

[v8s4me]

If it worked OK the way it was (ie no tyre scrubbing) then put it back that way and don't worry about it.

[John042]

Thanks Joe, my thoughts However the trailing arm mountings from RT are slightly different in that they protude further out in the mounting. I've dispensed with one of the large washers securing the pivot pin, couldn't really see the point of two washers and torque loaded to 40lbsft. I'll re-assemble the trailing arm with the original setting of 17mm and keep an eye on any tyre wear. Is the torque loading for the nut securing the trailing arm also 40lbsft? Thanks J C.

[v8s4me]

John042 said:

.... Is the torque loading for the nut securing the trailing arm also 40lbsft? Thanks J C.

My owner's handbook doesn't differentiate between the nuts but I'd guess you need to stick to the maximum torque for the smaller nut because when you tighten the large one you are tightening against the smaller one.

When you say...

John042 said:

..the trailing arm mountings from RT are slightly different in that they protrude further out in the mounting. ..

Do you mean the length of section 'C' in my drawing above is greater than 32mm one the RT one?