Lop sided rear

[bigmalcy]

Hi guys and gals

First post for a while having completed my project and shipped the car to Aus.

 

I've noticed recently that the car (1960 3A) is lop sided at the rear. The RHS is 20mm lower than the LHS.

 

Springs were removed during the re-build but refitted without much attention other than a good clean. Associated bushes were replaced, too, along with the front pins (pins done by others as i couldn't shift the old b@stards).

 

Tyre pressures are consistent on all four corners.

 

Any ideas what could cause the lop-sidedness? Any clever methods of altering ride height that doesn't involve removing / replacing springs?

 

FWIW, the car drives beautifully.

 

Is there any truth to what i have heard about different springs being fitted to compensate for driver's weight? I didn't hear this until after the build, so i didn't bother checking that the springs were put back on the same side as they came off.

 

TIA

PS - here's a photo of recent club run with the local Register group. That's mine on the right, dark green to left of lighter green (which is also a UK car originally).

 

 

 

 

 

[bob-menhennett]

Yes ,you've heard right Triumph did fit harder springs to the drivers side of the car. Noted / referenced in Moss' catalogue and other publications An issue for owners who swop LHD to RHD and vice versa.

 

You've appear to have checked / replaced all the obvious bits on the rear suspension with the exception of the rear shackles. However a worn shackle wouldn't account for 20mm , maybe a few just one or two mm. There is no inbuilt " adjustment " you can alter in the rear suspension on a TR3A that I've come across, other than changing spring rates. If the car "sat" OK before , I think your diagnosis of the springs having been put back on the car , on different sides , is spot on.

 

Having recently refurbished the set up , dismantling shouldn't prove much of a struggle. Spanner time to switch the springs , for you or a garage would be a morning or afternoon's work. We'll see if anybody else has other ideas or input about the problem.

 

Nice car by the way. Safe motoring.

Bob

Edited March 21, 2018 by bob-menhennett

[Drewmotty]

How does the front sit? Is th car low along one side or low at one corner and high at the opposite diagonal corner? Is the body or chassis twisted?

The discrepancy may be at the front.

The rear height can be tuned by putting spacers between the spring and axle to lower the corresponding side but if you are using original springs your problem is likely to be that one or more springs are just tired.

[iain]

Like Andrew, check all 4 corners.

I noticed a similar issue some years ago.......it was a front spring issue, although easier to notice from the rear.

Also check the body is evenly spaced on to the chassis. At the rear how much of the chassis end rails can you see below the rear valence, is this even both sides?

 

Iain

[RUBY131]

If I had reported this problem to the lady wife her one word answer would have been Diet ! They just dont' understand

[Graham Harris]

I think most of the cars sent to the USA had a short extra leaf added to the passenger side spring to make that side lower, I believe they were of the oppinion the male owners were over weight and this evened the car whith only the driver on board. My car was a USA car and it had the extra leaf.

 

Graham

[bigmalcy]

Thanks for the replies, guys...

So, did all 3A's come with uneven springs or was it just US cars? Moss says that they did that in 'early days'... whatever that means?

I'll get a heavy friend to sit in the passenger (high) side and see if she levels out.

 

It did occur to me that the body may be uneven across the chassis, so I will measure to the chassis and let you know what i find out.

 

I'd also thought it'd be possible to shim the axle up on one side (to drop the ride height), but it's pretty low already so would prefer to raise the other side! Still - it's an option to keep in the back pocket.

 

I was looking at the rear spring mount and wondering if altering the length of the shackle pin plates on the rear end of the spring would affect ride height? Anyone care to comment?

 

As for swapping springs - I'm not sure how easy it would be... the front pin is still VERY tight in the chassis and i had thought it would be a body off (or at least body raised) job to get the front end of the spring away from the pin?

 

Finally - yes, i measured the front end and it was pretty much level, although i do know that the anti-roll bar mounting bracket has slipped down slightly on the LHS. I doubt this is the cause of the rear lop sidedness but i will fix it and check again.

 

Thanks again...

[mjdearing]

Wrongly adjusted anti roll bar can cause it

[stuart]

Thanks for the replies, guys...

So, did all 3A's come with uneven springs or was it just US cars? Moss says that they did that in 'early days'... whatever that means?

I'll get a heavy friend to sit in the passenger (high) side and see if she levels out.

 

It did occur to me that the body may be uneven across the chassis, so I will measure to the chassis and let you know what i find out.

 

I'd also thought it'd be possible to shim the axle up on one side (to drop the ride height), but it's pretty low already so would prefer to raise the other side! Still - it's an option to keep in the back pocket.

 

I was looking at the rear spring mount and wondering if altering the length of the shackle pin plates on the rear end of the spring would affect ride height? Anyone care to comment?

 

As for swapping springs - I'm not sure how easy it would be... the front pin is still VERY tight in the chassis and i had thought it would be a body off (or at least body raised) job to get the front end of the spring away from the pin?

 

Finally - yes, i measured the front end and it was pretty much level, although i do know that the anti-roll bar mounting bracket has slipped down slightly on the LHS. I doubt this is the cause of the rear lop sidedness but i will fix it and check again.

 

Thanks again...

3a`s for US market had the extra short leaf fitted to the R/hand spring all the way through production.

Stuart

[vivdownunder]

So did Australian delivered TR3As and also my Durban assembled car. At TS26904 a slightly different passenger side rear spring was introduced. It had two short pieces of leaf sitting on top of the spring held in place by a longer centre bolt. Being underslung, the added pieces had the affect of lowering the passenger side by about 12mm, so with a driver one-up, the car ran level.

 

Of course when two-up the car went back to sitting 12mm lower on the passenger side, so it was a strange arrangement.

 

Over the years it's been speculated that the height variation was due to one rear spring being stiffer than the other. In testing over a few sets I found both leaf springs to be very close to 128 in./lb. It's unlikely regulations would allow one spring stiffer than the other on a road car.

 

Viv

 

(Hi bigmalcy hope you are enjoying downunder).

[Richardtr3a]

I found it impossible to shift the front pin . The body was attached by stainless steel fixings and it was very easy to take out the seats, unbolt the fixings and change the spring on the RHS It sounds like a big job but it can be done in a few hours.

 

My front spring on the LHS is too low and I have changed both sides with no improvement, and I am now thinking of a couple of extra rubber gaskets under the spring. Would it work ?

 

Thanks Richard

[bigmalcy]

S

 

(Hi bigmalcy hope you are enjoying downunder).

Hi Viv! Yes, thanks - got a soaking the other day when our trajectory happened to coincide with the only rain event in weeks! Has prompted me to get my finger out and get the weather gear sorted out. How are you going? With the TCCV now or somewhere else?

[Graham Harris]

Yes Richard Moss do extra thick spring rubbers that will lift the suspention, give them a go

 

Graham

[bigmalcy]

HI guys - so I adjusted the front roll bar which seems to have helped a little. Difference in height is now approx 10mm. Looking at the front, though, i reckon it's a little high on the LHS.

Going to take it to a specialist here in Melbourne to have the spring rates and corner weights etc measured properly.

 

Had the car out yesterday for a drive with a varied selection of cars (MGs, Porsche, Mustang, Caterham etc) and had a blast, so the wonkiness isn't bothering me too much

 

Thanks for the input.

[BlueTR3A-5EKT]

Where is the 20 mm lower measured from, chassis to ground or body to ground?

Could be body to chassis packing issue, plus a sagging spring.

Did you swap the leaf springs left to right, was there a change/improvement?

 

Peter W

 

PS are the tyres the same size and make left to right.....

[bigmalcy]

Hi Peter

I checked the body position relative to the chassis at each side, and it seemed pretty even.

Haven't changed the rear springs, just fixed up some uneven-ness in the front anti roll bar. Moving the leaf springs would be a very large PITA: probably involving raising the rear end of the body off the chassis.

Tyres and pressures are all the same.

 

Will see what the suspension gurus have to say about it. Hopefully they can give me some accurate spring rates.