Limit to shimming A arm

[InfinityAero]

Hey Guys,

Fiat build I'm working on its coming along well so far. 77.

I'm at 1 degree positive camber on the front left that I'd like to get to -.5 to -1 degree. Suspension shop I took it to put in 2 shims (look like 1/16" each) to get it to 1 degree from 1.5 degrees.

I was thinking I'd just continue to shim until it's in spec, is that ok or is that much shimming a bad idea? On the premise that it's ok, I was planning on tripling the number of shims, which should get it close to spec. Assuming it's OK to keep shimming, should I put in three 1/8 inch shims, or one 3/8" shim before remeasuring? Is there any difference in the end?

Never shimmed before, so please forgive my ignorance!

[bradartigue]

FIAT originally used washers - and many cars had a bunch of them, even new. They were a nuisance to work with ass you had to remove the arm to replace/add to the stack. Shims are much better; you're pretty safe with several, so long as you can maintain torque and they are at no risk of slipping out. That was the positive aspect of the washers, they did not fall off even when jarred.

[bobplyler]

3 1/8 shims should be the same a 1 3/8. Shouldn't make any difference.

[InfinityAero]

Thanks so much! Sounds like the best option is to pull the arm and install washers, or the shims will work if I'm feeling lazy. I'll try to build out a DIY article with pictures for the forum while operating on her, help with the knowledge base a little... prob start with shims since I'll be doing an overhaul of the suspension this winter, and I may as well save the shim removal and washer install for then.

After that, time to get some tires that aren't 18 years old and she'll be a rolling resto, as opposed to sitting in my carport looking forlorn...

[bobplyler]

Removing the arms to put in washers is not an easy job, considering you will probably have to do it several times to get it right.

[bradartigue]

Yep the washers were terrible to work with.

[InfinityAero]

Removing the arms to put in washers is not an easy job, considering you will probably have to do it several times to get it right.

I figured as much-- my thought was I'll shim it for now. When I get new springs and shocks in a few months I'll check where the camber is all around after that install, and then re-evaluate the shimming.

At that point I'll have good functioning components-- if it's set right with 1/2" of shimming for instance, I'll pull the arm at that point and replace the shims with 1/2" worth of washers. That way I can set the camber with the shims, which is the easier process, giving me a good number for how much washer spacing I'll need when I remove the shims.

Basically I'm thinking get the camber set right using shims and then use that measurement to replace the shims with washers for long term durability and an added safety factor. I can pull the arms off when I install the washers, and do some rust prevention on them as well.

I'll be ordering a shim kit today. I noticed this one from another thread that looks like it'll work: http://www.autopartswarehouse.com/shop_ ... t/124.html

[lglade]

As a quick FYI, there's an inter-relationship between caster and camber, so take some time to try to understand how adjusting for one potentially affects the other.

[InfinityAero]

Hey Guys, just figured I'd follow up regarding the autopartswarehouse link. If you follow that now you'll note that it probably doesn't work anymore, or will stop working soon. They sent me 1 piece of the "25 piece set", then followed up with this message when I reached out to have the rest of the kit sent:

"This is regarding the missing part of your order. The manufacturer confirmed that the AC Delco Camber and Alignment Kit with Part No. AC45K8006 is sold individually. Our Catalog Department is now revising the description/photo of the part. We advise you to re-order this part."

I got a full refund, obviously, and ended up having to do a search for an equivalent shim kit. What I ended up finding was a set of 25 1/8" shims from O'Reilly:

http://www.oreillyauto.com/site/c/detai ... &ppt=C0085

Hopefully they work-- it looks like the set from autopartswarehouse was 9/16-5/8", which seems a little small for a M10 bolt, but these should be the same size as the AC Delco kit.

[lglade]

Let us know how it goes. I'm planning to do mine over the Thanksgiving holidays, and I'd like to benefit from your 'lessons learned'. I know my stack-up of original factory shim-washers came in a variety of thicknesses and many are considerably thinner than the .125 thick shims you got from O'Reilly. So my gut feel is that you may need to sand some down, or find some thinner ones, if you want to hit the sweet spot in the middle of the tolerance band.

I've also done some additional research on the subject and it sounds like there may be some advantage in having a minor bias of camber. I'd be curious to hear about the alignment angles you end up with and your thoughts as to handling, steering effort, etc. when you're finished:

"...A crowned road means that the outside/right hand side of the lane is lower than the left side of the lane. This improves the drainage of the road but adversely affects vehicle handling. Road crown must be compensated for in alignment settings because a vehicle driving on a crowned road leans to the right, causing some weight transfer to the right, and the camber changes slightly more positive. This combination creates a pull or drift to the right. Most alignment technicians adjust the vehicle with a slightly more positive camber, usually 1/4°, on the left to compensate for the road crown. This slightly more positive camber will not cause a noticeable pull when driving on a flat road. However, if camber is unequal from side to side with a difference greater than 1/2°, the vehicle will pull to the side with the most positive camber. If the specifications allow, 0° to ±.5° is usually best for tire life and vehicle handling. "

http://www.aligncraft.com/terms/terms.html

In boca al lupo!

[InfinityAero]

Let us know how it goes. I'm planning to do mine over the Thanksgiving holidays, and I'd like to benefit from your 'lessons learned'. I know my stack-up of original factory shim-washers came in a variety of thicknesses and many are considerably thinner than the .125 thick shims you got from O'Reilly. So my gut feel is that you may need to sand some down, or find some thinner ones, if you want to hit the sweet spot in the middle of the tolerance band.

I've also done some additional research on the subject and it sounds like there may be some advantage in having a minor bias of camber. I'd be curious to hear about the alignment angles you end up with and your thoughts as to handling, steering effort, etc. when you're finished:

"...A crowned road means that the outside/right hand side of the lane is lower than the left side of the lane. This improves the drainage of the road but adversely affects vehicle handling. Road crown must be compensated for in alignment settings because a vehicle driving on a crowned road leans to the right, causing some weight transfer to the right, and the camber changes slightly more positive. This combination creates a pull or drift to the right. Most alignment technicians adjust the vehicle with a slightly more positive camber, usually 1/4°, on the left to compensate for the road crown. This slightly more positive camber will not cause a noticeable pull when driving on a flat road. However, if camber is unequal from side to side with a difference greater than 1/2°, the vehicle will pull to the side with the most positive camber. If the specifications allow, 0° to ±.5° is usually best for tire life and vehicle handling. "

http://www.aligncraft.com/terms/terms.html

In boca al lupo!

Will do, I may attempt the job as soon as this upcoming weekend. It looks like A arms will cause an increase in camber with suspension compression, so I don't think it'll need much camber to grip.

The 2 degree difference from L to R is a major contributor to the leftward pull, so I'm looking forward to resolving that. If I can't get the left to -1 degree I may just match the right to the left...

[InfinityAero]

May end up adjusting the camber by correcting upper arm connecting bolt position.

New thread here: http://www.fiatspider.com/f15/viewtopic ... 14&t=32026

[InfinityAero]

Let us know how it goes. I'm planning to do mine over the Thanksgiving holidays, and I'd like to benefit from your 'lessons learned'. I know my stack-up of original factory shim-washers came in a variety of thicknesses and many are considerably thinner than the .125 thick shims you got from O'Reilly. So my gut feel is that you may need to sand some down, or find some thinner ones, if you want to hit the sweet spot in the middle of the tolerance band.

I've also done some additional research on the subject and it sounds like there may be some advantage in having a minor bias of camber. I'd be curious to hear about the alignment angles you end up with and your thoughts as to handling, steering effort, etc. when you're finished:

"...A crowned road means that the outside/right hand side of the lane is lower than the left side of the lane. This improves the drainage of the road but adversely affects vehicle handling. Road crown must be compensated for in alignment settings because a vehicle driving on a crowned road leans to the right, causing some weight transfer to the right, and the camber changes slightly more positive. This combination creates a pull or drift to the right. Most alignment technicians adjust the vehicle with a slightly more positive camber, usually 1/4°, on the left to compensate for the road crown. This slightly more positive camber will not cause a noticeable pull when driving on a flat road. However, if camber is unequal from side to side with a difference greater than 1/2°, the vehicle will pull to the side with the most positive camber. If the specifications allow, 0° to ±.5° is usually best for tire life and vehicle handling. "

http://www.aligncraft.com/terms/terms.html

In boca al lupo!

Hey Lglade, figured I'd follow up in this thread since you're attempting it this upcoming weekend.

I ended up stripping one of the bolts on the drivers-side lower A-arm while trying to re-torque after shimming.

How did it strip? Well, apparently there is a practical limit to how far you can shim that A-arm. I was able to add in 2 1/8" shims, in addition to the existing shims. This resulted in the bolt not quite being flush with the end of the nut-- apparently that bolt needs the full nut threaded to avoid stripping. Before stripping it, things were looking pretty good. I had the camber at roughly zero degrees on the left, and -1 degree on the right, so I was about halfway to a balanced state.

My plan at this point is to get the assembly back together by removing shims, using the 3/8"X16 die to put on a new thread, and then retorquing the nuts to the factory torque spec. From there, I'll buy some new tires, re-adjust the toe, and see how she drives. After that, I'll be saving up cash for a bit, then removing all the control arms and other suspension components to do a full overhaul, including:

Remove and rust proof upper and lower control arms
replace all bushings, boots, and ball joints
replace panhard rod
Replace springs and shocks

I'm hopeful I won't have to remove the crossmember, but if I do, I'll have to figure out the procedure to deal with those bolts. If I end up having to drill out and replace one of the bolts, I'm thinking I should go with longer ones so that I'll have a little more play for shimming...

TLDR;
There is a limit to shimming the lower A-arms. Do not shim beyond the point where the nut is flush with the bolt.

[vandor]

It is not that difficult to replace those bolts, just need a welder to tack them in and to reinforce the crossmember. One could replace it with a longer one, so you have the adjustment you need.

[lglade]

Thanks for sharing your experience; I'll be sure to go slowly with the re-torquing of the nuts. And if the bolts aren't long enough, then I'll use Csaba's advice and swap the bolts for some longer ones.