A few front control arm bolt/washer questions.

[Brewhaha]

I'm currently in the process of reassembling my front suspension and I have a couple questions regarding the upper and lower control arm bolts/washers.

On the upper control arm bolts there are those two convex/concave washers and I'm not sure if they install so that the recessed part of the washer is is touching the inner sleeve, or if they go on so the outer part of the washer is pressed against the bushing.

On the lower control arms I'm not sure if there is a specific direction in which to install the cam bolts. It doesn't seem like it should matter but I want to be sure. I remember the front bolts slid out towards the rear when I was taking it apart, but I don't remember which way the rear bolts were oriented or if it really makes a difference either way. I also wanted to know if I need that regular smaller washer between the nut and cam-washer.

Sorry if these are stupid questions but I couldn't find any answers online and the repair manuals and I'd prefer to not end up making some silly mistake. I've attached pictures illustrating the questions. (and yes, I pressed the upper bushings the rest of the way in after taking the photo's). Thanks

 

[Dan_Gyoba]

See if the diagram on the TSRM page FA-21 is any help. I'd guess from the diagram that the concave washers were actually flat at some point. Maybe over-torqued?

 

[SC61 MK3]

All the ones I've seen were concave and from what I remember the recessed side in That's how mine is now atleast and no issues....

 

[Brewhaha]

See if the diagram on the TSRM page FA-21 is any help. I'd guess from the diagram that the concave washers were actually flat at some point. Maybe over-torqued?

Thanks! I was rummaging through the TSRM diagrams but somehow missed that one. That solves my lower cam bolt question. As for the upper washers, I just got two new ones (last ones available in the country!), and they come with that shape and are not a result of being over torqued.

All the ones I've seen were concave and from what I remember the recessed side in That's how mine is now atleast and no issues....

So in my picture of the uppers it would be like the one on the right? Seems weird having that gap, but then again it seems weirder/wrong to have them pushing on the bushing so hard if installed the other way.

 

[SC61 MK3]

Yes the right picture is how I remember it, not an expert though I'm sure someone else can verify

 

[Brewhaha]

Alright, hopefully someone else can chime in and confirm. I've seen this same question asked elsewhere in the forums but without an answer.

 

[boostintrdstyle]

The lower control arm bolts are suppose to be flat I just bought a new set and there flat , the upper control arm I think is flat to but mine have a curve to them.

 

[Asterix]

Upper arm washers go in like the left side of your picture. You want the polyu. bushing to rub on the washer, as it will keep the arm in place properly.
The lower cams go with the ears on the frame. The bolt doesn't matter so much. Do it the way it's easiest. Make sure you can get the bolt out later with everything installed.

 

[Brewhaha]

The lower control arm bolts are suppose to be flat I just bought a new set and there flat , the upper control arm I think is flat to but mine have a curve to them.

I know the lower cam washers are flat. I also know the upper washers are not flat. Being so, I need to know which way they face since it will either press more on the inner sleeve, or alternatively on the rest of the bushing but not the sleeve.

Upper arm washers go in like the left side of your picture. You want the polyu. bushing to rub on the washer, as it will keep the arm in place properly.
The lower cams go with the ears on the frame. The bolt doesn't matter so much. Do it the way it's easiest. Make sure you can get the bolt out later with everything installed.

Hmm, now I have two conflicting answers. If installed like in my example on the left, it seems weird that the the washer would push on the lip of the bushings with it being torqued to 121 ft-lb's (maybe i'm underestimating their strength). But I suppose it also seems incorrect if installed the other way as it would be pinching the inner sleeves to the subframe and probably be resisting the pivoting movement.

 

[Asterix]

pinching the inner sleeves to the subframe.

It'll do that no matter which way the washers are.

The washers, subframe tube, and 2 short inner tubes take the bolt clamping force, essentially making one long tube. The sleeves inside the red bushings should not turn. The only force between the washers and bushing faces is from the upper arm is flexing a little, and it probably under 50lb. Recall that the original rubber bushings worked like this - there's a steel tube inside the rubber which didn't rotate once the long bolt was torqued.

If you tried to tighten the long bolt to without the inner tubes, you'd just bend the arm into less of a triangle.

If the upper arm can slide forward and back at all, it'll change your caster, and you don't want that while driving. Put the washers in like in the left picture and it won't do that.

 

[Brewhaha]

Alright that makes enough sense to me, I appreciate the response! When tightening the long bolt it seems that the inner sleeve protrudes the tiniest bit so that the washer doesn't press on the bushing as much as I thought it would.

 

[SC61 MK3]

Yeah so I checked and my previous posts were wrong. Concave facing in is how it should be, sorry

Just noticed you're in Ft. Lauderdale also, what part? I'm out west of the turnpike, just off commercial blvd. and university drive

 

[Brewhaha]

No worries. As long as I know I'm putting things back correctly, I'm happy. I'm right off Broward and 95.