Technical Rear axle not perpendicular to the frame

Thanks, it will be up on a lift. No pan hard. Rough measurements shows about 1/4” difference. I think loosening the coil overs will be enough, we’ll see.

 

Thinking this out in my head ( I know a scary thought ! ) If you were to shorten the upper passenger bar the same as what you lengthen the upper drivers side bar, I believe the angle would remain constant on them and you would get the desired effect you are after. Of course you would have to move the lower bars accordingly to set the pinion angle. Only problem is it would bring the passenger side in a bit. Best of luck on whatever you try tomorrow.

 

Thanks

 

So your 4 link should be triangulated, not parallel, as you mentioned in the first post.
However, I looked online and the Brookville model A style chassis seems to be parallel, the 32 style frame is triangulated. The pics are such I can't spot which it is.
EDIT: Found this pic on your older posts, so it is a 32 style.
I'd be more comfortable doing this on your blocks shown. it looks like enough room to do the job.
You can make lines on the floor to check square with a plumb bob easier than having it 6 feet in the air. NICE car, BTW!

 

Gee !! Thanks. Brookville did special for me. This chassis model has a ladder bar rear. I wanted triangulated so they adapted it to a have the link mounts. They also welded tabs on the rear in their jig.

 

So the rear of the 4 bars are welded, so you can't adjust in place. They must at least be disconnected at one end (front would be easier) to adjust.
You have to make the call, minor adjustment with coil overs in place, moving the axle back on the left and toward the left to center, or block up the axle, support the body and remove everything (4 links, coil overs) and start over. Your measurements and efforts each way to determine which.
Once complete with each measurement where you want it, each bar should be able to be unbolted at one end and slip out and back into alignment without forcing anything. No binding or preload. If this was a race car or super light and you wanted to compensate for driver weight and axle torque, some preload might be nice. It might be something you fine tune later, but get it square and centered first.

 

Thanks

 

It is that an optical illusion from camera angle ore are both rear tires pointing in at the front?
Who did the welding on that axle and was it checked for true after the welding? For that matter was it ever checked for true before it was cleaned up and welded on?

Unless my 74 year old eyes are totally out of wack both wheels are pointing in at the front while as far as that left one is pointing in the right one should be pointing out to match.

 

upper bars .add length on the tight side and subtract equal on the loose side , for l to r adjustment the lowers do nothing on a triangulated setup, its the uppers that manage your l to right and the lowers handle the squareness in the car , and if your pinion angle (another topic but with car on ground on the tires the angles of both ujoints should be the same) lift lightly by chassis on stands take loose coil overs , set back down chassis on blocks to ride height , take both uppers loose. make tight side longer and count the turns and add that many to the other . have a buddy scootch the rear till ya can get the bolts in ,repeat till it looks right , just be sure to count so it all stays square ,,, smiles for miles

fabricator john
miss you dad

 

Chev, I'm sure it's perspective (vanishing point) https://en.wikipedia.org/wiki/Vanishing_point
exaggerated by the model A body being wider at the front of the rear wheel well are than the rear, but that's a good additional measuring point.
I'd imagine that it would hardly be driveable if it had a bunch of rear toe in.

John, yep! But tighten bar on top to pull axle over on tight side, loosen on loose side. Since he has to disconnect to adjust, this will be a try and check, not a twist and watch...

 

I hope that is what I am seeing.
Back when I was doing front end alignments every day after I got caster and camber set where I wanted them I'd center the steering wheel and lock it down with the wheel holder and then sight down the sides of the tires to the rear tires to see which front tire needed to be adjusted first.

It's hard to tell what's off without actually being there and measuring though.

 

Another thing
On your chassis photos the 4 bar bolts don,t look like they engage the nylon on the nylock nuts.
If they are still like that you might want to fix that.
Either that or I,m seeing things,which is a possibility

 

Chev, I bet you got cross-eyed doing Ford I-beams with a wider front track and that goofy angle!

 

Lots of good info here on how to solve the alignment/clearance problem. What concerns me, looking at the pictures of the links, is that to my eyes the bolts are not protruding out of (what appear to be) the nylock nuts. Common accepted practice is for the bolt to extend about 3 threads past the end of the nylock
(assuming a fine thread bolt). If not, you do not have a true bolt locking torque value, nor do you have any safety margin.

vic

 

Correct on the minimum 3 threads showing. Back in the 1980's I was a NSRA safety inspector for 4 years, boy the stories I could tell....

 

I don’t like seeing coil overs mounted on that angle ,,,,binding situation .
Yes,,,,many are mounted that way,,,,,it is still a binding situation as they travel through their arch .

Tommy

 

Thanks guys for all the helpful suggestions. Got it up on the lift today and adjusted the links. Spacing is better but needs a bit more in the same direction. The problem just might be the body. It’s not rubbing except over a big bump. Getting there.
The bolts on the links were too short. Was corrected before the body went on. Chassis pic is old.

 

Glad to hear, however, one more thing (isn't there always), nylock nut are assumed to be one time use.
Get it where you are happy, then replace them.

Re the body, if the frame is square, you should be able to measure how much overhang the body shows from the frame outward on each side and compare. If it is kicked over a small amount, you may be able to loosen the body mounting bolts and bump it to center it better. Remember there are a lot of things this may affect, depending on how far off center it is.

 

Good point, those bodies are so flexible, it’s entirely possible. Called Jason Slover at P&J’s. Last resort, get a wheel spacer

 

Just be careful, I don't want you to get it just to the right point and suddenly hear the paint crack, the trunk lid pop, or some other major uglyness.

 

Appreciate it

 

A wheel spacer will work , if everything else fails . Not the best solution for such a nice set up .

 

Thanks for the kind words. I’m happy with it.

 

It could be camera angle however it appears that the axle tubes aren't parallel to rear cross member and that LH side may be biased towards the front of the car? If not and axle is square, rear cross member isn't square in frame? I see more axle tube on LH side when compared to RH side. Or is it the way the suspension is sitting, is chassis level at rear?

 

So the floor is lower on the drivers. The suspension is lower on that side. This chassis came from Brookville bracketed. Everything on the chassis is square. Also the pumpkin is not in the exact middle of the axle.

 

Before and after. Not perfect but an improvement.
Pics might be backwards but you’ll figure it out

 

Looks better! Thought you had said you were using a 4 post, not a 2 post. Ignore if this is just somewhere else. Hope the final tightening was done with suspension fully loaded.
Also, did you try having someone hang out of each door and look at clearance when the body/chassis is leaning?

 

Was always a two post
Yes we looked at it from all angles. Brought it up and down a few times to double check. Seems to steer nicely, no difference turning right or left. After we were done I drove up the foot hills of the Shenandoah valley, no issues other than the smile on my face !

 

I think I’d add a 1/2” spacer on both sides to account for loaded sidewall bulge.

 

Ordered 1/4” spacers, see what it looks like. Little at a time
Thanks