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I did a few searches and can't find anything on lining up the subframe with the alignment holes.

I just re installed my subframe and want to be sure I get in place correctly. Any help would be great.
 

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When you do a search you will find many Threads devoted to this. Several will include measurement diagrams. I just installed a sub-frame last week. As I installed it, I used 5/8" bolts to line it up with alignment pin holes in the body. Then, as everyone seems to recommend, I checked the alignment using the measurements from the diagrams found in one of those threads. I did it using carpenter plumb bobs. My measurements came within a 1/16th of an inch with the bolts still fitting in the pin holes so I called it good and tightened down the sub-frame bolts. The biggest trick to using the plumb bobs is hanging them from the center of the reference holes. I temporarily removed the alignment pins (the bolts I discussed above) and used paper clips inserted into the holes. I straightened the paper clips then bent them in half and bent out "wings" that would hold the paper clips in the holes. I then centered the paper clip with the plumb bob hanging in the middle of the holes. Probably not as good as a Tram Gauge but it all seemed pretty good. Check out my thread "68 Z-28 Restoration" in the Build Projects forum. I put in a couple of photos. That's how I did it but as I said there are many threads on this topic so someone may have a better way. The Tram Gauge would be best but I am trying to watch my budget.
 

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I rem when /I was trying to align mine for the 1st time 30 odd years go....got totally messed uop in the head with leverage and science.
Then one nigh down the local hHot Rod Club was talking to one ofd the guys who had just finished a very nice '56.....who did the same as I.
He hot a bit of square note pad... then placed a match box on the pad.. and marked where the mounting bolts where.....
With this in front of me...knowing where the 'fixed' tight mounts where and the ones loosened off, /I could see which way to lever the chassis against the body to get it square....
For square have the diff mounted in the car...and take measurements from the bottom pin of the springs between the U bolts (or bottom of a U bolt) diagonally to a fixed piont on the chassis up front.... both of these diagonals need to be the same +/- 5mm... I got mine to 3mm.
Any 'error from there is taken up in the final wheel alignment.
 

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It's two sets of holes ahead of the middle body mounts.

Loosen the four body mounts, jam a tire iron through one set of holes, square it up and tighten that side. Do the same for the other side.

Go get an alignment.
 

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I agree more with Charlie. It is not as easy as just putting a tire iron or even dowels. Both holes are not the same. The holes are just to get you close to where you need to be. I just did one last week and with all the lines I pulled it took two hours to do. Took a long time, but dead on and will not crab down the road. Go to you tube and look up scared shiftless , he does one with everything attached and makes it look easy. He also shows how to install glass for dummies.
 

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Yep it is like Scott says....which works well when one does it each day and has it clear in there head the triangulation.....if not do as I suggest.. a match box , work out which way things need to be levered to get the result 1st....then once u have that clear in your head
do it.
 

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If I recall correctly I dropped 6 plumb bobs on mine. two on rear axle, two near rear of sub and two at ball joints. When the diagonals were off I measured straight, moved short side forward, rechecked diagonals. DONE!

Jeff
 

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two at ball joints
that rings a bell .. ?I think from memory it was those diagonals that confused me... because these points can be/ moved with wheel alignment shims later on.
 

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that rings a bell .. ?I think from memory it was those diagonals that confused me... because these points can be/ moved with wheel alignment shims later on.
Lower A-trays don't use shims.
______________________________________

Square up a subframe, yank a car on a frame machine, layout concrete forms and erect building walls. Same alignment principles.
 

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The one I was installing a chassisworks frame, and it was questionable on if it was true. Not the biggest chassisworks fan after installing the kit.
 

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Yes, the alignment holes are just to get you close. No substitute for a LOT of measuring (front to back, side to side, and diagonally from fixed points)
 

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Hey guys, I'm trying to align my subframe and was looking at the video that was posted. I measured the pinch welds and they are 5" on left and right sides in the rear and 5 1/4" on left and right sides in the front. Not sure if that is ok or not?

The other question I have is how do you get a good measurement from rear axle to front axle? I measured mine and was using a wheel stud on the rear and one on the front for reference points. But if you turn the wheel ever so slightly it can throw off the measurement by a 1/4" or more. Is there a better way to measure front to back?

Thanks,
 

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take the bottom of one of (the most convenient) end threads of a u bolt at the rear... to a suitable place on the chassis each side as far front as possible

And/ or a piont on the bottom of the diff to points on chassis up front.

get as straight is possible... not just within tolerance 1/8 or 1/4 "... this effects how many alignment shims u have each side IF the alignment guy knows what hes doing....
Often good chassis alignment can end up with crap alignment guy.
 

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Hey guys, I'm trying to align my subframe and was looking at the video that was posted. I measured the pinch welds and they are 5" on left and right sides in the rear and 5 1/4" on left and right sides in the front. Not sure if that is ok or not?

The other question I have is how do you get a good measurement from rear axle to front axle? I measured mine and was using a wheel stud on the rear and one on the front for reference points. But if you turn the wheel ever so slightly it can throw off the measurement by a 1/4" or more. Is there a better way to measure front to back?

Thanks,
Rear u-bolt to lower ball joint grease fitting might be good.
 
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