Moparts Tech Archive
Rear axle and back half installMr. Ivy
From: Visalia, CA. USA
Registered: May 2001
posted 06-28-2002 09:47 PM
I'm going to back halve my "69 Valiant. I've taken the rear out already and didn't get one critical measurement. I need to know the axle centerline measurement. In the Chris Alston Chassisworks installation guide, it shows them measuring centerline from the door opening. Is there anyone with a '69 Valiant 2dr that can get this measurement for me? Thanks in advance.
I'm talking axle centerline, as in wheelbase.
Are you talking about the centerline of the pumpkin, or the center of the axle, flange to flange??...
The axle will be offset a bit from the factory, but in alot of backhalf cars it is centered(the axle tubes are equal length from the center housing to the flanges)...If you are talking the center from the flanges, that gets set when setting up the rear end with a diagonal link....the welding of the brackets needs to be close too, but that can be laid out on the bench...
Personally, I would reinstall the rear and get the measurements you need. Do it once, do it right!
the door measurement is a good rough measurement, but to make sure its straight and square find some better points under the car and measure longwise (wheelbase) and diagnolly.
It probably had a 108" wheelbase, so if you have the front wheels or at least the spindles mounted, get a tape measure and mark off @ 108" on both sides to get your axle location. To make sure it's square, measure cross-wise also.
If you are going to run a big tire in that Valiant I'd stuff one in there and make sure you can run it with the stock wheelbase.
I really wouldnt recommend measuring off of any body point. You would be surprised at how much they move sheet metal around when they build those things to make them line up. And, the front suspension is the same thing, I have seen the front wheels as much as 3/4" different.
Now, drop a plumb bob down to the floor from each side of the torsion bar cross member and put marks on the floor. Take a chalk line and mark this line accross the floor. Now, measure from the center of your one wheel well to the chalk line, transfer this measurement to the other side of the car, make a mark and then chalk line these marks. You know have an axle center line that is square to the chassis.
With these 2 lines, you can calculate all of your cut lines, your cross memeber locations, shock cross members etc.
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