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Rear Suspension

Rear axle and back half install

Mr. Ivy
Moparts Member
Posts: 110
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.
I want to center the axle in the wheel well opening. In the installation guide they show a picture measuring from the door opening back to the center of the axle. Can someone get this measurement for me?

Moparts Member
Posts: 3066
Registered: Mar 2001
posted 06-28-2002 10:04 PM

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...

Moparts Member
Posts: 1453
From: Tucson, AZ
Registered: Aug 2000
posted 06-29-2002 01:44 AM

Personally, I would reinstall the rear and get the measurements you need. Do it once, do it right!

dr dodge
Moparts Member
Posts: 124
From: houston, tx
Registered: Jun 2002
posted 06-29-2002 08:25 PM

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.
good luck
(I don't have a valiant, otherwise I'd measure it for you)

Moparts Member
Posts: 2673
From: Tampa, FL
Registered: Mar 2000
posted 06-29-2002 08:33 PM

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.

Moparts Member
Posts: 642
From: Hamilton, Ontario, Canada
Registered: Jul 2001
posted 06-30-2002 02:34 AM

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 think I remember Darts running dangerously close to the front of the wheel openning when running something tall like a 29".
If this is the case, now may be a good opportunity to set it back about an inch.

Moparts Member
Posts: 2487
From: glendale, AZ
Registered: Nov 1999
posted 06-30-2002 10:24 AM

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.
Here is how we do it. Get the car up in the air, level and where you are going to work on it. Remove all the rear suspension, springs etc and measure one of the rear wheel wells. It doesnt matter which one, just pick one. Find the center of that wheel well and put a mark on the floor. Now, with a plumb bob go to a common reference point on the underside of the car. On mopars I use the back of the torsion bar cross member. All cars have some kind of alignment holes in the bottom of them where they were held while being built and are reference points for frame machines.

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.

info provided by members listed above


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