[Nailbender]

Just throwing this out there. If I could shorten my 8" rear end that has a new TJ tru loc or trac center section in it and 1/2" or better yet 5/8" I could fit an additional 1" in width of rubber under it. My car is now a trailered autocross car living it's life less than minute at a time. I want to keep the car squared as in the front tires and wheels can be rotated back and forth with the rears between events greatly extending tire life. I'm not exactly sure if there is anything other than the big ol bead of weld holding the ends on the housing or there is more involved? My new Moser axles have splines an additional inch over the factory axles so shortening them is no problem.

 

[patrickstapler]

Call Quick Performance. They’ll tell you what all is involved.

 

[Scode67FB]

I don't think you'd be able to shorten the axles that amount and re-spline. You might be better off finding a Maverick rearend. I believe its about an inch shorter than the 65 Mustang.

 

[macstang]

The axle tube needs to be cut inside the bearing position and the cuts need to be absolutely perfect to the housing so the ends will weld back on straight. Welding it back is recommended to be done with a TIG (from what I have seen on doing this) to keep the possibility of warpage down. Even using a TIG you are not supposed to run one continuous bead. You run 1 1/2 to 2 inch beads, let the thing cool down and on the next bead you join it to the end of the previous with just enough overlap that it is seamless.


Somebody sells a long bar with collets that make sure that when you put the ends back on that they are absolutely straight with the housing and that the housing stays straight. It isn't exactly cheap. It is the same gadget that is used to straighten a bent axle tube.


If your axles are cuttable and I would check with the manufacturer to be sure, cut slow because if you put too much heat into them when cutting it can mess with the temper.


Good luck. After looking at all that I decided to put a mild fender flare on just my rear for 275/60 tires. This has its own set of problems, issues and concerns too.

 

[awhtx]

I don't think you'd be able to shorten the axles that amount and re-spline.

If your axles are cuttable and I would check with the manufacturer to be sure, cut slow because if you put too much heat into them when cutting it can mess with the temper.

Nailbender stated that his Moser axles already have splines that are an inch longer than he needs so re-splining will not be needed. He can simply cut off the excess length with a cut-off wheel.



The spring perches on his rear end housing need to stay where they currently are to maintain the 43" distance between the perches. So the 1/2"-5/8" section of tube will need to be removed outboard of the perches. In my view it would be better to cut the bearing retainer/flanges off of the ends of the housing and weld new retainer/flanges onto the shortened tubes rather than cutting and splicing the tubes.
It may be better to start with a '67/'73 rear end housing to do this. The '65/'66 rear end housing necks down to a smaller diameter out near the ends. The later housings maintain full diameter the entire length of the tube. Of course you will need the later shock plates and u-bolts to fit the larger diameter tubes.

 

[Woodchuck]

There are a bunch of sellers out there who will make up an 8 or 9 inch rear housing in a custom length for between $300-500. That said, will the 1 inch of additional treadwidth REALLY make that much of a difference? I might think that instead of spending the $$$ trying to shorten the rear and, potentially, having to mod the inner wheelhouse at the same time, that maybe adding a Watts to the rear suspension will get it to stick BETTER than simply adding an inch of tread.

 

[wicked93gs]

As far as axles themselves go...Moser shortens and re-splines axles at a very reasonable price(wanting to say $120 per axle but dont quote me on that)

 

[Westmus]

My axle is shorted about 1" each side. Cut between the wheel bearings and the spring peach and welded back together. It's all homemade with basic tools. Made a jig to keep things straight, by putting a big heavy pipe through the axle. Everything was fixed with some "adapters" put on the pipe, I made those out of wood.

 

[Nailbender]

My axles have an extra inch of spline.

I am looking at this as a “free” mod I can do myself this winter.

Am I correct in assuming that if I carefully ground down the welds at the outer ends of the housing I should be able to press the ends off shorten housing and reinstall?

 

[Matter]

You could shorten the tubes at the housing as you described, but that opens a different can of worms. Not that easy to remove and pull the tubes back in place, also any deflection in tube alignment will be compounded by the length of the tubes as opposed to being closer to the bearing end and just pressing the tubes back in the housing will not insure them to be straight.

 

[awhtx]

Am I correct in assuming that if I carefully ground down the welds at the outer ends of the housing I should be able to press the ends off shorten housing and reinstall?

I don't think you could accurately grind the welds with a hand grinder. They need to be cut in a lathe. I have a 16" South Bend with a 10' (that's foot!) bed if you want to drive to Texas. And after you remove the bearing ends you need to cut the tubes in the lathe to insure they are square.

 

[Nailbender]

Oh well. Thanks for the responses!

 

[jgrote]

I just helped a buddy shorten an 8.8", and I was really surprised at just how easy it was. We cut it with a cold saw. What I would do in your position is cut off and replace the spring perches. It will make the job way easier. Then cut your 5/8" out of each tube in the middle of the tube. Clamp the tube pieces back together wit 2 pieces of angle iron to keep everything straight. With it all clamped up, burn it back together. You'll need to weld, wait, move the jig, weld, wait, move the jig, etc, etc. Spending a little time to make sure it cools while in the jig will keep everything straight.

 

[Rowdy]

NB,

I found my tubes/axle flanges to be bent. Thats what was causing it to eat the drivers wheel bearing and most likely the cause of my 70mph vibration. But I think the process for you would be the same..

The local chassis shop does a lot of rear end work and he has the long bar with collets that macstang mentioned. As well as a jig. He simply cut the flanges off, nudged the tubes straight with another tool and some heat then put the long rod through with it in the jig and welded the ends back on straight. I think he also faced the flanges too. I had no need for lengthening or shortening. shortening would obviously be easier. Remove some of the tube and just re weld! It looks like TIG welds. Some might consider cutting the tubes off at the housing and running the bigger ones with bigger bearing ends. Probably a complete waste of $$ with an 8in. Could just get a 9in housing from QP for a fraction the cost.

But maybe just cutting and shortening out near the flange might buy you that 1/2on you're looking for.

I think as a couple people have mentioned, you're going to hit the inner wheel house or the fender lip at a certain point. I'm not sure where as all these cars are a bit different. I know mine just gently rubs at full compression on the fender lip on the rear. More so on the drivers side. Similar story up front til I rolled them! Didn't you mention yours was the same?

 

[Nailbender]

There are a bunch of sellers out there who will make up an 8 or 9 inch rear housing in a custom length for between $300-500. That said, will the 1 inch of additional treadwidth REALLY make that much of a difference? I might think that instead of spending the $$$ trying to shorten the rear and, potentially, having to mod the inner wheelhouse at the same time, that maybe adding a Watts to the rear suspension will get it to stick BETTER than simply adding an inch of tread.

A Watts link is my next major upgrade and I was hoping to narrow the rear end at the same time. And yes every inch of tread matters as my current problem is traction when starting the run, I can't seem to find any. No wheel hop anymore but myself and others can't seem to get rolling quickly without blistering the tires. Starting out in second gear kind of worked but has toasted the clutch. I'm sure the clutch supplied in my T-5 conversion was not up to what I've decided to do with the car since and I was unaware of how much power it was making until I got sticky tires.

Both my and Rowdy's cars have at least a 1/4" less room fender wise on the drivers side I'll adjust the holes on the spring perches to try to center them and roll the car fenders. I'm not doing anything crazy, just going from 225/45/17 to 245/45/17 that won't work at the back without tweaking as I'm already rubbing. I know many people on this forum run bigger tires with no issues but I'm probably 2 1/2" lower than stock with the drop spindles and such.

 

[Rowdy]

Yep! I rub on the drivers side with 225's! And here was everyone telling me 235's would work 'no problem'.

Are you gonna do the SorT 3 link? or just start with his watts link?

 

[Nailbender]

Yep! I rub on the drivers side with 225's! And here was everyone telling me 235's would work 'no problem'.

Are you gonna do the SorT 3 link? or just start with his watts link?

Probably just the Watts link. I need to concentrate on getting the house ready to sell.