Tovars52

I have a 1967 Shelby GT-500 I am trying to put back on the road. The differential housing is bent and needs to be straightened or replaced. It is a 9inch gear housing that uses 31 spline axles. I was told that a 1967 Ford Fairlane station wagon uses the same differential housing. Can anyone provide some information?

1970

you can buy a new one for around 800 from curie

69mach1377

IIRC there is a sticky on top here that id's all the housings.
I would try to get an original given your model.

racer_dave

How bent is it? 1/2" they are pretty easy to straighten if you have a set of torches. I do it all the time with rears out of the racecars. It only takes an hour or two so most of the time. Certainly less time that putting on/moving perches on a different housing. This way you can keep the original housing.

67mustang302

Are you trying to keep it original? If you replace it, get a full floating rear from Speedway Engineering. Only a couple hundred more for a new housing and they work way better, but you'd probably have to change your brakes.

Otherwise, a junkyard donor since 9's are pretty tough, or a new one from Currie etc.

How id it get bent anyway? It takes a substantial amount of force to bend an axle housing, enough that it typically will damage other stuff as well.

1970

thats my ? how does a street car bend a housing

Tovars52

The car was damaged in a wreck that hit the right rear quarter panel. The wheel was bent and presume the axle housing was bent at the same time. It gets pretty squirrelly with speed when accelerating. I had a Chevy Blazer with the same problem and it was a bent housing. I would like to keep the original housing or find one exactly like it.

69mach1377

I would have the housing inspected thoroughly before doing anything.

gothand

Unless it's not repairable, I'd have it straightened by a reputable shop such as Currie as others have mentioned. This is especially true considering the value of the originality of your vehicle. FYI, I'm pretty sure that Currie stopped selling original housings quite awhile ago and now sells new reproductions. That is not a bad thing unless you're talking about an original GT500. Just saying...

racer_dave

to check for a bent housing...

Pull the rear from the car. Suspend it on jack stands/milk crates on the drums/discs so the housing can spin freely. Use another jack stand or chunk of 2x4 under the nose of the pinion to hold it in place. Use 2 pieces of angle iron about 4' long and clamp them to the wheel hubs, centered and horizontal. Measure the distance between the angle pieces at the front and rear, write it down. Now, rotate the housing 180* and block it back so it won't move. Now measure the spread of the angle again. The difference is how much its off. Do the same thing with the pinion faced up and down and record these measurements as well. Now decide which way it needs to be tweaked.

A bit of toe in is alright, IF its equal on both sides. Toed out will pull or act squirrely, toed in all on one side will drive funky, twitch on acceleration.

To straighten it Use the torch to heat up the side you want to pull IN.(they normally bend near the housing, not the axle flanges). Heat up an area about 1" wide and 2" tall, on the axle tube, near the center housing . Once its cherry red, quench it with a wet rag. Keep it wet using more cold water. This will pull the axle in in that direction. Go slow, its easy to pull it back 1/8" at a time using this method. If it doesn't pull in enough, heat up a larger area. Maybe another 1/2" wide and another 1" tall or so.

You just need to figure which way its tweaked and heat it in the right direction to pull it back. Heat it, quench it, remeasure it. If you go the wrong direction, just heat up the other side to bring it back. This isn't hard to do, it just takes some time and careful measurement.

Let me know if you have questions. No need to spend $600 on a housing if you can fix it with $15 in gases and a couple hours time.