Removing rear halfshafts.

Mike Puckett

SCCoA Member
I've got a 90 chassis that I want to remove the fat rear axle from the right side of the car. I've never done this so I was wanting to know what it involved. It looks like that there are 3 large bolts and nuts holding the rear hub on and that once those are removed the hub should come off and the halfshaft would pull right out of the differential. Is this all there is to it? Also can I bolt the hub back on minus the halfshaft so we can put a wheel on it to roll it up onto a flatbed?
 
Mike,

In order to get the rear halfshaft off the car you need to do the following:

1. Remove the axle nut
2. Remove the rear knuckle (the 3 bolts you mentioned)
3. Use a large screwdriver to pry the halfshaft out of the rear diff
4. Put the rear knuckle back on
5. Put the tire back on
6. Roll it up on the trailer.
 
Ok, so it is that easy or should I say simple since nothing on these cars is easy. 36mm?? Geez, where am I going to get a 36mm socket?
 
A tip about prying loose the half shaft from the diff:
Dont insert the tip of the screwdriver between the halfshaft and the bearing surface! Inseat, position the screwdriver so the shaft contacts the half shaft, and the tip is on something benign, like the diff case.

As for rolling the car up without half shafts: I once failed to torque my axle nut down tight enough, and it destroyed my wheel bearings with a trip around the block. The half shaft and axle nut keep the bearing races located.
If you just need to get the car on a trailer without turning the transmission et al, unbolt the drivershaft. If you need to get it on a trailer without spinning the diff, drop the pumpkin out. This can be done with 4 bolts, you don't even have to remove the knuckles (I've changed 4 sets of half shafts in 2yrs, and swaped pumpkins a dozen times).
Suspend the half shafts on a "cradle" made from a bungie chord or rope on both sides, so they can spin as you push the car without grinding on the lower control arms...or the ground.
Dropping the diff will probably take less time than dissasembly/reassembly of the rear suspenstion, that's what I'd do....don't wear anything nice. :)

I got my 36mm socket at Napa. It's simple, but may not be easy the forst time, depending on seized bolts. My bolts are nice ans mooth now, I can swap the diff and half shafts in my car in less than 1/2 hour (faster if I have some one working the trans).
 
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Thanks, I appreciate all the good info. It looked like a big project at 1st but maybe it won't be so bad. We're stripping the chassis so I may drop the pumpkin and keep it. The clutches are shot but it's rebuildable. I'll soak all the bolts and nuts and connections with PB Blaster tonight and start on it tomorrow. I was really surprised to find a fat halfshaft on an AOD car. It'll be just a rolling chassis when we're done and we just want to roll it out into the driveway and load on a trailer or flatbed.
 
Ok, so it is that easy or should I say simple since nothing on these cars is easy. 36mm?? Geez, where am I going to get a 36mm socket?
I knew it was big, that's why I asked. Thanks for the thread and info.

I'm quite sure my 1990 auto has a fat half shaft.

So is the best replacement for a bad half-shaft a good used one? My 1990 5-speed has a bad fat half-shaft.
 
Not so sure why you are so hot to put a Fat Shaft on the car. It is no stronger than the non-Fat Shaft side. Has the same yield strength. Now there is a half shaft that IS stronger but only by 200 Lbs of yield strength. Used on the Lincoln LSC later versions. But we are only talking 3900 Lbs vs. 4100 Lbs if memory serves. But it IS a bolt on. All critical dimensions match.
 
I was always led to believe that it was stronger than the smaller one. I just want to have some spares if I break one. I'm hoping I never need it but since it's in this chassis that's going to the crusher I'll take it. Are they available new? I didn't know about the Lincoln's.
 
Went back and checked......actually the Lincoln Mark VIII LSC 95-98 shafts are only 100 Newton Meters greater in Yield strength at 3900 Nm. All of the SC shafts are rated at 3800 Nm.

To my knowledge no OEM SC Shafts can be bought new unless obtained from a NOS Obsolete dealer. Don't know about the Lincoln LSC shafts.
 
I was always led to believe that it was stronger than the smaller one. I just want to have some spares if I break one. I'm hoping I never need it but since it's in this chassis that's going to the crusher I'll take it. Are they available new? I didn't know about the Lincoln's.

Hehe. Nobody mentioned to make sure that you have the car up high enough to clear coming out with the pumpkin on the jack (higher than you would imagine). Your options are limited once you find out it's not and you only have one jack. It's quite a handful under the car (87lbs) especially if you have to roll it off the jack to get it out. And the love potion that comes out when you tilt it smells really good on your shirt:)
I am puzzeled, however, as to why Ford would make one half shaft thicker/stronger than the other on a posi setup. Is the right rear the "default" that gets more torque than the left?

Bill
 
It was done to shift the drivetrain resonance frequency to lessen wheel hop. Again...all SC half shafts are equally as strong.
 
Unfortunately, about all you get is non-sc axle shafts in the aftermarket.

And changing the rear diff doesn't require the removal of the half shaft from the knuckle unless you want to pull the axle out. Pull the sway bar link, pull the top bolt from the suspension control arm, disconnect the lower shock mount and push the lower control arm down while popping the axle out of the diff.
 
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