Rebuilt 9 inch rear

[SevenT]

Asking some advice. Had the 3rd member rebuilt and 31 spline spiders added. Put the passenger side axle shaft in and after the bolts bottom out, the axle shaft will not turn. What could be causing this? Is that axle shaft too long and binding in the 3rd member? I have not tried to install the driver side axle shaft because I want to make sure I don't have to take the housing out again. Thanks.
v/r,
Mike Norton

 

[bax]

Ok not sure I got all of this. You went from 28 spline to 31 spline. You bought new 31 spline axles correct? Hope so because I know the problem if you didn't. So sometimes on new axles the axle right after the splines is too fat. Not by much but enough to not let it pass a little into the spider gear. Sometimes all it takes a a light touch with a flap wheel. It will bind up the rear with a fat axle

 

[SevenT]

Ok not sure I got all of this. You went from 28 spline to 31 spline. You bought new 31 spline axles correct? Hope so because I know the problem if you didn't. So sometimes on new axles the axle right after the splines is too fat. Not by much but enough to not let it pass a little into the spider gear. Sometimes all it takes a a light touch with a flap wheel. It will bind up the rear with a fat axle

Bax,
31 spline all around. The axle will turn if I loosen the nuts about 2 full turns.

 

[bax]

Take the axle back out. take a wrap of blue tape around the axle just past the splines. Put it back in . put the nuts back on to the point where it locks up. back off just a tad and then spin the axle. Pull it back out and see if the tape is torn up or marked at all. If so just dress off a little of the high material and try it again.

 

[SevenT]

Bax,
I will try that. Let you know what I find.

 

[Broncobowsher]

Do you have the brake backing plate installed? The thickness is part of the calculation of axle length.

I did a redneck disk conversion and I had to butcher the drum backing plates to act as a spacer between the housing end and bearing retainer. This was a full width truck 9"

 

[SevenT]

Do you have the brake backing plate installed? The thickness is part of the calculation of axle length.

I did a redneck disk conversion and I had to butcher the drum backing plates to act as a spacer between the housing end and bearing retainer. This was a full width truck 9"

Bowsher,
The entire brake assembly is in place to include the backing plate. I am going to try Bax's suggestion to see if the axle is too wide at the end of the splines.

 

[.94 OR]

I upgraded to 31 splines in the rear of mine. Passenger side axle was about 1/8" too long. Had to grind it down to fit. Otherwise it was pushing against the spider gear center shaft.

Blue line is where it stopped with the factory length. Red line is where the bearing seats in the housing end. I ground a heavy 1/8" off to afford clearance on the inside. There is obviously room on the splines on the inside of the side gear so I doubt I hindered any strength.

 

[SevenT]

I upgraded to 31 splines in the rear of mine. Passenger side axle was about 1/8" too long. Had to grind it down to fit. Otherwise it was pushing against the spider gear center shaft.

Blue line is where it stopped with the factory length. Red line is where the bearing seats in the housing end. I ground a heavy 1/8" off to afford clearance on the inside. There is obviously room on the splines on the inside of the side gear so I doubt I hindered any strength.

.94 OR,
Good to know, I had heard and read that the aftermarket shafts run a little long and some trimming may be required. I will check this out as well. Thanks.

 

[DirtDonk]

It’s not always the axle shafts fault either. More often than not a different differential, such as a limited slip or locker, is the actual culprit.
But slightly long aftermarket axle shafts certainly aren’t helping the matter!

 

[SevenT]

It’s not always the axle shafts fault either. More often than not a different differential, such as a limited slip or locker, is the actual culprit.
But slightly long aftermarket axle shafts certainly aren’t helping the matter!

Paul,
It is a locking differential. I am going to measure axle shafts this afternoon.

 

[Insayn]

Sounds like the axle shaft is bottoming out on the cross pin. The may need to be cut down a little.

 

[bax]

The end of the axle could be hitting the cross pin. Before you put the axle back in put a little paint on the end of it. Or something that will tell you if it rubs the pin. You also may be able to see it by looking into the other axle tube. Flashlight required. Good luck.

 

[SevenT]

Found out the bearing retainer is twice as thick as it should be. Ordered new bearings and the correct retainer. Hopefully will have it back together this weekend.

 

[bax]

well thats good then.

 

[DirtDonk]

Found out the bearing retainer is twice as thick as it should be. Ordered new bearings and the correct retainer.

Twice as thick? Aren’t these new 31-spline axles? Do they have tapered roller set-20 bearings, or stock type sealed ball bearings?
The bearings are not interchangeable on the same axle shafts.

There have been a few cases of too-big retaining collars lately, but those kept the axles from being able to fully insert into the housing.
The collar being “twice as thick” sounds suspiciously like a Set-20 bearing.

 

[SevenT]

Update. There are heavy duty bearings on these axle shafts that get lubed by the gear oil. I just need to take the seals out of the axle tubes and should be good to go.