"Rear Axle" --New Bearing / Axlels Will Not Go In - HELP!!

[T Lea]

1997 Astro AWD
I replaced the rear outer axle bearings. When I slide in the axles up to the bearing area, the axle will not go in. These axles are supposed to slide right in with a medium SLIP-FIT. The bearings were replaced with the same manufacturer & part # as the ones that were removed, ( TORRINGTON DK57509 ) OEM. I measured the axle OD. and the bearing ID, there is a .002 interference fit. I picked up another pair of bearings, different manufacturer, same thing. I also used the VIN# to cross match and that checked out. I measured a GM / AC bearings RW2012, it looks a bit better but I didn't install them to try, at $90 per bearing I can't keep throwing away $$$ just to try. Between bearings & seals I'm already $150 in the hole. Note: the rear-end is original to the vehicle.

Has anyone else had this problem?

[Drummernaut]

If it is .002 it should be a press fit. For the bearing sets at were I work we heat the bearings up to were you can't hold your hand on them(135F) and they slide right on. Not sure if this is your problem or if they are not supposed to be press fit. I do know .002 to .003 is a common press fit number.

[T Lea]

Perhaps I wasn't clear with my question. The bearing going into the axle housing is not the problem. It's that the axle will not slip into the bearing ID. It should slide right in.

[Drummernaut]

I understood, I just had the wrong type of bearing in my mind. It appears you have the right bearings. I would make sure you are going in as straight as possible. Any angle and it probably will not slide in.

After that I am not sure what could be wrong. May be there is a problem with the TORRINGTON. Try the SKF, see if your measurements match these: http://www.rockauto.com/catalog/moreinfo.php?pk=1836888

[Smiliesafari]

If the differential was rotated while the axles were out the side gears in the differential are probably out of place making it impossible to slide the axles in place.

[T Lea]

The problem is this.
The bearing goes into the housing just fine.
The ID of the rolls are then .002 to .003 smaller then the axle diameter and will not slide in.

[Drummernaut]

Since you are sure about your measurements, do your measurements match the measurements of the SKF bearings?

Width (in) 0.86
Inner Diameter (in) 1.395
Outer Diameter (in) 2.446

How did you press your bearings in the housing? Is it possible you deformed them during installation?

I have done these and full floaters and I have never had this happen. They are all tight and if they are crooked during press in any way that last bit could be tight, but you have your measurements to go by so compare them.

[T Lea]

Thanks Drummernaut for taking the time.

I've researched many bearing manufacturers to get their specs and most are the same as the SKF. As an example, lets use the sizes you found from SKF.

Both sides of my axle tube housings I.D. measures 2.4401 to 2.4408. The bearing O.D you listed is 2.446. This is a .006 interference fit, known as a "Heavy Press Fit" in the machine / tool industry. ( This is what prevents the bearing from falling out and the O.D. race from spinning )

That .006 of material has to displace somewhere. So, the I.D. of the axle tube expands some and the O.D. of the bearing compresses some causing the I.D. of the bearing to get smaller.

Now, the the SKF dim. for the bearing I.D. is 1.395 ( I don't know if this dim. is an "installed" size. or a "un-installed" size ). Both axles measure 1.3991 to 1.3994. And this is where the numbers don't work and why the axles will not slide in.

The axle diameters are correct because one of them is the original and the other is new and they are the same size and round & straight.

IT JUST MAKES NO SENSE !!

I've been looking for the bearing dimensions for the original GM / AC Delco ( RW20-12) bearing that the VIN# calls for. I'm also looking for the GM manufactured size of the axle tube housing dia.

Do you know these sizes or do you know where I can find this info ???

Thanks again !

[Drummernaut]

I have done some research for you. All of the bearings listed as a replacement for the RW20-12 have an ID listed as 1.395 accept the TIMKEN 513023 which has consistently been listed as 1.3995: http://www.rockauto.com/catalog/moreinf ... cc=1028056

I do not have in OD of the axle shaft, I suspect it is in the GM TURM manual which I have been trying to find a good copy of.

If you feel that your current bearings are truly under sized then it looks like the TIMKEN 513023 set is your best bet. Or new axles.

I hope this helps.

[LiftedAWDAstro]

Late to the party but I bet the issue was simply the end of the axle shaft hitting the inner spider gear and not sliding in. I have done tons of these and the shaft has to insert into the spider before it even hits the bearing.