NEED HELP Replacing LH bearing in front diff, have questions.

[gmcman]

Was surprised to find a loose roller bearing behind the LH CV axle seal.

Looks like I can simply unscrew the adjuster but is there a procedure for this, special tool needed? Any surprises lurking?

I can get the bearing buy never had to replace one.

I was able to locate the loose rollers.

 

[gmcman]

Looks to be the differential bearing adjuster, which includes the small roller bearings.

I scribed where the old one came off, and it didn't take much to knock it loose.

I suspect a few taps once the new one is snug is all it will need. I will try to source what the preload should be but I figure if I don't disturb what's there I should be good.

 

[Mooseman]

Dunno if you searched but I found some info:

Front Left Differential Seal and Adjuster Confusing Issue

Hello everyone, I have read many posts on here and the OS concerning the front drivers differential seal and bearing (adjuster). But I have yet to find anything posted asking the how and why (if you will) of putting the seal and adjuster back in the differential. I'll explain in a minute. To...

gmtnation.com

Front Differential leaking fluid, suspect the seal.

Hey guys, so yesterday I noticed my truck started making drip marks in the street, like bad and everyday. First I thought it was motor oil, but then I thought maybe power steering line or something else. Long story short I pulled the drivers side tire to find this: Fill level more then an inch...

gmtnation.com

Front differential seal part numbers needed, please

As the title says, I need the GM part numbers of the seals for the front diff. And, before I get reamed to search, I've searched the 3 boards and although there is a lot of help between them for all the work I need to do, the part numbers are absent. Well, except for: DS axle shaft seal (this...

gmtnation.com

 

[gmcman]

Thanks for the links.

I searched "bearing" but not "adjuster"

That adjuster is pricey for sure, almost $100.

I will try to ensure there's no parts in the bottom of the case, not sure what tore it up but the CV shaft looks good.

 

[littleblazer]

I did the one on the escalade... those adjusters absolutely sucked to work with... a shim pack would've made more sense as far as preload goes. IIRC the one in the escalade was just a slip fit and would pop out though. Many classes and problems since then to remember how I did it. All I know is that the preload on the carrier isn't super critical. As long as you go back in with some it'll be fine.

 

[Mooseman]

I searched "bearing" but not "adjuster"

I used google to search for front differential bearing. The forum's search function sucks.

 

[gmcman]

Looking over the threads linked, there was talk about tightening the adjuster to 55 foot pounds with new bearings, and 45 foot pounds for used bearings.

I tapped the adjuster with a screwdriver and hammer and it came loose, only needed about 1 tab width. Seems like a far cry from 45 foot pounds.

 

[TJBaker57]

Looking over the threads linked, there was talk about tightening the adjuster to 55 foot pounds with new bearings, and 45 foot pounds for used bearings.

I tapped the adjuster with a screwdriver and hammer and it came loose, only needed about 1 tab width. Seems like a far cry from 45 foot pounds.

This portion of the service literature from Mooseman might be where that 45 & 55 came from, but here it is in lb, not ft lb.

 

[gmcman]

This portion of the service literature from Mooseman might be where that 45 & 55 came from, but here it is in lb, not ft lb.

View attachment 99885

Excellent, thank you.

I won't be able to get the RH side adjusted but with it still untouched I believe I can get the preload correct from the LH side without disturbing the contact pattern.

 

[TJBaker57]

Excellent, thank you.

I won't be able to get the RH side adjusted but with it still untouched I believe I can get the preload correct from the LH side without disturbing the contact pattern.

In that service literature from Mooseman find the file "Front Drive Axle.pdf" and scroll down to about page 123 or so. There they talk of marking the existing location of the bearing adjuster(s) during disassembly and then just putting it back in the same place on reassembly.

I figured that knowing the whole business would be of use to you even if you cannot follow to the letter, you have the general idea now!

 

[gmcman]

There they talk of marking the existing location of the bearing adjuster(s) during disassembly and then just putting it back in the same place on reassembly.

I did that in case it was going back in. Unfortunately there's a portion of the cage missing so it will require a new adjuster.

The adjuster incorporates a roller bearing assembly used in conjuction to the main carrier bearing.

 

[gmcman]

New bearing adjuster arrived today.



Rotating the carrier and looking inside the best I can, I don't see anything that would cause alarm, all the teeth I could see look fine.

I will take an endoscope camera and try to see inside for any small broken parts.

This isn't my vehicle, so I was quite surprised and fearful at the same time when I removed the CV shaft and found missing needle bearings.

My first thought was the diff had to be removed, but so far so good.

 

[gmcman]

Update on this, everything is back together, all is working.....except....

Now the seal on the RH side of the front diff is leaking much more than when I started. It was barely wet on that side and now it's dripping, I'm guessing from the new intermediate shaft.

Can this seal be removed with the diff secured against the LH frame? Is there enough room to pry it out and reinstall?

I had my diff out like this when I removed my oil pan, didn't remember how much room I had.

 

[Mooseman]

You would have to secure it because I remember they are a bitch to pry out. I replaced all the seals when I had the diff out during my '02's engine swap and that seal just wouldn't come out. I think I used the slide hammer with the hook to yank it out of the loose diff.

 

[gmcman]

Definitely a fun time....

1.5 hours to this point.



If I can R&R that seal at this point I will be happy... fingers crossed.

 

[gmcman]

I started another thread in case others need to source a good seal puller.

That's my current situation.

Best seal puller for front differential

I wanted to start another thread so others could find help more easily. I'm replacing the two seals on the front differential, I already replaced the LH CV shaft side, now the oil pan side. The LH side I managed with a prybar, but the diff was also secure. I also don't want to damage the...

gmtnation.com

 

[gmcman]

A little persuasion and the diff rotated downward.




This was about 2 hours of constant wrenching from the time the coffee was brewed...

The A/C compressor needed to be moved forward and the cross member removed, in conjunction to both CV shafts, front propeller shaft, front 4WD actuator, and intermediate shaft.

Now I need a good seal puller.

 

[Tankcruiser]

any updates? might have to do same thing to mine leaks all over frame......

 

[gmcman]

Yes, will follow up later today or tomorrow. New seals installed, not too difficult, I'll try to get a how-to written up.

I would source the seals now, the outside is avail, the inside has been discontinued through the dealers but still avail from other vendors.

 

[gmcman]

@Tankcruiser I will do a more thorough write-up but just wanted to get you started.

The front differential outer seal part # is : GM 19257296
The front differential Inner seal part# is : GM 12471617

The outer front diff seal behind the LF CV axle can be installed with a regular flat-base seal installer. The inside seal between the diff and oil pan cannot. There is a raised portion where the intermediate shaft enters and using a flat-base installer will damage the seal.

The rearmost differential mounting bolt is a real peach. You will need a 18MM wrench and will likely need to remove the cross member under the steering gear. The cross member is easy, but observe all the small 15MM bolts that face forward, you can leave two of them, I believe the outer most bolts.

The cross member houses four 21MM bolts that secure the lower control arm brackets. Those require 177 foot-pounds so you will need a big torque wrench. Don't hammer away with an impact to tighten, don't risk breaking loose the welded nuts. Those bolts also keep the frame from sliding in the lower control arm when braking, ask me how I know......alignment shop's fault.

Also this is important, there are two short 15MM bolts that mount in close proximity to the high pressure lines of the PS gear, don't use the long bolts there.

Maybe you can get the diff to turn over once removed, I had to unbolt the A/C compressor and move it forward.

If you have over 140K miles on the front hub and bearings, I would replace those while you are at it.

When you pull the diff seals, observe the small roller bearings of the bearing adjuster just past the seal, make sure they are all there and in good condition.

The seals need to be flush when installing, the last 10% is where you have to beat on them a little as the tabs fold over inside the seal.

I'll add a few pics later from my cell, hope this helps.