[Chzyrider]

On my 1983 S-10 Blazer 4x4, I've rebuilt all but the differentials.

Now I got problems with the front diff; the passenger side output shaft moves in/out about 1/2 inch and the driver's side moves up/down a bit. My three regular (Haynes, Chilton, Clymer) repair manuals do not mention the full disassembly and rebuild process.

Figuring this is maybe about time/mileage for it, does anyone have procedures, instructions and specs for this?

Or...
Can this be fixed and replace the worn bearings without needing a full rebuild? I am not comfortable about resetting the pinion contact area if that is disturbed in the process.

 

[turbinesurgeon]

On my 1983 S-10 Blazer 4x4, I've rebuilt all but the differentials.

Now I got problems with the front diff; the passenger side output shaft moves in/out about 1/2 inch and the driver's side moves up/down a bit. My three regular (Haynes, Chilton, Clymer) repair manuals do not mention the full disassembly and rebuild process.

Figuring this is maybe about time/mileage for it, does anyone have procedures, instructions and specs for this?

Or...
Can this be fixed and replace the worn bearings without needing a full rebuild? I am not comfortable about resetting the pinion contact area if that is disturbed in the process.

You're going to need a factory manual, they are easy to purchase on amazon. Just use your vehicle year and model and you'll find a used one for about $50. They are worth every penny.

I just happen to have a 1998 S/T truck factory manual, you may want to skip it and part this work out. The driver's side has the differential carrier and the TM calls for 13 "J" tools, I'm pretty sure their is no substitute for 3 of them. J 8763-02 (holding fixture C clamp), J 22888 (diff side bearing remover), & J 33837 (pinion bearing cup remover). Bet you spend $400 on tools alone.

pm me if you get serious about doing it anyway, but I'll bet you can get a complete one from the junkyard for $300.

 

[big gear head]

I've rebuilt many of the 7.2 IFS differentials. It sounds to me like your problems can be fixed without a complete rebuild. There are 3 axle bearings in the IFS that can be replaced without complete disassembly. There is 1 bearing for the left axle and 2 bearings for the right axle. The right axle tube can be removed and the outer bearing and seal can be replaced easily. The right inner and left axle bearing are inside the spanners that adjust the backlash and bearing preload on the differential. The bearings are pressed in the spanners. You shoudl be able to pull them out without removing the spanners. This will require a slide hammer puller with fingers on it that will go inside the bearing and grab it from the back side. If these bearings are worn then the axles will also be worn because the axles ride directly on the bearing rollers. The left seal is in the cover that goes on the left side of the case, so it will be easy to replace. When you put the cover back on you need to stick the axle in to center the seal before yu tighten the bolts that hold the cover on. This will help prevent a leak.


Turbinesurgeon, what kind of turbine engines do you rebuild? You aren't very far from me.

 

[turbinesurgeon]

Turbinesurgeon, what kind of turbine engines do you rebuild? You aren't very far from me.

Mostly Rolls-Royce 250C/R3's, and General Electric T700-GE-701D's. I run an engine shop on Fort Campbell's airfield and average about 62 work orders a year. It's your tax dollars at work

 

[Chzyrider]

It sounds to me like your problems can be fixed without a complete rebuild.... The right inner and left axle bearing are inside the spanners that adjust the backlash and bearing preload on the differential. The bearings are pressed in the spanners. You shoudl be able to pull them out without removing the spanners. This will require a slide hammer puller with fingers on it that will go inside the bearing and grab it from the back side. If these bearings are worn then the axles will also be worn because the axles ride directly on the bearing rollers...

Thanks, I was kinda hoping to hear that I could do that. Hard to tell what is the "normal" amount of play that should be on this... either side; up/down, in/out.. I've got a slide hammer, are you sure it won't mess up any of the adjusments doing this? Should I get new shafts along with the bearings...with it being mating surfaces as you describe, or would other shafts from a donor vehicle work for replacements if they're clean?

 

[big gear head]

The only thing that holds the left axle in place is one bearing and the axle gear. This is a short shaft and the bearing is very close to the axle gear. If there is any wear or free play it will feel like it's a lot more on this side because the shaft is so short. The right axle is much longer and has 3 bearings. There is one bearing in the spanner, one bearing in the end of the axle tube and a very small pilot bearing in the short shaft that goes into the differential. These bearings can hold the right axle in place a little better, and the axle is much longer, so it will feel like it moves less than the short axle.

It isn't hard to pull the axles out and inspect them. There is a clip on the end of the axle that holds it in. Just pull hard on the axle and it will come out. You can get new clips if the axles feel llike they come out too easy. If you see signs of wear on the axles then the bearings will also have wear on them. If the axles look good then there is a good chance that the bearings are fine. If the axle seals are leaking then that can be a sign of a bad bearing. I haven't seen any of these bearings go bad yet.

 

[What?]

Moved.

 

[montec]

I've done one on the front of my '83 and it was a cake walk realatively. and I didnt use any special toos but a socke to fit those roller bearins in the axle tubes and a press to remove the old bearins off the carier and put the new ones on. was hard but really very basic just take your time and get a good kit. In a rebuild kit for the front you do not get all the axle bearins so may want to tear yours apart and get the @'s off the old ones just to make sure. Did mine last year just before the motor started knocking.

 

[FxsX24]

does anyone have pics to go along with this. the outside bearing (and possible others) on the right side of my 98 went. the cv has lots of room to move up and down.

i assume i need to remove the cv, then remove the extension housing to get to the bolts.

 

[Chzyrider]

does anyone have pics to go along with this. the outside bearing (and possible others) on the right side of my 98 went. the cv has lots of room to move up and down.

i assume i need to remove the cv, then remove the extension housing to get to the bolts.

With the high mileage, I just took the whole front diff unit from mine and had it redone at a local 4x4 shop. Turns out the carrier was worn anyway so I just had him get me a used one and he rebuilt it and set the pinion. Then I put the unit back into my truck making the last thing to be rebuilt on it.

I made this side-by-side image to show the in-out movement I was seeing on the passenger side of mine It was a worn thrust bearing.
If the up/down movement you are talking about is at this location, there is a bearing on the shaft at that end inside the tube.

If you are grabbing the cv shaft between the boots and wiggling up/down, there may a little play. It's suppose to slide in/out at the inner end as the suspension travels, but it should not be moving up/down. If it does, replace the cv axle. If it moves up/down at the outer end, identify whether the movement is at the joint inside the outer boot or at the hub bearing assembly.

If you see up/down play like I did at the flange on the driver's side, this was from the internal carrier wear I mentioned above.

If this doesn't cover your question, please be more specific where you are seeing the movement or post a photo or two.

 

[FxsX24]

the movement on mine is where your flange is. mine is the clip in style though.

 

[Chzyrider]

the movement on mine is where your flange is. mine is the clip in style though.

Here's a post from this site showing a later style diagram. Is this the style you have with the 'pop-in' axles seen in the upper image?
http://www.s10forum.com/forum/f220/exploded-diagram-of-the-front-diff-and-cvs-422946/

They just eliminated the flange and d-side stub axle to use a different style of one-piece cv end to connect to the differential. Most everything else should be similar to the older ones.

You may have some minor play (1/16" or so movement) with that type, but if you have excessive up/down movement similar to what is seen in the d-side image on mine pushing up at the flange, I would suspect it's most likely a bearing. Mine was caused from egg-shape wear at the carrier (#37 in that linked image).