G503 Military Vehicle Message Forums

I opened up my rear differential today. (yeah, I posted like a year ago it was done. Then I started building the front diff and decided to go back and re-look a layer or two deeper.)

Anyway, I came upon an interesting problem.

One of the carrier bearing races (cup) is really chewed up, but the other one is perfect. Is it acceptable to only change the bad race and leave all other shims and settings intact, or should I change both of them regardless?

Thanks. I'm sure more questions will surface out of this as I have not completed cleaning all the bearings and gears. The race that is ruined looks like it got chewed up by a stray fragment of metal.

The bearings should be replaced in sets.

hatchetdan wrote:The bearings should be replaced in sets.

Same with the races, right? I'm not replacing the bearings if I don't have too, but preliminary inspection, I think I have a bad one.

lt.luke wrote:

hatchetdan wrote:The bearings should be replaced in sets.

Same with the races, right? I'm not replacing the bearings if I don't have too, but preliminary inspection, I think I have a bad one.

You can see the damage in the cup, right? What makes you think the cone is any better just because you can't see it under the rollers & cage?

Luke,
Tapered roller bearings should be replaced as a set; cup and cone. Finish the teardown of the carrier from the differencial housing retaining shim packs and bearings marked for which side they came from. Inspect the cups and cones for wear and damage and if any one piece of that bearing shows damage that set should be replaced as a cup and cone. The preload of the bearings will need to be set to this new bearing(s) as described in the manual.
What you don't want to do is get everything done and the first test drive shows a real noisey bearing in the differencial. Do it once, it may cost a little more now but will save you more in money and time in the long run. Just my opinion.
Regards
Bill

The Bearings and Cups are ground to a very close tolerance. You did not indicate if it was the inner or outer. The inner Bearing is the one that is pressed all the way onto the shaft, it will have to go to a machine shop to be removed and replaced. pressing it on is very touchy as it can get cocked and will jam if not replaced on a press that applies even pressure. The Cup for the inner may be installed using the same shim settings, as the tolerances the bearings and cups are made to a very tight tolerance that is not enough to alter the depth of the inner cup. The outer bearing is the one where the preload is determined by adding or subtracting shims. It is best to order a pinion gear shim pack from your Jeep parts supplier. Adjust the preload before you install the pinion seal, then install the seal once it is adjusted. Pay attention to where the slinger on the pinion shaft is located, follow your manual.

Ben Dover wrote:The Bearings and Cups are ground to a very close tolerance. You did not indicate if it was the inner or outer. The inner Bearing is the one that is pressed all the way onto the shaft, it will have to go to a machine shop to be removed and replaced. pressing it on is very touchy as it can get cocked and will jam if not replaced on a press that applies even pressure. The Cup for the inner may be installed using the same shim settings, as the tolerances the bearings and cups are made to a very tight tolerance that is not enough to alter the depth of the inner cup. The outer bearing is the one where the preload is determined by adding or subtracting shims. It is best to order a pinion gear shim pack from your Jeep parts supplier. Adjust the preload before you install the pinion seal, then install the seal once it is adjusted. Pay attention to where the slinger on the pinion shaft is located, follow your manual.

Carrier bearings Ben, not pinion bearings. Can the bearings be replaced without changing shims?

I don't intend to remove the pinion.

I thought this thread was about the differential carrier bearings, not pinion bearings?
If so you can get external shims to move the bearing cups [adjust the crown wheel positioning & bearing pre-load]rather than internal, under the bearing cone type, which makes adjustments a breeze.
Rear Axle Differential Bearing Shim Kit
Ford GPW 18388
Willys A 6744

Sorry bout that, save it for the pinion gear in case you may need it. As for the Carrier Bearings, just replace the cups and bearings, do not disturb or mix the shims as the pack is likely thicker on one side. They are ground to the same tolerance and if the stars are shining in your favor, they will retain the preload and backlash adjustment. You will note a relief on either side of the case, if you are careful, you will be able to remove each bearing with a long tapered punch, and replace the same way. Just be cautious and do not let the tapered punch contact the bearing cage when driving them. If I were closer I would do it for you with the Jeep Tool Set I have. The job is not as hard as it appears.If the differential goes in without having to force it, the preload is likely insufficient and you will have to remove both bearings and shims and start the procedure as shown in your manual.

artificer wrote:I thought this thread was about the differential carrier bearings, not pinion bearings?
If so you can get external shims to move the bearing cups [adjust the crown wheel positioning & bearing pre-load]rather than internal, under the bearing cone type, which makes adjustments a breeze.
Rear Axle Differential Bearing Shim Kit
Ford GPW 18388
Willys A 6744

According to this, the bearings would go all the way on (bottom out on the carrier) and the shims you mention would go between th race & the housing?

No, the shims are placed on the Differential Case before the Tapered Bearings are installed.
A check of your SNL will confirm.

Thanks Ben. You said:

If the differential goes in without having to force it, the preload is likely insufficient and you will have to remove both bearings and shims and start the procedure as shown in your manual.

I do not have to "force in" the carrier now, just rotate the pinion gear & it goes in fairly easily. What's your definition of "force in"?

I've checked the bearings. There are no bad spots on the rollers, but they both gritty, & will be replaced.

The procedure for determining preload is install the bearings without shims and put the unit into the differential housing, force it to one side and measure the space outside the bearing cup (race) and the side of the axle housing with a feeler gauge, this will determine the zero clearance and a corresponding amount of shils are aded. To that 0.008" more shims are added to the previous total to give the bearings necessary preload. This is all in the TM you should have at your side.

you can get external shims to move the bearing cups [adjust the crown wheel positioning & bearing pre-load]rather than internal, under the bearing cone type, which makes adjustments a breeze

That is what I said. Joel is not the only person who ever did this task.
There are always easier shortcuts & this is one people who work on differentals for a living will use over & above what TM closetted specialists spruik. Thinking outside the box is a good thing.

I have done it by Willys (Spicer) procedure for over half a century, and still have the ordnance and factory tools on hand plus a stock of bearings, Spicer brand shim packs, and NOS Military and CJ differential Ring and Pinions etc. on hand just in case the need arises to do another. I am pretty good at it too.