Timken Bearing with Koyo Cup

[achampagne]

I am rebuilding my rear axle, and I have a question about shimming. I saw online that when replacing pinion bearing, there is no need to reshim the pinion. So I re assemble the axle, check the pattern on the gears, and the markings indicated that I need to thin my pinion shim. That confused me so I disassemble everything. After further analysis, I saw that the pinion bearing was Koyo but the bearing cup was Timken. Would the different brands cause the messed up pinion depth? I destroyed the bearing pulling it off the pinion, and went ahead and ordered a Timken bearing to match the Timken cup. Would this need reshimming too?

UPDATE: The answer is yes the difference in brands does make a difference.
Both the cup and the bearing were brand new but after inspecting the bearing, they were slightly different. The rollers for the Timken bearing were thinner and longer than the Koyo bearing. After putting the Timken bearing in, the mesh pattern was perfect.

NOTE: Make sure to check the branding on both the bearing and cup.
I bought a complete rebuild kit for the axle from summit, and failed to check the branding for the cup and bearing. They all should be the same brand, but make sure to double check.

Hopefully this can help someone out in the future

 

[sgtsandman]

The bearing and the cup should be replaced as a set. Whether that will change the depth and require different shims will depend on where the new bearing and cup sit in the tolerance range.

I would count on having to reset the depth so you have what you need on hand.

 

[dvdswan]

Any time you change something in the rear axle; axle, carrier, gears, or just bearings something is going to change specially if the makes are different. Keeping with the same manufacturer will make things easier, but as you did, "trust but verify" is always a good thing to do. I'm not a machinist, but machines will get worn over time. So a bearing made 10 years ago won't have the same tolerances a bearing made today will have.

 

[85_Ranger4x4]

Yeah, I would really rather not run a new bearing on a race especially in a rear axle.

 

[Curious Hound]

I am rebuilding my rear axle, and I have a question about shimming. I saw online that when replacing pinion bearing, there is no need to reshim the pinion. So I re assemble the axle, check the pattern on the gears, and the markings indicated that I need to thin my pinion shim. That confused me so I disassemble everything. After further analysis, I saw that the pinion bearing was Koyo but the bearing cup was Timken. Would the different brands cause the messed up pinion depth? I destroyed the bearing pulling it off the pinion, and went ahead and ordered a Timken bearing to match the Timken cup. Would this need reshimming too?

The "cup" is the outer race if the bearing. Although you can buy the inner race and rolling element without the outer race, it is best to replace them as a matched set. Especially don't mix and match different brands except for an emergency temporary repair. They may not keep the same tolerances. Bearings are precision parts, but only if used and treated properly.

 

[oldgeek]

machines will get worn over time. So a bearing made 10 years ago won't have the same tolerances a bearing made today will have.

I'm thinking you are referring to a 10 year old used bearing. New bearing, old race? Not good.

Otherwise I would have no issues with a new bearing that's been sitting on the shelf for 10 years.