Carrier bearing and cup pitted. Next steps?

[DaYooperTransplant]

Finally started to knock some things off my to-do list this weekend. Ball joints, inner axel seals and pinion seal. Ball joints replacement went well, but when I took the gear set out to get at the seals I noticed the driver side carrier bearing and cap were in bad shape. The only shims I see are under the bearing.
The bearings are Koyo, (see picture) do they need to be the same ones I replace with, so the specs are the same? I would replace both sides even though the passenger side isn’t bad. I’ve never replaced carrier bearings or messed with gears in general so I’m a little apprehensive. I would think if the width of the new bearing is different I would need more/less shims?
I’ve watched a couple videos and it looks like either the clam shell puller or cutting them off is the go to. And then installing using a press.

Is this something I should just bring to a shop to handle? If so, do I reassemble and drive there or can I just bring them the carrier?

Thanks in advance for any assistance you can share.

 

[hear]

This is an interesting question and I’ve wondered the same. Depending on where the shims go, a setup bearing might have been used anyway; the implication being that you can freely swap in new carrier bearings/races without worrying about affecting backlash or running a new pattern. I’m sure it wouldn’t hurt to check those things, but I’m interested to hear what the experts here say. But I would think you’d want to use the same brand to ensure the same specs, but then that also begs the question if Koyo & Timken carrier bearings have different specs? Thousandths matter here so there probably isn’t such a thing as “too safe.”

Subscribed.

 

[DaYooperTransplant]

Setup bearing. Is that a bearing that has been bored out so it slips on and off easily during the backlash and pattern process?

I found this link from Jerry while researching last night. The Spicer p/n 706016X includes LM501314 and LM501349, which matches the number on the cup, and I assume will be the number on the bearing once removed.

https://wranglertjforum.com/threads/timken-bearing-part-numbers-for-dana-30-carrier.47796/

At $40 for the set I will probably go ahead and pick them up and compare sizes but it would be nice to hear from someone who’s been there, done that.

Thanks for the input, and sending this to the top.

 

[BlueC]

Are you replacing just the carrier bearings or are you pulling the pinion too?

 

[DaYooperTransplant]

Just the carrier bearings. There is a small leak at the pinion seal that I had planned on fixing while I had it apart, but will probably hold off on that until I get these carrier bearings figured out and replaced. It only drips about once a week if that.

I would add that there was no indication there was a problem with the bearing before inspecting it. No noises or anything else that would indicate it was bad.

Thanks.

 

[BlueC]

Just the carrier bearings

So just put it back as it was when you took it apart. Press on the new bearings and put the shims back in as you found them. It would be a good idea to check the backlash, but if there were no problems before, you're just putting it back as it was set up originally.

If you decide to pull the pinion, you'll be setting up the gears from scratch (mostly). That's when you would need a setup bearing.

I would add that there was no indication there was a problem with the bearing before inspecting it. No noises or anything else that would indicate it was bad.

I found the same thing when I installed my rear locker. No noticeable noise or vibrations, but one bearing was pitted worse than yours. I didn't see an obvious reason why. Knowing the history of my Jeep, lots of sitting, I'm guessing it just had some moisture in it.

 

[macleanflood]

I think I would have checked backlash before disassembly... ultimately that's the number you're trying to match.

-Mac

 

[sab]

The bearings are Koyo, (see picture) do they need to be the same ones I replace with, so the specs are the same?

Koyo and Timken are the go-to manufacturers, and they are interchangeable - same basic dimensions and tolerances (I checked their catalogs).

I would replace both sides even though the passenger side isn’t bad.

Good practice. If one is bad, the other can't be like new.

I would think if the width of the new bearing is different I would need more/less shims?

You would. I've never done gearing changes (although I will be on my LJ) or changed bearings in a differential. However, I've designed vehicle parts using tapered roller bearings, and I've replaced bearings, many times over my career. Bearings have tolerances - they can't make them with exactly the same dimensions every time cost effectively. The manufacturers provide the tolerance information in their catalogs. As noted above, I just looked, and both Timken's and Koyo's tolerance on total width is -0.0000" and +0.0080", meaning that any given bearing's total width will be from 0.8437" to 0.8517". Here's where I get confused. I've seen countless posts of people successfully using setup bearings, and I've seen countless posts stating that you can use the same shims if you are just replacing bearings. However, if you replace both bearings, and both are at one end of that tolerance range, while the new ones are both at the other end of the tolerance range, this worst-case scenario would change the overall width 0.016". That would cause a big problem, but statistically, it's a low probability scenario. Perhaps in practice, the tolerances are tighter than the spec? I'd be interested to hear if anyone has measured total bearing widths...

I’ve watched a couple videos and it looks like either the clam shell puller or cutting them off is the go to. And then installing using a press.

Agreed. When I do my gearing changes, I'll be using a clam shell puller instead of setup bearings so that I don't have to worry about width differences from setup to actual bearings.

Is this something I should just bring to a shop to handle?

Only you can answer that. How's your attention-to-detail and patience?

If so, do I reassemble and drive there or can I just bring them the carrier?

They're going to want the vehicle so that they can ensure it's setup properly. You should be able to reassemble with all the same components and drive it there.

 

[DaYooperTransplant]

Koyo and Timken are the go-to manufacturers, and they are interchangeable - same basic dimensions and tolerances (I checked their catalogs).



Good practice. If one is bad, the other can't be like new.



You would. I've never done gearing changes (although I will be on my LJ) or changed bearings in a differential. However, I've designed vehicle parts using tapered roller bearings, and I've replaced bearings, many times over my career. Bearings have tolerances - they can't make them with exactly the same dimensions every time cost effectively. The manufacturers provide the tolerance information in their catalogs. As noted above, I just looked, and both Timken's and Koyo's tolerance on total width is -0.0000" and +0.0080", meaning that any given bearing's total width will be from 0.8437" to 0.8517". Here's where I get confused. I've seen countless posts of people successfully using setup bearings, and I've seen countless posts stating that you can use the same shims if you are just replacing bearings. However, if you replace both bearings, and both are at one end of that tolerance range, while the new ones are both at the other end of the tolerance range, this worst-case scenario would change the overall width 0.016". That would cause a big problem, but statistically, it's a low probability scenario. Perhaps in practice, the tolerances are tighter than the spec? I'd be interested to hear if anyone has measured total bearing widths...



Agreed. When I do my gearing changes, I'll be using a clam shell puller instead of setup bearings so that I don't have to worry about width differences from setup to actual bearings.



Only you can answer that. How's your attention-to-detail and patience?



They're going to want the vehicle so that they can ensure it's setup properly. You should be able to reassemble with all the same components and drive it there.

sab -
Thanks for sharing your knowledge. Based on that, I think I will ensure the replacement bearings are Koyo or Timken, keep the current shims in place and button things back up. Fingers crossed it will be the low probability scenario.

When you say 0.016" would cause a big problem, is that immediately ruined, or something I could identify based on noise or vibrations during the first test drive and tear it back down before there is major damage?

As far as my patience and attention to detail, I turned wrenches as a job in the Army for 21 years but that was mostly just removing old parts and hanging new ones. The 0.016" tolerances up the pucker factor, not gonna lie.

Thanks again for your input.

 

[sab]

When you say 0.016" would cause a big problem, is that immediately ruined, or something I could identify based on noise or vibrations during the first test drive and tear it back down before there is major damage?

First, off - that 0.016" difference would be statistically very unlikely to occur - but it could. For comparison, if you look up posts where DIYers ask for a "pattern check," you'll often see recommendations to change shims by just one or two thousandths when dialing in the pattern. Based on that, 0.016" is a big difference. I don't think it would be immediately ruined, but I also don't know if you'd notice any noise. Again, wait for some of the gearing gurus to opine. I'm just "book smart" on this one. @hosejockey61 and @Blackjack - thoughts?

 

[sab]

I think I would have checked backlash before disassembly... ultimately that's the number you're trying to match.

Mac may be on to something. That differential was run with a certain backlash. Ultimately, you'd want to match that. You could re-install the old bearing, measure the backlash, and then install the new bearings and check backlash again. If it's significantly different, you'd need to change shims to replicate it. I think. Again, no practical experience here!

 

[hear]

I've seen countless posts of people successfully using setup bearings, and I've seen countless posts stating that you can use the same shims if you are just replacing bearings. However, if you replace both bearings, and both are at one end of that tolerance range, while the new ones are both at the other end of the tolerance range, this worst-case scenario would change the overall width 0.016". That would cause a big problem, but statistically, it's a low probability scenario. Perhaps in practice, the tolerances are tighter than the spec? I'd be interested to hear if anyone has measured total bearing widths...

I've had these exact same questions. When thousandths matter this seems like enough potential slop to matter even when not at the edges of tolerance. I have setup bearings, but I also followed a YouTube where a guy drilled some new arbor plates to allow a bearing splitter to be used with a shop press. That works well but it's still a hassle (and a clamshell puller might've been cheaper after the cost of the steel, drill bits, and the fact that I broke my drill press in the process).

 

[Andy-WhiteTJ]

Mac may be on to something. That differential was run with a certain backlash. Ultimately, you'd want to match that. You could re-install the old bearing, measure the backlash, and then install the new bearings and check backlash again. If it's significantly different, you'd need to change shims to replicate it. I think. Again, no practical experience here!

Even so, if the bearings are worn (they look so in the photos above) that will change what the backlash is to what it was when the bearings were new(er). Running a pattern with a proper backlash after the new bearings are in is still the best method.

 

[Blackjack]

You are definitely going to want to change both carrier bearings. If it were mine I would also be taking a serious look at the pinion bearings as that seal leak is a pretty good indicator that they may have issues as well.

As for Timken vs Koyo, just like Spicer I use both interchangeably and can count on one hand the times that I ran into any significant dimensional variance that gave me an issue. Also since you are not making any changes to your ring and pinion you will just want to use the existing shims and not worry as much about settings other than the pinion preload if you change those bearings out.

When it comes to setup bearings I do try to use like for like just to keep things consistent but it is also just as easy to measure the bearings an adjust for any difference if there is one. This is more of an issue for pinon bearings than carrier.

 

[macleanflood]

I totally agree with changing all the bearings...pinion included. Everything will be fresh.

-Mac

 

[DaYooperTransplant]

You are definitely going to want to change both carrier bearings. If it were mine I would also be taking a serious look at the pinion bearings as that seal leak is a pretty good indicator that they may have issues as well.

As for Timken vs Koyo, just like Spicer I use both interchangeably and can count on one hand the times that I ran into any significant dimensional variance that gave me an issue. Also since you are not making any changes to your ring and pinion you will just want to use the existing shims and not worry as much about settings other than the pinion preload if you change those bearings out.

When it comes to setup bearings I do try to use like for like just to keep things consistent but it is also just as easy to measure the bearings an adjust for any difference if there is one. This is more of an issue for pinon bearings than carrier.

Yep, I suppose the best course of action is to replace the pinion bearings too. Damn my luck!

I think I will re-install with the old bearings to see if the backlash was in tolerance to begin with (0.005-0.008 in. I believe)

In the meantime, I will be searching around the area for someone that has more experience with this than me and see what the cost to have it done will be. If anyone in the greater Thurston/Pierce Counties has a name or number of someone, I sure could use it.

Thanks to everyone that chimed in. This is a great community.

 

[Blackjack]

Yep, I suppose the best course of action is to replace the pinion bearings too. Damn my luck!

I think I will re-install with the old bearings to see if the backlash was in tolerance to begin with (0.005-0.008 in. I believe)

In the meantime, I will be searching around the area for someone that has more experience with this than me and see what the cost to have it done will be. If anyone in the greater Thurston/Pierce Counties has a name or number of someone, I sure could use it.

Thanks to everyone that chimed in. This is a great community.

Do not worry about the backlash as it will not be in spec as the bearings and gears are used. Just put new bearings in using the existing shims where they are and let it run.

 

[macleanflood]

I would expect/guess used bearings gears would be 12 to 16. Less is better but the most important number is the one you have now and making it close to the same number after you swap everything.

That being said I'd bet any shop or experienced tech would slam a new set of carrier bearings in and throw it out the door.

-Mac

 

[hosejockey61]

I agree 100% with Blackjack. Change all your bearings and run it with the existing shims in their current place. This will pretty much reset it it where it was when it was first set up. Backlash might be a tad bit larger as the gears have worn down some, but it's still your best option IMHO.

 

[hosejockey61]

Less is better but the most important number is the one you have now and making it close to the same number after you swap everything.

I disagree with you. Once new bearings are installed it will tighten the backlash back up quite a bit which is fine. I would change the bearings out and run it as is with the original shims. If you try to match backlash in this case (keeping it loose) you are going to throw things off and open a can of worms that will most likely result in a new gear job.