Differential carrier bearing fitment probs (1 Viewer)

[Zjohnsonua]

I've got a 92 FJ80's rear 3rd member on the bench and apart for rebuild. The problem is that the new carrier bearings will not seat - there's probably a .025" gap remaining once the bearing stops moving.

All my searches are showing the new bearing numbers to be correct for this year truck, but there's no way that they'll fit this carrier without a spacer or some carrier clearancing. They're dimensionally the same other than the clearance radius made into the bottom inside corner. It's huge on the Nachi, and almost non-existent on the Timken. The picture below is worth a thousand words.

Any one got a hint as to what the heck is going on here? Was there a change somewhere that I needed to be watching out for?

 

[Pin_Head]

The ID of the Nachi bearings have a larger radius than the Timken. Either get the Nachi high radius bearings or machine the carrier to match the radius of the Timken bearings.

 

[Zjohnsonua]

I've been through a few 60 diffs and not run into this. Is carrier machining to accept new bearings a "normal" thing for 80s? That'll be a considerable weirdness for the 80 if that's the case.

 

[fjbj40]

The ID of the Nachi bearings have a larger radius than the Timken. Either get the Nachi high radius bearings or machine the carrier to match the radius of the Timken bearings.

I assume Koyo has the correct radius?

 

[Pin_Head]

You need the proper bearing with the suffix JA1: 32010-JA1. The suffix is important.

This might be the one:

32010 Nachi Tapered Roller Bearings Japan 50x80x20

Buy 32010 Nachi Tapered Roller Bearings Japan 50x80x20 at wholesale prices in United States. Check reviews and buy today.

www.vxb.com

 

[Zjohnsonua]

I wholly agree, @Pin_Head. I got the kit from Kurt, so I figured that's something that would have been considered and remedied given their volumes.

 

[use2bn83]

I wholly agree, @Pin_Head. I got the kit from Kurt, so I figured that's something that would have been considered and remedied given their volumes.

give them a call, I’m 90% @cruiseroutfit has the bearing you need. I’ve seen this several times, it happens.

 

[Zjohnsonua]

Yeah, I got in touch with the guys there this morning. They're working on getting some other bearings sent my way. I've asked to see what differentiates this carrier from other 80 carriers and if something definitive comes back I'll make sure and post it.

 

[Zjohnsonua]

As usual, cruiseroutfit set it right. Correct bearings are on the way. As for what indicates what carrier you have, it sounds like there's no definitive tell - you'll know when you pull the bearings.

I'll just keep a set of these larger radius bearings on hand for the next time.

 

[TexFJ]

This has to be more common than thought.

I recently was trying to purchase some carrier bearings for the rear diff and ordered 32010JR Koyo from RDV bearings. Due to an inventory issue someone contacted me letting me know there are substitutes. However he asked me what the application was and I mentioned Automotive. He then told me there was a difference between the 32010JR and 32010JRYA1(sold under the OEM#). And like you guys mentioned, it was the inner inside radius was much bigger on the YA1. These pics were sent to me by RDV.

Looking at the rear carrier, it seems to be kinda close and obviously caused @Zjohnsonua issues.

Since the preload is adjusted that would not be the problem, but I would think the real issue is not having these completely aligned with the carrier, hence potential vibrations and uneven wear.

NOW... since I'm installing Eaton eLockers, perhaps this is not an issue for me, but I'm not going to chance it.

 

[Zjohnsonua]

@TexFJ , I've now been through many more of these diffs, and haven't seen a pattern to which gets the high radius. I bet I've seen 4 or 5 diffs that needed the JA1 bearing. As a shop, I just keep the high radius ones on the shelf and tell people that are going to be doing their own builds to ask for the odd bearings up front or plan in an additional 4 days for the job in case they need to be shipped in.

 

[PIP]

For a machine shop to re-cut those radii to the required size would take about 20 minutes. Might be another option instead of buying a second set of bearings.

I have done machinework on many carriers. Especially Dana carriers where people bought the wrong carrier offset. It's pretty easy to turn one into the other with a lathe.