NP263 XHD Rebuild

[4RunnerGuy]

I bought the case half a while ago because of the pump rub issue. As a quick fix, I JB welded the hole and stopped the leak. That quick fix worked amazingly well.

I recently bought some new parts from MA. Unfortunately, the new case half output bearing pocket isn’t large enough to accommodate the new bearing. It makes sense that the tolerances need to be tight, but it flat out doesn’t fit. The main shaft binds up. This is problematic because it needs to be able to move enough to get the snap ring in the bearing grove.

The case half was purchased long ago from Idaho Transmission and I am well beyond the return period.

Outside of buying a new case half, does anyone have any suggestions/ideas?

 

[arse_sidewards]

Isn't large enough meaning it isn't deep enough for the bearing to go as far in as it needs to or the ID is insufficient for the OD of the race?

In any case, take measurements of the parts involved and report back.

 

[4RunnerGuy]

The ID of the pocket is too small to accommodate the OD of the bearing.

im confident it’s a casting issue with the case half, not the bearing.

 

[arse_sidewards]

The ID of the pocket is too small to accommodate the OD of the bearing.

im confident it’s a casting issue with the case half, not the bearing.

The casting is machined after the fact. Get a bore gauge and mic out and tell us what you have and we can tell you whether a heated/cooled fit is practical. Absurd heated press fits are more and more common with new stuff because as process control gets cheaper doing that becomes overall cheaper than more mechanical means of retaining things.

 

[4RunnerGuy]

I understand what your saying and the need for actual measurements. My caliper jaws aren’t long enough to measure the pocket and I don’t have a bore gauge.

You have to stick a screwdriver through this hole to seat the snap ring into the output shaft bearing groove. The screwdriver lifts the main shaft enough to do this. The bearing doesn’t slide freely into the pocket to do this.

the only thing I can think of is to “sand” enough of the pocket material away, so there’s less resistance and zero binding. I don’t have a precise way to do this. I think I’ll end up wobbling out the pocket.

I appreciate your willingness to help, I have instrument limitations.

 

[arse_sidewards]

#51 is the problem?

 

[4RunnerGuy]

Yes, 51.

Thats the output shaft bearing that has a small snap ring that retains it to the main shaft.

The case half slides on. There’s an access hole (my pic) that you lift the main shaft up slightly to get the larger snap ring in place around the bearing groove.

 

[arse_sidewards]

Yes, 51.

Thats the output shaft bearing that has a small snap ring that retains it to the main shaft.

The case half slides on. There’s an access hole (my pic) that you lift the main shaft up slightly to get the larger snap ring in place around the bearing groove.

So the bearing goes into it's bore but doesn't go far enough to let you move it up the last little bit to seat the snap ring?

 

[4RunnerGuy]

It stops or binds before it goes into its bore.

With the bearing off the main shaft, I can not slip it into its bore in the case half.

The first pic shows the old bearing on the main shaft. The entire bearing must be seated in its bore.

The other pics show the bearing on top of the bore and with it removed. You can see the grove in the case half as well as the snap ring that locks into the bearing grove.

 

[wvracer821]

If I remember correctly that bearing doesn’t press into the case half, it just slips in when you put everything together. I ripped one of these apart when disassembling my 05 Silverado. I wouldn’t be afraid to take some sand paper and work it around until the bearing drops in. Although this isn’t correct it would save you from buying another case half. I wish I still had mine here so I could measure things for you but I took it to scrap a couple months ago.

 

[4RunnerGuy]

You’re remembering correctly.

I called Idaho Transmission Warehouse on Friday. I bought the case half from them in March of last year. They said they had a bad run with some of those cases. In the interest of time I ordered a new one. They said once they have the original one back, they’ll confirm the issue and give my money back.

It’s not finished yet, but they seem like a stand up company.

 

[wvracer821]

You can’t ask for much more than that. I’m glad they took care of you.