Oh, that's not good - tcase oil

[Spook50]

So I stocked up on good Schaeffer's gear oil and went out to change the oil in my tcase and diffs today. When I drained the oil in the tcase, only about 3/4 of a cup came out. I blame myself because I haven't checked the level in several years. But at the same time, there was never enough of a leak to drip, just make it filthy underneath. And none made its way into the transmission because the ATF came out clean when I drained it a couple weeks ago, after about 10 years of use (though I did regularly check the level of the ATF and it was always good). So now, time to get a steam cleaner I can use under the truck (or take it somewhere to be steam cleaned underneath) to clean it up and keep an eye open for anywhere oil might be seeping out.

Luckily I don't think any damage has been done yet, but there was quite a bit of buildup on the magnet on the drain plug.

 

[OSS]

The oil in the transfer case most likely ended up in the transmission via a leaking input shaft seal. The transfer case gear oil can stay very clean for tens of thousands of miles as there's not much going on in there (unlike a manual transmission). It could easily be undetectable diluting the ATF in the auto tranny just by looking at it.
My guess (just a guess) is that there isn't an external oil leak out of the transfer case, but an internal one connecting to the transmission.

I'd replace the ATF in the transmission if no external leak is found

 

[Spook50]

The oil in the transfer case most likely ended up in the transmission via a leaking input shaft seal. The transfer case gear oil can stay very clean for tens of thousands of miles as there's not much going on in there (unlike a manual transmission). It could easily be undetectable diluting the ATF in the auto tranny just by looking at it.
My guess (just a guess) is that there isn't an external oil leak out of the transfer case, but an internal one connecting to the transmission.

I'd replace the ATF in the transmission if no external leak is found

Yeah I had done that just a couple weeks ago to install the tranny cooler (and it was overdue anyway). The fluid level was still dead on before I drained it, and I would think two quarts slowly migrating into the tranny fluid would've made the level rise. I think in the next year or two I'm going to tackle rebuilding the tcase and just for good measure put in a McNamara gear. Never attempted a tcase rebuild before though, so hopefully it's fairly straightforward.

 

[brownbear]

Is this the McNamara gear you reference? 36212-Mod34 Modified TC Input Gear - 19 spline mainshaft

 

[Spook50]

Is this the McNamara gear you reference? 36212-Mod34 Modified TC Input Gear - 19 spline mainshaft

I think so. Though that specifies manual transmission. I don't think there's a difference in tcase input gears between A440F and H55 trannies, but I'm not 100%. @orangefj45 can you clarify?

 

[brownbear]

They also listed an automative version. I just copied the link to the manual one for early t-cases. There was one there for later versions with the auto.

Are you doing the gear to maybe help with some wear that could be there? My concern with my t-case is when I open it to rebuild I have parts that could also be worn out with me.

 

[Spook50]

They also listed an automative version. I just copied the link to the manual one for early t-cases. There was one there for later versions with the auto.

Are you doing the gear to maybe help with some wear that could be there? My concern with my t-case is when I open it to rebuild I have parts that could also be worn out with me.

Ah okay, so yeah I'd be ordering the gear for automatic trannies. Interestingly enough, even after almost 300K miles I don't have the clunk when I shift into and out of reverse that's a telltale sign of spline wear. I'm sure there still is at least some wear, but I don't think it's nearly as bad as it can get on other rigs. If I lived closer to Valley Hybrids/Cruiser Brothers, I'd just take my 62 there and have them knock out the rebuild and input gear swap, and throw in one of Georg's twin stick kits. Back in 2010 I had bought an H55 with tcase from him that came with the twin stick parts, but with no place to do the conversion it's still sitting in my shop. And now that I've made up my mind to save for an engine conversion in the future, I decided to stay with the automatic. Now if it starts giving up the ghost I'll go ahead and do the conversion, but in that case I'd load it up and take it to Georg to do the job.

 

[orangefj45]

I think so. Though that specifies manual transmission. I don't think there's a difference in tcase input gears between A440F and H55 trannies, but I'm not 100%. @orangefj45 can you clarify?

The “Mod-32 Long Spline Input Gear” works for manual and automatic applications.
We have plenty of them in stock.

Georg @ Valley Hybrids & Cruiser Brothers
Shop 209-475-8808