Transfer Case Bearings

[randygk]

I'm getting ready to order all the bearings for the t-case on the M35A2 after the small input shaft bearings puked their cages. I still don't understand the single shielded bearings being used, was this part of the design and the way they were originally built? Seems like it would restrict proper lubrication and hasten their failure, has anyone used unshielded bearings? Thanks

 

[sandcobra164]

I spoke in length with Gringletaube at this past rally about this exact issue. If you're not sure who he is, ask around, he is the Deuce Authority in my opinion. They were built with caged bearings. The only way they want to become "uncaged" bearings is due to a clearance issue as in the shaft is worn and too small or the outer bushing is too large OR improper lubricant being used. He directed me to further research on Spicer Trans Cases. They don't want you to use gear oil in their transfer cases or anything that contains certain additives. I followed the advice after the GA Rally. I actually pulled off the road and had to wait for the transfer case to cool on my 180 mile trip back, much of it Interstate roads where I maintained a 45 mph pace or slightly better. The transfer was too hot to hold your hand on. When I got home, I tested it with the infrared and it was at 190 degrees, motor was at 210, trans was at 170, axles were at 120, hubs were averaging 130 on a 90 degree day. I changed the oil in the trans and transfer and I noticed about a 40 degree drop in temp on the same temp day, not as long a trip. 40W NonDetergant Oil from Tractor Supply seems to be the right thing to put in these trucks in the trans and transfer. You're mileage may vary.

 

[welldigger]

Yup strait weight 40 non detergent is the way to go. With maybe a touch of Lucas oil additive. I was turned onto the 40 weight by m35-tom. He was correct that my truck now shifts better and the drive train whine is a bit less. The old oil I drained out was as thick as honey......not really sure what that meant but all seems well for now.

 

[gringeltaube]

.............. is the Deuce Authority in my opinion...

LOL, thanks for comments, but no, we sure have REAL "Deuce-Masters" in our group; I'm still a student, with a lot to be learned...

The only way they want to become "uncaged" bearings is due to a clearance issue as in the shaft is worn and too small or the outer bushing is too large OR improper lubricant being used. He directed me to further research on Spicer Trans Cases. They don't want you to use gear oil in their transfer cases or anything that contains certain additives..................

hmm.., I'm trying hard to remember that part of conversation... (may be I had one beer too much?)

First of all, let me say that the viscosity of a 40W engine oil lays somewhere in between that of a SAE 80 and 90 - gear oil. So, I see no real advantage, in the sense of less heat generation. Although I may have mentioned synthetic oil like 75W90, for a possible improvement.
Ever since I had my first M35 (1988 ) I have been using Delo 85W90, and yes, these things can get real hot - after 2h @ 60 mph! Still, I never really felt the need to switch lubricants...

Of course, heat, water condensation and other contaminants will degrade any oil! And there is no filter or even a magnet here, so better watch what comes out when unscrewing the drain plug from time to time. I have dealt with dozens of these T-cases; most of them came from trucks that had been in service shortly before being parted out. You wouldn't believe what kind of goo I have found inside a lot of them...! Now imagine those poor bearings! The shields only help protect them from particles but NOT from accumulating all that sludge in between them!
We all know that quality and mainly CLEANLINESS of a lubricant is crucial for there service life!

Now, that may be just one of the reasons for premature failure. Another thing that comes to mind is that ball bearings aren't really happy with radial/axial loads and/or shock-loads, when working stationary; like when the large gear and shaft are both spinning as one piece (high range - most of miles). They will actually resist LESS, that way. And it seems to me that fitting #30210 roller bearings in there would only require minor modification work, but bring a big improvement in bearing life. At least the static load would be almost 3 times that of the stock BL210's.

One day we will know better...


G.

 

[Katahdin]

FYI, I've said this before, Tractor Supply SAE90 GL-1 has the same viscosity as 40W motor oil. (ISO Viscosity Grade : 150)

http://www.tractorsupply.com/webapp...ory_rn=&top_category=&urlLangId=&cm_vc=-10005