Bearing Selection

[JimInOz]

Hi Guys,
I posted a while ago,about a repair I need to do on a D31S Final Drive.
It's the right side,& bull & pinion teeth were damaged.
Finally got around to making a start,by pulling the Steer/Pinion Flange & it's bearing carrier.I removed the Final Housing & Bullgear a while ago.
I note that the roller bearing is Japanese & wondered if,during the course of my rebuild,I should try to obtain a particular brand of bearings for this job....& what to steer clear of?

Any other useful tips for the rebuild are appreciated.I have the shop manual,but experienced advice fills in the gaps....
This is my first Final Drive repair.I'm taking pics as I go.

Will probably source bearings from the USA,so some leads here will help.

Thanks
Jim.

 

[Komatsu 150]

We recently replaced a set of pinion bearings in a pickup for the second time, almost exactly a year later and less than 15000 miles. The Romanian bearing failed (Advance Auto) and the Japanese bearing looked like new. I can't believe we actually used a Romanian bearing. We got the second set from the dealer - Timkin.

 

[mitch504]

Toyo bearings are made in japan and are as good as anything. Mack trucks has started shipping bearings made in china, and I was real hesitant, but they've been fine so far,(2 years).

I tried a set of those Romanian bearings from Advance cause that was all I could get on a sunday, and they were junk.

 

[JimInOz]

Looks like I'll be asking for Jap bearings for this build.
I'm also wondering about press fitting the pinion back into the flange.....should the hydraulic jack be sitting on the opposite flange,or should I make a frame to ensure the jack's pressure goes onto the steering/bevel housing.??

Thanks
Jim

 

[TOM V]

Jim, hope this helps. Good luck.

 

[JimInOz]

Thanks TomV,
Your dozer manual pics are clearer than my loader version.However,I can't quite see where that press is located ,in order to press the flange onto pinion.I wouldn't want to put too much stress on the (bevel side) steering flange.
Been cleaning all the parts today.A few of the parts have light damage from the misaligned pinion ,etc....so I'll give them some fine filing or emery paper to get the scratches out.
Had to replace the Final Housing,Pinion & a retainer,which got chewed up .

Thanks Guys,
Jim

 

[Fran]

Hey Jim,
I find SKF or Timkin both make an excellent bearing. I would not hesitate to use any one of them.

 

[JimInOz]

Thanks Fran,
I'm finding the bearings are Japanese NTN,which I've used on other projects.
Maybe Komatsu used them originally.

 

[mitch504]

I've never had a problem with NTN from Japan either. Remember, Komatsus and Toyotas are made in japan.....

 

[Old Magnet]

I assume the D315 is in a D4-7U.
The pinion can be removed and installed as an assembly. Do your press work on the bench. Mount the pinion and cage assembly as one unit and bolt it in the case. There is a hole in the flange to access the bolts.

Be sure the oil drain hole in the bearing cage and the oil drain passage in the cover line up with the drain hole in the case.

 

[mitch504]

I believe this is a Komatsu tractor.

 

[Old Magnet]

OK, thanks, missed that one....Went back and looked at that model number and maybe it's D31S not D315. Old eyes ain't what they used to be, don't know anything about Komatsu.

 

[JimInOz]

Thanks Old Magnet & Mitch,
Yeah,she's a 1970s D31S Crawler Loader.I'm told these tractors were well liked,thus my reason for repairing & persisting with her.
I did notice some oil passages in the pinion bearing cage ,but it can only be refitted one way,so no mistakes there.
Have been using the welder to remove old bearings today.That certainly made life easier...
BTW,what's the best sealant to use on the Final Housing gasket area?

Thanks again,
Jim

 

[cps]

Hey Jim,
I find SKF or Timkin both make an excellent bearing. I would not hesitate to use any one of them.

I Agree, my local bearing supplier only supplies top notch bearings and these are the main brands he uses, he can be expenisve but you know what your getting!

Thanks Fran,
I'm finding the bearings are Japanese NTN,which I've used on other projects.
Maybe Komatsu used them originally.

I think your right Jim, my supplier tells me these are in his opinion the best taper roller bearing on the market!

 

[JimInOz]

Hi CPS,
The NTN bearings I'm removing look very solid & well made.I may try to souce them in the USA or Japan, if I can find the right supplier.

 

[AT&SW]

Just finished rebuilding final drive on JD dzer and the timkin bearings were cheaper through the dealer than after market. I was very suprised by this. For mating up the two halfs of the final can use locktite.

 

[JimInOz]

It's weird that dealer prices can be really good on some items & totally insane on others.I won't deal with them out of principle,unless the parts can't be got elsewhere.
Someone also mentioned Hemetite as a sealant.