743B (Kubota engine) rear main seal.

[Kens743B]

Working on another 743B with a Kubota V1702-6660 engine, anyways looks like it has been re-powered. Bobcat shows 2 different rear main seals for the engine depending on the serial number of the machine, but neither of them are the right size. Trying to find a rear main seal by size seems about impossible (I had taken the old rear main seal out of the engine, but someone threw away the old seal when they cleaned the table off it was sitting on). I've tried the Kubota tractor forums without much luck so far by giving the measurements. The measurements are 4.000" od x 3.352" (the od of the section on the crankshaft the rear main seal rides on). Anybody have any idea's, it's the only thing keeping me from putting the engine back in so I can put it back to work. I've also had no luck finding a serial number on the engine. Signed, Frustrated!

 

[antfarmer2]

Check and see if seals for a 2203 will fit alot of them were repowered with that engine 10 or so more hp

 

[OldMachinist]

Check and see if seals for a 2203 will fit alot of them were repowered with that engine 10 or so more hp

Are you sure about those dimensions? I find it strange that the OD would be a even inch size. The seal I looked up for the V1702 was 102mm(4.0157”)OD x 85mm(3.3465”) ID x 13mm(.5118”)wide. Part #19202-04460

The V2203 uses the same seal.

 

[Kens743B]

Are you sure about those dimensions? I find it strange that the OD would be a even inch size. The seal I looked up for the V1702 was 102mm(4.0157”)OD x 85mm(3.3465”) ID x 13mm(.5118”)wide. Part #19202-04460

The V2203 uses the same seal.

Yep, I am sure on those dimensions (had my 2 brother with their own calipers measure it, they both came out with the same numbers). I ordered the 2 different deals that Bobcat showed in their parts for the V1702 engine, 1 of the seals has the correct od of 4" but the id is .010 too small (and there is no speedy sleeve on the crank) the other seal measures 4.937 on the od, the id of the seal measures 3.062". I'm at a loss!

 

[OldMachinist]

Yep, I am sure on those dimensions (had my 2 brother with their own calipers measure it, they both came out with the same numbers). I ordered the 2 different deals that Bobcat showed in their parts for the V1702 engine, 1 of the seals has the correct od of 4" but the id is .010 too small (and there is no speedy sleeve on the crank) the other seal measures 4.937 on the od, the id of the seal measures 3.062". I'm at a loss!

If the seal ID is .010”(3 thicknesses of a human hair) smaller than the crankshaft then that's about right. It has to be a little smaller for it to have enough pressure to do it's job.