Cat scraper Trans oil transfer

[aussiedave]

Wondering if anyone out there has come across this problem.
I have a 627E Cat scraper that is transferring the transmission oil from the trans into the diff housing.
I have drained the diff so no oil was left in the housing, then filled the transmission and started the machine and the transmission oil started flowing from the diff drain bung.
Has anyone else had this problem and do you know where the transfer would be occurring?

 

[Bluox]

Wondering if anyone out there has come across this problem.
I have a 627E Cat scraper that is transferring the transmission oil from the trans into the diff housing.
I have drained the diff so no oil was left in the housing, then filled the transmission and started the machine and the transmission oil started flowing from the diff drain bung.
Has anyone else had this problem and do you know where the transfer would be occurring?

I'm going to assume you mean the tractor transmission so my wag would be the drive shaft tube O-rings. You can check that with a bore scope.Now what lead up to this point.
Good luck
Bob

 

[Mark250]

generally they leak at the seal indicated. it is a mechanical face seal and very brittle if the bearings are a bit loose on the pinion they will leak as well they can also leak at the front of the transmission where the shaft runs through to the engine as this area is pressure lubed ,also they can leak at the o rings on the tube that the drive shaft runs through
in order where they normally leak
pinion seal
tube orings
if it hasn't got the aux steering pump on the front of the diff case you can remove the cover and have a look

 

[Tinkerer]

Looks like you have done a few of those Mark. That is a very common problem in 631C's also. I never repaired one, but I saw a lot of them when I was doing service work on them. I got to give the bad news to the maintenance superintendent !

 

[Mark250]

Looks like you have done a few of those Mark. That is a very common problem in 631C's also. I never repaired one, but I saw a lot of them when I was doing service work on them. I got to give the bad news to the maintenance superintendent !

Scrapers have been my blood since I was 16 (all them years Ago)I have owned them, operated them and repaired them and cursed them. Cat Mainly but also wabco with a few early john deeres

 

[DPete]

Yeah, I had my 623 E leak internally, seems like oil went the other way though, from diff to tranny. I remember being concerned about 80/90wt getting in the trans. PIA for sure, ended up rebuilding trans & diff

 

[Mark250]

before you get too deep did you check your case breathers

 

[aussiedave]

Sorry for the late reply. Pulled the trans and split the diff. The diff bearings were about to explode so re raced and re sealed the diff. Im thinking the pinion seal was the problem but also resealed the axle tube while i was in there. No more transfer.