Just bought a 1978 955L 13X machine and took oil samples of the fluids before I bought it. Everything came back clean except for "excessive water" in both finals. Desided to take a chance, because of the condition of the machine and no operation problems or noises. I don't know how long it has been in this condition, so a oil change is the first thing before any use. Does anyone recommend going as far as droping the lower "sump" sections of the finals to inspect and clean or is it more trouble than its worth? Doesn't look that hard, about 12 bolts or so it looks like. Does it use a gasket to seal it back together? This is my first machine and need all the info I can get. I'll post some pictures later. Thanks
Mike,,, as long as the sample's came back as good as they did, i'd just drain them and put the new oil back in. As far as your question is there a gasket on the sump, the answer is Yes there is... good luck Grandpa.
Had the machine been standing for a while before you bought it..? If so the water could be the result of condensation. If the oil that you sampled looked clean & bright then I wouldn't go any further than to change it. This would be especially the case if you couldn't pin down when the oil was last changed. Oil should be an SAE50 meeting TO-4 specification.
The oil looked old and dark, but not milky. The owner has records of it being changed in 2002. When I took the fill plugs loose for the sample, they almost hit me in the face from the pressure built up in the cases. I had just run the machine for about 30 minutes. I asked if the vent was stopped up and he said there was no vent and the pressure was normal? I later found the vent on top of the trans case covered with dirt. I thought about condensation aswell because it has sat alot and the way the pressure was built up when I removed the plugs, but the caterpillar lab tech seemed to think it came from an outside source. I doubt it came in past the seals the way the cases were holding pressure. The lab tech said the samples had greater that 2% water in them and thats what they deem excessive. Because of this they couldn't test for metal counts. They suggest changing the oil and resampling after 250hrs. The only trouble is, this machine is going to be used for farm clean up, and I don't think I'll put 250hrs. on the machine in the next 5 years!
if the oil was last changed 10 years ago then it's more than due for another oil change IMHO, maybe change it once then run it for 10 hours or so and change it again. Pressure in that compartment is perfectly normal after the machine has been worked for a while. The fact that there was pressure inside the final drives indicates that the source of the water is internal rather than external. If it was getting in from outside they would not build up pressure. There is no breather for the final drives, the one you found is for the transmission. The Cat lab will say 250 hours because that's the standard service interval. If you're not planning on putting many hours on it I would suggest change the oil, run the machine for say 3 months then take more samples. "Excessive water" is considered anything in excess of 1%. Shame they didn't do metal readings because the water only makes it impossible to do particle counts, not metal content.
Great information Nige. I thought for sure I had found the right breather!! I still have the oil that came out of the finals. I drained them into clean containers. Is there someone else I can send a sample to other than CAT for a metal count or is it worth it? If they can't tell anything, I think changing it now and then agian in 3 months like you mention is a great idea. Might run it as much as a year then resample. Do you all feel that the CAT 50wt oil is worth the extra $30 more than Chevron drive train 50 I priced today for the final drives. Cat parts man says it holds 2.25 gallons per side.
I wouldn't go to the expense of more oil analysis at this time. You said the oil looked dark and obscure rather than clear. Save your analysis money for the oil you're putting in, not what's coming out. Another thought, check the magnetic drain plugs. If the finals are in good condition the plugs should have a small amount of what appears to be a shiny silver paste on them, nothing more. Oil. I'd personally go for the cheaper stuff if you're not intending leaving it in for long. You don't in any way have to use Cat-branded oil because it has a Cat logo on the pail and so does your machine. You can use ANY branded oil like the Chevron you mentioned so long as it meets TO-4 spec, just don't go buying "re-refined" cooking oil collected from your nearest fast food joint and sold as top quality by Joe Blow's Gas, Tackle, & Bait Shack.