Is it better to use gear oil or trans fluid in front axle of FWA Kubotas?

[Greenfield Dave]

Surprising there are soo many blaming oil for the failure of the front axle components.

Yet that same oil causes no issues in the numerous seals, bearings, and gears of the transmission and rear end.

If Hydraulic oil really wasnt good enough, there would be separate reservoirs for the hydraulics, and you would be using gear oil in the trans/rear end.

I'm not necessarily blaming the oil. I do alot of loader work and that, along with thin oil could have caused the parts to wear our prematurely. I just wanted a thicker film of oil between moving parts. Call it insurance!

 

[LD1]

Just because the oil is thicker, doesnt mean you get better protection.

 

[RickB]

Just because the oil is thicker, doesnt mean you get better protection.

+1. Gears seldom fail in front axles until after a bearing failure. If oil is too cold & thick to lube bearings, they will fail.

 

[sixdogs]

+1. Gears seldom fail in front axles until after a bearing failure. If oil is too cold & thick to lube bearings, they will fail.

Is bearing failure more the problem than gear wear?

 

[RickB]

+1. Gears seldom fail in front axles until after a bearing failure. If oil is too cold & thick to lube bearings, they will fail.

Is bearing failure more the problem than gear wear?

Let's see. Did you read my post, or just quote it?
You had my answer to your question before you posed it. Others may have a different response.

 

[Gary Fowler]

Folks are talking thicker for the 80W-90 gear oil vs hydraulic oil. I just had to add 2 quarts of gear oil to the front axle on my LS and the gear oil (Mystic 80W-90) does not seem to be any thicker or less fluid than hydraulic oil even though the weight is much higher. There must be a different spec for gear oil than hydraulic oil. This stuff pours faster than 10W-30 motor oil.
BTW: The last time I checked the oil was at 50 hours and it was full, now at 120 and half gallon low with no visible leaks. I would have thought that if it had some voids at manufacturing time, they would have been filled after 50 hours of run time. I will have to keep an eye on this for a while and check the level again in a few months/hours.

 

[Oldpath05]

My l3400 front end is now leaking/seeping/wetting/sometimes slow dripping, inside both front wheels after 750hrs., just started this past week. Top seals must be getting bad on the front gear cases, (guess that's what there called). Now like others, I'm searching threads/post/stars/universe, trying crying to find out the age old question, in his name (WHY), is this 07 tractor is having another issues to deal with. I wouldn't complain if I had 7,050hrs. or had plenty of $$.

I bought a service manual few years ago from Mesick's tractors online at around $75.00, and that manual is useless with a few small fuzzy pics. and some design drawings that don't tell me anything. I'll take trip down to where I bought the tractor and see what they have for a service manual with good pictures, I'd rather find one online if that's possible, don't like going somewhere on my day off, spend time and waiting in line.

 

[sixdogs]

Oldpath--there was a thread not too long ago that dealt with how to fix this type of leak. Seemed pretty straightforward and worth a search to try to track it down. Maybe even start a new thread?

 

[big bubba]

question: most vehicles have a breather valve on the transmission/differential, etc. for pressure build up. in the 4 kubotas i've owned, do not see any. do notice pressure build up when checking ft axle level. surely they have figured it out...but to what extent can pressure build up cause premature seal failure esp in high temp workloads? just a question...no issues for me on any K i have owned...btw after 1st 50hr change, always go GL5 80/90 wt on ft end.

 

[RalphVa]

Hope you're not suggesting auto transmission fluid. It is WAY DIFFERENT from any gear oil. Auto transmission fluid is about 5w.

I'm sure your owner's manual will say to use 85-145 wt gear oil. No reason to use synthetic there, unless it's a terrible chore to replace.

Ralph