I have just changed front axle oil at 400 hours

[tassiedevil]

I have just changed front axle oil at 400 hours on the ck20 HST, and it is a very dark grey[/B][/B], I have noticed a whine in the front axle in two wheel drive mainly going up hills, but not so much in 4wd. I was wondering (not kinowing that much) whether the colour of oil was due to fine metal in suspension.
I hope not of course .. but I do give it lots in 4wd while working with the loader but never in high range on the bitumen.
I was hoping someone could shed some kind light on this potentially bad oil.
Love this Website by the way, you guys have made my life so much simpler when it come to tractor related stuff.
ps , new oil hasn't made much difference to the whine slightly better ... and is some noise normal

 

[IslandTractor]

Was that the first oil change for the front axle? I don't recall the recommendations on the CK20 (I used to have one) but I think it certainly should have had at least one previously like at about 50 hrs and ?200hrs.

If you have any of the removed oil left you could pretty quickly find out if it is full of metal shavings by using a magnet or even just letting it settle in a glass container.

It is not clear from your post but did the whine start after you changed the oil? If so are you sure you added enough? I recall the CK20 doesn't have a sight glass but it would be important to check the oil level again even if it seemed you had added enough when you changed it as those front axles can be tricky and the level can change once you start using it after an oil change.

 

[WTA]

That gray color is probably water in it. It's good that you changed it now. Water and bearings don't get along too well.

Also if you are running synthetic oil in the gears then don't. Unless you really work it hard and get them hot you will keep getting water in it. I've run into this problem more and more lately as car and truck makers are switching to all synthetic fluids in the differentials. Every time I can remember replacing a bearing or rebuilding a diff lately it's been on a rear end that had synthetic fluid in it. All I can guess is that it doesn't allow it to get hot enough to take care of the water from condensation and it just keeps building up.
Pinion bearings always seemed like they were the first to go. Side bearings next to that. Pinions are usually the ones that make the high pitched whine and the sides are a lower pitch. I've never been able to hear one on a tractor though till it was grinding or something was obviously broke. It might be a good idea to inspect the gear carrier on it. You'll see water damage real quick in the form of pitting on the bearings.

 

[tassiedevil]

Thanks for that , will check the oil and consult the dealer on this I think but your suggestion that you haven't heard a whine on a tractor is encouraging for now. will also scrutinise the drained oil when it settles, will the water separate after time.

 

[WTA]

If it is really stirred up then it won't separate out unless it's heated. I was an engineer in the Navy for a long time. This is why I'm so paranoid of oils nowdays.
We constantly purified the oil in our main engines and always had a batch in the settling tank cooking out the water. The purifiers we used were delaval disc types that would spin out all the water and impurities and it had to be heated to about 180 I think it was in order for them to work good. They called the oil 2190TEP but it was just basically gear oil with EP additives for high speed turbines is all. Not much different from gear oil in a tractor.

If you can find a safe way to heat it to 180 degrees I'd bet the water would separate then. There are several labs you can send a sample to also around the country. On something as high dollar to repair as a tractor I strongly recommend this on all of your oil sumps at least every other year. The lab report you get back will tell you every thing that is in your oil from water content to all the different types of metal. That is helpfull in determining if that shiny stuff is babit from engine bearings or steel from gears. Aluminum and tin also indicate bearing failures.

 

[Skyco]

Also if you are running synthetic oil in the gears then don't. Unless you really work it hard and get them hot you will keep getting water in it. I've run into this problem more and more lately as car and truck makers are switching to all synthetic fluids in the differentials. Every time I can remember replacing a bearing or rebuilding a diff lately it's been on a rear end that had synthetic fluid in it. All I can guess is that it doesn't allow it to get hot enough to take care of the water from condensation and it just keeps building up.

Could be but some types of polyol ester synthetics are also very good at pulling moisture from the air, much more so than petroleum products. I've seen this with RedLine products and will no longer use them because of it.

 

[WTA]

That makes a lot of sense. I never gave any thought to what synthetic gear oil was made of but that stuff you mentioned is real similar to the newer refrigerant oil and it is extremely hydroscopic. I have to run the vacuum pump a lot longer on a 134A system than I ever did on an R12 system to get all the air and moisture out.