G900 transmission/differential oil

I recently acquired a 1969 G900LP which needs the transmission oil topped up, or probably drained and changed. The transmission warning light stays on most of the time. I want to drop the oil and clean the filter. I've gotten conflicting advice on the proper oil to use. Some say use 80/90 gear oil and some say to use a modern hytran type oil.

What say you?
 
I do not believe 80/90 is recommended. Someone with an owners manual more handy than I should be able to confirm this. My 900 has a much thinner, HyTran type oil in it. I drained mine a couple of years ago for the same reason you state. I'm such an idiot that I discovered not a plugged screen, but rather a broken wire between the sender and the light. Also, I think the pump pressure is adjustable just like your engine oil pressure and a simple adjustment is all you may really need.
 
I have an owners manual, which gives the old Minneapolis Moline part number, but not the oil's specifications. I tried looking up the old part number on the internet, but nothing comes up. The people at the farm supply store are no help, and I have gotten conflicting recommendations.

The tractor's maintenance history is unknown to me and I want to change the transmission oil, especially since the warning light comes on a lot.

Ronnie
 
I agree on the lighter oil. If it has the supply pump above the pto like the Vista and my G950, that might be a place to check as well. On my G950, my transmission light stayed on also, and when I bought it was told it was probably a plugged filter. Turned out to be a broken gear in the supply pump. I believe the G900s have a plate under the rear end to gain access to the filter? The 50 series don't have the plate so it is accessed through the rear end cover. Keep us posted.
 
I will take a look in my 950 book to see if there is a mention of the "type". If that can be found you can talk to your oil supplier (bulk oil station if you have one there). They should have on record what was used years ago and what supercedes it. For example the old MM hydraulic oil was "type 55". I believe if I remember right was Dexron III now days.
 
Since we're all striking out here a bit, a quick call to Sally or Lois at Welters would probably solve the issue pretty quick. Alan, you are correct, there is a plate in the bottom on a 900. When I pulled the plug on mine, I seem to recall something in excess of 10 gallons and it was similar to hydraulic oil. I didn't bother to analyze it, I just put it back in after I determined that the filter was fine. THEN I discovered the broken wire grounding itself on some other part of the tractor.
 
I didn't find anything in my books other than MM Transmission-Differential fluid listings with part numbers. You can call Welters Farm Supply in MO, as they work on MMs. Their number is 417 - 498 - 6496.
 
I called Welters. They said the light coming on means the screen in the lube pump pickup needs to be cleaned. It is accessed through a cover on the bottom of the differential. They recommended using a period correct hytran oil, such as that meeting the old John Deere 303 specs. I'm off to Orcheln's.

Thanks everybody.

Ronnie
 
The owners manual gives the pressure that the pump should be set at and it also states that it is normal for the light to come on at an idle, particularly once it has been ran for a length of time.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top