Differential Lubrication

The only maintenance that the average owner can do is change the oil. You will need a “Little Red Hand Transfer Pump” from WalMart or your favorite Auto Supply Store. $10 to $12 bucks. The original oil from GEM is 30 weight. Most of us guys replace it with 90 gear lube. You cannot make a mistake, the gear box will work with any quality oil.

Remove the rubber plug in the cover on the gearbox and pump out as much of the old oil as you can and refill it with new. It’s surprizing how little it takes. I think it’s about 12 oz. Fill to the bottom of the hole.

Gem uses 30 weight to get the most range out of the batteries. Most of us use 90 weight cause it makes us feel good and some claim it reduces whine.

Hello, sorry to bring up an old thread. I have a 2002 E825 4 seater and I am getting noises and vibrations from the front center. When I purchased the car the previous owner never took care of it, it needed a new motor and I decided to give it a full service.
I put a ride for fun 7.5 on it with some new batteries replaced the center plug and the drive shaft as it was worn to the point that it was slick.
I also decided that since it was empty I would just remove the excess oil from the transmission through the driveshaft hole and then pour an entire quart of:

Lucas Oil 10043 SAE 80W-90 Heavy Duty Gear Oil - 1 Quart

Road tested it and there is a bit of noise and vibrations coming from the front. Is it time for a new diff/tranny?

If you replaced the input gear a set of bearings can work wonders. 50 bucks worth of bearings from Ebay and a tube of Permatex Blue. If you really want to do a delux job replace the intermediate shaft cover plugs and axle shaft seals.

You over filled it. Proper level is to the bottom of the fill hole in the bottom cover.

Takes about 2 to 3 hours to go thru the gear box when out of the car.

Strange, I do not see any issue with it being over filled. There was a nice amount of oil going up the gears, that should have only made them quieter.
I replaced the bearings in the motor.
Is there some sort of guide for the bearings? I am assuming you are referring to the bearings in the intermediate shaft…
Or am I not understanding that there are other bearings needing replacement.

Thats not a problem I have the time just need to know what steps to take before I can give up and say this tranny is toast.

The issue that happens from overfilling is that the oil can be forced past the input bearing seal and foul the motor. and burn it out.

Bearings that should be replaced include: input shaft,- intermediate shaft, - differential carrier. Usually I don’t replace output shaft bearings and seals. You should also replace the intermediate shaft seal caps. In a pinch you can reuse them by sealing the screw hole with a small screw and sealer. You will also need a tube of Permatex Blue.

The only critical bearing is the input shaft which should be an NTN 6005 LU series.Because of the LU seal design you have a better chance of keeping the oil out of the motor. Since your gearbox was built most bearing manufacturers lightened the seal preload and they won’t hold oil in the box.

While your doing this I suggest drilling a 1/4 hole in the bottom of the motor to drain any oil. Use a stop on your drill bit so you don’t damage motor windings.

Feel free to PM or call me 251-269-3182

Rodney

Where is this rubber plug? I am searching and can only find the bellpump. 2010 e4.

On the sheet metal cover on the bottom of the gearbox.

Overfilling is not good. Unless the input seal has been updated, there is a good chance the oil will leak through the bearing and into the motor. To correct the oil level, just park level and remove the rubber plug from the gearbox. The excess oil will drain out.

Daniel

[quote=GEMmechanic;10763]The best time to change the gear oil is immediately after driving. There is a rubber fill plug on the stamped cover of the differential. You cannot easily drain the oil by removing the cover as the cover bolts also hold the transmission to the frame. The way I have always drained the oil is to siphon it out through the fill hole. This does not get all of the oil out. The factory recommends SAE 30 non-detergent oil. However, many of us use SAE 90 gear oil instead because it reduces gear noise.

Daniel[/quote] Can you tell me the oil capacity for an 02 E825 differential?

12 oz plus or minus. Fill until oil runs out of the hole.

Rodney

I plan to replace the differential oil in my 2002 E825 with 75-140W synthetic motor oil, as recommended by a friend who services cars for a Toyota dealer. Can anyone tell me how much oil is required?

Between 12 and 20 oz. Fill until oil runs out of fill hole.

Rodney

[quote=GEMmechanic;8188]I have been using 80W90 in all four GEMs for several years now. Gear noise has been reduced, especially on the older GEMs. There have been no problems in cold weather. If you choose to run “motor oil,” I would suggest “non-detergent” motor oil.

Daniel[/quote]

Hi Daniel,
I’m having a tough time wrapping my mind around how to go about refilling gear oil back into the diffirentail housing. I have found the rubber plug on the bottom of the housing and when I started to remove the plug, oil gushed out. So my confusion is, if the oil dumps out when I remove this plug that is on the bottom of the housing and it drains the old oil out, how do I get the new oil in since gravity is not going to allow that to happen? 2005 g4

The plug is not on the bottom and you have to pump the oil out. A little Red Suction pump from Walmart works well. You refill to the bottom of the plug hole.

what is the location is the plug and what does it look like then, because my 2005 most definitely has a rubber plug that plugs a drain hole at the bottom of the housing. When I started to remove it, oil came gushing out. thank you for your help