Transfer case oil change procedure

[HereinDaRockies]

Looking to change my transfer case gear oil after grinding it while shifting from L to H. Want to flush out any potential metal shavings

The fluid spec I found cites two volumes - 1.8L and 2.64L

I am just doing a drain & fill. I am not clear what the 2.64L indicates.

Is the fluid change procedure similar to other 4x4 transfer cases? Just fill until oil comes out of the fill hole?

 

[landmannnn]

Looking to change my transfer case gear oil after grinding it while shifting from L to H. Want to flush out any potential metal shavings

The fluid spec I found cites two volumes - 1.8L and 2.64L

I am just doing a drain & fill. I am not clear what the 2.64L indicates.

Is the fluid change procedure similar to other 4x4 transfer cases? Just fill until oil comes out of the fill hole?

View attachment 7877126

There is a cooler in the front bumper, the higher quantity is if you have drained that as well as the transfer case.
You are probably best to drain the whole thing then add the specified quantity of oil.

 

[HereinDaRockies]

Are there instructions on draining & filling the t case cooling system?

 

[landmannnn]

I've not seen anything.

 

[C-Mack]

I would assume there is a 12V oil pump on or near the T-Case which is activated by either the DME or transmission software once temperature reaches a set point to push the fluid through the cooler in the bumper? If the pump is external with a plug-in electrical connector you could hook a Power Probe up to it and trigger the pump manually.

In theory, you could open the drain plug on the T-Case and let the fluid drain out first. Then you could activate the pump with the power probe and push the remaining fluid in the lines/cooler back to the T-Case so it can drain out. In reality, I don’t think you’d get every last drop out but refilling the T-Case would be the reverse process. Fill the T-Case first until oil flows out the fill port then activate the pump and the fluid level should drop down allowing you to top it up until it drips out the fill port again.

That said, I’d recommend measuring accurately the amount of oil you drain out of the system with a clear graduated painters bucket (or something similar) so at a minimum you would know the exact amount which needs to go back in. There will always be residual amounts left in the system and before draining anything make sure the vehicle is sitting as level as possible front to back and side to side.

I’ve known folks who have burned up differentials because they filled it up on a sloped driveway and thought everything was fine because the oil was leaking out of the fill plug while in reality they only got half the amount in they needed. Likewise, for vehicles with tall lifts and the axles housings have rotated in such a way the fill plug sits lower not allowing the proper amount to be put in so don’t just go off of the fill port method always measure.

Not sure what I’ve describe above will work specifically for the Grenny but it’s a way to drain fluid on systems which have cooling circuits… proceed with caution or consult the dealer first.

 

[Ron50]

Tip: Make sure you can undo the filler plug before draining the oil.

 

[255/85]

Providing there are no check valves you might be able to get the front cooler to drain if you jack up the front of the vehicle. The cooler lines are fairly convoluted so you may have to go up a foot (300mm) or more.

 

[ORSO]

How often should the t-case oil be changed?

 

[HereinDaRockies]

How often should the t-case oil be changed?

60k miles replace.

12k miles to check and top up

 

[ORSO]

do you have any pics of the filler and drain plug locations? tightening torque?

 

[ItalianAmerican]

Looking to change my transfer case gear oil after grinding it while shifting from L to H. Want to flush out any potential metal shavings

The fluid spec I found cites two volumes - 1.8L and 2.64L

I am just doing a drain & fill. I am not clear what the 2.64L indicates.

Is the fluid change procedure similar to other 4x4 transfer cases? Just fill until oil comes out of the fill hole?

View attachment 7877126

Can you point me in the direction of finding these service details, as well as, torque specs?

 

[HereinDaRockies]

I posted the info that I have in the original post…

 

[HereinDaRockies]

do you have any pics of the filler and drain plug locations? tightening torque?

I don’t have the actual picture of the IG’s tcase.. but all t cases are fairly similar in exterior attributes.

Look up YouTube video for transfer case oil changes…

Here is a random pic I found.. fill plug at the top.. drain plug at bottom, except for the IG, the drain plug faces the ground.

 

[NQ94]

Older photos of the fill and drain plugs.

 

[LWA55DAL]

Just did the T case oil change this past week. I did not ty and drain the cooler so put in just under 2 quarts after the drain. Not nearly as bad as the differentials and I did those at 8k. T Case at 9k. Breaking in the T Case and I had a fair amount of gear grinding so wanted to be careful but honestly - not nearly as bad as the diffs.

 

[HereinDaRockies]

Just did the T case oil change this past week. I did not ty and drain the cooler so put in just under 2 quarts after the drain. Not nearly as bad as the differentials and I did those at 8k. T Case at 9k. Breaking in the T Case and I had a fair amount of gear grinding so wanted to be careful but honestly - not nearly as bad as the diffs.

What gear grinding?

 

[LWA55DAL]

What gear grinding?

Shifting between low and high. Had to break in the cables when I first received the vehicle and a couple times it would pop out of the locked position. Had to keep shifting it to break in the cables.

 

[Greasemonkey]

Just did the T case oil change this past week. I did not ty and drain the cooler so put in just under 2 quarts after the drain. Not nearly as bad as the differentials and I did those at 8k. T Case at 9k. Breaking in the T Case and I had a fair amount of gear grinding so wanted to be careful but honestly - not nearly as bad as the diffs.

The transfer case on my Grenadier Trailmaster Diesel was changed as part of a recall campaign at ca. 5000 km. Since I am currently changing all oils (now 18,000 km), I also changed the transfer case oil.
The car was therefore driven into the garage and sat there for about 30 minutes. After opening the top control screw, approx. 600 ml of oil immediately ran out. Then I opened the bottom drain plug. Now another 1.9 liters of oil ran out of the transfer case. (see pictures) The new oil (Fuchs Titan Sintopoid 75W-90) is as light as water. The drained oil was already noticeably dark after 13,000 km. After 75,000 km it will be black. I didn't notice any abrasion from the gearbox. The way I see it, the oil level in the gearbox cannot be checked using the control screw, because when the vehicle is stationary the oil from the oil cooler immediately runs back into the gearbox and is therefore much higher in the gearbox than the control opening. I filled in the new oil (2.55 l) using a lever pump. Because of the oil cooler, the transmission must be over filled to get the correct level of 2.64 l of oil.

PS: The engine oil has been changed since new twice by myself and once through the dealer.
Pictures of the diff oil I will post later.

 

[HereinDaRockies]

The transfer case on my Grenadier Trailmaster Diesel was changed as part of a recall campaign at ca. 5000 km. Since I am currently changing all oils (now 18,000 km), I also changed the transfer case oil.
The car was therefore driven into the garage and sat there for about 30 minutes. After opening the top control screw, approx. 600 ml of oil immediately ran out. Then I opened the bottom drain plug. Now another 1.9 liters of oil ran out of the transfer case. (see pictures) The new oil (Fuchs Titan Sintopoid 75W-90) is as light as water. The drained oil was already noticeably dark after 13,000 km. After 75,000 km it will be black. I didn't notice any abrasion from the gearbox. The way I see it, the oil level in the gearbox cannot be checked using the control screw, because when the vehicle is stationary the oil from the oil cooler immediately runs back into the gearbox and is therefore much higher in the gearbox than the control opening. I filled in the new oil (2.55 l) using a lever pump. Because of the oil cooler, the transmission must be over filled to get the correct level of 2.64 l of oil.

PS: The engine oil has been changed since new twice by myself and once through the dealer.
Pictures of the diff oil I will post later.

When I opened the fill plug, no oil flowed out. Zero.

 

[Greasemonkey]

When I opened the fill plug, no oil flowed out. Zero.

What should I say? I was surprised too. Was too much filled in at the factory or by the dealer when changing the gearbox? I also can't tell whether there is some kind of thermostat between the gearbox and the oil cooler that initially holds back the cold oil. It always comes down to the fact, that we absolutely need the technical documents.