Transfer case oil change procedure

[C-Mack]

Without the actual service technical documents or a prescribed procedure I’d hold off on a transfer case oil change (or at least have the dealer do it). Judging by the different quantities of oil being drained out by various folks it suggests the oil cooler is playing a factor and there is probably a very specific procedure to make sure the cooler is drained and the exact right amount is put back in the entire system.

If for example, you catch the thermostat open and the entire system drains out but you can only get sufficient back in to fill the transfer case you’d be short the amount of oil that is supposed to be held in the cooling circuit. With no way to get the remaining amount in the fill port without it overflowing back out you’d be running the entire system low of oil. I don’t think you can rely on the fill port as a confirmation the level is correct like you can on most differentials.

I bet my left lug nut there is a fill procedure which requires certain temperature parameters be met and/or some kind of recirculating pump needs to be triggered electronically, or the transfer case needs to be ran with the vehicle on a lift stationary to circulate the oil in the cooler circuit before a final top up.

I’d would also like to be able to do the transfer case maintenance myself but would want to see actual service procedures beforehand. It would be an expensive mistake to make running the transfer case low even though you had serviced it with the best of intentions.

 

[LWA55DAL]

When i did mine I had nothing come out of the fill hole on the 1st transfer case fluid change.

 

[S52]

Does anyone know what size socket is needed for the transfer case fill/drain and the differential fill/drain?

They look like allen head bolts?

 

[HereinDaRockies]

Does anyone know what size socket is needed for the transfer case fill/drain and the differential fill/drain?

They look like allen head bolts?

Yes Allen head.. forget what size….

 

[LWA55DAL]

So talked to the tech in San Antonio and apparently the max fill on the diffs is supposed to be a couple MM’s below the top of the fill hole. So you aren’t supposed to fill it all the way up or it is over filled.

 

[HereinDaRockies]

So talked to the tech in San Antonio and apparently the max fill on the diffs is supposed to be a couple MM’s below the top of the fill hole. So you aren’t supposed to fill it all the way up or it is over filled.

Couple mms bElow. That’s the dumbest design. Doubt the transfer case specifies that level of precision

 

[LWA55DAL]

INEOS actually has a tool to measure it and the tech said it was basically an Allen wrench.

 

[Tazzieman]

Couple mms bElow. That’s the dumbest design. Doubt the transfer case specifies that level of precision

Need to get that tech to spill the service document. Is it 2mm , 2.1, 1.9 - we need to know.

 

[Greasemonkey]

Does anyone know what size socket is needed for the transfer case fill/drain and the differential fill/drain?

They look like allen head bolts?

8 mm Allen , See picture page 1

 

[HereinDaRockies]

Need to get that tech to spill the service document. Is it 2mm , 2.1, 1.9 - we need to know.

Then it should also prescribe the exact angle the vehicle rests at. Do the techs use a level, to determine how thr transfer case is situated?

Couple mm.. lol. The goddamn grenadier is not a spacecraft.. pretty sure the tech was intentionally fking with him, to make the diy service sound daunting

 

[LWA55DAL]

He was dead serious. He said they have a tool, again like an Allen wrench, that you are supposed to insert in to the fill hole to measure the level.

I filled mine like every other vehicle I have ever owned and it was coming out of the diff breather.

 

[Tom109]

He was dead serious. He said they have a tool, again like an Allen wrench, that you are supposed to insert in to the fill hole to measure the level.

Seriously pulling your chain!

I filled mine like every other vehicle I have ever owned and it was coming out of the diff breather.

I hope you mean "fill hole" and not breather!

 

[Tom109]

Picked my Gren up last Friday from its first Service. I asked about the t-case change and they confirmed it is like any other mechanical - open fill hole, drain, refill until oil appears in the fill hole.

 

[HereinDaRockies]

Picked my Gren up last Friday from its first Service. I asked about the t-case change and they confirmed it is like any other mechanical - open fill hole, drain, refill until oil appears in the fill hole.

But for the IG, there is a cooling system for the transfer case. Did you ask how they performed a full bleed as well? This is highly nonstandard

 

[Tom109]

But for the IG, there is a cooling system for the transfer case. Did you ask how they performed a full bleed as well? This is highly nonstandard

I didn't ask. I can't see the cooler system dumping back into the sump, our you (or the dealer) could never verify the level. So a cold drain and fill is probably in order (measure was is drained), or you could do multiple drain and fills.

 

[HereinDaRockies]

I didn't ask. I can't see the cooler system dumping back into the sump, our you (or the dealer) could never verify the level. So a cold drain and fill is probably in order (measure was is drained), or you could do multiple drain and fills.

Ineos does have published volumes for a tcase drain only vs tcase drain + cooling system bleed

 

[C-Mack]

Ineos does publish two different oil capacities for the transfer case, one includes the cooling circuit capacity and the other for the case only. My question is what is the exact refill procedure and what conditions must be met in order to make sure you get the right total amount back in? Transfer case temperature hot or cold, vehicle level, cooling pump status, etc…? I could see scenarios where you could either under or overfill the entire circuit and cause damage.

For example, if the system is cold and all the oil is in the transfer case and is above the oil fill level how would you get the right amount back in? Likewise, if the system was drained hot with oil trapped in the cooling circuit and the level is below the fill plug could you not run the risk of overfilling if you went with the old fashioned fill it until it comes out of the fill port method?

 

[HereinDaRockies]

Ineos does publish two different oil capacities for the transfer case, one includes the cooling circuit capacity and the other for the case only. My question is what is the exact refill procedure and what conditions must be met in order to make sure you get the right total amount back in? Transfer case temperature hot or cold, vehicle level, cooling pump status, etc…? I could see scenarios where you could either under or overfill the entire circuit and cause damage.

For example, if the system is cold and all the oil is in the transfer case and is above the oil fill level how would you get the right amount back in? Likewise, if the system was drained hot with oil trapped in the cooling circuit and the level is below the fill plug could you not run the risk of overfilling if you went with the old fashioned fill it until it comes out of the fill port method?

This is the bait n’ switch Ineos employed, which everyone is mad about. Obfuscation of basic maintenance info for a “world traveling” vehicle.

 

[C-Mack]

This is the bait n’ switch Ineos employed, which everyone is mad about. Obfuscation of basic maintenance info for a “world traveling” vehicle.

Totally agreed, but like everyone else I just want the correct procedure as basic maintenance like this can usually be done DIY style and would be more convenient than having to arrange and travel to a dealer for what used to be easy stuff for mechanical sympathetic folks to take care of themselves.