Gonna be cold under that Jeep!
Gonna be cold under that Jeep!
Looking for a comment. About gear lube and its flow from trans to xfer case?? Can not find it, and re educate me on over filling and what happens, took bottom plate off and re gasket ed it damn ting better not leak
The 18 transfer case has a "balancing" lube system. The transmission gear case has a lube hole shared with the transfer case. The level in the transfer case is lower than the level in the transmission. As the transfer case gears rotate, they lift the lube up to the shared lube passage in the transmission. This sort of refills the transmission case. When the transfer case gears stop rotating, the lube drains back from the transmission to the transfer case. So if you drive it and it losses lube from the transfer case, the trans will keep filling it. The transfer will steal a lot of lube from the trans and vice versa if things are leaking. It is a good idea to keep an eye on both levels.
Overfilling causes the oil to foam up, break down and overheat. When there is to much of it, it gets in its own way so to speak. All the turbulence aerates it and it gets hot. The air bubbles can get between the bearing surfaces and score. Usually it desperately finds a way to start leaking out. In the T90 trans it starts to come out the shift tower. On the Dana 18 it can come out the vent cap.
We're glad you're feeling better.
So back to the transmission and transfer case. Do you add the oil in one place and check it in one place? There is a plug up on the side of the transmission I can see. Mine is a 3 speed. The manual shows two No. 8's for checking the grease then at the bottom it says they are separate for the 4 speed. Which place do I need to check mine or are they both the same?
Since it was explained to me that the flow of lube from trans to xfer is really quite low, my plan is to fill the xfer first then the transmission only to whey i can feel lube on finger at fill hole
Basically, you fill each one till it just drips out. If you overfill the trans it will spill into the transfer case. If you then pull the fill plug from the transfer case, it would spill out until the transfer-case and the transmission balanced out so to speak.
So the transfer-case lube is slightly lower than the transmission and the transmission will spill into the transfer-case when overfilled. The transfer-case constantly dumps lube into the transmission. It drains back through the hole into the transfer-case. If you fill them each up individually until the lube just weeps out, then take it out for a run, the transfer-case will be slightly overfilled, if you were to pull the fill plug (Don't pull the plug this is the correct condition). It's a unique way to keep the lube in circulation.
Last edited by bmorgil; 01-09-2020 at 06:02 PM.