D1 Transmission and Transfer Case Fluids

kdigby13

Member
Sep 6, 2021
7
1
New Orleans, LA
Hey Y'all,

Hope you're well. I've got a 'new' 97' D1 5-speed while back that I'm still getting to know. She drives great, and had a clean record when I got her, but to be safe I've been slowly replacing all fluids/grease/filters when I can. The last ones on my to-do replacement list was transfer case, transmission, and greasing the prop shafts.

However when I took the T55 bolt off the transmission this am, I was surprised when clean red transmission fluid came out of the refill bolt. It seemed like it was recently replaced, so I decided to leave it as is. When I took off the 1/2" refill bolt for the transfer case, it was also overfilled, and also seemed clean.

I was positive that the truck was level, and quite honestly very surprised when about a pint of clean fluid came out of each location. How was that even possible? Either way, do y'all think I'm fine leaving both transmission fluid and transfer case fluid as is?

I'm planning on driving to duck lease north of Tyler, TX this weekend from New Orleans, so would like to know if I should bother with replacing them or not? Could I have possibly done myself a favor by checking and rereleasing the over filled reservoirs? Thanks, and look forward to hearing back from y'all soon.

-K
 

Swedjen2

Well-known member
Sep 12, 2018
582
123
California
What does the manual say?

"If you do get it, switch to Redline MTL. They came with ATF in them, but L/R released a TSB later saying they should have manual transmission fluid. The transfer case takes the same on both, 85/140 gearlube, or the like.
 
How was that even possible? R380 manual gearbox is the only one gearbox that after an oil change you can fill it working better. For the rest, to change oil is only a preventive task.
So last owner was used to do gear oil change frecuenly.
Nowadays recommended oil is MTF94, this is a 75w90 GL-4 each 40kkm.
And transfer/diff oil suggested is 80w90.

Regards
 

kdigby13

Member
Sep 6, 2021
7
1
New Orleans, LA
That is what I'm so concerned and confused about. About to go on a 500 mile trip and there is less fluid in both reservoirs now than when I started out this am but at the right levels. I have no idea how the previous owner could have even filled them up past the filler plug...I would understand overfilling if there was a leak, but neither of them leak. Still shifts extremely smoothly though. I'm assuming there shouldn't be anything for me to worry about?
 
Aug 20, 2007
2,710
35
Nashville TN
That is what I'm so concerned and confused about. About to go on a 500 mile trip and there is less fluid in both reservoirs now than when I started out this am but at the right levels. I have no idea how the previous owner could have even filled them up past the filler plug...I would understand overfilling if there was a leak, but neither of them leak. Still shifts extremely smoothly though. I'm assuming there shouldn't be anything for me to worry about?
you can overfill if it's parked at an angle with the filler plug on the uphill side.
 

rover4x4

Well-known member
Apr 21, 2004
5,216
42
39
North Carolina, Raleigh
Redline MTL is great choice for the R380. Overfilling shouldnt hurt, FWIW I have always overfilled my transfer cases by a pint or two to help the input shaft.
 

lance cowley

Active member
Feb 9, 2021
25
6
Lincoln CA
What is the fluid capacity recommended on the 5 speed? I would assume mine has never been changed... I am asking so I know how much MTL to purchase?