Gearbox oils

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Jan 21, 2013
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Boise, ID
I've got a BJ71 that I picked up last spring. I'm taking it to the garage this weekend to replace a gasket on the top of the transmission. While I'm in there, I'm planning on checking the T-case oil level and the PTO gearbox oil. Problem is, I have no idea what type or weight oil to use if I need to top anything up as the rig didn't come with any manuals. Do any of you guys know what's supposed to go in there?
 
The FSM states that you are supposed to use API GL-4 or GL-5 SAE 75W-90 IIRC. So, unless you are in a part of the world that sees some extreme temps, you can safely stick with that and be good. There are a bunch of oils in the Dino and synthetic range that you can choose from.

Do a search, there are oodles of threads on "what gear lube do I use" to choose from.

Sent from my interwebz doo-dad
 
GL-4 rated 75w/90 for your transmission
The sulphur in GL-5 is hard on syncros.
Amsoil makes a nice synthetic fluid that I have had good luck with so far.
I believe redline makes a specific fluid also
 
You guys are awesome! Thanks a lot!
 
My 1988 BJ74 specs 80-90 in everything. Diffs, transfer, H55 transmission, PTO case and winch. I did all mine a few weeks ago and it was something like 14 quarts total.
 
I've got a BJ71 that I picked up last spring. I'm taking it to the garage this weekend to replace a gasket on the top of the transmission. While I'm in there, I'm planning on checking the T-case oil level and the PTO gearbox oil. Problem is, I have no idea what type or weight oil to use if I need to top anything up as the rig didn't come with any manuals. Do any of you guys know what's supposed to go in there?

A little off topic but when you say your replacing a gasket on top of the transmission it raises a red flag. If my suspicions are correct your t-case is going to be low on oil?? Common problem on the H55F combo is when the seal between the trans and t-case goes oil transfers out of the t-case into the tranny and eventually overflows out the tranny breather which is the shift tower.
 
Sorry a bit off topic

My 1988 BJ74 specs 80-90 in everything. PTO case and winch.

The PTO winch might not like the 80-90 oil.... needs a proper worm gear oil... Been there done that... Tried some Amsoil gear oil.... couldn't handle it and started screeching.. Started to damage the bronze gear...Also some of the gear oils have an additive which eats away the bronze worm gear in the pto winch.
Here in NZ we use the Elf Reductelf SP 680 .... Great oil.... Handles some serious winching (used in comp trucks)
Here is a link to the spec sheet
http://www.totaloil.com.au/Pages/content/NT0000C8C6.pdf
 
I've got a BJ71 that I picked up last spring. I'm taking it to the garage this weekend to replace a gasket on the top of the transmission. While I'm in there, I'm planning on checking the T-case oil level and the PTO gearbox oil. Problem is, I have no idea what type or weight oil to use if I need to top anything up as the rig didn't come with any manuals. Do any of you guys know what's supposed to go in there?

You can check the level quite easily open the filler bolts (24mm or 22mm) and if oil comes out its overfull (i.e. water is in it or in the case of the gearbox/tcase ) the seal might have gone and the tranny is full of oil from the tcase.

You can refill to the level off the filler bolts/plugs without having to remove the gearbox.
 
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