Limited Slip Question

[kewball417]

Hello,
I just bought an 88 4wd Mighty max and I'm wanting to service the differentials, trans, and transfer case. Forgive my ignorance on this. How do I determine if my truck has a limited slip rear differential or not, so I know which fluid to use? Also is synchromesh appropriate for the transmission? I apologize if this has been gone over already on the forum, but I was unable to find this information. Thank you in advance.

[camoit]

Just leave the truck in neutral and jack up one wheel. Then try to turn it. If it turns the wheel and drive line with the other wheel on the ground then you don't have limited slip.
All these trucks take just plain old gear oil in them. Unless you have an automatic. If you do have a limited slip you will need the friction modifier to add into the oil. Just keep in mind there are 2 filler ports. One on the trans one on the transfer case. They do not share a common oil path. And always remove the filler plug before removing the drain plug. This way if there is a problem with the filler plug coming out you don't render the truck useless.

[DroppedMitsu]

Or check to see if there is an orange sticker in the door jamb or rear diff that says you need to add LSD additive to the oil.

[kewball417]

Thank you camoit for the advice.
That's a great tip on removing the filler before the drain. Thank you droppedmitsu for the tip on the sticker. I have one on the door jamb and that answers my question. Thanks again.