[TwoBills]

Long story short, time to change the gear oils. FSM recommends 75w90 GL-4 (only) for the 5 speed and 80w90 for the LSD rear. After visiting 8 local parts stores, the best I could come up with was 75w90 GL-5 w/all the parts guys saying that would be ok. Well, I don't like to second guess the FSM, so I got online. A half hour later, I came up with Amsoil.com . Amsoil has been around for a long time, maybe one of the first synthetics, and they have the GL-4 we need for the tranny.

75w90 GL-4 = $7.80/qt. (tranny)
80w90 GL-5 = $7.40/qt. (rear)
additive for LSD = $6.45
$60 shipped

Now I just need to get that stinky stuff in there.

 

[JOHNNYXB9]

God I hate the smell of gear oil. :x The crap coming out of the truck is even worse. Keep us posted on the Amsoil. I considered doing the same.......in another 20K.

 

[WylerFronty]

I've changed the tranny gear oil 3 times now and each time have used 75W90 sycnromesh fluid from Pennzoil. I originally tried a GL-4 75W90 but after sloppy meshing, I called the dealer and they confirmed the tranny is a syncromesh. Since then, no problems. I get the Pennzoil for $5.99/qt. at Autozone. Let us know how it goes.

 

[TwoBills]

Yeah, I've got sloppy meshing w/the valvoline synthetic I've got in there now.I put it in 2 years ago, and didn't pay any attention to the GL rating, so it's probably GL-5. That's why I was adament about the GL-4 rating this time.

If the amsoil doesn't smoothe out the shifting, I'll try that Pensoil. Is it GL-4 or 5?