Lubrication experts: gear lube weight question

[TomGolden]

Howdy all,



As I was changing the gear lube in my 6 speed manual transmission today, a question occured to me:



Why is the lube in the transmission so light weight compared to what goes in the differential(s)? I would think the transmission and the rear differential do about the same amount of work when driving, regardless of towing or not.



Just wondering,

Tom

 

[Vaughn MacKenzie]

Tom, if you think that is odd, what do you think about the transmissions (and transfer cases) that use ATF? That stuff is even thinner. I think it has a lot to do with reduced friction/improved MPG, at least that is part of the reason I assume. One thing for sure is to not second-guess the transmission engineers and go sticking a different viscosity (or type) of oil in there other than what it was designed to use.



Did you fill yours with the Mopar stuff or go with Amsoil 5W30? I am going to change mine at 50k (real soon!) and stay with the OEM stuff in my 6-speed.



Vaughn

 

[TomGolden]

Vaughn,



Well, I tried every possible avenue for getting the MTX 1874, even calling a place in Texas that Texas Diesel (TDR member) got a 5 gallon pail from, but the guy told me the shipping cost to CA would basically end up costong me the same as if I went to a Dodge dealer and bought it at their rediculous price. I called Texaco directly, and every one of the distributors in CA they referred me to doesn't carry it.



So, I decided to go with the Amsoil series 3000 5W-30 oil. I know some people are very uncomfortable with going with anything other than what was recommended by the OEM, but if there weren't several other TDR members that have been using the Amsoil for quite some time, I would not have been brave enough to try it. Will see how it goes.



Tom

 

[Riflesmith]

I have been using the Amsoil Series 3000 5W-30 Diesel oil in my six-speed for 13,000 miles. Shifted smoother than stock right from the start and still does. You won't be dissapointed. It is also kind of handy being able to use the same oil in the engine and the transmission.