FYI - I replaced my ZF-6 lube last week (truck has 135k - trans has ? miles since last change but fluid looked only slightly brownish) with 5W-30 Mobil 1 as recommended to me by a very reputable shop that rebuilds them locally. Much improved the 1st and 2nd gates and reduced the countershaft grumble at low rpm's. I would HIGHLY recommend the switch. Better get a 6 pack though....the ZF fluid capacity is 5.8 qts!!

Happy shifting!!!

 

You put engine oil in your tranny?! You should have used Mobil 1 synthetic trans fluid rated "Mercon".

 

powerstroker250,

Can you tell me what's so special about "mercon". Lube has three duties in my view.... 1) provide film stregth 2) transfer heat 3) clean and prevent foaming.

Since hypoid oil is not required, then it makes sense to me that any thin oil that meets the above requirements and viscosity numbers should be fine. Heck, Mercon was originally designed for auto trannies and is now used in manuals and power steering boxes too (at DC anyway).

I'd be interested to hear from a chem. eng. about the differences between typical tranny fluid and engine oil besides the coloring...

I can say for sure that my trans shifts easier, is quieter, doesn't leak anywhere and I probably saved money over the synthetic tranny lubes. The viscosity is the same too.

 

Well it sounds like you know more about it than I do. I've just never heard of using engine oil in a tranny.

 

powerstroker250,

I know enough to get me in trouble

I was just acting on a tip from the shop and it seemed reasonable. They warranty the work, so what the heck...

 

[QUOTE]Originally posted by pick_up_man
[B]powerstroker250,

I know enough to get me in trouble

LOL Me too usually

 

I put Red Line MTL synthetic manual trans fiuid in my 2001 5 speed. Its supposed to replace ATF and motor oil in manual trannies, (not 90 weight!) They claim that motor oil does not have the proper friction modifiers for the synchros that their juice has. It does seem to shift a bit smoother than when it had the factory stuff in it.