Heres some API-GL4 70W80 oils that can be used in place of the Texaco MTF94 that seems to be unavailable outside the dealership.Amsoil MTF 70W80,Redline MTL 70W80,Castrol VMX 75W80 and Shell Spirax GSX 75W80

 

If your Midland blows, and one of these oils is in the tranny, can they refuse to do warranty repairs?

I actually think you can prolong the life of your Midland by changing to a full synthetic such as Amsoil, Redline or Royal Purple.

 

My research tells me that the Texaco MTF94 is a fully synthetic GL4 70W80 oil but you cant get the stuff where i live other than the dealer who quoted USD$300 and dont have any in stock thank god ,thats what has led me to do some research.I'm out of warranty as most will be if you have a Midlands tranny so thats not an issue, in any case they'd have to do some serious homework to figure you've changed the oil unless you fill it up with the purple stuff .So my post was to aid the DIY guys.I've filled with Amsoil MTF and the box has a cleaner feeling,was getting a little rake into 2nd under hard revs,this prob seems to have vanished.The oil that came out did not look clean and clear.This is my second box doing about 25K so maybe these aftermarket oils are better who knows.But it shure cant hurt after what i saw come out.The Amsoil MTF and Redline MTL both have excellent reviews on the net,i used Amsoil as it was available.Peter

 

I had read that Texaco MTF94 was a semi-synthetic oil, but if you researched it I'm sure I'm wrong. I think Amsoil or Redline would most likely be better than the Texaco MTF94, though I was leaning toward Royal Purple.
Until my warranty is up though, I think I'll go with the more stealthy Amsoil or maybe Redline. Wonder if there is a reason to prefer one of those over the other?

I have heard several comments from people who changed the Texaco "lifetime" oil at 20,000 miles or so about how dirty it looked. The Midland needs all the help it can get and changing the fluid to something better is a good idea.

 

When i read it it said to be synthetic not semi or fully as some oils do on the label.Whats really important is change the oil.All i can say Resmini is that i can recomend the Amsoil as i'm using it and shifting is definatley smoother,I'm also shure the Redline is great stuff but if you have some warranty left i would'nt put the purple stuff in.I will be changing the oil more frequently now having seen what was in there.