SBU Tranny Fluid (Amsoil) - Benzworld.org - Mercedes-Benz Discussion Forum

Chas Stricker · 12-10-2012, 07:44 AM

Howdy All,
I didn't want to hijack another general fluid thread for this/these questions on Amsoil fluids.

I'm running Royal Purple in my tranny (the last 40-50,000 miles) and changing it soon. I'm looking at Amsoil to see if it will help with the 5th gear SBU fun. The RP may have helped a little and it does run nice and cool with it, but, since it's time to change I thought I'd try it out.

Question to all of you viscosity sharp guys. With the way companies measure viscosity in different oil types (gear, engine ect) what is the "true" viscosity between oils like Amsoil MTF(5-50w) and MTG (75-90w)? In talking with Amsoil tech they don't want to go further than to say use the MTG because it sounds like to them a better fit or more of the same with what Mercedes wants. I know Bob(Hammoger) is/has used the MTF and his shifting is much better. Is this an either or situation: use the MTF for shifting but the tranny will not have the long life.......or use the MTG and gears and bearings love it but be more careful when cold? Amsoil wouldn't comment on if the shift/synchro goodies they put in the MTF are the same as the goodies they put in the MTG.

Is anyone using the MTG that would comment on the shifting change? I'm leaning towards the MTG and testing it out.

Thanks,
Chas

DokaTD · 12-10-2012, 08:25 AM

They do t want you to know its te same as everyone else, just different color and sticker on the bucket.

Just my 2¢

m37charlie · 12-10-2012, 08:35 AM

Use an oil that is the viscosity MB calls for: 75W85. MTF is too thin, MTG too thick.
Redline, however, does make a 75W85. Or mix MTF and MTG 50:50 if you insist on using Amsoil.

Charlie

tlane · 12-10-2012, 08:52 AM

Chas--I just changed mine out to Mobile Fluid 50, Delvac 1300 synthetic. is a GL4 fluid
and is rated at 75W-90---my tranny is now running/shifting much smoother than the dyno oil that was in it---even when cold. Comes in a 4 gallon case $152. Is designed for all standard truck trannies---especially the big 15 speed trannies our Peterbilts have. --Is a premium lube.
TL

flighht2k5 · 12-10-2012, 09:17 AM

What's the 5th gear sbu fun?

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Chas Stricker · 12-10-2012, 10:00 AM

Flight....the "fun" is a difficulty going into 5th gear....especially when cold.

Terry I have looked into the Mobile 50 which is the oil viscosity ish, which is like a 90w gear viscosity. Did you have the cold issue with your ambulance?

Chas