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Trans Fluid

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vping

vping

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I know we have talked about this before but is there any advantage to using Redline MT90 over 20/50? This is on my list to do next but just wanted to check again. I read this on another post in regads to TD's. I was wondering if the same applies to B's. If I'm gonna do both, I'm stocking up on 1 type of fluid.
 
If the viscosity is similar then I'm sure it will be fine. Redline makes very good products. Just be sure not to use a sulfer-type fluid in the TD or it will attack the brass.
 
The Redline will cost you closer to $10 a quart vs the $2 for 20/50. Synthetics cost more, and tend to leak out a bit more. In my opinion the shifting is smoother in my Healey. Since you only need to change the gearbox oil about every 6000 miles (about 3 years of driving for me), I find the extra cost worth the smoother shifting.
 
How thick is the Redline MT90? What viscosity?
 
I was told it is 90W.
 
Then, you definitely do not want to use it in an MGB transmission - they take the same as the engine: 20W50!
 
Gear oils & motor oils are rated under two DIFFERENT systems. RL MT-90 GL-4 transmission oil is rated at SAE 75W90 for gears & is equivalent to SAE 40, 10W40, & 15W40 motor oils. RL MTL GL-4 transmission oil is rated at 70W80 for gears & equivalent to SAE 30, 10W30, & 5W30 motor oils.

Being GL-4 oils, they do not contain sulphur which the GL-5 oils have. Sulfur is harmful to bronze or brass parts. However, hypoid type axle gears should use the GL-5 rated oils.

The main difference in viscosity ratings is that motor oil is rated at 210 degrees F. & gear oil is rated at 100 degrees F.
D
 
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