Tranny Fluids

[Chris]

What is the choice fluid to run in a close ratio tranny, and why? Thanks

[jim martin]

chris when i head out to the garage later i will look at what gear oil rancho sent me after they had inspected/repared my tranny.can't remember the name but i know its a moly based gear oil,i remember mentioning it to geoff and i think he new were to get it locally.in the past i had used a gl-5 80/90 weight which was recomended .but for extreme duty this stuff is suposed to be the jiz and was told to use this product only.

[Chris]

thanks jim

[Geoff]

Been using Penzoil 80-90 since 88, works great! If you want to spend some money use Swepco aprox $13 a litre, very nice stuff. I use that in the 911 gear box.

[Chris]

Hey Jim did you ever find that bottle or tranny fluid or what?

[jim martin]

hey chris.
just went out and looked at the jug.
SWEPCO 203   moly gear lube,
i believe it's 90 weight as there is a decal with a 90 on the top.
i'm not sure where to get it locally .looks like geoff may have the scoop

[Bruce]

When I switched the gear oil in my Mexican Beetle (at 10,000km) from whatever the factory used to Amsoil synthetic 75W-90, I noticed a significant improvement in the shifting.  I'm sold on synthetic gear oil.

If you look at the fine print, you will see the API ratings.  The one that is common today is GL-5.  Over the previous GL-4, the GL-5 oil has a better extreme pressure rating.  IMO you must have this for any high performance gearbox that sees higher than stock loading.  

Every time your swing axle trans is out, pull out the side gears from the diff and inspect the gear teeth.  Note the wear on the teeth that was caused by previous inferior gear oil.  I've seen plenty of side gears with teeth that were badly worn out.

[jim martin]

bruce you should of seen my side gears and fulcrum plates and spade end of the axles,very heavy scoring and wear.that's why rancho switched me to this oil,if i remember it has a very high shear strength.they also reminded me to run no synthetic,not sure why.

[neil68]

Anyone tried Lucas 75W90 synthetic?  It's all I could find locally that wasn't GL-4 only, and it's got some of the later specs:  GL-5, MT-1, etc, so I assume it's suitable.  I have this gear oil in my Rancho Pro-Comp.

[buddy boy]

i use redline syn 75w-90.

[Bruce]

  It's all I could find locally that wasn't GL-4 only,

That's very odd.  All of the common cheap gear oil around here is all GL-5.  Valvoline, Q-State, Pennzoil, they're all GL-5.

If your Lucas is GL-5 go with it.  Being a 75W-90, it will shift well when cold compared to an 80W-90.

[neil68]

Lucas was the only "synthetic" 75W90 GL-5/MT-1 gear oil that I could find in the three shops I checked today (except Parts Source also had Motomaster).  There were some synthetic GL-4's (eg. Pennzoil) and lots of 80W90 regular oil and tons of ATF...