Good GL4 Gear Lube?

[GMC_Guy]

I just got done rebuilding a 1950 GMC 3 speed manual transmission, and everyone is telling me to go with a GL4 gear lube, due to the yellow metals in the synchronizes. It seems the GL4 market is pretty limited. So far I found a Pennzoil GL4, and a Redline GL4. Everything else seems to be "GL4 and GL5" rated, and I would have to dilute to get the GL4.

Of the Pennzoil and Redline, which would you recommend if it were your rebuilt transmission? Any thoughts?

Thanks in advance,
Jake

 

[MolaKule]

Quote:
It seems the GL4 market is pretty limited.


I don't think so.

Technology of Manual Transmissions and Lubricants

Any 14 cSt oil (SAE 75W90) such as Redline MT-90 or Amsoil MTG should work.

 

[BigCahuna]

I was looking for some Gl-4 a while back. The only place that had it by me was Napa. Straight Gl-4 not 4&5.,,

 

[GMC_Guy]

Let me rephrase the "limited market". Of the 3 local auto parts stores I went to, only 1 store had 2 quarts "GL4 gear lube", and it was the Pennzoil. The other two only had full synthetics. I know I can order just about anything online, and that is why I was thinking the Redline. I have heard good things about them.

I was mainly just seeking a few opinions of Redline vs. the Pennzoil, which I can buy locally.

Thanks,
Jake

 

[suspiciousmind]

Look into Motorcraft xt-m5-qs.... Available at Ford dealership.

It's full syn, and pricey, but really good stuff. Made in Germany by Fuchs.

 

[EddieCairns]

It's just a GL4 oil.

Apart from people on here everyone just buys it off the shelf.

Stop wasting your time and buy the GL4 at the store.

End of story!

 

[aquariuscsm]

Was the Pennzoil GL4 called Gear Plus? I've seen the GL5,but didn't think they made the GL4 anymore.

 

[Keith_Stone]

AAP has the RP. Works as good as any other I've tried.

 

[aquariuscsm]

You can get Sta Lube 85W90 GL4,Nissan 75W85 GL4 at the Nissan dealer,which both are pretty cheap.

 

[aquariuscsm]

If I were to recommend one,it'd be Amsoil MTG 75W90 GL4.

 

[UrS4]

I got VAG G 052911A2 in my 6speed manual. It shifts very smooth at any temp, or at least down to -20 deg.C. I guess it will be OK at -35 deg.C also- but the transmission won't stay that cold for long anyway

The G 052911A2 is relabelled castrol syntrans transaxle 75W-90 GL4+ (former TAF-X)

That oem fluid is very expensive and the castrol labeled version is a fair bit cheaper but still expensive. Last time I checked the price of the syntrans transaxle it was about 12€/L

Motul also makes some good stuff, Gear 300 75W-90 GL4+. I haven't tried the motul product but according to a lot of user reviews it is way better than Redline MT90


Cheers

 

[expat]

Some MTL's like Pennzoil Synchromesh are yellow metal compatible.
I have been very happy with it in my Triumph.

 

[MolaKule]

Originally Posted By: Keith_Stone
AAP has the RP. Works as good as any other I've tried.


But the RP may be too low a viscosity lube at 7.5 cSt@100C.

Most of these older transmissions require a 75W90 with a GL-4 protection rating.

And since the OP lives in Arizona, I would not go with a low viscosity MTL.

 

[mrgrim]

To answer your question: if it meets the transmission's specifications and money isn't an issue, I'd go with the Redline.

I must disclose that I have no experience with that product though — I've only tried Stalube (85w90 GL4) and Napa-brand gear oil (80w85w90 GL3/4/5) with success and by success I mean the transmission didn't blow up in the 60k miles they were both used.

 

[Keith_Stone]

Originally Posted By: MolaKule
Originally Posted By: Keith_Stone
AAP has the RP. Works as good as any other I've tried.


But the RP may be too low a viscosity lube at 7.5 cSt@100C.

Most of these older transmissions require a 75W90 with a GL-4 protection rating.

And since the OP lives in Arizona, I would not go with a low viscosity MTL.

Thanks for the updated info MK.

 

[Olas]

Redline MT90 is probably easier to get where you are, but if you want the very best, lowest friction, highest protection you can get from a GL4, you need to look at Millers.

Links here;

http://www.opieoils.co.uk/p-60230-miller...ission-oil.aspx

or

http://www.opieoils.co.uk/p-74217-miller...ission-oil.aspx

both absolutely fantastic gear oils - use with confidence

 

[My442]

Sta Lube makes an excellent GL-4 gear lube.

Amazon sells it in gallons.

Nothing works better in my 70 442 with a Muncie M21.

 

[Doug Hillary]

Hi,
UrS4 - I have had considerable user (some millions of kms) and development experience with Castrol's driveline lubricants. Many were developed in Germany and all Syntrans/Syntrax/ATF are excellent products

Pay the extra and get Syntrans Transaxle as you note!

 

[SuzukiGoat]

If you're just worried about yellow metals safeness...which I feel you are... check the backs of Coastal and Supertech gl5.

100% yellow metals safe.

I only run coastal in my transfer case

 

[SOHCman]

Excellent shifting from MT-90 in both my f250 and toyota pickup, i'm sure the amsoil MTG is also an excellent product but I have not used it yet.