Hey guys,

I just bought 4 quarts of Redline MT90 75W 90 synthetic oil for my transmission,and rear axle.The problem I am having now is the sticker under the hood calls for GL-5 fluid for the rear axle,and the bottle of MT90 does not recommend using it in a rear axle that requires a GL-5 oil.What do you guys think about this?Also do you guys think 4 quarts are enough for the tranny,and rear axle?I will buy more if need be,but I may have to buy something else for the axle anyway.any help on this subject would be appreciated.

Chris
5/78 GS
83 LE parts car
74 RE/PU
92 Ram D250 Cummins diesel "for sale"
03 Ram 1500 2wd quad cab Hemi

 

Hello,
The reason it says this is because the rear end needs extreme pressure (EP) hypoid gear oil (also known as GL-5). You can use the MT-90 in your transmission (thats what its used for, notice the MT part), but you will need to use some 75W-90 for the diff I recommend using the redline 75W-90 (its different than the MT-90). The oil capacities for the transmission and differential are both about 2 litres.

I hope that was of some help!
Dan_s_young

 

Transmission requires 2qt almost exactly, and RedLine MT-90 is exactly what I'm running there.

For the rear end (it takes about 1.5qt, but you can't buy half-qt bottles), I have a non-LSD rear end and I'm running just a generic 75W90 Synthetic Gear Oil.

I'd return 2 qt of your RedLine (since it's bloody expensive) and go pick up some generic synthetic gear oil. Since you have a GS, you have the same rear end as I do (unless you swapped to one with discs and LSD, then you have to find an oil that will work with that type of rear end). Just your generic parts store's 75w90 is good.

Jon

 

By the way, just to get a little off topic, do you have the wheels from your '83LE parts car? Are you using them? Would you consider selling 'em?

Jon

 

Thanks for all the help guys.I figured out I have 6 quarts of Amsoil 75W 90 synthetic gear oil that I bought for my diesel a few years back,and never have gotten around to using it.It is rated as a GL-5 approved oil,so I think i am going to use that stuff,and the MT-90 for the tranny.I think I will keep the extra quarts of the Redline for future use though,as I plan on having this car for a long time.

Hey Vipernicus,I do have the LE wheels still,and actually I have an extra set.I just had a set of Falken Azenis 615's mounted on the better of the 2 sets,and I have yet to make up my mind on what I am going to do with the set that is on my LE now.I may sell them,or maybe refinish them,and have as a spare auto-x setup.I will let you guys know if I decide to sell them.

Chris

 

holy poop is it hard to find this stuff anywhere in Minnesota! I did some searching and found the site jscspeed.com which seems to have the best prices compared to what I have found so far. Has anybody done business with them before?

 

I can get Redline or Royal Purple at the local speed/circle track/truck shop.

 

Redline is HQ'd in Benecia,not far from me.
Around here you can just about get Redline at any gas station..........its not any cheaper though!!!
Great stuff,as mentioned.....MT90 in the tranny and 75-90W in the rearend.Ive run it in all my vehicles for years and Ive not had a drivetrain related failure yet,even in my rock crawler.