I am doing a transmission service and putting a new clutch, throw out bearing, and rear main in my uncles 93 Jeep yj 2.5 4cyl, and I was curious when I fill the transmission back up with fluid is it ok to use 75w-90 full synthetic gear oil in it?
Can you put full Synthetic 75W-90 gear oil in a AX-5 manual transmission?
- Thread starter Tzerambo
- Start date
Only if it says 'Safe for yellow metals' or words to that effect on the back label. Some GL-5 gears lubes can but most can't. I don't know if that one is safe for yellow metals (transmission gear synchronizers) or not.
Personally I'd run Redline MT-90 which is a GL-4 75W-90 in your AX-5 transmission.
Personally I'd run Redline MT-90 which is a GL-4 75W-90 in your AX-5 transmission.
Last edited:
Would this be ok to run?
Ok I am using a Napa store right now for parts and I will see if they have something similar to that because I don’t want to use the wrong oil.
Also is it ok to run Napa atf +4 in the transfer case the guys at Napa say it’s just Valvoline with a Napa sticker on it.
Absolutely that'd be a great choice. Actually any good quality ATF is fine for the transfer case.
Ok good and I think my Walmart might have some of that redline in stock but it is expensive at almost 20 dollars a quart.
What is something that I can use that is readily available in most auto parts stores in stock because I am putting my transmission back in tomorrow and I need to oil tomorrow
I’m running pennzoil synchromesh in my 04. Got it at Napa. Hasn’t blown up yet and actually shifts a lot smoother. This was before I learned of this forum and redline MTL. I’ll be switching to that if I ever have a need to change the fluid I put in it.
That'd be my last choice, the full synthetic Redline MT-90 would be a much better choice.
Not many like how the AX-5 or AX-15 transmissions shift after being filled with Pennzoil or GM (the same product) Synchromesh, especially in cold conditions where a conventional transmission gear lube doesn't work as well. Technically it meets the minimum specs of the AX-5 & AX-15 transmissions but that's it.
Well I was wrong my local Walmart doesn’t have any redline in stock other wise I would go pick some up and the only thing that would work in my area that anyone has is the pennzoil synchromesh manual transmission fluid. I might just have to run that untill I can get some redline ordered.
My local Advanced Auto was able to order the Red line mt90 for me and have it in about 3 hrs. later. Sometimes it doesn't hurt to ask.
Yeah I can but the problem is my uncle who I’m fixing his old yj for has an account at Napa and I can just go over there and tell them what parts I need and put it on the account but if I go to another store which would be easy to do I’d have to go get cash from him which is a pain because I work on his Jeep usually while he’s a work.
I was not really talking about a specific store so much as saying you might ask your parts store if they could get it for you.
Yendra Built
Member
I used the Pennzoil Sycromesh in my 05 six speed and it really shifts smooth, Advance had it in stock.
If you're in a pinch and are worried about using the wrong oil for your transmission, I've been running full synthetic 10W30 for about 12k miles no problem in my AX15, which my understanding is an Aisin-approved lubricant. I'll likely go with Redline for my next change, but I found water in it the day before a trip and didn't have time to go hunting.