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-   -   Tranny fluid (http://www.wranglerforum.com/f210/tranny-fluid-230400.html)

Melvin 03-26-2013 12:49 AM

Tranny fluid
 
I have a 98 tj with a 5 spd. What transmission fluid should I be running?

Dextreme 03-26-2013 01:06 AM

Redline MT90 is great to use in the AX5 and AX15.

Melvin 03-26-2013 01:57 AM

Will 80 90 work? Regular gear oil?

All Terrain JK 03-26-2013 06:32 AM

Quote:

Originally Posted by Melvin (Post 3553433)
Will 80 90 work? Regular gear oil?

Do not run any gearlube with a GL5 rating. GL3&4 are ok.
1st choice Redline MT90
2nd A good synthetic 10w30
3rd 75w90 GL3 or 4
http://www.wranglerforum.com/f5/ax15-fluid-156196.html

Melvin 03-26-2013 02:36 PM

At the parts store all I am seeing is "meets or exceeds gl4 and gl5"

Jerry Bransford 03-26-2013 02:50 PM

Very rarely will any gear lube with a GL-5 rating be the right stuff for the AX-5 or AX-15. Most GL-5 gear lubes have a sulphur-based additive that is harsh on the synchronizers inside a manual transmission. I'd go with the above recommendation for Redline MT-90 which is a pure synthetic GL-4 75W-90.

Not to mention an 80W-90 viscosity would make shifting tougher in very cold weather, the factory specified viscosity is a 75W-90. Not to mention synthetic gear lubes also do better inside manual transmissions in extreme cold conditions.

NC Bear 03-26-2013 02:59 PM

I put in Penzoil Syncromesh after the recommendation from ALL of the guys at 4WD in Raleigh. I noticed an immediate improvement in shifting. Even at 26* I shift into 2nd like a hot knife through butter.

Jerry Bransford 03-26-2013 04:29 PM

Quote:

Originally Posted by NC Bear (Post 3555456)
I put in Penzoil Syncromesh after the recommendation from ALL of the guys at 4WD in Raleigh. I noticed an immediate improvement in shifting. Even at 26* I shift into 2nd like a hot knife through butter.

Pennzoil Synchromesh doesn't meet the specifications for the AX-15 used in '99 and older TJs with the 4.0L engine like the OP has. Pennzoil Synchromesh should only be used in the NV1500 behind the 2.4L, NV3550 behind the 2000 and newer 4.0L, or NGS370 6-speed. And not everyone reports such great results with Pennzoil Synchromesh which is a conventional (non-synthetic) gear lube.

Melvin 03-26-2013 05:49 PM

None of the parts stores around have such a thing. 4wheel parts which is a local shop has no clue. Figured they would know something about jeeps.

Melvin 03-26-2013 05:50 PM

The lucas synthetic says meets and exceeds gl4 and gl5. Is lucas something I can use?

Jerry Bransford 03-26-2013 06:09 PM

Quote:

Originally Posted by Melvin (Post 3556055)
The lucas synthetic says meets and exceeds gl4 and gl5. Is lucas something I can use?

No, why not just go with the Redline MT-90 recommended three times above?

Lucas' gear lube wouldn't be the right choice because it has the bad sulphur-based additives that make it a GL-5 mentioned in my above post #6. Those sulphur-based additives that make it a superb axle/differential GL-5 lubricant also make it a bad lubricant for manual transmissions due to how the sulphur attacks the yellow-metal (like brass) gear synchronizers.

There are some (!) GL-5 gear lubes that are safe for use in a manual transmission but they don't derive their GL-5 traits from sulphur-based additives. Those rare GL-5 gear lubes that are safe for use in a manual transmission will say 'Safe for yellow metals' somewhere on their back label.

Melvin 03-26-2013 06:33 PM

Quote:

Originally Posted by Jerry Bransford (Post 3556114)
No, why not just go with the Redline MT-90 recommended three times above?

Lucas' gear lube wouldn't be the right choice because it has the bad sulphur-based additives that make it a GL-5 mentioned in my above post #6. Those sulphur-based additives that make it a superb axle/differential GL-5 lubricant also make it a bad lubricant for manual transmissions due to how the sulphur attacks the yellow-metal (like brass) gear synchronizers.

There are some (!) GL-5 gear lubes that are safe for use in a manual transmission but they don't derive their GL-5 traits from sulphur-based additives. Those rare GL-5 gear lubes that are safe for use in a manual transmission will say 'Safe for yellow metals' somewhere on their back label.


The parts stores dont have the MT 90. haha I understand what you are saying. I just got off the phone with a guy at a 4 wheel drive store telling me to run that lucas. Thats why I asked.

Jerry Bransford 03-26-2013 07:35 PM

You can safely run Royal Purple Max Gear 75W-90 Max Gear - High Performance Gear Oil - Royal Purple which is safe for yellow metals and gear synchronizers. You can likely find that at at least one of your local auto parts stores.

The manufacturers of your Aisin AX-15 transmission also added synthetic 10W-30 engine oil as a suitable lubricant several years ago. They did that due to the right kind of 75W-90 being so hard to find. Don't worry about the the seemingly widely varying viscosities, 75W-90 gear lube vs. 10W-30 engine oil. Engine oils and gear lubes are measured on two different viscosity scales so 10W-30 engine oil and 75W-90 gear lube are actually very similar in their actual viscosities.

So if you can't find the Royal Purple Max Gear 75W-90, you'll certainly be able to find a good synthetic 10W-30 engine oil which will work fine too.

Melvin 03-26-2013 08:39 PM

Quote:

Originally Posted by Jerry Bransford (Post 3556471)
You can safely run Royal Purple Max Gear 75W-90 Max Gear - High Performance Gear Oil - Royal Purple which is safe for yellow metals and gear synchronizers. You can likely find that at at least one of your local auto parts stores.

The manufacturers of your Aisin AX-15 transmission also added synthetic 10W-30 engine oil as a suitable lubricant several years ago. They did that due to the right kind of 75W-90 being so hard to find. Don't worry about the the seemingly widely varying viscosities, 75W-90 gear lube vs. 10W-30 engine oil. Engine oils and gear lubes are measured on two different viscosity scales so 10W-30 engine oil and 75W-90 gear lube are actually very similar in their actual viscosities.

So if you can't find the Royal Purple Max Gear 75W-90, you'll certainly be able to find a good synthetic 10W-30 engine oil which will work fine too.

Thank you for your help.


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