Manual Transmission Fluid

RayOvac

New member
1050967

OK here we go....My new (well new to me) AX5 transmission should be here either today or Monday. I was just wondering what you guys think the best fluid (besides Redline (don't want to order online) to put in the new transmission would be. I know that the GL5 fluid will eat the brass synchros in the AX5 & AX15. I am thinking about using some Mobil1 Full Synthetic 75W90 GL5. Will that eat my brass synchros? Is it just the "dino" oils that do it?[addsig]
 

1050972

I´m not gonna swear, the synthetic won´t mess with the brass (don´t know for sure). But I have been in a couple of motors that have run mobile one, all there lives and I´m sold, Engine wear was minimal (I mean really good) all of the engine brass looked good. The cylinder and ring wear was really phenominal (no or hardly measurable ridge in the cylinder walls). These motors had been run at high speeds for extended periods (usually around 130,000 miles). The repairs were usually for gaskets or detonation damage, nothing to do with lubrication. I did notice one thing though, I pulled a can of mobile one off the shelf, that had been forgotten for 10 years, and noticed when pouring, it seemed to be a little better refined and a clearer color.

I have filtered mobile one through a couple of coffee filters and reused it, as a throw away after rebuilding a motor, to help get rid of the trash that invariably falls in there. And have noticed synthetic doesn´t seem to shear as much as normal oil (get thinner with useage) sure some, but not like regular oil.[addsig]
 
1050978

Check out this site:



http://www.redlineoil.com/dealers.htm



I found a dealer within three miles of me. Little Harley shop. Kinda funny, really, I just changed the fluid to

MT-90 yesterday... Took 3.5 quarts. Kinda expensive, but it fixed the problem.



Maybe this'll let you use the good stuff without ordering online...



Cooper.[addsig]
 
1050981

Thanks cooper...but the closest dealer to me is the one in Dallas, TX which is still 7-8 hours away. uugh[addsig]
 

1050995

I do remember someone saying not to use mobil 1 in the transmission... I am a fan of synchromesh fuild... i know pennzoil sells a version of it.... But its a good thing that you are taking the precaution to make sure what you put in there is right[addsig]
 
1051020

Well after some more research I have found that the mobil1 is indeed bad. However I could not hear enough good things about the GM syncromesh fluid...most guys seem to swear by it. I went ahead and bought 4 quarts of the Penn syncromesh today...at $5 a quart its much cheaper than the mobil1 stuff I was gonna buy ($8). I'll let you guys know how it turns out (arrgh...its 5:30PM and the transmission is still not here...does anyone know if UPS delivers on Sunday???)[addsig]
 
1051040

you're getting your transmission via ups? i didnt think they'd ship something that heavy, i had to have mine shipped frieght[addsig]
 

1051123

Never heard a bad thing about the Synchromesh, yet.



I use Redline MT90, it can be ordered online at www.summitracing.com or www.redlineoil.com
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1051145

Yeah Quik8slvr its UPS...the transmission is an AX5...it only weighs about 75lbs dry. UPS's limit is 100lbs I think. Now if it was an SM465 or NV4500, yeah I would have had to ship it freight cuz it would have been well over 100lbs.[addsig]
 
1051188

i use regular castrol gl5 gear oil for 1/2 of the and Lucas oil stabilizer for the other 1/2 in my transmission 91 ax5 thats the one with the 4 banger right? if so i have 158,000 on mine with no problems except a little noise in 5th gear and for my x-fer cas where it calls for atf i use the lucas auto trans fluid every thing works fine and keeps my floor boards cooler in the summer kinda miss them in the winter but you would think i have insulated floor boards instead of spray in liner hope this helps



marc

oh dont use the lucas in the engine i had a lot of trouble from when i put it in a lot i mean a lot of valve train noise took two back to back oil changes to flush it out (just my experence)[addsig]
 

1051192

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font class="pn-sub">Quote:</font><HR></TD></TR><TR><TD><FONT class="pn-sub"><BLOCKQUOTE>i use regular castrol gl5 gear oil for 1/2 of the and Lucas oil stabilizer for the other 1/2 in my transmission 91 ax5 thats the one with the 4 banger right? if so i have 158,000 on mine with no problems except a little noise in 5th gear and for my x-fer cas where it calls for atf i use the lucas auto trans fluid every thing works fine and keeps my floor boards cooler in the summer kinda miss them in the winter but you would think i have insulated floor boards instead of spray in liner hope this helps



marc

oh dont use the lucas in the engine i had a lot of trouble from when i put it in a lot i mean a lot of valve train noise took two back to back oil changes to flush it out (just my experence)</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>



Im an Amsoil fan myself. Won't use nothing but. as for Lucas... its good stuff. Never had any problems with it in an engine[addsig]
 
1051195

With the castrol gl-5.... that IS corrosive to brass... but with the stabilizer... it might be helping out... when you change again... I would suggest going to a gl-3 or non corrosive gl-4[addsig]
 
1051202

Hey Rayovac, just wondering where you got your research info. and what

you found out about that Mobil-1?



I`ve got a Trans. full of it so let me know please?
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1051227

ad5at, wouldn´t worry about it to much, took a 135,000 miles for my 2nd gear synchros to start acting up a little (GL5)(mil spec.).

The only questions, or potential problems, I´ve heard about, synthetic gear oil, is it´s long term affects on some gasket materials, not to be used in a wet clutch (like motorcycles) and some cam makers when it first came out, recommended against using it (why I don´t know), I suspect because it was unproven.

Guess there could be a potential problem in clutch type limited slips, possibly the synchronizers in the transmission, could slip a little more (you´d notice). Synthetic has been rumored to be to slick for some applications.

If a synthetic is labeled for manual transmissions, it probably has an additive (friction enhancer). Like the anti-foaming additives in Red-line.

GM makes an additive (friction enhancer) for limited slips. Wonder if they make one for syncros.

[addsig]
 
1051272

Well I checked several other forums and did many searches looking for those that had asked the same questions as myself. The mobil1 oil would be great for diffs but I have heard because it is a GL5 oil, it is indeed corrosive to the brass snychros in the AX5&AX15 and should not be used in those transmissions. So far I have found that the only fluids that are okay to use are the GL3 and GL4 rated gear oils. Napa sells a GL4 oil that some people use and the Redline is supposedly really good too. The pennzoil snychromesh is a GL3 oil and its also a good choice. If you go to the jeep dealership you can buy Mopar gear oil that is a GL3 and made specifically for the AX5&AX15. It all really depends...the GL5 is SUPPOSED to be bad for the brass synchros but I have heard of people running it for over 100,000 miles with no probs...The reason the GL5 is supposedly corrosive is it contains a sulfer additive that is necessary to meet the GL5 spec...some companies claim that their oil meets the GL5 spec without the high sulfer additive but they still may contain enough sulfer to do damage...most of the damage done is long term. Your transmission may indeed last longer if you put a GL3 or GL4 oil in it instead of a GL5 oil.



Edit: After checking out the mobil1 website, I took a look at their synthetic gear oil product sheet. Mobil1 Synthetic Gear Oil Product Sheet



It says specifically "It [Mobil1 Synthetic Gear Oil] should not be used in any transmissions requiring an engine oil or automatic transmission fluid, or GL-4 performance level."



So I guess that answers your question....Mobil1 Gear Oil should not be used in your AX5 or AX15. Mobil1 says it themselves.



[addsig]
 
1051353

Well I can`t argue with that kind of Info. That`s what makes this site so great.

There is always someone with a little more information than you.



I guess that as soon as it warms up a little, I will be changing some fluids!



Thanks a bunch for your replies guy`s.
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1051375

I´m convinced, thanx for the info, will file it away in the old gray matter for future reference. Goes to show you, when all else fails read the destructions.
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1051391

I went and picked up 2 quarts of gl-4 and 2 quarts of synchromesh yesterday... 5 bucks each for synchromesh... and 2.79 each for the gl-4... not bad[addsig]
 
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