Biotex Posted January 24, 2013 Share Posted January 24, 2013 I'm hearing/reading conflicting opinions on what is best to run. I read that GL5 is hard on the brass syncros, and that 30wt motor oil is the best etc... I went to Novaks site and here is what they recommend: Transmission Fluid The factory manuals call for 75W90 GL-3 gear oil for the AX15 transmission. It is the experience of some that a 50W fluid provides quicker shifts and especially so in colder climates. So, what do you all use/recommend, and why? I saw this thread: http://comancheclub...._hl__ax15 fluid and it answers a lot of questions, but then again leaves a lot hanging. Link to comment Share on other sites More sharing options...
mvusse Posted January 24, 2013 Share Posted January 24, 2013 When I had an AX15 (in the XJ I traded for my dd MJ) I used Mobil 1 full synthetic 10w30. Same as I use now in my AX5. Link to comment Share on other sites More sharing options...
skidoo_j Posted January 24, 2013 Share Posted January 24, 2013 I use Redline MT Link to comment Share on other sites More sharing options...
Biotex Posted January 24, 2013 Author Share Posted January 24, 2013 When I had an AX15 (in the XJ I traded for my dd MJ) I used Mobil 1 full synthetic 10w30. Same as I use now in my AX5. I like the idea of only having the engine and tranny oil the same. Once I get my front seal leak repaired, I will probably go MB1 synthetic also. :thumbsup: Link to comment Share on other sites More sharing options...
87MJTIM Posted January 24, 2013 Share Posted January 24, 2013 I just picked up my trans and Tcase from the shop that rebuilt the trans. (BA 10/5 and 231) The guy told me to use Penzoil Synthetic in the trans and 5/30 in the tcase. But the prior link said not to use Penzoil?!?! Should I just use the 75/90? For the tcase, he said that ATF will foam up while driving and could blow out the vent tube. He said 5/30 will not foam the same way. I ask for your $0.02 (US and CA $) Link to comment Share on other sites More sharing options...
jimoshel Posted January 24, 2013 Share Posted January 24, 2013 Fluid?? You're supposed to put fluid in them? Link to comment Share on other sites More sharing options...
Biotex Posted January 24, 2013 Author Share Posted January 24, 2013 I just picked up my trans and Tcase from the shop that rebuilt the trans. (BA 10/5 and 231) The guy told me to use Penzoil Synthetic in the trans and 5/30 in the tcase. But the prior link said not to use Penzoil?!?! Should I just use the 75/90? For the tcase, he said that ATF will foam up while driving and could blow out the vent tube. He said 5/30 will not foam the same way. I ask for your $0.02 (US and CA $) It's real hard for me to go against someone like Novaks. They have a lot of experience with trannys and cases. I'm thinking the 50W is the way to go at this point, but I started the thread to get other opinions, so I'm still open minded as to what works best from real world experience. Link to comment Share on other sites More sharing options...
NotMatt Posted January 25, 2013 Share Posted January 25, 2013 GM Synchromesh. Gear oil and others are hard on brass synchros, and cause notchy shifting in my experience. Link to comment Share on other sites More sharing options...
flint54 Posted January 25, 2013 Share Posted January 25, 2013 I switched to Redline MT recently and the improvement was dramatic. Much somother shifting. Link to comment Share on other sites More sharing options...
Biotex Posted January 25, 2013 Author Share Posted January 25, 2013 I switched to Redline MT recently and the improvement was dramatic. Much somother shifting. Not familiar with Redline MT. Is that a 90W? Being in Florida, i'd think that to be ok, but what about in freezing climates? Too thick? Link to comment Share on other sites More sharing options...
mvusse Posted January 25, 2013 Share Posted January 25, 2013 I just picked up my trans and Tcase from the shop that rebuilt the trans. (BA 10/5 and 231) The guy told me to use Penzoil Synthetic in the trans and 5/30 in the tcase. But the prior link said not to use Penzoil?!?! Should I just use the 75/90? For the tcase, he said that ATF will foam up while driving and could blow out the vent tube. He said 5/30 will not foam the same way. I ask for your $0.02 (US and CA $) Jeep says use ATF in 231, Jeep says use ATF in 242, GM says use ATF in 241, and I have NEVER in over 200,000 combined miles on those three vehicles had the fluid foam and come out the vent tube. This ranges from hard core off road to city driving to hours on end running 75 only interrupted by fuel stops. (Strasburg to Chicago 400 miles, Strasburg to Canada 400 miles, Strasburg to Daytona, Ormond or Orlando 900 miles, Strasburg to Columbus, GA 800 miles) Link to comment Share on other sites More sharing options...
Pete M Posted January 25, 2013 Share Posted January 25, 2013 I'm hearing/reading conflicting opinions on what is best to run. I read that GL5 is hard on the brass syncros, and that 30wt motor oil is the best etc... I went to Novaks site and here is what they recommend: Transmission Fluid The factory manuals call for 75W90 GL-3 gear oil for the AX15 transmission. It is the experience of some that a 50W fluid provides quicker shifts and especially so in colder climates. So, what do you all use/recommend, and why? I saw this thread: http://comancheclub...._hl__ax15 fluid and it answers a lot of questions, but then again leaves a lot hanging. the official Mopar replacement for use in AX-15s is synthetic 10W-30 oil. :thumbsup: Link to comment Share on other sites More sharing options...
Comanche County Posted January 25, 2013 Share Posted January 25, 2013 the official Mopar replacement for use in AX-15s is synthetic 10W-30 oil. :thumbsup: I've been using 10W-30 in my AX15 for 4 years now. I've probably put 30K on it and it still shifts like new. IIRC, that's what Chrysler recommends for the AX15. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted January 25, 2013 Share Posted January 25, 2013 For the tcase, he said that ATF will foam up while driving and could blow out the vent tube. He said 5/30 will not foam the same way. Ummm, yeah...not so! Link to comment Share on other sites More sharing options...
mountainman Posted January 25, 2013 Share Posted January 25, 2013 Gm syncromesh or redline MT90. NO motor oil in a transmission! Kthxbai. ;) Link to comment Share on other sites More sharing options...
Blue88Comanche Posted January 25, 2013 Share Posted January 25, 2013 I was going to use 10w30 in my ax15 but after I finished topping it off I noticed I grabbed 0w20.... I am eventually going to replace it with 10w30.. Link to comment Share on other sites More sharing options...
Bounty Hunter Posted January 26, 2013 Share Posted January 26, 2013 ATF in the tcase, Redline MT90 in the AX transmissions. Redline is a synthetic so the shifting is very smooth, even in cold climates. It's specially formulated to be easy on the soft brass syncros and will often times improve notchy shifting from synchros on their way south. The Redline MT90 is pricey but worth it. Link to comment Share on other sites More sharing options...
Dirteatr717 Posted January 26, 2013 Share Posted January 26, 2013 I picked up pennzoil synchromesh today, in the middle of replacing my clutch and slave cylinder, didn't put everything back together yet, I'll let you guys know how it shifts tomorrow :thumbsup: Link to comment Share on other sites More sharing options...
Garvin Posted January 27, 2013 Share Posted January 27, 2013 I use ATF in the transfer case and 75W90 in the transmission. The transmission has close to 200k on it and still shifts as smooth as new, even behind a 300hp Chevy 350 for the last 10-15k miles. Link to comment Share on other sites More sharing options...
Bonzii Posted February 13, 2022 Share Posted February 13, 2022 Mine has Royal Purple synchromax in it smells horrible runs like 5w-30 my books don't say anything about using 75- 80 regular gear lube it's too heavy. Link to comment Share on other sites More sharing options...
Bonzii Posted February 13, 2022 Share Posted February 13, 2022 I use Royal Purple in mine. But it's also a 94 Dodge Dakota Sport. V8/ 5 spd. Link to comment Share on other sites More sharing options...
MiNi Beast Posted February 14, 2022 Share Posted February 14, 2022 Gotz gear lube in mine and it is a stiff sob. Gotta replace that here soon, being i gots the Mileage in to clean it out. Will run atf in tcase as always and ill pick-up some redline. Link to comment Share on other sites More sharing options...
PIKE Posted February 15, 2022 Share Posted February 15, 2022 You can also use this. https://www.redlineoil.com/75w90-ns-gl-5-gear-oil Link to comment Share on other sites More sharing options...
rokinn Posted February 15, 2022 Share Posted February 15, 2022 7 hours ago, PIKE said: You can also use this. https://www.redlineoil.com/75w90-ns-gl-5-gear-oil This is what I've been using too. When I went to buy it I was going to buy MT90 but the distributor asked if I would like him to look up the prescribed oil for my vehicle. After I questioned what he came up with he called the chemist at Redline and he confirmed 75w90NS. Seems to work well. Link to comment Share on other sites More sharing options...
224ftlb Posted February 16, 2022 Share Posted February 16, 2022 Are we supposed to pull the tower and add an extra quart? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now