AX-15 issues

[XJNick]

Hi,

My '97 TJ's transmission developes an interesting problem. When I drive it and the engine is cold, everything is smooth and fine.

However, after about 12-15 minutes of continuous driving, second gear will try to grind when I upshift into it (but not during down-shifting). It appears this occurs when the transmission is hot and it becomes worse the longer I drive it. Also, no other gears are affected (although reverse is sometimes hard to get out of when the transmission is hot).

My guess is I have a fluid issue?, especially since the transmission seems to be getting hotter than it should. However, I can't get the **** fill plug to budge. Anyone know what size the AX-15 plug is? I've tried a 15/16" socket, but it was a tad to big, I'm guessing it is a metric size (or is mine just stripped out)?

Thanks for any ideas :mrgreen:
-Nick :!:

 

[Snitty]

you're singing the brass synchro blues... i'd get some pennzoil synchromesh in there as soon as possible... it is going to start happening to your other gears soon if not.... if you are too late, you should start looking for a new transmission.... but lets hope that GOOD fluid will help

 

[Bounty__Hunter]

Redline MT90 is a good choice too. Sounds like bad synchros, and it can be saved yet by switching to the right fluid.

The Jeep owner's manuals incorrectly recommend GL5 rated gear oil for the Aisin Warner AX5 and AX15. The GL5 is high in sulfer, which is very corrosive to the soft brass synchronizers in these trannies. Use a GL3 or a specially formulated GL4 like the Redline which is easy on the soft metals.

 

[XJNick]

I changed the Transmission fluid to syncromesh today. My second gear problem seems to have gone away, but driving in rush hour traffic next week will tell...

I still don't understand why the problem would only occur when up-shifting into second??

Thanks :mrgreen:
-Nick :!:

 

[Bounty__Hunter]

Aren't there different synchros for each gear? Just so happens the synchros for 2nd are the first to go south for you.

 

[Bounty__Hunter]

How'd the fluid look when you drained it? Any glitter? Usually the brass filings look like glitter in the gear oil, at least on trannies further along than yours.

 

[Snitty]

the most common shift made in most transmissions is the 1st to 2nd shift... you do it mostly every time you start out... and with corrosive fluid, that is what takes toll

 

[XJNick]

Sorry, I guess i'm not being clear. What I was asking was how come it wouldn't ever grind while down shifting from 3rd to 2nd. Instead the problem only occured from 1st to 2nd (upshifting). I thought the syncronizers have an effect on downshifting as well?

The fluid was actually changed by a shop, as the fill plug stripped out and I was unable to remove it. They ran a test on the old fluid and said that there were some metal shavings found. I'm going to be optimistic that the syncromesh has solved the problem... or at least prevented it from becoming worse. The shop of course wanted to put gear oil back in there, but I insisted on the Pennzoil syncromesh, and that's what I got 8).

-Nick :!:

 

[BostonJeep]

just make sure you keep your cell phone charged for next couple of trips :twisted:

 

[Snitty]

good boy on being firm with the shop... the only thing i can think of with the downshift thing would be that you may have been downshifting at the right speed, where the synchros really don't even affect the shift