I recently bought a 94 cherokee 4.0, Went to get it inspected and tagged today and it is appartent that there are transmission issues lol. I can shift into 1st fine and 1st to 2nd but grinds through 3rd and 4th gear sometimes in 5th. Can not down shift from any gear with out grinding even with rev matching. Im pretty sure that it is not the clutch itself because 1st and 2nd gear work fine. I have also noticed that if i start the jeep and attempt to put it in 1st without the clutch it hits a detent if you will and won' go any further but if i try the same thing with 3rd and 4th it hits the gear immediately and grinds. So im thinking its the synchros going bad/ crapped out already. Also it doesnt grind as badly if i double clutch. Is my assumption correct from ya'lls knowledge? if so i have looked at a few rebuild kits but not sure the difference. Thanks in advance for any and all help

 

I am in the same spot. My synchros were going bad when I got mine, and now a few years later it wont even stay in 1st. Rebuild kits that I have found complete are in the $250 and up range, junkyards want $600 for one and a local rebuilder wants $650. By the time I buy a gear puller I need and then the rebuild kit i'm atleast $350 plus into it with no kind of warranty...

 

I've found kits on eBay for 180ish but they come with synchro rings. Idk if they will work or if I need the entire synchro. I have all the common hand tools but no gear puller nor bearing press. I've been quoted 400 + tax just for labor so I'm not sure lol. I'm so confused on the rebuild kits still.

 

Yeah you'll need a press and a few other uncommon things to rebuild it. If you can afford the downtime you may be able to find a press for rent.

You sure there's fluid in that thing? My first change had basically WD-40 come out...

Does it shift fine when you're sitting still with the clutch all the way? Just to rule that out

 

I'm gonna drain and fill it this weekend. Its not my dd so I can afford the down time. What fluid does it take? 75w90, 10w40, or what? I just need something cheap the first time to see if it fixes it and if it does I'll buy good fluid.

 

I'm not 100% sure but I think it does it while sitting still also in 3rd and 4th

 

75w90 API GL-3 or GL-4 is the real spec. 75w90 GL-5 can be used in a pinch but long term use will cause (further) damage to the synchronizers. 5w30 or 10w30 can also be used if you're in a tight spot.

If you save your transmission the best fluid you can run is Redline MT-90, Pennzoil Synchromesh, or Royal Purple Synchromax. The fluid spec for the AX-15 I guess is no longer trendy so we're left with specialty oils, but they really do work great

If you get grinding while sitting still and the clutch pedal down, your clutch isn't releasing all the way. It should shift the same as if the engine was off.

 

The $180 ish ones may be all you need but they aren't complete rebuild kits thats bearing and syncs and a couple of seals if I recall correctly. I am at the point of do I buy these tools I will only need once, or do I pay for someone else to do it. I am a mechanic by trade, but never need many gear pullers etc... I know a lot of manual trans rebuilders want only motor oil in these trans's... like 20w50 or 10w40 etc

 

My shifted terrible when I bought it. Went with Royal Purple and have been driving it fine for three years since. Doesn't even grind reverse anymore.

 

I use redline in mine look it up the ax-15 loves that stuff

 

I'll look for royal purple next time I head to the parts house. I'm a mechanic also with the air force but I work on planes and they supply all our tools. I've also bleed the clutch system thinking that was the problems. Manually pumped the slave and also bled through the bleeder. It had s new mc and slave. If I pull the trans I will prob put a new clutch in it. It sounds like the throw out bearing is starting to give out. This jeep was neglected service wise.

 

And by neglected I mean water in the steering system, brake fluid looked like motor oil, same with the clutch. I haven't had time to check diff fluids, transfer case, or anything else.

 

What, you didn't think it stood for "Just Expect Everything Pristine", did you? These things run so well nobody seems to bother with maintenance...

 

True, everyone I know beats there jeep harder than anything.

 

Is this the oil you used ?
Or this?
After reading the reviews i'm leaning towards the redline fluid for the trans. Sounds like some good stuff.