eric.toupin Posted March 9, 2013 Share Posted March 9, 2013 Hi All, I installed a clutch kit, new master cylinder and new hydraulic lines a few weeks ago in my 1990 Jeep Comanche 2.5L. The clutch had frozen on me (all fluid drained out of a busted slave) while highway driving. I had to force it into a couple gears to get home (drove in third a lot of the way). That was before I knew what the problem was. With help from this forum and elsewhere, I figured out it was the slave and made the installs listed above. All fixed. Mostly. So now the transition between first and second, and to a lesser degree second to third, are a little rough. Already bled the clutch, and it seems to be disengaging fully. The symptoms are worse in cold weather (FL, so 60's is cold.) And they alleviate a lot once the truck is warmed up. Down shifting is considerably more rough. It's not terrible now, just to the point where I can feel some very soft grinding sometimes -- not audible yet. Very drivable, but will need to get fixed sometime. So anyway I think the transmission is either naturally beginning to fail, or my episode driving with a failing clutch broke it or took it over the edge. From what I can find online, I'm thinking maybe the synchros or whatever they're called are failing. So enough backstory -- the question is does anyone have experience with transmission rebuild kits? And AX5 rebuilds in specific? Could this fix the problem? How long does it take? After just doing the clutch kit, I feel like I can pull / replace the transmission pretty easily, but have no idea what to expect from the rebuild itself. Any experience or tips would be really appreciated. Thanks much, Link to comment Share on other sites More sharing options...
dasbulliwagen Posted March 9, 2013 Share Posted March 9, 2013 Did you put new oil in the trans while doing the clutch? I once changed the oil in my Hyundai Accents manual trans with full synth 75W145 and noticed problems like you are describing due to the heavier oil, especially in colder weather.... though when I say cold, it was winter in Michigan. It would shift hard and sometimes grind like you are describing.... until it got warm, then it was fine. Are you thinking of rebuilding it yourself? Its not a job for a novice. You may be better off outsourcing something that in depth. Good luck, and let us know what you end up doing. Link to comment Share on other sites More sharing options...
mvusse Posted March 9, 2013 Share Posted March 9, 2013 I combined a partly good AX4 with a partly good AX5 to make one mostly good AX5. They are not overly complex transmissions. Make sure you have a manual that covers the transmission rebuild, good set of tools and a lot of clean workspace to keep stuff organized to help you get everything back together in the correct order. I used a 4x8 worktable with a melamine covered fiberboard top. Two main problems I had: Snap rings. Lots of snap rings. And not ones with the eyelets that would have made removal easier. Older style AX5 use a crimped nut to hold 5th gear on the shaft. That nut is a royal PIA, worse than the snap rings. 94 or so and newer are a lot easier to work with. Link to comment Share on other sites More sharing options...
eric.toupin Posted March 9, 2013 Author Share Posted March 9, 2013 Thanks for the replies. I replaced my transmission fluid with new 75W90. Is there a thinner oil that would work better? There was definitely not this sort of soft grinding before the original clutch issue, so that's something I guess. Yes, I am a novice. Installation of the clutch kit, master and new lines is the only real mechanical work I've ever done on a car / truck. That seemed mechanically simple, although messy, time consuming and a general pain. Is rebuilding it myself unrealistic? I feel like with a detailed manual I'd be ok, but of course don't know because I've never tried. How long might this take? It seems like if I could just buy a rebuilt AX5 for $750 that might be cheaper than the $100 - $150 an hour I'd pay a mechanic to rebuild it. But really I'm more interested in learning how to do it myself. My AX5 is older. So yes, probably the crimped nut PIA. Link to comment Share on other sites More sharing options...
Geonovast Posted March 9, 2013 Share Posted March 9, 2013 Rebuilding the trans requires a good gear puller, a hydraulic press, and lots of patience. There are many small, oddly shaped parts that can get easily broken if installed incorrectly, or get lost. If you decide to rebuild it yourself, it would be a very good idea to get ahold of an already dead AX-4/5 and just play with the guts for awhile first. Several years ago I was able to convert an AX-4 into an AX-5 just by using a bucket of parts... but I didn't pull any of the gears or pressed bearings off of the output shaft. I don't remember which it is, but there's a type of fluid that eats up the synchros in an AX-5 because of an additive. Link to comment Share on other sites More sharing options...
mvusse Posted March 9, 2013 Share Posted March 9, 2013 Thanks for the replies. I replaced my transmission fluid with new 75W90. Is there a thinner oil that would work better? There was definitely not this sort of soft grinding before the original clutch issue, so that's something I guess. Yes, I am a novice. Installation of the clutch kit, master and new lines is the only real mechanical work I've ever done on a car / truck. That seemed mechanically simple, although messy, time consuming and a general pain. Is rebuilding it myself unrealistic? I feel like with a detailed manual I'd be ok, but of course don't know because I've never tried. How long might this take? It seems like if I could just buy a rebuilt AX5 for $750 that might be cheaper than the $100 - $150 an hour I'd pay a mechanic to rebuild it. But really I'm more interested in learning how to do it myself. My AX5 is older. So yes, probably the crimped nut PIA. The AX5 is really not all that complicated. Just take your time. It can be done in a few hours (after it's been taken out of the vehicle), but taking your time and counting for unforeseen circumstances assume one day to take it apart, one day to put it together and one day for getting things you didn't think of. As for oil, GL5 will eat up the brass syncros. Even GL4 is not great for brass. Either find a GL3 gear oil, or use 10W30 synthetic motor oil. Link to comment Share on other sites More sharing options...
mvusse Posted March 9, 2013 Share Posted March 9, 2013 Rebuilding the trans requires a good gear puller, a hydraulic press, and lots of patience. There are many small, oddly shaped parts that can get easily broken if installed incorrectly, or get lost. If you decide to rebuild it yourself, it would be a very good idea to get ahold of an already dead AX-4/5 and just play with the guts for awhile first. Several years ago I was able to convert an AX-4 into an AX-5 just by using a bucket of parts... but I didn't pull any of the gears or pressed bearings off of the output shaft. I don't remember which it is, but there's a type of fluid that eats up the synchros in an AX-5 because of an additive. I don't have and didn't use a hydraulic press. Did use a gear puller, though. Link to comment Share on other sites More sharing options...
Geonovast Posted March 9, 2013 Share Posted March 9, 2013 I don't have and didn't use a hydraulic press. Did use a gear puller, though. What did you use to get the bearings and hubs back on? I never pulled mine off, but I was under the impression that a press was needed to get them back on. Link to comment Share on other sites More sharing options...
mvusse Posted March 9, 2013 Share Posted March 9, 2013 Can't remember any more, I did this almost a year ago. But I know I didn't use a press because I don't have one. And I did have the shafts apart all the way down to 1st gear and reverse. Link to comment Share on other sites More sharing options...
eric.toupin Posted March 9, 2013 Author Share Posted March 9, 2013 Thanks for all the replies. I'll need to take a look at grabbing a gear puller / press. Mvusse, you mentioned not using GL5. I just checked and mine is GL5. It's been in the transmission for about a week now, I guess. How bad is that? I can probably change to 10W30 Synthetic motor oil tomorrow. Thanks, Link to comment Share on other sites More sharing options...
mvusse Posted March 9, 2013 Share Posted March 9, 2013 The sulphur in the GL5 will eat the brass. The longer it is in there, the worse it gets. As for how fast it happens, I have no idea. Link to comment Share on other sites More sharing options...
dasbulliwagen Posted March 10, 2013 Share Posted March 10, 2013 One week of that being in there isnt going to hurt anything. The sulfer damage is cumulative, over time... it wold take a bunch of years to cause any real damage. Change it and see what happens before you tear this thing apart. Link to comment Share on other sites More sharing options...
64 Cheyenne Posted March 10, 2013 Share Posted March 10, 2013 :agree: with the 10-30 synthetic first. Link to comment Share on other sites More sharing options...
Eagle Posted March 10, 2013 Share Posted March 10, 2013 I would try the Pennszoil Synchromesh transmission fluid. I have heard good reports on how it performs in the Jeep transmissions, even though it wasn't formulated specifically for them. Link to comment Share on other sites More sharing options...
mjeff87 Posted March 11, 2013 Share Posted March 11, 2013 I just did a switch on my AX5 in my TJ @172K. Was running Mobil 1 synthetic since 80K and swapped in Redline MT90. Shifts like butter now. Ordered it thru a local speed shop, next-day delivery at $12.99 a quart. Jeff Link to comment Share on other sites More sharing options...
eric.toupin Posted March 20, 2013 Author Share Posted March 20, 2013 Hi all -- just following up: I wasn't able to get ahold of synchromesh or redline at any location near me. I swapped to 10W30 Mobile 1 full synthetic engine oil. There's a significant improvement, much worth the change, not a miracle. Shifting isn't "buttery" but I'm able to shift from first to second and second to third, at reasonable rpms, with no grabbing or the soft grinding I was experiencing. Certainly long-term drivable. Before the switch, I could not downshift hardly at all from third to second, unless the vehicle was basically at a standstill. That, too, has improved -- to the point where I can engine brake using 1st or 2nd with a smooth shift. It still soft-grinds if I try to shift from speeds of above 25 or so into first or second. 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