Transmission noise

[ekulrenlig]

My 87 Comanche 4cyl, 5sp, 4wd, has a rattling/chattering noise coming from, or around, the transmission when the truck is running. When I push in the clutch pedal the noise quickly fades and stops. As far as I can tell it makes this noise in all gears and seems to get a little louder with increase in speed. Any idea what this could be? I had a new clutch kit put into it, but that didn't help. Please help!

[Oizarod115]

is that the AX-5 or the BA-10/5?

does it happen while idling in nuetral as well?

[ekulrenlig]

I'm not sure, I think it is the AX5. Is there an easy way to identify it? Yes, it does this in neutral as well, but fades away when the clutch is pushed in.

[Oizarod115]

are you near the truck now?

the BA10 has a split that runs straight down the middle of the case in line with the rear shaft, and also has a round fill plug with a square hole for some tool in it.

 

I'm pretty sure the AX5s came behind the engine you're referring to but its good to know.

 

 

my truck has a similar noise but its a whining/squealing that acts the same way, all gears and nuetral only fading when the clutch is pushed in.

 

what caused mine was low fluid, it never did it til i ran it out of fluid (DOH!) for a couple months (DOH!!!!!!!!) so id say check the fluid.

 

EDIT: now that i refilled it it still makes the noise though, i think i fubared something by running it empty. so check it sooner rather than later

[Pete M]

Should be an AX-5. I'm guessing it's the throwout bearing making the noise?

[ekulrenlig]

Yes, I believe it is the AX5. It has an 8 digit serial number code on the bottom, which I believe is true for the AX5 and AX4. It also has the intermediate plate in the center of the transmission (perpendicular to shaft). It does not split in middle, parallel to shaft.

 

I will have to check the fluid level, that would be a relief if that is the problem. How long have you gone on yours with that noise?

 

Pete - I thought it was the throwout bearing as well, but I just put a new clutch kit into it, including the t/o bearing, and it still makes the noise.

[Pete M]

Did you replace the pilot bearing too?

[87manche]

x2 on the piloat bearing/bushing.

Especially since a bad one of those will leave the shaft unsupported and eat an input bearing too.

[ekulrenlig]

Pilot bearing eh? I had a mechanic put in the clutch kit. You'd think he would have at least checked that if not replaced it, don't you think? On the box of the kit it said it included the "pilot bearing (where applicable)" whatever that means.

So what does the pilot bearing, and why would it cause a noise like this? How long before other problems start happening? Thanks

[JOMJ87]

Most mechanics only do what you tell them to do usally for example one of my comrads took his car to the mechanic because it clicked when he turned and the CV axle BOOT was ripped so he told the mechanic to chack the boot and metioned it was clicking. After $250 and the clicking returning :mad: :headpop: he took it somewhere else and the guy had only changed the boot not the axle which was already destroyed. Lesson to be learned is make sure of what work was REALLY done. :cheers:

 

Cole

[Hot Rod Jeep]

Definetly sounds like a throw out bearing to me. I knew a guy who went thru like 3 or 4 clutch kits before he got a good throw out bearing. Quality control has really gone down hill. 8)

[ekulrenlig]

Yes, the pilot bearing was replaced with the clutch kit. I've also determined the noise does not occur in 4th gear. Any other ideas as to what this might be?

[JOMJ87]

In my AX4 that was original to the MJ I somehow exploded the input shaft :roll: And it would make horid noises in 1-3 but in forth it didnt 1st was the worst gear it barely moved to. I don't know if this helps but i know it clanked and chattered but it sounds like your issue. BUT i had about a 1/3 of the teeth ripped of the input shaft maybe if its just chipped or something. :dunno:

 

Cole

[aemsee]

You have an internal trans problem that will require rebuild or replacement. In the trans 4th gear is the one closest the the bellhousing, attatched to the input shaft. All your power goes in throught the input/ fourth gear and down to the counter shaft. Then depending which gear you are in it travels back to the main shaft through that gear set and out the out put shaft. During all this the input shaft and the rest of the main shaft are spinning at different speeds, with a bearing btwn the input/4th gear and the rest of the main shaft allowing this, BUT, when you shift in to 4th gear, you are locking input/4th gear shaft to the rest of the main shaft, bypassing the counter shaft, giving you the 1 to 1 ratio of 4th gear (hence "direct drive").

Now, the counter shaft is still meshing with the main shaft and spinning, but no "power" is going through it. I am guessing that you either have a bad bearing btwn the input and main shafts, or a bad counter shaft bearing. .my 02

[ekulrenlig]

Thanks, that is helpful information. Someone else mentioned to me that it could be the "pocket bearing." Does this sound correct? How long before it starts causing other problems? Anyone got an extra AX5, or know where to get a good rebuild kit?

[aemsee]

It is hard to say, but it won't take long to grenade the whole thing if there are pieces floating around in there.

[Wildman]

aemsee - Nice little write up on the tech side there, Good info, Thanks for posting it :thumbsup:

[ekulrenlig]

So would it help to stay in 4th gear more often?

[ekulrenlig]

Well......I am looking at a rebuild kit for my transmission. I found one that says "Jeep Wrangler AX5 Overhaul Kit 88-up." The kit comes with synchros, bearings, and gaskets. Would this fit into my 87 Comanche AX5? Is there a difference in the AX5 throughout its production? Would a kit like this help to solve the bearing problem I am having?

[Twisty]

Well......I am looking at a rebuild kit for my transmission. I found one that says "Jeep Wrangler AX5 Overhaul Kit 88-up." The kit comes with synchros, bearings, and gaskets. Would this fit into my 87 Comanche AX5? Is there a difference in the AX5 throughout its production? Would a kit like this help to solve the bearing problem I am having?

 

long shot, but you could call a jeep dealership and ask if there was a difference between the trannys. just a thought :cheers:

[fiatslug87]

Well......I am looking at a rebuild kit for my transmission. I found one that says "Jeep Wrangler AX5 Overhaul Kit 88-up." The kit comes with synchros, bearings, and gaskets. Would this fit into my 87 Comanche AX5? Is there a difference in the AX5 throughout its production? Would a kit like this help to solve the bearing problem I am having?

According to the Crown Automotive catalog, there are some differences. Some parts are listed as 1986-Nov 5, 1988 and Nov. 6, 1988-1999. I've posted the Crown explosion diagram and parts list if you're interested:

http://home.comcast.net/~fiatslug87/wsb/html/view.cgi-photos.html-.html