Transmission clang when hot

Ok, this is a weird one to me. After I do a lot of driving and the Jeep has heated up real good, when I shift from drive to park, there is an odd clang noise and my radio cuts out and restarts. This is when I first noticed it, but it also happens whenever switching between any of the Park, neutral, reverse and drive gears.

Anyone ever heard of something like this before? The transmission operates normally in ever other aspect.

Wow, figured someone on here would have had something like this happen before. This problem must be as odd to everyone else as it was to me. Guess next time it happens I will get out and see if I can tell where it is coming from.

At any rate, the trans is due for a fluid change. Maybe I'll pull the pan and see what's goin on in there. Although, i doubt I'll be able to see much. Just checking the fluid would probably be a good idea.

radio cuts out and restarts..... loose ground wire or short somewhere....

Sounds like its either the u joints getting sloppy or the slip yoke on the driveshaft.

Check your motor and trans mounts, as well as exhaust bushings.

when my trans gets warmed up it has a nice clunk and clang coming from the bellhousing but cant find out wat it is. ur probly looking at u-joints mounts or even control arm bushings. have some one look under while u shift and watch for any exsesive movement

beastlydumass said:

when my trans gets warmed up it has a nice clunk and clang coming from the bellhousing but cant find out wat it is.

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Flex plate cracked?

If a 96 or newer pull the rear driveshaft out and lube the splines inside the yoke, they become dry and dont slip as needed.
Ron

What would cause the radio to cut out then? It only happens when this noise happens and every time the noise happens. So they are surely related. Definitely doesn't seem like a u-joint. I actually just replaced them recently, but will still double check. I'll take a look at the mounts and slip yoke while I'm at it.

This problem hasn't happened for quite a while, but had the chance to catch it today and take a video of the sound. Actually happened again just the other day, but was unable to take a video at the time.

http://youtu.be/gERsN2QLbVU

With the Jeep in park, I rocked it forward and back to look for any bad U-joints or excessive transmission movement. U-Joints are solid and the transmission barely moved at all.

I doubted the U-joint and mounts anyways, considering this even happens from going from Park to Reverse, Reverse to Neutral and Drive to Neutral as well as the other directions. Then it also causes my radio to lose power just long long enough to where it restart.

Only thing I can think of would be some sort of actuator that's not functioning correctly. Even then, why would it cause my radio to restart?

WTF

That is a new one to me. I have never heard a jeep make anything like that noise.

It sure sounds like something bouncing off the muffler but I have no idea what... or how that would be related to the radio at all. I am going to have to go with muffler bearings as my diagnosis :anon:

First off, I'd be surprised if the radio etc. was related to the tranny sound...BUT...if it is, it would either have something to do with movement of the tranny or engine, creating a contact short when either of them move, so motor or tranny mounts would be suspect.

OR...they are NOT related and the flexplate is contacing the bell housing because it is either bent or cracked.

Secondly, remove the inpection plate at the front of the bell housing and...well, inspect the flexplate. If it was cracked I think you'd know it though. You can run the engine at idle with the inspection plate off (safety first, put it in Park and block the wheels) and look to see if the plate is moving back and forth as it goes round & round. It could also be as simple as one or more of the FP bolts loosened up and just barely making contact

If it's broken or bent to point that it's hitting something you'll likely be able to see it right off, whether it's "clanging" at the time or not. The flex plate is always moving when the engine is running, keep your fingers out of there. Remember to replace the inspection plate when you're done.

OR...while you're under there have someone rev the engine a bit (safety discalimer again) and look to see if the engine or tranny is moving around as it gets revved and/or shifted (with same helper standing on the brakes of course so you don't get run over)

This is a strange sound...so that's the way you need to approch it IMHO.

That made me think... check to make sure your mechanical cooling fan isn't slapping something it isn't supposed to when the motor mounts flex. I guess it might ring like that when smacked once against something like a broken fan shroud.

kastein said:

That made me think... check to make sure your mechanical cooling fan isn't slapping something it isn't supposed to when the motor mounts flex. I guess it might ring like that when smacked once against something like a broken fan shroud.

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Now that I hear the noise on my home computer with decent speakers and the volume up...it sounds exactly like the mech fan, and it sounds EXternal, not like a flex plate which would be somewhat muffled behind the insp. plate. But it also sounds like it's hitting something metal, and solid. My fan shroud cracked a few years ago and it sounded like thud-d-d-d-d-d-d-d-d-d-d-d....not "tink tink tink".

If I were the OP I'd be looking for a shiny spot on the fan itself and corresponding it to anything in it's path that might also have a shiny spot.

I'll check the fans and that stuff, I don't think that will be it though. I can be doing anything else and this sound will never happen until I shift between the top four gear selections. Then it happens immediately, right before you feel the shift happen. Not only that, but it also happens from a gear into neutral or from reverse into park, where no momentum is generated by the shift like there would be from P or N to R or D.

In the Beginning of the video, the two quick clangs are me shifting from P to R to N. Quicker then the transmission would shift itself. Then at the end, the two clangs are from N to R to P. Not as quick, but still probably less time then it needed to actually shift into R before getting to P.

My thinking is that shifting from any of those gears (P to R, R to N, N to D, any combination) to any of those gears results in the driveshaft having torque applied in a different direction, which is making the driveline slide around in the motor mounts as they might be worn. That would result in the fan shifting around in the fan shroud.

It could also be the exhaust bouncing off the crossmember right to the right of the trans mount, I guess, but that's a long shot. Normally you get a horrible rattling vibration in R/D while stopped (or under heavy acceleration in D) that will go away or change note when you put it in P/N if it's that exhaust mount.

I think that is a likely choice. I had that problem when a shop did not install the lower half of the fan shroud properly. I also had that noise when the harmonic balancer rubber was coming loose and slapping stuff.

I was thinking alternator noise and radio, but not sure what connect a loose alternator to shifting gears?

I guess he should check for dangling O2 sensor wires or hoses near a drive shaft, but it sure sounds like the fan hitting the fan shroud to me, been there done that noise before.

Also motor mounts and tranny mount with too much give letting the fan blade slap the fan shroud.

kastein said:

That made me think... check to make sure your mechanical cooling fan isn't slapping something it isn't supposed to when the motor mounts flex. I guess it might ring like that when smacked once against something like a broken fan shroud.

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Perhaps A bad ground related to said movement?

ParadiseXJ said:

First off, I'd be surprised if the radio etc. was related to the tranny sound...BUT...if it is, it would either have something to do with movement of the tranny or engine, creating a contact short when either of them move, so motor or tranny mounts would be suspect.

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I'd bet money, if I was a betting man, the tranny mount is not working, bad..... Mine was missing the mount bolts when I bought the 87 rig, LOL. check for a loose or damaged fan shroud and any slop in the flex fan clutch as well, maybe both.

el_roy1985 said:

I'll check the fans and that stuff, I don't think that will be it though. I can be doing anything else and this sound will never happen until I shift between the top four gear selections. Then it happens immediately, right before you feel the shift happen. Not only that, but it also happens from a gear into neutral or from reverse into park, where no momentum is generated by the shift like there would be from P or N to R or D.

In the Beginning of the video, the two quick clangs are me shifting from P to R to N. Quicker then the transmission would shift itself. Then at the end, the two clangs are from N to R to P. Not as quick, but still probably less time then it needed to actually shift into R before getting to P.

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Haven't had the issue lately or the time to really take a good look at it.

If it was the mount, why would it not happen when I'm driving? That should cause the engine to shift both directions much more then a gear change would do. Especially since I regularly downshift on hills to use engine braking to slow down.

I'll be replacing my engine grounds soon, as I'm also having charging issues and a new alternator didn't fix the problem. It charges, but not when I turn on too many things.