Deceleration noise driving me crazy [VIDEO]

[Limegrntaln]

Dude, I have no idea what a trebuchet is. But it's definitely a thump. I'm wondering if the lobro joint is smacking underneath the car.

I took my T-Case off and the tail shaft is tight, however, watching Jacks video, the input shaft side doesn't seem right. I had some Mechanix gloves on and stuck my index finger in the coupler and spun it with absolutely zero effort. So watching Jacks video where he puts the input shaft in and says you should feel resistance, then it clicks, or gets to a spot where it let's go, yeah, mine does none of that. So while the car is decelerating and I let off the gas and I start hearing this aweful noise, there is no resistance in the t-Case at all.

I shot another video and showed Jack where I was revving the car and he wants me to take the tranny out and send it back to him so he can take it apart and inspect it. If there is anything wrong with it, he will fix it and pay the return shipping. I'm impressed with the customer service.

 

[Trav83]

Mine makes that same noise upon deacceleration, just not quite as loud. It's been doing this for as long as I can remember so I doubt it's hurting anything. I can't blame you for still wanting to figure out what causes it, I wouldn't mind knowing myself.

 

[xXEclipse]

I have the same deceleration noise, also not as loud as yours, im on stock transmission..

 

[Limegrntaln]

Mine makes that same noise upon deacceleration, just not quite as loud. It's been doing this for as long as I can remember so I doubt it's hurting anything. I can't blame you for still wanting to figure out what causes it, I wouldn't mind knowing myself.

Is this on your NT? or an AWD car?

I have the same deceleration noise, also not as loud as yours, im on stock transmission..

I'd like to get someone in here that knows a lot about these drivetrains. I pulled the xfer case for about the 5th time the other day and realized that on the coupler end of the tcase, there is no resistance. It's all free play. The tcase output shaft doesn't wobble, but the internals are extremely loose. So I'm wondering if the car is having a free wheeling effect when I get off the power. Like the driveshaft is spinning faster than the tcase wants to spin because the tcase is so loose. Sent an email to TRE asking this question, trying to see if he has an answer. I'll try and send Shep a shout next. I also have Jack looking at it from Jackstransmissions. He said take the trans out and send it back to him anyway. He will take it apart and make sure there isn't anything wrong with it. If there is he will fix it and ship it back all on his dime.

 

[Colt4G63 also]

I think it's the pressure plate. Only because mine started making that noise when I swapped out my clutchmasters set for a new one of the same.

So far I have tried both of my transmissions (one with a center spool, one without).
Both of my transfer cases (niether has play in the gears or bearings).
I replaced all my u-joints with new OEM.
Replaced both carrier bearings with new OEM.
Took them back out and put my urethane filled ones back in. (eliminates the decell shake)
Upgraded my 3 bolt rear to a 4 bolt.
And replaced my CM 6 puck sprung disk with an ACT 6 puck sprung disk.

I'm pissed now that I didn't put my old CM pressure plate back in when I last replaced my clutch, because it never made that noise until I replaced my CM pressure plate most recently.

Ps. I've heard mine do this on the lift, (while standing underneath) and it's loud! It's also definitely coming from the transmission or clutch. Since everything else has been replaced I'm almost 100% certain the pressure plate is the culprit.

 

[Limegrntaln]

I heard that the lightened flywheels make noise, and I can totally understand that, but this is something that shouldnt be like this. I mean it literally breaks the hatch seal when Im coming off the highway, from the vibration and I can feel the pressure difference when I have the windows rolled up and the A/C on.

If have the CM in there right now. I like the clutch, and overall I wanted something a little lighter than the ACT 2600. I've had that in a few other DSMs, but I've never had a problem with it either. Im at the point where Im going to be extremely pissed if I take the trans out, and put the new ACT Flywheel in there and leave the CM Clutch in there and put everything back together and it still does this. So now you've got me wanting to change out the clutch too. This one has 13,000 highway miles on it and I've never had a problem with it either.

Jack offered for me to take the trans out and send it back to him and he would take it completely apart, so I still think Im going to do that anyway. I just want to be sure there nothing wrong with it. its making some weird noises also. It looks like I have more than one problem here.

These are 2 more videos that I took

YouTube - ‪Transmission Noise‬‏

YouTube - ‪Clutch actuation‬‏

 

[Colt4G63 also]

I liked my CM setup too. That's why when I replaced it last year I got the same thing. I've always had an ACT streetlite flywheel, and the noise didn't happen until my second CM plate and disk went in. The first one never chattered as badly as the second either.

After over a hundred 1/4 mile passes, and a bunch of random street launches (just up to the speed limit of course), my second one started slipping, and I just got a 6 puck ACT disk. I figured the springs in the disk had been making the noise, and a couple of them looked a little beat up, so I left the pressure plate be. Imagine my suprize when the noise persisted.

That video of you revving the engine sounds horrible. Mine doesn't do all that when I just rev my engine, only on decell, or engagement with no load. I would think the clutch had blown apart at that point. I would pull it immediately before you have a hole in your bellhousing.

 

[Limegrntaln]

That sucks! And the noise has been like that for a year. I keep asking about it and I keep hearing that lightened flywheels and modified motors cause harmonics issues. Well, the whole damn car is bone stock. It's not even lowered. And I should suck it up because modified cars sound like that. Well I'm not modding this, my 5th DSM, until I get this figured out, because it's not just noise, everything shakes and it sounds like hammered dog shit.

 

[Colt4G63 also]

It shouldn't be shaking. You must have a broken part in your clutch that's throwing the whole thing out of balance.

 

[Limegrntaln]

I would think if the clutch was broken at all though it would act a little funny. Clutch is flawless. The front driveshaft vibes and shakes the car. Lobro joint might be bad. May just get a DSS driveshaft to take the lobro joint out of the picture.

 

[Colt4G63 also]

To make sure the driveshaft is causing the vibration, get up to speed, and throw it in neutral and shut off the engine. Don't lock the steering, and don't hold the clutch. If it still vibrates, then it's your driveshaft. I can't see a lobro joint causing a vibration, unless it's missing balls, or completely dried out and worn to hell. If your driveshaft was ever taken apart, it could have been re-assembled out of phase. All the parts have to be reassembled in the exact same alignment as they came from the factory, or you'll get a vibration. Even a speck of dirt/rust clamped into the edge where the two halves of the lobro meet will cause a vibration. Same goes where the u-joint flange squeezes down against the carrier bearing. Any time work is done on a driveshaft you should draw a line down the length of the shaft to make sure it all goes back in the same orientation.

As for the clutch noise when you rev it. Does that happen in neutral with your foot off the clutch, or do you have to push the clutch to get that sound?

 

[Limegrntaln]

I'll definitely try that on the highway. And I did take the driveshaft apart because I thought the problem was the carrier bearings. And I did index the shaft (draw a line across the joints) the carrier bearings changed nothing. Still vibes and shakes like a mad man!

 

[Colt4G63 also]

I recently balanced my driveshaft through process of elimination, and it's so freaking awesome to have a smooth ride.

Here's a little instruction manual I copied from this really good read:
DRIVE SHAFT ALIGNMENT :: 1984 - 1991 :: Jeep Cherokee XJ :: Online Manual Jeep

DRIVE SHAFT BALANCE TEST

1) Drive shaft imbalance may often be cured by disconnecting
shaft and rotating it 180 degrees in relation to other components.
Test by raising rear wheels off ground, and turning shaft with engine.

NOTE: DO NOT run engine without ram airflow across radiator for

prolonged periods, as overheating of engine or transmission may occur.

•On most models, balance testing may be done by marking
shaft in 4 positions, 90 degrees apart. Place marks approximately 6"
forward of weld, at rear end of shaft. Number marks one through 4.

•Place screw-type hose clamp so clamp head is in number one
position, and rotate shaft with engine. If there is little or no
change, move clamp head to No. 2 position, and repeat test.

•Continue procedure until vibration is at lowest level. If
no difference is noted with clamp head moved to all 4 positions,
vibrations may not be drive shaft imbalance.

•If vibration is lessened but not completely gone, place 2
clamps at that point, and run test again. Combined weight of clamps in
one position may increase vibration. If so, rotate clamps 1/2" apart,
above and below best position, and repeat test.

•Continue to rotate clamps as necessary, until vibration is
at lowest point. If vibration level is still unacceptable, leave rear
clamp(s) in position and repeat procedure at front end of drive shaft.
If vibration can be eliminated or reduced to acceptable levels using
this test procedure, send drive shaft out to be balanced.

The only thing I did different was I put my car on a lift, removed the wheels, bolted the rotors on with two lugnuts, and instead of hose clamps I used washers, paper and tape. Wrap the paper strip around the shaft, place washer on paper, then wrap it in tape. The tape isn't stuck to the driveshaft, so you can rotate the weight. When it's all good you can retape the washer in the same place and leave it.Then if you decide it's really that good, you could even weld the washers in place.

 

[Trav83]

Is this on your NT? or an AWD car?

My N/T

 

[Limegrntaln]

My N/T

Interesting.


Also I shut the car off a few times on decel and the vibe is still there. It changes nothing except the RPMs drop to 0

 

[Trav83]

Click on my profile and you can read my mod list, maybe that will help you figure it out, I don't know. I do have a Fidanza light weight flywheel

 

[Limegrntaln]

When I pull the trans and send it to Jack, he said he has a jig to set everything up on to make sure it all works correctly. So I'm sending my clutch and flywheel to him with my tranny. And he's gonna make sure it's all setup to work together.

 

[PieEyedPiper]

Sounds good! Cause that's no deceleration noise.

 

[Limegrntaln]

Sounds good! Cause that's no deceleration noise.

I'm looking at 2 separate problems here. The tranny or flywheel, pressure plate, clutch are making noise, then I shut the car off on decel the noise doesn't change.

 

[-red97rum-]

Hmm sounds like my car did when a couple of my torque converter/flex plate bolts came loose. My car's auto so it's a little different but I swear it had the same symptoms on decel and it sounded horrible.

*Edit: just watched your vid on the 2nd page and it doesn't sound at all like my car did. Your first vids did though.

 

[Limegrntaln]

Hmm sounds like my car did when a couple of my torque converter/flex plate bolts came loose. My car's auto so it's a little different but I swear it had the same symptoms on decel and it sounded horrible.

*Edit: just watched your vid on the 2nd page and it doesn't sound at all like my car did. Your first vids did though.

Like I was saying in the other post, I have 2 separate events going on here. The videos on the front page are with the car moving. I can't show the decel rumble and shake on video well at all. But the noise in the first video while the car is in motion is the same rattle that you hear when I'm just revving in the 2nd page videos. So I have the rattle and the decel vibration going on. I'm about to get a rebuilt T-Case and a DSS driveshaft and replace the clutch and flywheel with new parts. Even though the flywheel and clutch are brand new already. This way, the only thing left will be the rear end. Which isn't LSD btw.

 

[-red97rum-]

How would you figure the t-case is making noise when the car isn't even moving?

 

[Limegrntaln]

How would you figure the t-case is making noise when the car isn't even moving?

Not that the T-Case is making any noise when the car isnt moving. The trans is definitely rattling, or the clutch, pressure plate, flywheel. Im replacing the t-Case because when I removed it the other day, there was no no resistance in turning the coupler end. I was able to put my finger in the coupler end and turn the t-case with no problem. It spun freely, which if you watch Jacks video, its supposed to give resistance, then you hit a spot where it frees up. Mine is just free spinning.

 

[Limegrntaln]

I was reading a GVR4 thread about something similar to what I have, and some of the guys were using a angle gauge to shim the carrier bushings. I haven't had time to do anything this weekend with it. Im hoping to get it back on the lift this weekend and take the flywheel inspection plate off and see if the flywheel feels loose. I have a brand new ACT Flywheel standing by. I may also get a new clutch kit and have it balanced with the flywheel just to save downtime. Ill feel better if I replace everything from here on out with something new.

Also reading the Galant thread, the actual noise, for one guy, ended up being a bad transmission bearing. I need to get the trans out and get it back to Jack to have it inspected.

 

[bsbllfit7]

its the lightweight flywheel for the record. It increases the harmonics of the engine, if you have a puck disk too this makes it even worse. I knew this was the issue because when i first got my new clutch and flywheel put in i researched the topic for days and heard from many people they had the same issue with their cars. Also if your Crank Position Sensor goes bad and its a 2g no its not crankwalk its the engine picking up the harmonics and throwing off when to fire. The way to fix this is by putting a 1g CAS into the head of the 2g. Fixes the problem like a charm. Unfortunately no way to get away from the vibration. My car vibrates like a MF with the 2.4l and balance shafts removed with light weight flywheel and 6 puck unpsrung clutch. But hey that is one of the sacrifices of having a fast DD