http://gerrycondez.com/LRnoise.MOV

 

I've had a cracked flex plate (there are photos on the forums, somewhere) and it didn't sound like that. Yours sounds like a bell. Mine sounded like a chirp.

 

 

I was going to mention a flex plate in your other post. I had to deal with a cracked one on an 05 Jeep Wrangler Rubicon and it was a total PITA to diagnose!!!

First my Jeep had to have it's transmission dropped with just 18K on it. They had it for nearly a month, gave it back to me, and the same issue of limp home mode happened two miles from the dealership. They finally went part swapping crazy until they replaced the PCM/TCM. Then I was left with a dented transmission pan, and a leaking gasket (which I fixed myself vs taking it back to them). I got to around 30K when I started hearing this crazy sound like nothing I'd ever heard. Took it back in and they said it was my cat's (which was under warranty). Got it back and the noise was still there!!!!! Except now I had O2 sensor faults... Took it back for that and they finally got that solved, but could not duplicate the sound I was originally complaining about!!!

At 32K it was so bad that if I went thru a drive thru at MCD's the people in front or behind me would actually roll their window down, or get out thinking it was their vehicle making the sound which I can only describe as a clucking chicken..

I took it to a local garage and the guy suggested I just drive it until it breaks then he can fix what broke.... I was like oh heck no so I got home, removed the tiny little transmission inspection plate, and I checked the torque convertor bolts, then as I laid under it with the engine running I used a piece of rubber hose and I pin pointed the sound to around the flex plate!!! I then sprayed some WD40 up in there and I got the noise to change/go away!!! BINGO I said to myself! Well I took it back to the Jeep Dealer saying the noise is my flex plate, and they you guys must have done something when you had it all apart at 18k. They said oh well sorry sir your 3/36 warranty is up. I said ummm what about my 7/70 warranty? They came back with some BS that I did not pay the 300.00 fee to transfer it over to me after I bought it (was a dealership demo with 2,500 miles on it when I bought it). I said you never mentioned the 300.00 fee and that umm of coarse I'd have paid that.... Well I fought with Jeep for well over two months and finally they said sorry, we can't warranty it, but we can fix it at the sum of nearly 1,400.00.... I was truly pissed off at that point and I so wanted back in a Land Rover!!

Well being a member of a local Jeep club did have it's advantages as another dealership told me to bring it down, and they'd drop my transmission for free as long as I had the part to fix it or bought one from them. I quickly ordered the 54.00 pie pan looking piece of crap that Jeep called a flex plate, and I went down and helped drop my transmission. Everyone said no way that's what the problem was, but once the last bolt was removed and we inched the transmission backwards we heard a ding.... as the transmission barely touched the flex plate.

Sure enough once out of the way the flex plate was cracked 99% around all 6 mounting bolts..... It had maybe 1-2mm of metal holding it together at the most. The reason the sound would go away with lube was the lube temporarily filled the gap so it wasn't making a metal to metal sound until the lube dried up or flew off the flex plate. The guys at the dealership were shocked as they'd never seen one on a Jeep with just 32k on it. I told them about it's history at 18k and we all came to the conclusion they must have banged into it during the removal/install of my transmission at 18k and caused it to be un-balanced or stressed. Then eventually it cracked enough to start clucking like a chicken. Had I left it alone it would have destroyed my bell housing on the transmission, my driveshaft, and my $$$$ cat's. All over a 54.00 pie pan!!!!

After I fixed it I got that Jeep up to 54K and finally had enough with it's other 1,000's of issues it had.

On our D2's we do have 3 little inspection places. 2 Rubber covers, and a small round metal one at the bottom. My advice would be to remove the covers, use a rubber hose to listen, and then spray some lube up in there (aiming for the center of the flex plate) and see if the sound stops or changes. That is about all you can do besides drop your transmission to inspect it.

I even tried one of those small bore scope type camera's but the area was so small I couldn't see the crack.

I agree with Charlie it's more of a cluck/chirp when a flex plate is cracked. Being that it sounds kinda like a bell it really sounds more exhaust related.

 

I'll try to check those inspection holes. I did drained/replaced all the transmission fluid and gear oil yesterday thought it leaked and empty. But no leak, replaced the trans filter etc. Still have the noise. Ill probably replace the catalytic 1st. Its very hard to get accurate location of sound because the tire is balding and too much road noise. When I drained the liquids I tried checking if there are bits and pieces of metal, but none.

If it happens that its the flex plate, which is harder to replace, head gasket or the flex plate? I just want to gauge the amount of time to do it. I did the head gasket a month ago. With the flex plate, do I need some assistant to do it?

 

I think they are about the same. At least, the way I do it (remove engine). If it wasn't for the transmission bolts it would be a breeze.

Alternatively, you can remove the driveshafts and drop the transmission and torque converter as a unit. But that's the same amount of trouble and you are stuck in a tight work space.

 

If you take a a rubber hammer and tap the cats do they rattle? If they rattle then they can make all sorts of sounds depending on how the guts are bouncing around inside it.

You'd have to drop the trans to gain access to the flex plate so it's a good deal of parts coming off. I haven't looked into those small access holes with a bore scope on a D2, but maybe you'll be able to see if it's cracked or not. Those things are like dirt cheap at Harbor Freight and even Wal-Mart sells them.

 

Is it possible to raise the truck on 4 metal stands and run it to verify where the noise is coming. The noise is audible only when moving and not heard when parked even reving the engine.

 

I'm not able to listen to the video...format doesn't work on my tablet. So, not sure what the noise sounds like, but normally...a flexplate noise will change tones while in neutral or drive. Try listening to the noise in neutral, then put it in drive and give it a bit of gas (with your other foot on the brake and parking brake applied). See if the noise changes at all. Even rocking the shifter into reverse, while gasing it a bit, can sometimes change the tone enough to help diagnose the problem.

If it turns out to be the flexplate, me, I'd probably pull the trans and transfercase. Granted, I have a bad back and would rather lay on my back underneath...than lean over the fenders. Either route will be a pain in the butt. Took the heads off my wife's LR last week...and it's been a week since even looking at it again. I'm hoping by next weekend I'll be able to get after it.

Anyhow, good luck fiding the issue.

Brian.

 

Replaced my flex plate a few months back. It was not the same sound and it only occurred at idle. Once you were in gear it went away.