I am assuming that I have an ATS TC, as I looked into the inspection cover to check for cracks that may be on the flexplate. If any of you are reading this post, please assist me in the troubleshoot if you would:

All of a sudden, after turning down my stereo, and at speeds of 50 mph, I hear a clunking noise, which is loud, and a loud shaking roar up towards the front or underneath the engine, frontward(hard to tell while going WOT). As I step outside the truck while idling, I hear the clunking, like loose metals underneath, and sounds are more defined under the rear of the engine. At 2nd gear and building speed, all sounds OK, but at sudden WOT, loud roar. I hope this is the sound of a cracked flexplate and not some rods that I may have bent. Let me know your thoughts on the sypmtoms given.
Upon inspection of the flexplate, I notice 4 of 6 bolts are somewhat loose, not finger loose, but loose, and one of those bolts was have way unthreaded. It took (4) 360 degree turns to tighten. Anyway, the TC was purple. The previous owner said he had a DTT transmission installed around 40,000 miles ago, but having never seen a DTT TC, I am assuming ATS. Let me know your thoughts on that find as well. BTW, it was too hard to tell if lines were cracks (need glasses!).

Finally, as a sum to my problems, if it is indeed an ATS TC, will a 2nd gen flexplate or the other one I have seen in the search subject on flexplates, (the one Dave BC847 used that cost around 160.00. Apparantly a thicker flexplate) work with an ATS TC?

So my questions are:
1. Do I have a flexplate problem? Oils and coolant all check good. No over heating or a change in oil pressure, BTW.
2. Do I have an ATS TC? Who else would paint their TC? Is DTT TC's painted?
3. Which is a better flexplate to use, and if there is one other than 2nd gen, a link would be nice
4. If it IS NOT the flexplate, what else should I be checking? (got a new drive belt, clutch fan, and belt tensioner. KDP tabbed a month ago)

Sorry for the long post and requesting all the answers. I don't ask for help any much more, especially with the awsome sticky and search feature. This one I need help on. Thanks, fellow 1st genners.

 

you tightend the bolts and its still there?
we have a off brand rebuilt tq from a place here in oregon and it's purple.

did you check the trans mount bolts?

 

I am not understanding, that is, you comment on "it's still there?" Are you meaning that you feel it is the flexplate causing the ruckus and that it should have fallen apart in pieces after tightening? I did start it up after tightening and the sound is still there.

I also checked my turbo, just in case. All is well, as it is only a couple of years new. After I pulled the inspection cover off, the sound was the greatest, or shoulf I say, more defined, from the area of the TC and rear of the engine. Wonder why it would sound like it was coming from the front of the truck at WOT?

 

I think he was asking if the clunk was still there after your fixed the loose bolt issue.

 

Unbolt all the converter bolts and slide it all the way into the pump, start the motor and see if you still have a vibration, if yes than it is most likely engine related, if not than my guess would be flexplate or tc.

 

thats what i ment.

 

I have a 518-89 DTT torque converter and it is painted blue. Just purchased it for $200 with 20,000 miles on it from a friend who wrecked his 93 4X4. He purchased a 2003 with manual trans and used the Gear Vendor off the 93.
He said the DTT was great for towing up hills and with a heavy load, but it would require a little more brake when stopped at a stop sign. He said his running rpm went down a little but could not remember how much at what speed ,also seemed to get about a mile per gallon more. I have not installed it yet.

 

I had an off brand tc when I bought the truck, it was purple, and looked very similar to my current purple ATS converter.
I run a second gen flexplate with this tc, got it directly from Cummins.

 

I guess it must be a DTT TC, and the color then is blue. (color blind- can't tell purple from blue). I appreciate all the feedback from you all, and most answered my questions. I am concerened about the diagnosis, still. All comments on the search forums describing flexplate cracking seem to match mine, but I still have yet to read of someone hearing a roar towards the front while idling high or at WOT. Is their a possibility that the noises generated from the possibly cracked flexplate is able to transfer sounds to up front?

 

Could the roar you are speaking of possibly be a faulty fan clutch? I have seen them do exactly what you are talking about and throw in a vibration as well. My work truck fan clutch kicks on at 200* and you cant even talk to anyone around without yelling.

 

Maybe, maybe both the flexplate and the fan clutch. All I know is that I started the truck up tonight and the sounds of clanking steel are getting worse, and loudest by the bell housing. Up front under the hood the sound is generating towards the front, around the valve covers. I am wondering how long those flexplate to converter bolts have been that loose...I am guessing that could have led to a crack in the fp. Again, I am assuming strongly, and hoping it is the flexplate, and not rods, bent valves, fried pistons. Having never experienced any noises form these items, I would not know. I was hoping you experts out there would be able to tell me if my sound diagnosis would rule out the rods, pistons, etc.

 

If its kind of a tinny sound it won't be rods or pistons or main bearings. I would stick with the flex plate idea. Maybe go by a shop that knows these dodge cummins trucks and have them take it for a drive. Also I just put on the Stans 4" and have developed a drone noise cause but the system vibrating. The harmonics (frequency) of the vibration cause something in my truck to turn into a speaker and hence the drone noise. The vibration is no different that before its just the way the system is caring it. This only happens around idle.

 

I had two 1st gen flexplates break and both times it sounded like the valve train had was coming apart. It rattled and hammered like crazy. I would recommend you go ahead and pull the trans. If those bolts backed out they most likely egged the holes in the flexplate. The bolts will need replacing also. Depending on how much the converter's been moving you may need new parts on the front of the trans, pump bushing etc.

 

I really appreciate all your help, guys. If any of you have stopped driving your 1st gen for a week now, it must have bugged you like it is buggin' me now. So, a lot of comments here leading to the flexplate. In a way, I am feeling a little better. I went ahead and ordered from Cummins West the 2nd gen fp, rear main seal, 8 new bolts, and if there are any seals I should need or upgrade isolation bushings (like for the tranny) could any of you advice me of which ones you reccomend I change out whie I have the A518 and NP205 down, and possible part numbers? I wish their was a step by step instruction on how to change out the flexplate on a 4 x 4, sorta like the instructions in the sticky for tabbin' the KDP or valve adjusting.

You know, I have been chasing a clunk noise for a year and a half now. I hear it on my left side everytime I hit an indentation in the road or if I drive by brail. All shock mounts and U bolts are tight, and suspension bushings recently changed. I wonder if all this time it was related to the flexplate? Anyway, keep the advice comin', guys. Thank you.