Reverse issue w/ my '97 T&C LXi AWD

ok, here's the deal.......SOMETIMES when I go reverse, my car makes this loud thump noise and it feels like I hit something reversing. It does it only sometimes. Nothing wrong driving though. I just changed my trans fluid/filter hoping that would resolve it but it didn't. Any insight on what this could be? Hoping the tranny's not going out on me.

Broken or weak engine mounts ??????

What you describe is exactly what my wife keeps complaining about with our 1998 T&C. She, too, encounters a random, mysterious CLUNCK in the front end when backing up. In our case, it happens when backing up AND the steering wheel is turned one direction or the other. I was in the passenger seat once, about three years ago, when it happened, but I have not been able to make it repeat when I have been behind the wheel, even by doing donuts in a parking lot, both forwards and backwards, and with the wheel turned to both extremes.

I just replaced both front driveaxles and front wheel bearing hub assemblies, but the noise has still occurred, according to my wife. I think this is an issue with the one or more of the lower control arm bushings. Each control arm has two. I have encountered similar noises in my older Mopars that I could trace directly to worn suspension bushings. But, then again, I just got a four-wheel alignment on the T&C and no issues were noted with the bushings.

Maybe, if we put our heads together and find others with a similar problem, we can get to the cause. Knowing that someone else has the same problem helps give credibility to my wife's complaints.

BTW - ours is a 1998 T&C LX AWD with 98,000 miles.

KManiac-my wife, too, initially told me about it and I didn't believe her. After she told me about it, I took it for a spin and it didn't happen. So I used the car for a week and sure enough, it happened several times (ONLY BACKING UP THOUGH). It's an actual scary feeling when it happens because it REALLY feels like you hit something backing up (loud thump noise and the car jerks). Anybody our there have any similar problems? It NEVER happens when driving though.

I have the same issue on my 1999 AWD, only when reversing and it does not occur all the time. A clunk. At first I thought that the transmission was not engaging reverse properly but, it is a similar sound which occurs when I drive forward in snow and lose traction, clunk as if something has been hit.

I'm wondering if it is something to do with the AWD system. It is almost as if the overruning clutch sticks.

I haven't experienced it driving forward yet but then again I haven't driven in snow or other extreme conditions. I wonder if this a known issue with the AWD systems.

Ive got a 2000 T&C LXi AWD ands its got the same problem. I really cant find what causes the noise. The guy is really bugged by it but I just cant track it down and im not willing to waste his money and throwing a used rear into it. anyone else got any ideas ?

...verrrrryyyy interesting! (...a little Arte Johnson lingo there. I guess this dates me real good!)

This clunking noise may very well be something inherent to the AWD system. I think its no coincidence that everyone experiencing this is an AWD owner or driver. Living here in the lowlands of sunny California, our van has never seen the snow or had any reason to lose traction going forward. Maybe if it did, we would hear the clunk under those conditions.

I am personnaly not that concerned about the occasional clunk. I would only begin to worry if it was more frequent and I could figure out how to reproduce it on demand. But if I could figure out how to reproduce the clunk on demand, then I would have a better understanding of what is causing it.

Now for the next big question, "Any FWD only owners experiencing this mysterious clunk?!?" Let us know, if you do.

Well folks, I have been thinking about the clunk noise (Me thinking, a scary thought all by itself.) and I now have a theory as to what is causing it. All we need to do now is test this theory. I want to thank "Vats" for his earlier comment that helped be develop this theory. I believe this clunk is coming from the AWD unit. Here is what I think is happening:

First of all, the AWD system is NOT a full-time system that splits driving force equally between all four wheels continuously. It is a standby system that works in similar fashion to the old "limited slip" differentials used in RWD cars. The front wheels are the primary driving wheels in these vehicles with the left front receiving more driving force than the right front. When either one or both of the front wheels begin to loose traction, the PTU engages and transmits driving force to the rear wheels.

What I think is happening in all cases is that the left front tire is sitting on an unstable surface (dirt, gravel, oil-soaked concrete, wet leaves, paint stripe, etc.) when the throttle is applied. This front wheel will suddenly loose traction, causing the PTU to engage suddenly. Since the left front wheel receives most of the driving force to begin with, the sudden redirection of the driving force to the rear wheels would most likely cause the clutch packs in the PTU to emit a loud clunk upon engagement.

The one time that I heard the clunk was when my wife was backing out of a parking space at a shopping mall with the wheels turned to extreme right. It is possible she backed the left front tire over a painted white line, losing traction on that tire momentarily. Also, the last two times it clunked on her this last month, she was backing out of the left side of our driveway, that is littered with fallen leaves. Since she has been parking on the right side of the driveway, that is free of leaves, the clunk has not returned.

The way we can all test this theory is to take our AWD vans to a dirt or gravel parking lot, bring them to a stop, crank the wheel all the way to the right, put it in reverse, then "goose" the throttle. Better yet, if you can find a way to put the left front tire on dirt or gravel and the other three on pavement, do it. Do this several times and see how many times you can get the van to clunk. I will try this when I get the chance. Trying to pry this car away from my wife is a real challenge. You guys try it and let us know what you find.

Has anybody out there tried my test? Does anybody have any thoughts or opinions on this matter? Let us know. I don't particularly want the last word on this subject.