Ok I have been struggling with this problem for some time now and just wanted to open a thread and keep getting feedback on this until the problem is solved. I have seen many posts with similar complaints but havent really seen any resolution yet. So hopefully some of you experiencing similar symptoms will speak up.

Here are some of my symptoms. When there is a sudden change in acceleration or if i take my foot off the gas really fast (while under high engine load) the car will let out a loud violent clunk and kind of sway a little. It sounds like someone is hitting the rearend with a sledgehammer. Sometimes it will clunk 2-3 times in a row quickly like something is bouncing(this is not the exhaust... it feels much more violent). Also when Im taking turns quickly at the threshold of traction there is kind of a jackhammer feeling and noise. The driveline just feels sloppy in general as well.

Here is some background on the problem. Months ago I went to the dragstrip and blew out my differential so a friend and I put in a cusco 2 way. When we first put it in.. the car drove perfectly(this is why it seems to me its not a problem with the differential). Then progressively got worse(im guessing as cracks got bigger). Now it is at the point where everytime I drive the car I am getting pissed off.

The differential bushings seem fine. They are not cracked and still seem to be very stiff. The PPF had 3-4 cracks in it and they have all been welded and reinforced about a week ago(after this the car still has the same symptoms). I have also put in M2 control arms and endlinks to reduce wheelhop. Some say that I need to get the differential shimmed again(I dont understand why it would drive fine at first though if the shims were wrong). I was all ready to do this but noone could fit me in for like 3 weeks though... so I had to put my car all backtogether because I needed to drive it. Everything is torqued down to the proper specs also. Are there any other common break points I need to check? Thanks for the help.

 

Try your lower end links. the one the tie rod bolts to... I think thats what is causing my car to wheelhop in reverse. Also replacing all of the pillowball bushings did wonders for my car... I was going to say diff bushings but you already covered that... good luck...
Ryker

http://www.maxcooper.com/rx7/how-to/...lls/index.html

 

Yea I know for a fact a few of mine are worn out. Those are on my list of things to do. Seems like my problem is something bigger though. Its not just a clunking sound... i can feel it too. It is very exaggerated if I change gears while turning also. What were you experiencing before you changed your bushings?

 

Cracked PPF(Power Plant Frame)?

 

correct

 

I experienced a thump... sometime a few... sometimes a bunch... I can prob get you a good deal on those bushings if you need it... used to get a clunking while turning but that went away... for some reason. how many miles are on your car?

 

U-joints ok?

 

Your talking about u-joints on the driveshaft right? Am I looking for cracks, physical damage, or just excessive play?

 

Yes, and yes to all 3. Ive had similar symptoms on another vehicle of mine and it was the U joints. Happened twice actually, first time the U joint was just worn and sloppy. Second time it was broken and getting ready to fall out (actually was able to pull it out by hand).

 

Cool thanks a lot. I will check it this weekend when I go back home and let you know what i find.

 

Usually bad U-Joints will make a roaring noise which increases and decreases with speed. BTW: I have the same looseness problem. I was thinking it was my diff bushings...