Well I started off at a red light and all of a sudden BAM!!!!!!!!!!!!!!!!!!!!!! from the rearend.

Now I have replaced the front diff mount with Mazdatrix racing mount. I just yanked my exhaust off and it was in perfect condition.

The driveshaft joints have no play in them and I'm stumped. I am about to check the trans mount but I think it's fine.

I heard there are other diff bushings. Where are they? and how woulds I figure out what's wrong.

Also it only clunks when I shift and not when I'm in reverse.

 

im having same problem/sound. just bought car so dont know whats all going on yet till school gets out and i have time to work on car.

 

it's not like a clicking type noise is it, like, sort of a loud click?? is it hard to change gears sometimes?? if so, it could be the synchros in the tranny

 

Theres two other "doughnut" type mounts in the rear. Mazdatrix sells them for $62 each I believe.

 

yeah, i saw them on mazda trix when I was looking around a minute ago

 

My brother had a broken front diff mount that we replaced with a with a good one. We took the car for a test drive and BAM the noise is still there. Its not as bad as before but it was still annoying.

Those "doughnut" mounts youre talking about are the two rear mounts? I've read and talked to rotary shops about those but everyone says they rarely go bad.

My brother and I are going to put his car on jackstands to see what exactly is making the clunk sound. I'll post what we find later today.

 

Not a click.
a HUGE CLUNK!
Like someone just hit the rearend with a sledgehammer.

I haven't found any dents so I'm stumped.

 

its your transmission mount mine is bad and i got the same anser from four different rotary guys.

red

 

in that case, write me down as stumped also, i have no clue what it is,but would like to hear whn you figure it out

 

OK, I justed dropped the car and watched the under side as my dad went forward.

The differential tilts up in the front like it's on an axis.It doesn't move forward or bacl just up in the front and a little down in the back.

Anyone got a better clue now?

 

Also. If it were tranny mount wouldn't it still clunk when I go in reverse??? Or am I just stupid?

 

Well it has to be some part of the stuff that holds the diff back there. maybe you forgot to Tq something to spec and it is allowing it to pivot on its axis?

 

I used to get a huge clunk taking off at the lights. Even when I was being good it still did it. I'd broken the diff mount right through, couple hundred $'s later I could stop living in fear.

 

I replaced the main diff mount (the one which you gotta drop subfarme for) and I looked at it and the rubber is perfect and new. Maybe I'll try testing the mount again/

 

There is a brace (or there is suppose to be) on the top of the diff with a rubber stop on it. When you accelerate hard the diff rotates (front up like Digi7ech said) and the rubber stop hits the body pan. Check that the stop is still there, or that the brace isn't bent.

 

I just did the same thing right now and got the same results. I was expecting to see the diff move alot but all I got was very little movement but could still hear the clunk sound from inside the car. I'm thinking about replacing the two rear mounts just for ***** n giggles. Digi7ech, if you find out anymore info, please post them here. I'll do the same if I find out anything.

 

I've never seen one of these "braces with a rubber stop" on any of my RX-7s. This sounds like a pinion snub (spelling?) that a previous owner could have installed. Youre not thinking of the front diff. mount are you?

 

Yea chances arent too high that they would. But depending on how long you've been going on a bad front mount, it may have an effect on the rears as well I assume.

 

Ddi you check to see if the subframe mount is broken at the front diff mount?

 

Funny you said that Icemark.

I haven't posted until now because I just finished.

The mounting point for the Diff mount had broken partially.The middle metal part between the 2 bolts completely broke off!

There was a 1 square inch piece sitting in there.
After 2 hours trying to get the mount close enugh to the bolts I tightened it back on as best I could. About 60% of each bolt has a good contact with the bracket.

I am sooooo hoping this will last. I will be driving very carefully now. So i guess the Mazdatrix racing mount was tougher than the metal was.

 

MOTHERLLkjhl;akjfd;laksjf;laskjfalksjf;aljj^%*^%@( &%^^^$#WDYUIASDHA&SD%^(ASDKJLASDAN(*S^)DAS^&D(*&D( )A&D@N_ASD ING POS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
AHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!

The piece of **** just broke again!!!! Not even 3 days after I fixed. ****!!!!!!!!!!!!!!!!!!!!! Of course the ******* subframe side of the mount had to ******* break!!!!!!!


So what's going to break with me driving like this??????
From the huge jerks the diff does I'm guessing joints on driveshaft and possible breaking the joints off.