Enthu

iTrader: (1)

I have been experiencing a terrible clanking and shuddering from the rear center or right rear of the car from how it sounds while driving here are the symptoms:

- "Bouncing" under 1st gear take off. Also bounces and sounds like a clank when I push the clutch in to come to a stop.

-Shuddering and banging over bumps at speed. it's almost like something is rapidly hitting the bottom of the car over bumps on the highway. I can feel the shuddering in the shift **** and seemingly on the driveshaft tunnel/armrest.

-Shuddering over bumps at low speed. when I have come to a stop in the city and driven over a pothole or bump, I have felt the bouncing/banging/shuddering as well.



So far, I have replaced all the Struts and shocks with Koni yellows and all 4 strut mounts with Tein Pillow *****.

I am about to buy a new front diff mount, but just want to make shure I am not going to be throwing parts at the car only to leave the problem unsolved. Thanks for any helpful input!

cmanns

Why dont you just look for something broken...

Enthu

iTrader: (1)

I did. I couldn't see The diff mount being obviously broken, but it seems to be inline with the symtpoms and the mount looked at least worn.. I did look. I just want to be certain there isn't some less obvious cause.

Enthu

iTrader: (1)

I went ahead and replaced it. The old front diff mount was not broken, but likely just severely worn out being at near 160k. The install went great. I started at 4 and finished up around 10:30-11. I was fortunate to have power tools and the impact gun made taking the front moount off easy enough with some extensions on it.

I would say this was the hardest thing I have done on my FC next to an engine swap. It was just very tedious. though rather straightforward. The clunking seems greatly reduced or eliminated. If this doesn't solve it, I will have to change the subframe or rear diff mounts.

another7driver

Replacing the axle shafts and differential mount fixed the clunking in my t2.

The shafts had crazy backlash in them.

Good luck hunting this down.

Enthu

iTrader: (1)

The axle shafts shall be replaced then! I beginning to worry a bit as it is only getting worse. it seems.

slpin

iTrader: (9)

if it dont fix it
check driveshaft!
broken ujoint?!

KhanArtisT

iTrader: (2)

The diff mount doesn't need to be broken to make noise. To eliminate it you can jack up the car and have a friend engage the clutch roughly in first gear a few times and check for up and down diff movement.

staticguitar313

iTrader: (2)

add a pinion snubber, I did, diff mount still broke, but it moves less in broken mode. Now i just have to get under there again to do the competition mount.

npena80

okay, what is a pinion snubber?

KhanArtisT

iTrader: (2)

A piece of rubber or polyurethane with a stud sticking out of it. It goes between the chassis and the diff and can be adjusted with shims or cutting to have little or no gap.

All you have to do is remove your storage bins, find the dimple in between them, drill through it and install it. You can get the polyurethane one from Energy Suspension at your local autozone for like 12 bucks I think. Search pinion snubber for more info. I'm running it with a bad diff mount and I get no movement at all that I can hear.

Enthu

iTrader: (1)

I bought the snubber. I will install it. I did install a new Competition front Diff mount. I swapped the driveshaft out of my parts car that did not have this problem.
I am going to do the axles and install the snubber.

Hypertek

iTrader: (3)

imma go do this tomarrow if im not lazy.. also started to get the clunk as of 2 days ago.

MaczPayne

iTrader: (5)

Glad to see people doing the pinion snubber instead of just welding the mount! Dissipate the energy, not localize it!

tigerbite

I get some strange noises as well. But it seems to be around 2k rpm only, in any gear. Started happening when when I swapped out from an open differential to a clutch type differential and housing. Same diff mount that had no noise before. The only thing I have done is just used one stud on the diff mount.

Enthu

iTrader: (1)

I installed the snubber and finished that all off late last summer. However, the banging continued. The car felt MUCH better after installing the new MazdaTrix competition front diff mount and snubber. It also removed the rear banging and brought o my attention the front was banging!

So I got some new poly-eurathane engine mounts and installed them yesterday. I wasn't surprised to find the passenger side engine mount COMPLETELY BROKEN. Not just cracked, but the rubber had totally disconnected and the engine was free to jostle around. This may have broken the rear diff mounts and the tranny mounts have been toasted as well.

New tranny mounts are in order and will be installed over the weekend. I was so happy to feel just the initial bump from the road and not the additional bumps of the engine baning around. It feels like a whole new car! albeit, one with alot of vibration while the mounts break in.

rx-7 obsessed

even though u did this already here is a really good write up for the pinion snubber incase anyone was interested
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/pinion-snubber-diff-mount-replacement-convertible-876959/

Enthu

iTrader: (1)

That's a good write up. The pinion snubber makes alot of sense for our cars. Mine is an NA and it still had a bad diff mount. I had previously had an NA break it before too. It's not the easiest, but if you are changing the front diff mount it's less than $10 to do the mod and it makes shifting feel much better, not to mentions save your new mount!

rx7_FREAKKK

iTrader: (1)

If it was your Front diff mount when you start from a stop the rear end would come up hitting the bottom of the car making a huge bang. trust me. I been there.

If thats not the problem i would start by getting a wrench and making sure the rear end is tight TWO BOLTS. and the Sub frame is Tight TWO BOLTS and also check the TIE rod bolts... That can cause alot of noise when taking a corner or going over bumps

PistonLessRX

iTrader: (4)

Mine did it and i didnt even have to have a friend help. I jacked the car up and had both rear wheels up and pushed up on the front of the diff and it went to the floor and realized that was the mount casue the noise got rediculous only after about a 10 min drive.