88GTU_AutoX

iTrader: (1)

Hey guys, it really isn't a big issue, but I was wondering if the clunk as described in the title was associated with bad mounts or, as a fellow rexer once said to me, "the rx-7 transmission is kind of notchy." Usually it's in the lower gears, and my clutch is WEAK AS BUTT (not dropping it). The only way the noise and jerk goaway is if I'm REALLY soft on the clutch when easing out.
Thanks for the help in advance, guys!

RotaryEvolution

iTrader: (30)

some clutches just chatter and there is no way of doing anything to get rid of it besides changing the clutch again and resurfacing the flywheel.

soft and weak engine and tranny mounts will make the issue more prevalent, check yours to be sure they are intact. replacing all of them should either cure the problem or make it much less prominent.

88GTU_AutoX

iTrader: (1)

Sweet man, thanks for the help; I'll put in some good mounts while changing the clutch this winter.

rx7_FREAKKK

iTrader: (1)

Nah.. You better Double check. Just incase. Make sure its not the rear end mount that broke

RotaryEvolution

iTrader: (30)

good point, if the clunk is coming from the rear of the car check that first and fix it asap.

88GTU_AutoX

iTrader: (1)

Rear end mount? Are you talking diff mounts?

RotaryEvolution

iTrader: (30)

yes, the mount at the nose of the differential goes bad quite often and causes a sharp clunk in the rear of the car when put under a load.

88GTU_AutoX

iTrader: (1)

Oh... That sounds like the problem. The part is more commonly called the diff front mount? There is a guy on the forums selling one for cheap. Is the install any trouble?

RotaryEvolution

iTrader: (30)

the install is a bit of a pain in the ***. drop the driver's side rear subframe and remove the passenger side subframe mount as well to get to the bolts and then weasel it out. takes about 2 hours minimum.

good idea to pick up a pinion snubber while you are in there, will help keep it alive a little longer.

88GTU_AutoX

iTrader: (1)

Thanks, man. Sounds like a bit of a job. What kind of damage can occur if driven with a bad mount for awhile? Mine's been this way since bought, three months past.

RotaryEvolution

iTrader: (30)

u joints can fail as well as damage to the chassis of the car and/or cut through e-brake cables if driven too aggressively.

88GTU_AutoX

iTrader: (1)

Alright, drove the car again just now, so let me update while it's fresh in my mind. The clunk comes both with a slightly hard clutch engagement OR when coming from acceleration to coasting in gear (on to off load) OR when accelerating to shifting (on load to disconnection from load. Also, when driving slowly, if the pedal is not kept perfectly still, the car will "bounce" back and forth between "loaded" and "unloaded".
If you had ever run hobby-grade RC cars, it's as if the pinion and spur gears are too loosely connected, and the motor and the wheels are not in perfect sync. The car is moving at a constant speed right when load is given OR taken, as if a gear tooth is bouncing between two loose teeth. I don't know what to make of it...

Sorry for the re-complication

ryan2949

iTrader: (2)

My car does that "bounce" back and fourth when I'm driving slowly and let off the throttle and get back on. I made a thread about it a while ago but can't seem to find why. First gear is the worst and it will do it in any gear when driving slow.

Sometimes when I accelerate then push in the clutch I hear a weird clunk from the transmission but only when I accelerate then depress clutch. I think I may have the same problem but not as bad.

rx7_FREAKKK

iTrader: (1)

Another issue found Often is when the output shafts inside the rear end that goto the CV Joints go bad they move.. Creating to much slack in the drive train Creating too much Null. If you have a rear diff mount out you will know. For a few reasons. One the trans will be Leaking at the rear because of its moving in and out of place. AND huge clunk under load. Even Light load before the car even moves. Hard launching Ruins these Stock rear Diff Mounts. They are Weak. Most of the time the metel itself breaks. Then you need a new subframe or welder

88GTU_AutoX

iTrader: (1)

It definitely sounds more like the first. That also sounds much tougher to fix. What can go wrong other than a lot of "null", as you put it?

clokker

iTrader: (2)

OP, have you gotten under the car and looked at anything yet?
That would eliminate a lot of idle speculation.

88GTU_AutoX

iTrader: (1)

Haha, unfortunately not. Sorry, I'll do that tonight, and I'll post what I find.

ps: you said "idle speculation". I just had to laugh. Sorry. :p

midnightbluefc

iTrader: (19)

I have had my fair share of broken front diff mounts... straight forward install of the new mount, take ur time and goodluck