junito1

OK. I just recently put new motormounts, tranny mounts, And all 3 diff mounts(2 sumbframes and 1 front diff)

I also got a new oem spec mazdatrix driveshaft.( with replaceable u-joints.)

But even after all this. I can feel play in the drivetrain.
For example i could be in 2 gear cruising at about 2 to 3000 rpms. and i release the gas and then jump on it. and i do this about 2 to 3 times over and you can just feel it has plenty of play and im getting some small clonking noises when it wigglesw around. also when you leave in high gear and slowdown it will kick around like a kangaroo. Can also feel drivetrain wobbleing back and fourth.

I am also getting some vibrations in high rpms... and on 4 and 5th low rpm loads.

I almost wnt to say its the driveshaft... BUt mazdatrix is reputable enought arent they? I mean i dont know if the driveshaft came balanced or anything.. I never asked.

any ideas to what, or why it could be?

Fault Bucket

First thing I'd check is whether all of the new mounts are actually bolted up firmly. When replacing stuff like that you can think you have them all tightened correctly, but you may still have some slack in one or more just from stuff moving around as you tighten them down. Check that the rear subframe-to-unibody bolts are tight too.

-chris

jdmdavey

iTrader: (3)

yeah I would check and make sure you torqued everything down.. Also, was that drive shaft balanced from the factory? It may need to be that could be causing your vibrations...wheel bearings all sorts of things can cause vibrations.

Dave.

jgrewe

iTrader: (1)

Check for play in the diff. How much can you turn the driveshaft back and forth with out either wheel moving?

junito1

what do you mean-- play in the diff?

As in the pumpkin itself?

I will check the driveshaft and will go over the nuts and bolts to the subfame mounts,tranny and motor.

I will most likely do this on the weekend. GEt back to your guys in about 4 to 5 days.
THanx

RotaryEvolution

iTrader: (30)

holy **** people...

first of all, jouncing the drivetrain like that is EXTREMELY hard on it and you can break drivetrain components if you try hard enough. second, a small amount of slack in the drivetrain is perfectly normal.. you shouldn't be looking for slack in the drivetrain with those methods. if it was clunking while taking off from a stop for example i might say you have a problem but this is just abuse not diagnosis in this thread.

if anything you are feeling slack in the gears in the transmission, if you really want to dive into it then check ring gear backlash, if it is within spec then the transmission is probably just worn from abuse.

junito1

ok-- play in the transmission case itself? never heard of this...

rotaryperv

Have you checked the rear sub frame for cracks ? i had the same problem , i drove around with a broken front diff mount for so long that the rear sub took all the punishment

junito1

my front diffmount, actuall wasnt in that bad of shape...Had one clean crack on it. my crossmember mounts thought were worse and my motor mounts fell out in 2 peices....
tranny mounts wernt so bad...

but this weekend ill look for rear subfame cracks also..

oh and karack... i wasnt WOT then letting off then jumping back on it... i was only giving it a small amount of gas and letting off.. thats all it takes to feel the play... and it doesnt clunk THAT hard... its just that it has enough play to make noises... even after ALL new mounts...

RotaryEvolution

iTrader: (30)

you will still get a clunk-clunk noise from the shifter area when doing a bucking motion with the throttle, that is normal. with stiffer mounts the noise will only be more pronounced.

i said what i said because "jump on it" doesn't sound like tapping the throttle lightly to induce drivetrain 'rubber banding'.

junito1

true, my wrong choice of words...

but is it possible for a tranny itself and the diff itself to have some sort of play from being old and abused?

OK.. i am also getting some vibrations on load and higher rpms. after the new(used tranny w/ less miles[supposedly]) was installed.

Jzavala

im having the same problem, exact same symptoms....if someone can figure this out it would be of great value to me as well.

edit: except in 2nd if i let it off, it'll buck on its own, im replacing the driveshaft in hopes of this is the solution myself, im getting the same driveshaft as the op.

junito1

SUPER !!BUMP!!!! I still havent figured out my problem GUYS!!! But i do have one new piece of evidence. Since im semi newbish to rx7's I did not know there was some sort of motor mount seat bushing thingy. I realized it when i seen someone here on the forum selling his. I KNow for SURE my car does not have these motor mount seat/bushings.(with teeth on them)

Can this be the cause of my vibrations.? And does anything else like the rear end use similar bushings?

junito1

BUMP@@@ these things..... https://www.rx7club.com/showthread.php?t=647969


and i remember the rearend original subframe mounts had little teeth like these before i had someone put new mounts all around.

junito1

plz tell me now.. cause if it is.. i will buy those imidiately

junito1

I think its the transmission crossmember. I still havent fixed this hahah!.


I will order new one and let you guys know.