Wankel7

I have an 86 Base model with 184,000 miles (orignal engine) and it apears the car is falling apart around the engine

When I start off from a stop after it goes foward a little there is chatter that is felt through out the car. Feels like it is coming from the rear end. If I start off VERY slowly with little acceleration it will not chatter.

I was thinking U joints. So I crawled under it and twisted the driveshaft (in 1st geat) and the only play i felt looked like it was coming from the tranny. I also lifted up on it. Nothing. I did not do that hard though.

I have looked over the rear suspension and nothing apears to be falling off. Any ideas?

Not sure what is up. Started after I let my ex girlfriend autox it for one run. I should have not done that. She is too old for that (the car).

Samps

The only way to really check the drive shaft is to remove it. It is only four bolts, and a little frustration. I had the same symptoms as you and low and behold it was the U-joints. Mine was busted up pretty good on the front u-joint going into the tranny. There will be no obvious signs when just crawling under the car and shaking. I bet if you take the drive shaft out you will find your front u-joint is in terrible shape and ready for replacement. Mazdatrix sells a replacement for a reasonable price.

Liquid Anarchy

iTrader: (2)

One of my local RX-7 owning friends had a very similar problem. It turned out to be (of all things) that both of his engine mounts were broken.

His used to have the same problems your're mentioning. Got his mounts replaced, and it's like a brand new car.

Turbonut

iTrader: (1)

Yup, inspect driveshaft and all the mounts. Don't forget the infamous differential mount!

RX-7Impreza

sounds sort of like what is wrong with my car. does it do it worse after the car is warmed up???

does it do it only in first gear from a stop??? and if you drop the clutch hard does it do it???

if you said yes to all of these questions then you either have oil or tranny fluid leaking onto your flywheel or a warped flywheel.

bad u joints dont normally affect start off, only when you hit a certain speed (depending on severity) does the car start to shake.

the warped flywheel feels like it comes fromthe rear end and it basically shakes the **** out of the whole car...

Justin

Juan

iTrader: (28)

Differential mount "clunks" when shifting or letting off the accellerator while in gear.

Wankel7

Ok, no clunking between shifts. Can rule out that.

I firmly believe the clutch is fully engaged. But I will not discount the idea of oil contamination on the clutch matter. I will take off the inspection plate and look around in there. Will also check the slave cylnder.

Hum, good way to check my motor mounts? Is there one? Can I jack up the engine and inspect them?
I have put an engine in before and know the rubber is supposed to be there. It seems like motor mounts maybe a good idea.

Ujoints. Yey. I remember this lengthy post about them. The are not replacable. However, somebody found a way to do it! No search so can somebody help me!

I found this on Mazdatrix....if you car is making this noise sort of thing.
http://www.mazdatrix.com/g2.htm

I believe it to be both my joints. $240 something for a driveshaft. Err, the shaft is bloody fine. My joints are probally gone.

Of course, there is this small side issue. My exhaust is so bad right now. If I take it off it would be a SIN to put it back in. Exhaust upgrade time? Murder she wrote. When it rains it pours.

James

Liquid Anarchy

iTrader: (2)

Grab hold of the engine, and shake it. If it shakes, you need new mounts.

If you'd like to go further than that, then try and jack up the oil pan... your engine should lift off the broken mounts. If your front end gets light, then back off, and look for a different cause.

Wankel7

I think I will try that! Probally jack it up under the tranny. Don't wanna risk messing up my pan.

James

JusRollin

You can change the u joints.. see the welds on the drive shaft that go all the way around it right under the u joints? you grind those, but don't get too carried away.... next finds some perfectly fine U joints and slap them in your driveshaft.. ( this takes a hammer and sometimes the aid of a punch) then take it to someone who can weld.. and have them weld it.. them take it to a machien shop with the capability to balance it and get it balanced.. slap it back in there.. and if it still chatters.. check the CV type joint on the rear axle! ( this is a lot of work "god forbid!", I had to shorten a driveshaft for my RX-7 SE still need to get it balanced though stupid long freaking turbo II or whatever driveshafts..)

jacobcartmill

iTrader: (6)

its the Ujoints. same thing happened with my 300zx. i had to buy a one piece. (yes, those big *** cars come with 2 piece driveshafts that weigh like 60 lbs)

Wankel7

Uh, maybe I should just take it up the **** for the $240 replacment shaft at mazdatrix

James

jacobcartmill

iTrader: (6)

get an aftermarket one. i'm sure you can find a cheaper aftermarket one than an assfuck oem replacement from the dealer. go to www.powertrainindustries.com

Aaron Cake

iTrader: (1)

Are you sure it's the driveshaft? This issue is usually caused by a worn or contaminated clutch disk.

First, check all mounts (remove and check). Remove driveshaft and check. If that is not the cause, replace clutch disc and have flywheel resurfaced.

RX-7Impreza

yes Aaron is saying the same thing i am. a bad u joint wont affect start off. if it is only on start up then it is probably a problem in the clutch engagement, meaning it "catches-slips-catches-slips-catches" causing the drivetrain to shake like hell


Justin

jacobcartmill

iTrader: (6)

a Ujoint was badly stuck on my 300zx and it would vibrate and sometimes clunk til it got spinning up.

Wankel7

Not sure about the clutch matter. The clutch has engaged. It occurs after moving foward about 10 feet. Unless it is a really delayed clutch engagment. I dunno...won't rule it out though.

I sent an email to that company Jacob. Thank you for the link!

James

Rotorific

iTrader: (1)

Im gonna be the third amigo and say that it is the clutch and clutch chatter is what is happening. -Gabe

Rotor13B

I had this problem once too. ended up being the ring gear in my differential. The teeth had worn down to point where the were barely catching, and one morning went to take off and clank clank clank, no more diff...lol

RX-7Impreza

does the shaking occur at all after start up.... at high speed. if it doesnt then i can assure you it isnt the driveshaft.

Justin

jacobcartmill

iTrader: (6)

it happens after hes going about 10 mph.

RX-7Impreza

he said it happens after about 10 ft..... i want ot know if it continues to happen up to 40 or if it stops and doesnt come back. if it is steady at high speed then it would be highly unlikely for it to be the driveshaft. start-up chatters are generally in a bushing, mount, or clutch-flywheel

Justin

Wankel7

There is a real bad chatter after about 10 feet. Then it goes away. However, there is a constant vibration.

At high speed the car does vibrate.


Now that I have got some many things to look at when i ge it on the road again tomorrow I will look and listen more carfully.

James

RX-7Impreza

ok if you have vibration at speed then it is probably U joints

Justin

Wankel7

Thanks again for the link. I was quoted $204 includng shipping! And a one year warrenty. Almost seems to good to be true.

I just need to take a deep breath and dig the money out of savings for the shaft and new exhaust.

Probally going to go with the RP50 (RX7.com) and the bonez superflow system.

James