as th4e title says my car has a death wobble at 35mph. Car shakes pretty hard in all gears at 35mph, even nutral. slower then 35 and faster then 35 I can still feel it although it is liveable.

Where to start looking ?

 

front wheels, lift them off the ground, and shake them with your steering wheel ignition locked.

hands on each side to tire, try to move back and forth, if it moves you have a pitman arm bushing, or tie rod end problem, there will be about 1/4 inch movement which translates to steering wheel.

hands on top and bottom, try to move back and forth, if it moves you have a wheel bearing problem.

Also your wheel lug nuts might be loose. but they would have come loose by now, wheel would have fallen off, and you'd be dead.

 

less likely, but possible - check that you have all the bolts @ the rear of the drive shaft. Or possibly your shaft is bent.

 

Bad tire?

 

new tie rods about three weeks ago and they are good still
new wheel barrings about two weeks ago and they are good still
rotated the tires a few mins ago

 

checked the driveshaft and its cool

 

nah checked the tires when I rotated them a few mins ago

 

If it only happens at a certain speed, not reliant on the engine RPM, It is most likely something to do with your driveshaft, rear end, or wheels. It could have to do with the rear part of your transmission but thats unlikely... It seems like you did some repairs not too long ago...when did the problem begin?
There are lots of possibilities for problems even though everything "looks fine" so pinpointing what was worked on and when the problem started is key.

 

Also, if you dont feel it any more in the steering wheel than the whole car overall, chances are its somewhere from the transmission back.. And if you do feel it in the steering wheel, then its most likely a problem in the front suspension/wheels.

 

drive speed shouldn't be a factor then, or the driveshaft or axle wheel etc.

 

I assumed he just meant coasting at 35 mph in neutral...unless the car shakes in neutral when the car is stopped its irrelevant.

 

Sounds like wheel balance problem to me. Check all lugs are correctly secured also.

 

i don't think that the problem is tranny/engine/clutch related for the fact that the shaking happends in 2nd at 35, 3rd at 35, 4th at 35 and even in neutral at 35.

I just went for a test drive after rotating the tires and checking the steering/undercarige and it seemed to shake less, I'm not really sure. I have a feeling that one of the wheel balance weights might have fallen off on my 150 mile road trip I made last weekend.

I will be getting an allignment (needed anyways) and I will have them re-balance the tires (last time they were balanced was about three years ago by previous owner) and see if that helps out.

 

Is there a weight balance on the drive-shaft that could have come loose ?

What about engine mounts/ transmission mounts <--could they be the cause of the shaking ?

 

yeah thats what I'm hopeng lol

 

as my drive shaft u joints went out, there was an intermittant banging noise. It didn't shake the car, it made a lot of noise. I'd put the clutch in, coast, and then it would stop, release the clutch, and it would not return.

Your mentioning the specific speed points to the drive shaft, differrential, or rear/front wheel assembly.

Interesting problem though, let us know how it turns out.

 

When you rotated the tyres one of the balance weights might have been knocked off. That happened to me and i got the vibration at a slower speed. It can cause a pretty bad wobble when they're out of balance. Its pretty cheap to get them balanced and its a good place to start before changing driveshafts around

 

yes coasting, nothing ab-normal happends while stopped in neutral

 

another question, the car is a 85GS, the driveshaft/rear unit is a 82 GSL. I forget from my swap if the u-joints can be replaced on the 82 or on the 85.

Which year is it because one of the years cannot be replace and one can ?
thanks for all the help everyone

 

83 and up have non servicable ujoints according to Mazdatrix site. I've heard of folks replacing the ujoints on these drive shafts but I think they had a tranny shop do them. You may be lucky if its really an 82, because then they are like 20 bucks for each ujoint and pretty easy to replace. Didn't you do this when the new rear end went in ? Tsk tsk.

BTW, my best guesses are engine/tranny mounts, ujoints, or bent rear axle. If it was a wheel balance issue it would follow the wheel around and you'd be able to feel which corner was wobbling.

 

1) Remove driveshaft
2) Get it balenced
3) Reinstall driveshaft

If you don't do this you are just pissing into the wind

 

I'd start by checking the idler arm bushings. They're easy to check, and chances are they need replaced anyway. It's definately a good investment at $30 bucks, and 10 minutes.

 

In my opinion, the fact that it changed when you rotated the tires pretty much narrows it down to a tire/wheel issue...

 

+1 with Kentetsu..I'd try Checking/Rotating Tires Again (It's FREE)..checking Wheel nuts.you could have just Put on a Wheel a little ****-eyed.(you know,when you tighten up the wheel nuts and they all "seem Tight" but the Wheel is still not Flush on )..

 

yeah its a for sure 82 gsl rear end, I remember now that the 82's had replacible u-joints. No I did not replace the u-joints, lol that prolly would have been the correct way to do it but I just pulled the driveshaft off a junk yard car and put it in to mine.
Wheel barrings are pretty new -within the last year I had then both serviced in the last month cause they were becoming loose.