I am hoping someone can help me confirm my mechanics diagnosis on this. I am getting two distinct sounds coming from the drivetrain of my '85 GSL-SE, both of which my mechanic blames on a failing U-joint making replacement of the entire drive shaft the necessary fix.

Sound number one...
On launch in forward gears I hear a repeating "tick, tick, tick" coming from the back end. It almost seems like the sound a creaking door makes but with a more pointed, defined "clink" sort of sound. It does not necessarily follow the speed of the car in repetition. It is more prevelant the harder I accelerate on launch. I hear it consistantly in 1st gear, some also in 2nd and occasionally in 3rd with hard acceleration. With very light acceleration the sound is not there.

Sound number two...
In reverse gear, also from the back end I get a "shing, shing, shing" sound which seems to speed up as the car speeds up. As soon as the clutch is engaged the sound stops. I get a similar "shing, shing" sort of sound on the road, although not as prevelant, if I get off the throttle and leave the car in gear, decelerating by use of the engine and drive train. Again, as soon as I engage the clutch the sound goes away.

Are these both attributable to the U-joint/driveshaft??

Any ideas you have are appreciated.

 

When a u-joint goes bad on me, it's always been the one at the trans, either way, that's what it sounds like to me. But the joints can be replaced instead of the entire shaft.

 

Can't do that on an 85. I think you got to do the whole shaft. But you can buy new shaft with replaceable ujoints

 

I've found someone who has a drive shaft (used) I can get from the same year, model and trans. as mine. He says it has less than 40,000 miles use and will sell it to me for around $100. That's what I am thinking of trying.

Again, can anyone say if they believe the second of the two sounds I described may be coming from the shaft as well as the first??

 

go to http://www.uneedapart.com they found one for my 84 dlvd. for $60 w/ guarantee its a salvage yard best I have used

 

by the way that was delivered

 

So here is a real novice mechanic question.

How difficult is it to remove and replace the drive shaft on my '85 GSL-SE? Would I need any unique or special tools to get the job done?

With a replacement drive shaft on the way for this car I've been looking around to find someone to swap the part for me and am not having much luck. The only sources I've found that say they can do it don't inspire much confidence. You know, "Yeah, sure we can do that for you. That has that rotary engine in it doesn't it?" That and I'm not anxious to get ##@%ed by my local Mazda service department.

 

All you need is a couple wrenches (12mm box wrenches) and a prybar to keep the axle from turning.

It's just four bolts, slide the old shaft out, slide the new one it, bolt 'er up, and you're done!

 

That is music to my ears!!

 

Wait.... wouldn't u-joint noise continue even if the clutch was engaged? Seeing as how the driveshaft, diff, and wheels and tranny continue to turn by the movement of the car... I had a clunking problem, and it turned out to be a loose wheel (Never let friends torque wheels on). Check all the possibilities... could it be the throw-out bearing? Clutch assembly?

The best way to diagnose u-joint failure is to do the following:

Put the e-brake on
Put the car in first gear, and give it some gas
Let out the clutch fairly fast, but not fast enough to stall the car
Listen for a clunk
Do the same in reverse


The other way to check is to simply grab the driveshaft and pull on it in all directions. If it moves and the u-joint, then you know it's the problem.

We always tend to ignore the simple things, so make sure you exhaust all free options before spending $100+ on a new driveshaft...

Jeff

 

They usually stop making noise when no longer under load.

 

hmmm... ok, jst thought I'd mention to try the small things first...

 

I did get a mechanics diagnosis that the U-joint is failing. He told me it shows movement when grabbing and moving the drive shaft around.

I get a "shing-shing" type of noise on the road when the car is in gear and decelerating against the driveline. Engage the clutch and the noise goes away. On the road, in gear, with neutral forces on the driveline (no engine braking & no acceleration) the noise is gone. Under acceleration I get the "ting-ting" kind of noise.

A couple of noises but only when there is some kind of tension in the driveline.

I hope I'm not wrong but with the mechanics input and some similar problems discussed in these forums right now I'm betting on the drive shaft / u-joint.

Thanks for your thoughts.

 

i am taking my ride in for the same noises since a engine sap, i hope you're right, so it is not a tranny swap. thanks for your input! i will express these ideas to my mechanic.