Backlash in the Transaxle?

[DoctorDex]

Originally Posted by KORMEX

Try to eliminate the engine (crank walk) and motor mounts by doing this :

1.) put the car in 1st then speed up
2. ) press the cluth and put it in neutral
3.) with the car still coasting and the clutch depressed put it in 1st .

Just for the sake of clarity, when you say "clutch depressed" you are saying I'm supposed to put it into 1st without using the clutch?

Declanl

[KORMEX]

Originally Posted by DoctorDex

Just for the sake of clarity, when you say "clutch depressed" you are saying I'm supposed to put it into 1st without using the clutch?

Declanl

Not exactly , you will have the clutch pedal pressed down (depressed) and the car will be coasting,

What you are trying to do is engage all the components from the rear wheels to the trans and listen for the clunk. by having the clutch depressed the engine and its components dont come into play. for example: imagine your car coasting downhill with the clutch depressed and the engine off, now if you where to shift into 1st gear (clutch still depressed) you would be able to hear the slop in the components, because you are apllying the drag of a few more gears (inside the trans) to the spinning components.
does that make sense ?

[DoctorDex]

Yeah that makes sense.

I tried your test and it doesn't make a clunk with the clutch pushed down and I shift it into 1st. Once I release the clutch it still doesn't make a sound. However, I hear a clunk as soon as touch the gas. Is this driveline noise?

Declan

[KORMEX]

Originally Posted by DoctorDex

Yeah that makes sense.

I tried your test and it doesn't make a clunk with the clutch pushed down and I shift it into 1st. Once I release the clutch it still doesn't make a sound. However, I hear a clunk as soon as touch the gas. Is this driveline noise?

Declan

just to make sure , the car was coasting when you shifted into 1st correct ?


If I where you , I would check all the motor and trans mounts , and also you may want to get a large pry bar/screw driver and try to move the crank pulley in and out . If you had the problem in the trans or driveline you would have heard something while doing the test .

[DoctorDex]

Ok, I tried it again, but this time I tried the test using 2nd gear. I accelerated in 2nd, pulled it out of gear, coasted in neutral with my foot off the clutch, and then I pushed in the clutch and put it into 2nd again. No noise. As soon as I let off the clutch the car lurched and it produced the awful sounding clunk. I take it this is definitely driveline noise? When I had the trans out 3 months ago, I checked the front, rear and transaxle mounts and they were all in good shape.

Declan

[KORMEX]

Originally Posted by DoctorDex

Ok, I tried it again, but this time I tried the test using 2nd gear. I accelerated in 2nd, pulled it out of gear, coasted in neutral with my foot off the clutch, and then I pushed in the clutch and put it into 2nd again. No noise. As soon as I let off the clutch the car lurched and it produced the awful sounding clunk. I take it this is definitely driveline noise? When I had the trans out 3 months ago, I checked the front, rear and transaxle mounts and they were all in good shape.

Declan

Driveline to me means from the engine to the rear differential , The test you are doing is to determine where in the driveline the clunk is comming from, and from the results you are reporting I would look from the center differential forward . Another place where I have seen this sort of problem is the front differential carrier (they wear down), make sure that the front drive axles fit tightly in the carrier (check for movement up and down) you can do this by hand .

[DoctorDex]

Once again I'm confused. How would a driveline clunk present compared to an transaxle/engine clunk? If it is a transaxle clunk, what can I test to prove it?

The dealer adjusted my rear backlash to within spec., but I do have quite a bit of play in my propeller shaft, I can rotate it by hand ~ 1/6 of a turn. Is this normal??

I have new front drive axles (the boots on the old axles were cracking so I replaced them) so I'm assuming that these are still good. However, I didn't check the front differential carrier. I take it the front differential carrier is where the front drive axles insert into the trarnsaxle? How do I check this, just push up and down on the front drive axles from underneath the car?

Thanks for your help.

Declan

[KORMEX]

Originally Posted by DoctorDex

Once again I'm confused. How would a driveline clunk present compared to an transaxle/engine clunk? If it is a transaxle clunk, what can I test to prove it?

The dealer adjusted my rear backlash to within spec., but I do have quite a bit of play in my propeller shaft, I can rotate it by hand ~ 1/6 of a turn. Is this normal??

I have new front drive axles (the boots on the old axles were cracking so I replaced them) so I'm assuming that these are still good. However, I didn't check the front differential carrier. I take it the front differential carrier is where the front drive axles insert into the trarnsaxle? How do I check this, just push up and down on the front drive axles from underneath the car?

Thanks for your help.

Declan

OK Drivetrain is Engine transaxle
Driveline is propeler shaft/driveshaft My mistake (was in a hurry)

A driveline clunk would be more pronounced in 1st or reverse gear and barely noticeable fron 4th to 5th .

A clunk comming from the transaxle would be noticeable and decell while in gear. also you would feel it throughout the car

A clunk comming from bad engine mounts would ba almost unbearable on takeoff and you would probably have a noise/vibration with the pitch getting higher while accelerating .

I once test drove a customers car here that had a clunk , by luck, as I got out of the car I noticed some aluminum shavings on his wheels . It turned out that the wheels where loose (someone had tried to steel them )

Yes the front carrier is where the axles insert into the transaxle ,Yes to check you just get a good hold and move them , you should not be able to wiggle them much.

[keithmac]

If you can rotate the prop shaft 1/6th of a turn (near the rear diff) the backlash must be a mile out of spec? or the rear diff`s worn out. I can turn mine 1/8th and that`s enough for a clunk from the back.

The limit`s 5mm on the diff casing (see link), that`s probably 1/16th rotation or less!

Backlash Testing

If you`ve had it set up at a garage I`d be taking it back personally.

[DoctorDex]

Originally Posted by KORMEX

A driveline clunk would be more pronounced in 1st or reverse gear and barely noticeable fron 4th to 5th.

A clunk comming from the transaxle would be noticeable and decell while in gear. also you would feel it throughout the car

The clunk I'm experiencing is noticeable in all gears, but it is more pronounced in 2nd and 5th. I notice it especially when I'm accelerating quickly in 2nd and then I let off the gas suddenly. The car will literally jerk back and forth and my head bobs like bobblehead doll. This also happens in 1st gear, in the lower rpms range, which makes driving around parking lots tonnes of fun... The only way to soften the clunk and make it less noticeable is to slip the clutch when shifting into every gear, and to push in the clutch every time I want to decelerate and to slip the clutch back into gear.

So, just to clarify things here. You don't think the fact that I'm able to turn my propeller shaft 1/6 of a turn is significant/the cause of my problem and you think it has to do with my transaxle? If it is the transaxle, what components could be causing the clunk? I just finished replacing my OS and VCU and this made little to no difference.

Thanks again.

Declan