Massive shaking in Reverse

[SHOkid13]

Okay, I haven't been able to figure it out... After putting in my Quaife and a full tranny rebuild, I got a massive shake when I am in reverse, especially at lower RPMs. All of my mounts looked good when I had it all apart, and they are all connected and tight now.

To explain the shake: Feels like the engine wants to drop out of the car!

Could it be the combination of clutch, Quaife, flywheel, etc?

It didn't do it when I had the new clutch only.

Thanks...

 

[sdpatt]

Does the car actually try to move when letting out the clutch in reverse? When you reassembled the transaxle, were you following a service manual or more detailed procedure?

 

[Bizzy]

What kind of clutch did you put in? Flywheel? (I realize you have a list of stuff in your sig but sometimes these change and people forget to update their info)

Sounds like a sort of drive train chatter to me, as in, your clutch doesn't like to be feathered. Are you sure the quaife was shimmed properly for the tranny case? Does it do this after the clutch pedal is let all the way out or just while you're starting to engage the clutch?

I'd think also that if the quaife wasn't shimmed properly you'd see more symptoms in other gears, not just reverse. Give us a few more details to go on.

 

[SHOkid13]

Does the car actually try to move when letting out the clutch in reverse? When you reassembled the transaxle, were you following a service manual or more detailed procedure?

It definately moves backwards. I just have to release as soon as it starts shaking and try again at a higher RPM.

I used the Helms book and Josh's video...

 

[COliveira95]

Sounds to me like clutch chatter. My car does this in first gear as well. I have the 9puck fibertuff clutch and the 17lb steel billet flywheel. I really am getting annoyed with all the chatter but it does grab very well.

 

[SHOkid13]

What kind of clutch did you put in? Flywheel? (I realize you have a list of stuff in your sig but sometimes these change and people forget to update their info)

Same stuff that's in my sig. I have the stock ground flywheel with some weight removed as discussed in a thread from awhile ago. It was done at a highly respected machine shop in the area.

Sounds like a sort of drive train chatter to me, as in, your clutch doesn't like to be feathered. Are you sure the quaife was shimmed properly for the tranny case? Does it do this after the clutch pedal is let all the way out or just while you're starting to engage the clutch?

The quaife was shimmed with Josh's rental tool and it was tight after instalation (I don't remember the exact torque it took to turn it now however). I never let the pedal out all the way when it started doing it. But, there is only a slight "grippy" feeling in the forward gears.

I also replaced the input shaft bearings and checked after to make sure it was tight too; not super tight, just snug.

 

[Bizzy]

Sounds to me like clutch chatter. My car does this in first gear as well. I have the 9puck fibertuff clutch and the 17lb steel billet flywheel. I really am getting annoyed with all the chatter but it does grab very well.

Welcome to Fibertuff land. I can't wait to leave it.

If you can get past feathering the clutch pedal with those you'll have a great feeling clutch. Unfortunately it's a habit not easily corrected.

 

[SHOkid13]

Sounds to me like clutch chatter. My car does this in first gear as well. I have the 9puck fibertuff clutch and the 17lb steel billet flywheel. I really am getting annoyed with all the chatter but it does grab very well.

I am guessing, based on the previous info about shaving the flywheel, that I have lost about 3-4 lbs off the original weight. I didn't have a scale available to weigh it after. It is more difficult to start out in first than before, but not to the point of getting annoyed yet.

 

[SHOkid13]

Welcome to Fibertuff land. I can't wait to leave it.

If you can get past feathering the clutch pedal with those you'll have a great feeling clutch. Unfortunately it's a habit not easily corrected.

When you say "feathering", are you reffering to the adjusting of the clutch pedal to keep the right ammount of torque level to the wheels? Example: Starting out I let the clutch out to far and the RPMs drop down, to correct, I keep the throttle at the same place and push the clutch in slightly more until the RPMs recover.

Is that right?

 

[Bizzy]

Same stuff that's in my sig. I have the stock ground flywheel with some weight removed as discussed in a thread from awhile ago. It was done at a highly respected machine shop in the area.

Is there any chance the flywheel could have been slightly warped at all? I don't really think that'd be the issue though, again, you'd see symptoms in more than just reverse.

The quaife was shimmed with Josh's rental tool and it was tight after instalation (I don't remember the exact torque it took to turn it now however). I never let the pedal out all the way when it started doing it. But, there is only a slight "grippy" feeling in the forward gears.

The not letting the pedal out all the way indicates feathering to me. Try letting it out enough to barely get the car moving, then once the car is moving let it out all the way without giving it much gas. See if it does it then.

I also replaced the input shaft bearings and checked after to make sure it was tight too; not super tight, just snug.

Explain more on this please. The bearing should be pushed all the way up to the bottom of the bottom gear and down to the top of the top gear. The bottom of the race should be touching the gear. If they weren't put on all the way be on the lookout for problems.

 

[Bizzy]

When you say "feathering", are you reffering to the adjusting of the clutch pedal to keep the right ammount of torque level to the wheels? Example: Starting out I let the clutch out to far and the RPMs drop down, to correct, I keep the throttle at the same place and push the clutch in slightly more until the RPMs recover.

Is that right?

Feathering is where you gradually let out on the clutch pedal. It allows a slower engagement and a with a clutch that doesn't allow much slip it tends to cause chatter. I've experienced some very harsh chatter in my car from time to time where it felt like it was going to vibrate the dash off the firewall. Fibertuff + feathering = big no-no

 

[SHOkid13]

Is there any chance the flywheel could have been slightly warped at all? I don't really think that'd be the issue though, again, you'd see symptoms in more than just reverse.

Acording to the machine shop, no. It was "perfect."

The not letting the pedal out all the way indicates feathering to me. Try letting it out enough to barely get the car moving, then once the car is moving let it out all the way without giving it much gas. See if it does it then.

I'll do that when I leave the office shortly...

Explain more on this please. The bearing should be pushed all the way up to the bottom of the bottom gear and down to the top of the top gear. The bottom of the race should be touching the gear. If they weren't put on all the way be on the lookout for problems.

Sorry, I didn't explain myself gooder. The bearings were pressed on all the way with a multi-ton press: they are tight. I meant I put the case halfs together before final assembly and turned the input shaft with none of the other gear clusters installed (same kind of thing for testing the quaife fit). I was able to turn it by hand, but it had plenty of pre-load.

 

[SHOkid13]

Feathering is where you gradually let out on the clutch pedal. It allows a slower engagement and a with a clutch that doesn't allow much slip it tends to cause chatter. I've experienced some very harsh chatter in my car from time to time where it felt like it was going to vibrate the dash off the firewall. Fibertuff + feathering = big no-no

OIC! And probably feathering with a DXD would have similar results... maybe I just need better mounts (ie - SHOnut extreme?)...

 

[JoeHoe_SHO]

Sounds like the problem I have. I think its the drive shaft or the intermidiate shaft with the u-joint. Everyone thinks its tranny or clutch related but I'm telling you its not. Let me know when you figure it out. My car does the same ****

 

[Bizzy]

OIC! And probably feathering with a DXD would have similar results... maybe I just need better mounts (ie - SHOnut extreme?)...

No mount you get will stop drivetrain chatter, as a matter of fact I think the more extreme the mount the more pronounced the chatter will be because the heavier duty mounts don't allow as much cushion like the stock mounts would. If you had stock mounts and stock subframe bushings on your car it probably would be noticed, but it wouldn't be as harsh.

 

[SHOkid13]

The not letting the pedal out all the way indicates feathering to me. Try letting it out enough to barely get the car moving, then once the car is moving let it out all the way without giving it much gas. See if it does it then.

5 Points awarded to Beth! It doesn't do it if I let the clutch out all the way and then apply throttle, even if I floor it or "tap" on the throttle.

Old driving habbits retired, and new ones in the works!

 

[NotSoSlowSHO]

Same stuff that's in my sig. I have the stock ground flywheel with some weight removed as discussed in a thread from awhile ago. It was done at a highly respected machine shop in the area.

Was it balanced properly AfTER being machined?

It needs to be spun-balalanced WITH the pressure plate to be dead on balanced.

 

[SHOkid13]

Was it balanced properly AfTER being machined?

It needs to be spun-balalanced WITH the pressure plate to be dead on balanced.

Really? Not to sound stoopid but I've never done that before when balancing any of the ford or toyota motors I have built... Never had any issues with them... We would always send down the crank, flywheel, harmonic balancer, pistons, rods, etc. and never sent the pressure plate...

But, if it was a balance issue, wouldn't it also do it in all forward gears?

I think Beth hit it right on when she said feathering; I stoped it and now I don't have the issue. My brain wasn't used to a hi-po clutch yet.