I've had this horrible shaking while releasing the clutch pedal in 1st and Reverse. It only happens while getting the truck moving at first. It is a horrible shaking. It shakes the entire truck violently. The clutch is smooth as silk every other time, except maybe hard downshifts. I really don't think it's clutch contamination, because I was pretty careful about avoiding that. It's also not a worn clutch because I have fewer than one thousand miles on this clutch. I was very careful to apply the proper torque to all flywheel and pressure plate bolts.

I've done a little bit of reading that suggests that worn or broken motor mounts can cause this condition. I believe that could be the case because when I was on automatic transmission programming, I would get a rompy start occasionally, and there seemed to me like there was excessive motion in there while romping.

What's the best way to discern the condition of engine mounts? Also, how difficult would it be to replace them? I've read the manual, and it seems like it's not too bad.

Thanks in advance.

Also, what's a good brand to go with on motor mounts? Most places I've seen carry the Anchor brand, but some of my reading suggests that Anchor parts are less than optimal in the quality department.

 

Sounds to me like a grabby clutch (new Valair) that isn't broken in yet...

 

So... It's normal and I should just get over it for a while? I'll adopt a "wait and see" approach. It's a brass-woven organic clutch if that helps.

 

I'm no Valair clutch expert, but someone else can chime in and give their $.02. That just sounds to be the case to me and from what I have heard some of the Valair clutches can be a little on the sticky side until they're broken in a little.

As far as looking at the motor mounts for wear, I generally employ the help of a helper and have them put the vehicle in reverse, and 1st and watch for excessive movement of the engine. You have to apply some force to the engine somehow to know whether they're worn or not. I guess you could do the same thing with a hoist or a jack, but if you have someone to help you the forward and reverse trick is a lot easier.

 

Joseph, mine does this on occasion. I attribute it to glazing. After I tow it seems to be this way. There a way to use the clutch to wear away the glazing. So, I just drive it that way and it goes away after a 100 miles or so. Not sure about the mount thing.

 

That clutch ain't one for much slipping. A little more go pedal and a slightly faster clutch release is about all that will make it any better. Mines the same way after probably 20k miles. It just wants to go, now.

And fix the mounts if theyre broken.

 

Oh well, no surprise Nate beat me by at least a mile but I am surprised we were thinking on the same level.
Joseph consider this a bump. It doesn't seem likely to be a motor mount problem, just because that seems to be very uncommon. I got a valair clutch kit about a year ago and it has smoothed out a lot with the gear rollover and I had some clutch chattering when engaging in second gear starts, it still dose it but maybe I have made adjustments and feather (let it slip) as i release just a little. I wouldn't know the technical way to check motor mounts but I would visually inspect for anything unusual. Then I would set the brake, block the wheels then very gently release the clutch in 1st and then Reverse looking for abnormal movement or rocking of the engine from the torque when slightly engaging the clutch. Helpful to have an observer.

 

I just watched the engine as my brother partially engaged the clutch with the brake on. It slightly rotated but was still, not a whole lot of vibration and jerking like what I was expecting. Reverse was a little more fidgety, but still not bad at all. I don't think it's the mounts. I guess I'll just drive it.

 

Yeah, I would say the mounts are probably alright. The way the mounts are built on these trucks they're pretty stout. Honestly, I haven't heard a lot of people having trouble with the OBS motor mounts. I would just drive it a while and start in second gear if it was me. I have never driven a ZF where I needed to use 1st gear much unless I was towing heavy or really hauling a lot of weight. Reverse I can see would be a problem though until the clutch wears in a little.

 

I'll try starting in second and see if that helps. I'm worried that it'll make it worse, since it will require more slipping, but the slipping will have less mechanical advantage on the rear end with which to shake the truck, so I can see how that would help.

 

The S5-42 and 3.55s aren't the best of friends during a 2nd gear start. Mine is pretty good during the first few cold take offs then it's 1st from there on. It did pretty well with my 4.10s and 2nd gear. Supposedly the 47 isn't bad during a 2nd gear takeoff but I've no idea why. That's just what Ian said. BTW, where the heck is that guy anyway?

 

When my Trans mount gets loose, my truck does this more aggressively.

I only have one bolt for my trans mount because the other ear is broke off. (thanks PO!)

After 40k miles on this clutch I still get jerky starts, but I expect it from mine.

You have a stock style replacement, It should be smooth.
Since its smooth in 2nd, i'd expect it to be fine.

Reverse is always jumpy for me no matter what clutch or vehicle i'm driving. I think it has to do with the gearing.

My only thought other than the rear trans mount is that the clutch is hanging up on the input shaft.

 

If you're talking about plgebbia, he is busy as heck. I think he's too busy for the internet. I could be wrong, though. It's been a while since I've talked to him.

 

Hmm... It's the 350hp clutch or whatever, not the stock style. The stock style is just organic, where mine is brass-woven organic. Also, I don't start in second, so I don't know if it's smooth or not. I can speculate, but I have no real answer.

I'm going to go over all of the fasteners down there tonight or tomorrow. That should tell me something. After that, I'll see what a second gear start feels like and get back to you.

 

I just put the brass woven clutch in my truck and I get the shaky down shifts. Not so much on 1rst or 2nd gear take offs. I've got the S5-47 and 4.10 gears though. I think what you're experiencing is normal for the new clutch. I think if it were a broken motor mount, it would feel like it was gonna jerk the shifter right out of your hand.