When backing up and slipping the clutch (like trying to back up to a trailer or something) the whole truck will start to bounce.

It gets pretty bad, and will start to clunk if I continue.

Whats the deal?

Dont tell me not to slip the clutch, it has to be done.....

When backing up and slipping the clutch (like trying to back up to a trailer or something) the whole truck will start to bounce.

It gets pretty bad, and will start to clunk if I continue.

Whats the deal?

Dont tell me not to slip the clutch, it has to be done.....

is when you are backing and turning? could be the locker?

Well first off you must have a pretty good load on so why no put it in 4 wheel low, thats what I do that way you don't have to slip the clutch. Just my $.02.

It does it regardless of wether or not I am turning.

Even when backing out of a parking spot it will do it.

I have put it in 4x4 before, but thats not an option when Im turning and on pavement.......

Its not subtle either, the truck really bounces and will start to clank bigtime.

manny,

Mine does it sometimes also. I can stop, then re-engage the clutch and it may stop. If not I push in the clutch and try it again. Usually within 2 or 3 tries, the bouncing will stop. I believe it is the clutch/flywheel chattering...my $0.02.

MaxRock

From my experience with this this same problem it appears to be the rear differential. It is switching from side to side very fast. It happens to me all the time in snow when I back up with the truck unloaded in 2wd. If you give it more gas then both sides spin up and it smoothes out. My '88 would do it in sand going forward.

Manny:

Sounds like you are trying to 'finesse' the truck while in reverse, that is you are varying the throttle while backing. Ever do the bouncy while going forward? It's the same in reverse.

While backing, you are probably letting up on the throttle. The engine will slow and the truck will slow. At some point the engine senses that things are getting to slow and adds fuel to maintain engine speed. This results in the engine accelerating the truck (and load). Then the engine senses 'all is well' and defuels.... Then things start slowing down again and the vicious cycle starts all over again....

As stated above, your best bet is to push in the clutch to break the cycle of accel/de-accel, then slowly re-engage the clutch.

L8r

Manny the problem you refer to is common in larger trucks. The fix is rather $$ it is
most likly caused by flywheel ware. The fix is to pull the flywheel and have it
reserfaced or replaced. Clutch\flywheel grab is a common complant among
truckers IMO hope this helps

KOTR

hey ... i'm not much of a diesel guy, but clutch operation is similar on a gasser too. I don't know how you drive your truck or how hard you are on the clutch... if you slip your clutch and burn it bad enough, it creates "hot-spots" on the surface of the clutch disc, pressure plate, and flywheel. these "hot-spots" are inconsistencies in the surface of the metal and do not grab as well as normal parts would... this would cause the "chattering" you are describing... just my $.02

I think L8r is probably correct. I have the same problem, though worse than most who posted on this thread. The dual disc clutch grabs like gears !!! If I dont have the throttle and the clutch pedal in sync the rear wheels jump and bounce significantly. In fact, I occassionally have the same problem going forward because of the grabbiness of the clutch kit. The best solution is to concentrate and if it starts to jump, push the clutch pedal and start over.

hope this helps.




Manny:

Sounds like you are trying to 'finesse' the truck while in reverse, that is you are varying the throttle while backing. Ever do the bouncy while going forward? It's the same in reverse.

While backing, you are probably letting up on the throttle. The engine will slow and the truck will slow. At some point the engine senses that things are getting to slow and adds fuel to maintain engine speed. This results in the engine accelerating the truck (and load). Then the engine senses 'all is well' and defuels.... Then things start slowing down again and the vicious cycle starts all over again....

As stated above, your best bet is to push in the clutch to break the cycle of accel/de-accel, then slowly re-engage the clutch.

L8r

Mine does the same thing....I am not sure about the other comments but I will say we used a three disc cluth system in a race car and it acted the same way, so I have come to the conclusion it is rather normal...I had my clutch, pressure plate and flywheel replaced last month....acts the same as it did before.