1998dsmtalon

My Truck is a 2001 2500 4x4, when I take off from a dead stop I get what feels like a hopping or shimmy.

I checked the transmission fluid and it was where it should be. I am new to Diesels and Auto transmissions.

Is this normal?

busa

Not normal, maybe a torque converter going away?

1998dsmtalon

How would I test that theory?

busa

First I would check the u-joints for slop. As for checking the converter I'm not sure besides dropping the tranny pan and checking for metal. You could load it up in gear slowly without moving(think brake stand without the tires moving) and feel for any jerking or jumping. Should be smooth.

1998dsmtalon

Switching from gear to gear is smooth. I just bought the truck and I am planning on changing to oil and tranny fluid as well as pan gasket and T. filter. As soon as I get a nice day to do it.

Fueling around

What condition are the tires?
Diesels have more torque off the line than a gasser. Bad tires will slip, skip, & hop.
Torque converters usually fail in the lock-up clutch, not in fluid coupling. A first gear clutch would be the weak point.

okish

also check the center support for the rear driveshaft. alot of times the rubber comes apart and the bearing wobbles around.

JHew84

May sound stupid but when I first got my truck it had terrible tires on it and I was convinced for about a week that the clutch was slipping. Then one night I had my window down and heard the tires spinning , kinda surprised me because I really wasn't driving it hard at all, just normal take-offs and acceleration. But like fueling said at times it would kind of jerk around and almost feel like it was surging in power, it still does it sometimes when it's wet out.

RacerRon

I 2nd the U-joints and driveshaft carrier bearing. The carrier was the solution for me when I had the same problem.

nickg

Usually a carrier bearing will cause the shudder/vib under inital take off or when you lug the motor, as you come up to speed of the load comes off the motor the vibration pretty much dissapears, a U-joint can do the same but typically will do it all the time
note: a U-joint can be completely shot and you might not feel the slop. because the needles grind themselves up and get rid of the play, if you see rust near the seals on the U-joint cups they are shot. best way I found is to remove the drv shaft and rotate the ujoint by hand thru its range of motion, if its bad you will know, as it will bind or not allow you to articulate the joint. it should rotate smoothly

busa

Good point Nick, a siezed u-joint will vibrate just as bad as a loose one. Pull the shaft and wiggle those joints around.

1998dsmtalon

Carrier is some what new. As are the tires. I am going to take a look at the U- joints and the rest this weekend.

Thanks for the input.

smokewagon

also could be axle wrap were the axle actually is moving forward and back under the truck my truck does it and i've check my u-joints and everything is fine so it could be simple as that if it is doing it when it's raining or is slick outside

1998dsmtalon

Threw the truck up on a buddies lift and there is no abnormal play in any of the joints or carrier. The axles as well are good.

I am going to do a transmission flush soon and see if that helps at all.

nickg

Did you pull the drv shaft off and rotate the U-joints by hand??