Automatic transmission question.

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milefile

milefile

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Sometimes when I shift my 1998 grand Cherokee into reverse it makes a clunk and sort of lunges back, not very smooth. Other times it is very gentle and smooth like you'd expect it to be. It seems to do it when it is warmed up. I can't think of a time it did it when it's cold. Anyone know about transmissions and whether or not this is a big deal? What should I do?
 
I'm not a Jeep expert, but it sounds like it could be the U-joints in your driveshaft. If it is worn, the extra play in the joint can cause a clunk when shifting into reverse. It could also be the rear diff or CV joints... but the U-joints the first place I'd check for play.

I'd do a quick 'net search and see if it is a common ailment to your model. Perhaps "they all do that"... good luck.


///M-Spec

EDIT: sigh. U-JOINTs, that is... that's what I get for typing in a hurry... :rolleyes:
 
Originally posted by ///M-Spec
I'm not a Jeep expert, but it sounds like it could be the U-jolts in your driveshaft. If it is worn, the extra play in the joint can cause a clunk when shifting into reverse. It could also be the rear diff or CV joints... but the U-jolts the first place I'd check for play.

I'd do a quick 'net search and see if it is a common ailment to your model. Perhaps "they all do that"... good luck.


///M-Spec
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I would agree. It sounds like there is slack somewhere in the drive causing a jerk or "clunk" when everything changes direction.
 
Yeah, universal joints are a good start. You can sometimes check them by getting underneath and seeing if you can rattle the driveshaft. You shouldn't be able to.

Another place to check on a Mopar product is the motor mounts. In the mid-90s Chrysler tended to use a concentric rubber suspension ring for the mounts, at least on the FWDs. These tend to tear inside and let the drivetrain move a small amount. Not catastrophic failure like your engine is going to fall out, but enough to let the engine move during a spirited shift. I'm not familiar with the RWD/4WD applications, but it's another place to look.

Try www.allpar.com .
 
My 323 "lunges" when shifted into drive or reverse. It could, and this might sound silly, be the motor mounts. I'm pretty sure that's the problem in the 323, since when I drive down the road if I give it little bursts of gas the car jumps(not into the air, though that would be something...). It's still fully driveable ofcourse, just a small issue. You might want to check that by having the brakes on hard with the hood open, and having someone watch the engine as you shift. You can even hit the gas a little to brake torque it(not like flat out, naturally) and check.
 
I'll have to check the drive shaft and the mounts then. It's easy to forget about because I hardly ever go in reverse when it's warm. Luckily I have a drive train warranty with a couple years left on it, and it's about time to take it in for a bad hub anyway. Thanks for the suggestions ad resources everyone.
 
Now that I think of it, it does seem to happen when I am turning around. Pull in > go from drive to reverse > back out. I'll try not being so fast abou tit.
 
Same here Hyroaki. If I let the 323 go down to its correct idle, it shifts pretty smoothly. Other wise, the car jerks...then again, the shift into 2nd when flat out breaks the wheels lose on dry pavement. :)
 

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