Engine/Transmission (1998.5 - 2002) Third gear clunk

[JCarrell]

it's only doing it under a load. . it's not a real fast clunk but every so often it doe it. . The trans shifts fine no grinding ect. . this is a 99 w/ a 5 speed. . nebody have any ideas

 

[LEerkes]

Boy, didn't get many responses to that one did you. Post a little more information and it will likely help.



Does it do it under load or mainly when you are on flat ground just maintaining speed?



Does it do it mainly at around town speeds and not at highway speeds - 3rd gear only right?



If so, then I would guess that it has something to do with some play in the drivetrain. Likely in the driveline or rear end. Check the U-Joints and check for play in the rear end. Set the parking brake, shift the transfer case into neutral, and try to turn the driveline back and forth. Does it have enough play to make a clunk?



You won't notice it a highway speeds (because of wind resistance) or under acceleration or deceleration because these situations place constant pressure on the drivetrain. While just cruising along in 3rd gear maintaining a constant speed the drivetrain pressures can bounce back and forth between accelerating, neutral pressure and decelerating allowing that slop to make a clunk.

 

[JCarrell]

Originally posted by LEerkes

Boy, didn't get many responses to that one did you. Post a little more information and it will likely help.



Does it do it under load or mainly when you are on flat ground just maintaining speed? only under load or slowing down



Does it do it mainly at around town speeds and not at highway speeds - 3rd gear only right? any time in 3rd all other geras are fine



If so, then I would guess that it has something to do with some play in the drivetrain. Likely in the driveline or rear end. Check the U-Joints and check for play in the rear end. Set the parking brake, shift the transfer case into neutral, and try to turn the driveline back and forth. Does it have enough play to make a clunk?



You won't notice it a highway speeds (because of wind resistance) or under acceleration or deceleration because these situations place constant pressure on the drivetrain. While just cruising along in 3rd gear maintaining a constant speed the drivetrain pressures can bounce back and forth between accelerating, neutral pressure and decelerating allowing that slop to make a clunk.