Gen 2.5 transmission "clunk"

[airbox]

Hello all,

Ever since I've had my 99 it has had a severe and loud "clunk" when downshifting from 4th to 3rd. It only happens when travelling at about 35mph to 60mph, mostly on medium-speed highways and city roads (no issues on interstate). It happens the instant I touch the throttle after coasting at those speeds. I have tried to have my wife sit in the back and listen to where the noise may be coming from but we cant really pinpoint it. I have been underneath and wrestled with the driveshaft and it doesn't seem to have any play (maybe I'm not using my big boy pants, idk). The tranny fluid seems nice and red and to the proper level.

Has about 230k miles on the odometer so I'm not surprised this is happening. I have an extra transmission with low miles that I can put in, but I am making a last ditch attempt to maybe save some money in finding out what is causing this. Could I be looking in the wrong place? Thanks for any help!

 

[jeep-N-montero]

With your foot on the brake put it in drive and then reverse while parked and see if the clunk is there, I would say that most driveline clunks are the u-joint more often than not. You can also unbolt it at the rear flange and examine it without removing it from the transfer case, if you pull it from the case you will lose gear oil.

 

[Chili]

Yeah, driveshaft u-joint is the first thing I think of. Not sure what the Montero setup looks like, but the I know I also had a 'clunk' in my old '90 Bronco that ended up being the slip joint on the drive shaft.. It just needed lubrication (and a new boot as it was torn, probably why no lube). Get under and try to move the driveshaft around (up and down, left and right). You might even use a prybar or something to apply pressure different ways around the u-joint(s) themselves, but don;t use enough force to damage anything. You just want to see if there is any play at all. Kind of like checking ball joints where you lift the tire off the ground and try to wiggle it top to bottom.

 

[airbox]

Thanks, guys. I'll play around with the driveshaft and see what i find.

 

[airbox]

With your foot on the brake put it in drive and then reverse while parked and see if the clunk is there, I would say that most driveline clunks are the u-joint more often than not. You can also unbolt it at the rear flange and examine it without removing it from the transfer case, if you pull it from the case you will lose gear oil.

I went ahead and tried the shifter first and there was a definite loud "clunk" when shifting into drive from reverse or neutral. It seems to take about 2 or 3 seconds to shift into reverse/drive, also. I tried really twisting the driveshaft and using a prybar to jostle the U-joint and theres no play at all. I will try unbolting the flange this afternoon.

 

[Salonika]

23A-30 in the FSM...........maybe? That page reference sounds similar to your problem....idk