Clunking sound while accelerating

[ponch68]

I have a 97 XLT , 4WD, 199K miles. I had the transfer case rebuilt earlier this year. Now, when I'm exelerating, I have a loud clunk underneath. This happens multiple time while building up speed, but doesn't seem to be associated with shift points. Nor does it happen when initially starting off. I do not believe it is the U-joints since it happens multiple times while accelerating. I notice to loss of power or RPMs, so I don't think it's a backfire or miss. Any thoughts before heading to a shop would be appreciated.

 

[thunderhorse]

check your 4WD shift motor, make sure it's really out of 4 wheel drive.

 

[theSLEEPER]

Do Explorers have a slip-yoke on the rear driveshaft?

 

[ponch68]

slip yoke

I went ahead and followed some advise on this forum and lubed the slip yoke. No luck. It seems to bang while excelerating under load conditions. I'm starting to think it's trying to engage in 4WD. Since this is electrical, can I pull a fuse to help diagnose this problem? Maybe just remove the front drive shaft? Thoughts anyone? Thanks in advance for the inputs.

 

[91explorer93]

i had a clunking noise while decelerating, i found it it was my radius arm cross member bracket was broken where the bushings go into, its a common problem, its worth a check... im not sure if it would clunk while accelerating but it sure did when i was stoping

 

[ponch68]

I finally took it to a transmission shop and they confirmed what I suspected. I found excessive play in the transfer case rear output shaft that was just rebuilt last year. They told me the continual clunking was in fact the transfer case. Although they rebuilt the case with a 3 month warranty(because I just brought them the transfer case to rebuild), they would work with me since it should have lasted much more than 10 months. Especially, since I don't use 4WD or go off pavement.