front drive shaft spins even when in 2wd

[bigmax88]

ive had a clunking noise in the fron of my 98 4.6 expy with limited slip axles for about a year now, more of a clanking bull dozer sound. its most noticeable going slow in a parking lot, it isnt nearly as loud when i put it in 4wd, but it is still there. i jacked up the truck and in 2wd the front wheels spin freely from each other and do not turn the front drive shaft, but when i drive down the road the drive shaft still spins. i did a burnout and had a friend look under the truck to watch the front drive shaft and the front drive shaft spins in 2wd doing a brake stand, so the transfer case IS turning the ds, but what is my clanking?ive noticed it "clanks' about 5 times to one rotation of the wheel. the noise is NOT coming from the wheels, but rather somewhere behind them., ive noticed the front u joit on the front ds is bad, since my tranfer case is turning the drive shaft, could i be hearing this bad u-joint? also why is my ds still turning in 2wd? i just put a new transfer case motor on it, and a4wd, 4x4hi, and 4lo shift fime, although sometimes it siound like it has to try and shift to 4 lo twice, like it makes 2 or 3 clunks going to 4lo instead of just one. is my transfer case bad? i always thought till recently that the sound was whatever disengages the front axles not fully disengaging.

 

[panda24619]

idk what the clanking is but the front drive shaft should spin in 2wd if you are moving. since the front hubs are locked on permanently the front drive shaft dose that. it could be the cv joint on the front shaft. but i dont know what exactly the clank is. and yeah my 4 low takes a few times somethings. like it clunks unclunks and reclunks into 4low. something with these electronic shifters that i dont like. i rather have a mechanical shifter and a shifter threw the floor boards.

 

[bigmax88]

hey thanks for the reply, my expy is a 98 and has a 2wd setting, the front hubs do disengage, and they spin freely from each other when in 2wd. the front drive shaft spins in 2wd mode while doing a rear wheel burnout with the front wheel sitting still on the ground doing a brake stand burnout. the noise is the rear u-joint on the front drive shaft, but im still worried as to why the drive shaft is spinning with the front hubs disengaged and the transfer case in 2 wheel drive

idk what the clanking is but the front drive shaft should spin in 2wd if you are moving. since the front hubs are locked on permanently the front drive shaft dose that. it could be the cv joint on the front shaft. but i dont know what exactly the clank is. and yeah my 4 low takes a few times somethings. like it clunks unclunks and reclunks into 4low. something with these electronic shifters that i dont like. i rather have a mechanical shifter and a shifter threw the floor boards.

 

[Racenut]

Not to sure but since your truck has the setting for the A4WD your T-case is probably sending power to the front drive line ( Via the Magnetic Clutch in the T-case ) since it senses the back tires spining and the fronts are not. The reason the fronts would not spin is because you have the switch in 2WD so the hubs are unlocked. I have read of a lot of guys doing the BROWN WIRE mod which disables that magnetic clutch part of the T-case but that also disables your A4WD feature as well. I guess you could try to wire it into a switch some how if you wanted to keep that feature for future use. All other positons on the switch will remain the same and work normal, you just would not have the A4WD.

Check out this link on the forum it may help you out a bit more.

http://expeditionforum.com/showthread.php?t=3586

Hope this helps.

 

[bigmax88]

thanks man. im not worried about it as long as its normal for this to be going on. i was just worried something was wrong.

Not to sure but since your truck has the setting for the A4WD your T-case is probably sending power to the front drive line ( Via the Magnetic Clutch in the T-case ) since it senses the back tires spining and the fronts are not. The reason the fronts would not spin is because you have the switch in 2WD so the hubs are unlocked. I have read of a lot of guys doing the BROWN WIRE mod which disables that magnetic clutch part of the T-case but that also disables your A4WD feature as well. I guess you could try to wire it into a switch some how if you wanted to keep that feature for future use. All other positons on the switch will remain the same and work normal, you just would not have the A4WD.

Check out this link on the forum it may help you out a bit more.

http://expeditionforum.com/showthread.php?t=3586

Hope this helps.