astro drivetrain help!!!

got a 98 astro automatic trans with awd and i have now gone through 2 transfercases... A bearing or something inside the transfercase keeps blowing and making the van hum while driving at every speed and fluid is leaking out of the tail of the transfercase. I have had both of the u-joints in the rear driveshaft replaced with new u-joints, changed the fluid in the differential and the transmission shifts smooth. Everytime i replace the transfercase it seems to stop then get bad again.... and yes there was fluid put in every transfercase before it was driven. PLEASE SOMEONE HELP!!!! :banghead:

Just curious, but do you have 4 matching tires on the van?

Are you using AutoTrak II oil in the XFER case?

i am having the oil changed in my transfer case. my mechanic says to try it to see if my problem goes away. my problem started when i got the trans rebuilt. shortly after a gear stripped in the differential after i got a weird noise that appears only when i make turns. it's as if i have posi instead of limited slip. one tire drags around turns. very wierd. i think i am gonna strip another gear soon.

My 2000 has AWD and a rear locker (ordered that way, with 3.73 gearing). Pop the rear cover and look. It's a good excuse to service the oil anyway.

Hey Blue Bowtie. mine is a 2000 astro with AWD. Tires match transfer case oil just replaced and i still have the noise but not as bad. What is a "rear Locker"?

a "locker" is a mechanism that locks the two wheels of an axle together. This gives you better traction off road and on poor road conditions as it will not allow one wheel to slip. The down side is that as you make turns, the outside tire has to turn faster than the inside tire. With a locked diff, you end up "dragging" the outside tire.

Hey Blue Bowtie. mine is a 2000 astro with AWD. Tires match transfer case oil just replaced and i still have the noise but not as bad. What is a "rear Locker"?

This:

http://www.wwdsltd.com/files/373Carrier3.jpg

Put auto-trak II from the dealership in my transfer case today. After 100,000 miles of jerking, noisy turns it is instantly gone! Unbelievable!

Don't wait another 100K to do it again. Your chain will thank you.

a "locker" is a mechanism that locks the two wheels of an axle together. This gives you better traction off road and on poor road conditions as it will not allow one wheel to slip. The down side is that as you make turns, the outside tire has to turn faster than the inside tire. With a locked diff, you end up "dragging" the outside tire. I have this on my 02 Safari that is RWD---Why would a rear locker be put on this type of vehicle? I do have the towing package--(tow button on shift lever) I am presently trying to diagnose a grinding noise that seems to be coming from this area--It is only apparent at higher speeds (30 mph +) and pressing the gas increases the noise slightly while letting up on the gas makes the noise almost go away. While on the highway, veering left will make the noise almost go away and veering right has the opposite effect as the noise will increase..... I have changed my rear axle bearing and fluid and also u-joints---I am at witts end---what the hell is left???

It could be a left outer axle bearing, a carrier bearing, or excess play in the side (spider) gears. Opening the rear housing to take a peek might be revealing.

well soon after my last post, the transfer case got to oil changed and the noise went away. till today that is. i replaced the oil with the same good stuff(trax 2) and the noise is still there. looking thru the drain hole i could see the a pair of gears and when i torqued the rear driveshaft with my hands the gears met and pushed away from each other slightly. i know what i need now huh? weird but this happened after i went thru a huge puddle of water. the old oil was baby blue and not clear like the new stuff but i think that is expected. any one know how much a rebuild for a transfer case is? any one know if it can be done by a handyman? i just did the diff on my wifes jeep. it was time consuming but it worked out for me. thanks boys and good luck.

Many times a case can be rebuilt with basically a new chain, clutch friction discs, a tailshaft bushing, gasket set, and oil pump. Sometimes there is wear in the case which can be resolved with inserts, such as the case-saver shims for the oil pump or liner for the clutch.