front drive shaft

[muddog321]

You seem to be left hanging on this one. Have a few of these, so:
The 4 button autotrac xfer case uses autotrak II syn fluid thats blue (dealer item about $7 a qt and it takes 2 qts). This case has known problems and GM says to get it hot, change the 2 qts with new, drive 100 miles, flush again and add 2 more qts. There are clutch packs in it that have friction problems especially if you drive alot in "Auto" 4Hi. I'd change it once and see if that helps before the 2nd change. That front shaft CV joint on the xfer case end has some play but the u-joint should not. Blazers have unequal length CV axles and this also creates some vibration. Make sure the front diff is full too with 80w-90.
Finally - if you look at the NP 243 and 246 xfer cases thay ARE both always active chain driven so the drive shaft always turns (does not pertain to the older manual xfers with manual hubs). The drivers side CV axle always is locked into the front diff and the passenger side has a coupler that is vac actuated.

[tikoy47]

Thank you for the comments. Alright, so I'll just go ahead and let them replace the u-joint in the front shaft.This way they will know if I need a rebalance.Or I might also need bearings for the T-case. Okay, i'll do that.

[tikoy47]

Muddog321 i appreciate your input.And as you have said i'll also put the autotrac II in my xcase and 80w-90 to the differential. Thank you a lot. Now i know that the cv joint to xcase will have a bit play but the u-joint to differential will not.Thank you .

[tikoy47]

Where is this xcase drain plug lacated at on my 2k blazer? Is it the one next to solenoid(black tubular or cylindrical) or by the rear of xcase. And i've heard there is another one plug for filling her up with autotrac II. I appreciate your help.I always like to read this forum but i can't find the answer and if there is a pic that would really help for any one here.Thank you again.