I just found your forum -- what a great resource. I'm a newbe to Blazers but not a newbe to vehicle maintenance.
A family member just bought a 2001 Blazer (4dr/4WD), so nowI need to familiarize myself with it and I'm having a couple of issues.

1) (And maybe this isn't an issue) when it's in2WD, the front axles and front driveshaft still turn when driving. They are not being driven --but they're "free wheeling". Are there automatic hubs on this vehicle that should disengage the front drivetrain when not in 4WD, or is this just the way they are?

2) There is something loose rattling around in the bottom of the transfer case. It's right under the front drive gear at the rear, so when the front wheels are spun,whatever it is gets moved by thedrive gear and makes a clicking sound when itdrops back to the bottom of the transfer case. Any ideas as to what it could be? It looks like I can just remove the rear of the transfer case to gain access. Is this correct?

Thanks in advance for any insight you can share.

jp

 

With #1, the front axles will turn at all times. The front axle in your truck disengages at the differential. I do believe that the front driveshaft should not turn when in 2wd, but that all could be determined by how much drag is being applied to the differential carrier. The front axle shift fork only disconnects the passenger side axle from the open differential. It is possible that drag through the spider gears in the diff to the diff carrier, spinning the front driveshaft.

I'm not sure what could be floating around in the transfer case though... Doesn't sound like it could be good...

 

Thanks for the info on the front axle. (boy do I miss the days of manual locking hubs) So in2WD,I should be able to hold the driveshaft with my hand, and the passenger side wheel should spin freely, but the driver's side should not? What's the purpose of this... won't thedrive shaft always spin when driving down the road? (unless you're doing a Joey Chitwood drive on 2 wheels manuever).

Regarding the transfer case: yeah, it doesn't sound good at all. I may take it apart this weekend to investigate further. I'll post back with what I find.

Thanks again for the info.

jp

 

The front driveshaft should not turn in 2wdr. not even by parisitic drag. The halfshafts will turn with the tires, they are splined into the front hubs and the wheels are bolted to teh hubs.

Noise in the t-case is not good. Youneed to pop that sucker open and see what is going on. They weigh about 100 pounds. Benching it out of hte truck is an option if you can handle it over your head.