Now that I've just recently gotten my fuel system problems all sorted out (rebuilt VP44, FASS, Vulcan drawstraw, and column mounted DiPricol mech fuel pressure gauge) - as if that wasn't enough, I'm driving down the road on a sub zero morning, w RPM around 2K when my 4X4 surges then begins to growl. Now in 4X4, I'm hearing an abrupt and disturbing growling noise - doesn't sound good folks.
When I go back into 2X2, the growling ceases. I live up in the rockie mountains of Colorado. It is sub zero now, and the roads are slick this time of year. Without 4X4, my year 2001 truck is just not fit to be road worthy.
Before I take her into the mechanic yet again, can anybody shed some light on what to expect will repair the growling noise? Is it U joints in the front end or a bearing? Thanks, DD

 

I'm pretty sure it's the U-joint's. More specifically the double joint near the transfer case. But everything is possible, but usually it's just the driveshaft.

You could take your front driveshaft off and try your 4x4 then, does it do the same noise... If it does, then it's coming from somewhere else. Either from transfer case or the front axle, but I doubt it...

 

Thanks Erska! I'll at least have something knowledgeable to discuss with mechanic - to see if he's able to make the repair before slip sliding over to the garage. DD

 

I just started having a similar noise when my truck is in 4x4. I had my drive shaft rebuilt last winter. I haven't taken it out and drove in 4x4 without the shaft yet to see if its bad again.

 

I agree, pull the front driveshaft then you'll eliminate the front diff and driveshaft. If it's still there could be in t-case, but I'd bet on u-joints, not greasable and make all sorts of weird noises.

 

If you're in sub-zero conditions, you might thaw it out first. Ice in the wrong places can make all kinds of weird noises. It can cause major imbalances in wheels, driveshafts, etc. Just a thought.

 

OK.. here's the bad news: The mechanic called to inform me that I had spun the front transfer case pinion bearing, and that there are two additional bearings in the front gear box that need to be replaced - saying when the pinion bearing goes, the other bearings are adversely effected as well. Total cost is going to be $700.00 for parts and $700.00 labor - a whopping $1400. I asked - yes, the transfer case was full of oil?
Here's the scenario when this all happened: It was a sub-zero morning, I got out on the highway in 4X4, as the transmission was shifting, I noticed the RPM were about 2000. Right after the auto transmission shifted into 3rd gear (about 45 MPH), there was a surge in power, from there on this awful growling noise coming from the front end. I shifted out of 4X4, and the noise stopped although there's no way I can drive icy snow packed roads safely without 4X4. Meanwhile, I've asked the mechanic to service the transmission and rear differential as well, and while at it might as well inspect the brakes and any other potential problem.
Wondering if the price of $1400 is reasonable for a R&R front transfer case bearing rebuild? Thanks, DD

 

Just curious what steps they took to come to this resolution? I am experiencing the same issue. Only happens in 4 high at 40-50 mph. If you kick it out of OD, noise goes away! In 2x2 it shifts through all gears and runs like a raped app.

 

gellibee, nope, not the same symptoms - after the castastrophic moment, there was a growl even crawling along at say 5 MPH. As soon as I disengage 4X4, the growl would go away. Good luck with getting your truck sorted. DD

 

usually when you spin a bearing you have to resize or replace the part the bearing spun in. you're saying you're only replacing bearings?

 

Duner, bearings for sure - not sure about resizing, but I'll ask - thanks. Since I'm no mechanic, I'm trusting that the work will be done correctly - especially in that the parts to rebuild the xfr case are $700 and labor another $700. Is $1400 a reasonable cost for this job? Thanks, DD