[wireman121]

I have a 92 jimmy with the 233 electronic shift tansfer case. I originally thought it was a bad bearing noise, and after taking it to 5 different mechanics, they all said the same thing. I replaced every bearing in the case (along with the dif, just in case) and I still have the noise. I brought it to 2 other mechanics, after I replaced the bearings, and they still said bad bearings. I am just looking for any ideas of what could be causing this noise, because physically I dont see anything wrong with the case, or the parts inside, nor could I find anything wrong with the old bearings....

 

[Jay72]

Heres the most difficult thing to do on a message board...could you describe the noise and when it happens?

It could easily be a transmission noise or rear end noise.

I even had some weird noises coming from my trans at one time and found out it was just a drywall screw driven it to hold the carpet down touching the trans case, I didn't find this out until I took the trans out, it was transfering noise through the whole floor board like a stethescope or something.

 

[wireman121]

it is a whine, only when i put the truck into 4 wheel drive (hi or lo). The best way I can describe it is, take a manual 4 cyl. put it in 1st gear, drive it to red line, leave it in gear and take your foot off the gas.....you know the noise it makes when it slows down using the engine against itself? yea...that is more or less what this sounds like

 

[fmfredrider501]

when youre in 4wd the t-case and front diff always whine, and the higher speed you go the louder and higher pitched the whine is, thats normal...is it doing it really bad or something?

 

[wireman121]

yea its a whine that isnt supposed to be there

 

[Jay72]

Maybe remove the front driveshaft and run it in 4x4 to see if the problem persists, if it goes away then you know it's the front differential.
Thats what it sounds like to me if you already had the t case apart and it only does itin 4x4 then it has to be the front differential.

 

[wireman121]

already did bearings in the front diff as well. it doesnt make the noise unless it is under a load. i had it up on a lift, and it made a very faint noise from the t case, but after replacing all the bearings, i dunno what it is now

 

[Jay72]

Did you check the tooth contact pattern on the front ring and pinion when you were done with everything?

 

[wireman121]

Yes. It was making noise before hand. Its definately coming out of the transfer case, I had my friend hang out the window and see exactly which area it was from, and he said directly under him, not in front. Plus, when it was on the lift, the noise was coming out of the transfer case as well, but very faint after I revved it up to about 40 and then took my foot off the gas, it made a faint whine as the speed dropped. I am bringing it to a trans shop tomorrow and having a friend drive it. If he says it is definately the transfer case (which I am pretty sure it is) I am going to stop wasting my time and just buy a junk yard transfer case for $300. The encoder motor on mine is bad anyway (it doesnt come out of 4 wheel drive until you put it in reverse) and a new motor is $300 alone, so I am going to go for the whole case and see what I end up with after that. Hopefully my noise will be gone and everything will be ok!

BTW, anyone have a plow for sale? hah

 

[lostintexas]

is there any chance that a thrust bearing is what is causing the noise? these control the endplay of your mainshaft, output shafts and counter shafts. there is also a bushing that your drive shafts slide into that may have too much play. bearings are not always roller bearings.

if there is abnormal whine, i would look at how the teeth of the gears mesh(thrust) together and if the chain is running true (end play).