I'm getting concerned that I have a bum bearing in my transmission or even worse...something up with my transfer case. (ACD)

I can't tell if the noise is coming from the rear diff, transmission, or x-fer case... but when I'm going a steady 65mph in 5th gear and I lightly (very lightly) accelerate or decelerate I hear a whining noise. If I lift off throttle all the way it goes away. If I give it more load...it goes away.

It seems that I really only notice this at this speed and in this gear....

I have the usualy 1st gear whine that fades very quickly part way through 2nd gear. 3rd and 4th are quiet.

Any suggestions? It's not super loud, but I can hear it through my catless 3" exhaust droning down the road.

It sounds like a high pitch whine that oscillates at a low frequency...maybe 2Hz or so. You also have to hold your head just right to hear it... passengers don't hear it, but people in the back seat have.

Thanks in advance.

 

Its really hard to tell without being in the car but It does not seem like anything to worry about. Change the fluids and take a look at the magnets while you are there.

 

Will do. Thanks again Emery.

I'll drain and inspect... this is my current fluid situation. I'm at about 7k miles on the current fluids.

Redline Cocktail (2qts of MT90 and 1 qt of MTL) in the gear box
Redline Heavyweight Shockproof in x-fer case
Redline Heavyweight Shockproof & LSD additive in Rear Diff.

 

I have the issue and its my Tcase. it starts @65mph and goes a bit louder til right before 80mph.

 

May I enquire how it is that you know that it's your transfer case? Do you know mechanically what is actually failing?

 

The ring/pinion in the tcase can be failing/getting weak which is why it could be whining or howling. That's what it was in my situation

 

crap.

 

Unbalanced wheel? lol

Does it sound/feel like its definitely coming from the drivetrain?

 

I had that issue myself and its the t-case for sure...it started at 65 to 80 mph....just basic signed to replace it...good luck

 

I forgot to mention one thing... If I take the car out of gear at 65mph or push in the clutch... the noise goes away.

<-- Has Exedy Twin

 

There you go... 100% your t case the noise goes away Because... One out of gear there is no more strain on the drivetrain/tcase then put it back in gear and it comes back... give it a few more weeks it will get louder then just break if its the tcase which based on your description sounds like it

 

How do you mean... just break?

Does it actually seize?

 

Mine is built by Shep. When I sent my TC to him he saw it. Ring/pinon needs to be changed. That time I sent my tranny too but Fedex lost my tranny but I didnt insured it. Long story short I cut corners to fund my tranny built. lol But he said it may or may not last but I have been driving it with a whine for 3 years now/76k miles and its still holding together (fingers crossed)

Yes the noise goes away and this confirms it that its your TC.

 

I guess you can say it seized up ya.. Car wouldn't move once it broke

 

mine seized up then when you went to put it into a gear and try to move it didn't Long story short I also had mine built