whine - drivetrain?

[euclid]

I have an odd noise. Would you help me with diagnosis? 155K on the truck.

It's a whining noise that starts off lower in frequency and transitions to higher frequency as speed increases. Sounds like it's coming from the front of the truck.

Thing's i've noticed about the noise:

• goes away completely when I let off the accelerator no matter what speed.
• goes away when going down a hill. This is what makes me think it's drivetrain instead of engine.
• seems to get louder at higher speeds.

Likely coincidental but the noise began within a few hundred miles after doing timing belt, water pump, fan tensioner service.

The noise does not go away when the truck warms up.
NAPA premium CV's have about 12K on them.

Wheel bearings?

 

[Supra88]

My guess is the NAPA CVs, people have been getting very few miles out of them before they become problematic.

 

[euclid]

My guess is the NAPA CVs, people have been getting very few miles out of them before they become problematic.

Have you seen posts about CV failure being evidenced by any of the symptoms I described? I haven't had time yet but based on your guess I'll do some searching about CV failure symptoms. Mine are not leaking.

 

[REDrum]

if whine goes away when you lift off throttle, then focus on engine not driveline. If driveline is whine source it should keep wining based on road speed and not go away when you lift. Check AC/power steering/water pumps and/or belts. Sometimes water pumps let you know when they are about to give up the ghost.

Can you put on a lift and check? And/or, find nice long building or wall you can drive along close to with windows down. Listen carefully to whine as you drive along next to it, varry road speed and throttle position listen for correlation... FWIW...

 

[euclid]

The whine is not there when the truck is not in motion so I don't think it is engine related. I'm leaning towards CV's.

 

[smm3]

I have ridden in the truck and heard the sound he is trying to describe. To me, it has the resemblance of a turbo whine. It definitely gets louder with speed and stops when you let off the accelerator. The whine does seem to be coming from the front of the truck.

To add to the discussion, if it was a CV that is going bad, wouldn't there be some vibration? Wouldn't there also be some clicking if the CV was about to fail? Euclid and I discussed this before he posted a question as we were at a total loss...

 

[euclid]

u-joint?

 

[yuji]

I've been trying to figure out the same issue on my 2000 130k.

Keep us posted on where you've looked!

One thing that confuses me about a lot of these threads; why do people suggest Steering pump? Is it related to throttle position?

Can any of these suggestions be excluded by gassing in N?

I'm planning on asking a friend with a high quality Mic to record sounds so that I can post it. You should try getting a video with sound.. if you can capture it.

I just tried with an iPhone for my problem and it's not quite sensitive enough to pick out the whine.

 

[euclid]

Not sure what you are speaking of on steering pumps.

My noise goes away when gassing in N and the truck in motion. The noise is not there unless in motion and power is going through the drivetrain. Has to be drivetrain related.

 

[Kev UZJ100]

I think it might just be the transfer case, before it warms up. Guys?

 

[euclid]

Does not change based on temp.

 

[APKhaos]

The transfer case whine sounds like a typical gear meshing noise and comes from the floor area below the shifter. Does not seem to fit Euclid's description.

Sounds like his noise shows up when power is being delivered. Quiet on coasting. Suggest you check fluid level in the front diff. If its dry then that could be where the noise is coming from.

 

[euclid]

Drivetrain shop says it's the front diff. I'm switching out the fluid to 85-140 in the front diff today to buy some time while I source the parts and the dough. Any suggestions on parts source for R&P?

155K. My guess is that the shop that did the CV's for me failed to top off the diff when they were finished and now the ring and pinion is toasted.

 

[APKhaos]

Dammit. Hate to hear that kind of stuff, but you may be right about the monkeys leaving your front diff low on fluid. The R&P may not be a bad as you think. Run it full of new fluid for a while before you move on R&P replacement. If the whine stops when its filled you may have dodged that bullet.

 

[euclid]

Took almost 2 quarts. 1.8 capacity.

It's significantly quieter now.

 

[APKhaos]

You might want to go kick some a$$ at the shop that did your front axles!

 

[euclid]

Looking for a used diff if anyone knows a good source. Still waiting to hear back from some mud vendors for new parts.

 

[spressomon]

Used 4.30 front's = hens teeth

 

[GaFJC]

Looking for a used diff if anyone knows a good source. Still waiting to hear back from some mud vendors for new parts.

I had some success with car part.com after another MUD'r recommended it. Ordered a part for my 100 from a salvage yard in Michigan. Seamless.

Sent from my iPad using IH8MUD

 

[euclid]

I had some success with car part.com after another MUD'r recommended it. Ordered a part for my 100 from a salvage yard in Michigan. Seamless.

Sent from my iPad using IH8MUD

http://car-part.com?


2000 to 2004 should interchange, right?


What are the risks associated with driving without a front driveshaft? How many miles have mudders driven in rear wheel drive?