Differential question

[LSlayer]

I have a progressive whine/howl that I'm pretty sure is coming from my rear end. It starts as a low pitch wine from 20-50 mph then by 55-60mph it turns to a higher pitch whine that sounds like its coming from up front near the trans tunnel. I jacked up the rear and turned the wheels. When I turn the left wheel slowly the right wheel turns in the opposite direction. However if I turn the left wheel faster the right stops turning. I didn't turn the right wheel to try to duplicate the condition but I'm pretty sure it happened in gear and neutral. Is my diff going bad? I'm running a TruTrac differential. I plan on changing the oil this weekend since its synthetic like its apparently not supposed to have. I'm not real keen on rear end setups but I'll definitely give everything a good look while I'm in there. Thanks for any help.

 

[randys06v6]

When was the trutrac installed?

 

[LSlayer]

2006-2007

 

[randys06v6]

Sheesh lol if it was recent i was going to say sounds like gear whine but nope lol. Do you hear any clunks when turning hard left or right?

 

[stkjock]

Trutracs seem to be inherently noisy.

 

[94tbird]

mine never made a peep. Either one i had, in the 8.8 or the 9". not until they were gonig bad.

 

[LSlayer]

Mine clunks every so often while turning. I thought trutracs were supposed to be quiet for the most part. The fluid that the shop showed my was pink so maybe water got in there. I don't know how since my car doesn't go swimming and its never had any leaks from the diff. I plan to take a look for myself this weekend and change oil to dino oil.

 

[randys06v6]

Clunk while turning is a no bueno! (no good lol) last time I had a clink in my trutrac it exploded! lol

 

[stkjock]

let me expand my comment, noise vs. a stock diff, not like a locker

 

[94tbird]

let me expand my comment, noise vs. a stock diff, not like a locker

I understood what you meant, but even so, I had zero noise from either unit. That is until they started popping when turning which means youve cracked a gear inside and its going to kaboom on you.

 

[bradleyem]

More importantly...what gears are you running?

Motive gears are inherantly whiny...any ratio from what I understand.

Ford Racing gears 4.30 and up are also noisy. I have FRPP 4.30s and they are pretty loud.

If the noise just appeared, then its likely an issue with the gears/bearings.

 

[LSlayer]

More importantly...what gears are you running?

Motive gears are inherantly whiny...any ratio from what I understand.

Ford Racing gears 4.30 and up are also noisy. I have FRPP 4.30s and they are pretty loud.

If the noise just appeared, then its likely an issue with the gears/bearings.

410A, ford gears, not motive. Initially after I had the gears and trutrac installed they whined. It was a different whine at different speeds as well. Then I put a spydershaft in and it went away. Maybe its cause the pinion nut got retorqued. I torqued it to 150 ft-lbs. That was about 60k miles ago. Now its whining/howling at anything under 80 mph. No increase in vibration.

Today I pulled the diff cover and discovered some unusal wear on the very outside of ring gear. Nothing that I could see on the pinion gear. No metal in the old gear oil or plug. Maybe something is coming out of adjustment. This whine started about two weeks ago.

 

[05stroker]

410A, ford gears, not motive. Initially after I had the gears and trutrac installed they whined. It was a different whine at different speeds as well. Then I put a spydershaft in and it went away. Maybe its cause the pinion nut got retorqued. I torqued it to 150 ft-lbs. That was about 60k miles ago. Now its whining/howling at anything under 80 mph. No increase in vibration.

Today I pulled the diff cover and discovered some unusal wear on the very outside of ring gear. Nothing that I could see on the pinion gear. No metal in the old gear oil or plug. Maybe something is coming out of adjustment. This whine started about two weeks ago.

It could be the pinion bearing. I had on go bad on my F150 and it was as you describe. There would be traces of metal in the fluid usually though. Also the synthetic fluid could have damaged the Truetrac if its been in there for 60K.

Good luck .

 

[LSlayer]

Thanks. I'm going to try a 4x4 shop since there seems to be no good or competent car shops in town. As far as the diif though, when I turn the left rear wheel the right wheel turns the opposite way. Normal operation right? But if I turn the left wheel too fast the right stops spinning. That's my main question about the diff.