4.11 true-trac

[IWANTA(ss)]

Originally Posted by gunchamp

If you dont mind me asking, what was the price from gpi? Thanks

Around 750 to install the gears lpw cover and h.e. bushings and tru track

Originally Posted by bkevind

Man I had Yukon 410 put in with my Truetrac of my 1LE. It was unbearably loud and never got any better.

I also had LPW cover, upgraded diff bushings, and the solid cradle bushings put in at the same time.

One issue is that whatever whine the diff is making will be greatly amplified by the solid bushings.

The noise wasn't so bad on the track, but driving to and from the track was unbearable.

Long story short I've got the GM 3.91 going back in with the Truetrac and hope it's a decent bit quieter.

The diff shop had a hell of a time taking the diff apart, they had to fab up a tool to get it open. So the original install was probably at fault, and maybe defective Yukon gear set.

These are motive gears and GPI set them up. I gonna change to the Lucas and do a heavier weight and see if that helps.

Originally Posted by Pro-tuned

I have full “polyurethane” BMR including cradle and diff bushings along with Tru-track and 3:45s no issue since installation 12,000 miles now. If I had to guess the issue I would say improper gear alignment...

I kno nobody’s perfect but I don’t feel like GPI messed up I never had a gear swap done on a 6speed car so it maybe just normal

[Pro-tuned]

Eaton suggests specific mineral based GL5 rated 80W 90 without friction modifiers or synthetic type oils...

https://www.eaton.com/us/en-us/produ...trac-faqs.html

[alice]

If the noise is as pronounced as you indicate, one can be sure that the contact pattern is incorrect and/or the backlash needs to be adjusted. Setting up proper gear contact patterns on both the drive and coast side is very time consuming and in most all cases, requires several teardowns and incremental adjustments in order to get the patterns correct.

This noise will NOT go away no matter what lube you use or what bushing you have. If it is annoying, the only way to fix the problem is to tear the diff down again and make shim changes. Be sure all bearing pre-loads are mandated first, then on to pinion depth adjustment and backlash until the patterns on both drive and coast sides are all but perfect. Then and only then will the diff be quiet. Hope this helps. Good luck.

[IWANTA(ss)]

Originally Posted by Pro-tuned

Eaton suggests specific mineral based GL5 rated 80W 90 without friction modifiers or synthetic type oils...

https://www.eaton.com/us/en-us/produ...trac-faqs.html

I’m running that now it’s just cheapo parts store brand.

Originally Posted by alice

If the noise is as pronounced as you indicate, one can be sure that the contact pattern is incorrect and/or the backlash needs to be adjusted. Setting up proper gear contact patterns on both the drive and coast side is very time consuming and in most all cases, requires several teardowns and incremental adjustments in order to get the patterns correct.

This noise will NOT go away no matter what lube you use or what bushing you have. If it is annoying, the only way to fix the problem is to tear the diff down again and make shim changes. Be sure all bearing pre-loads are mandated first, then on to pinion depth adjustment and backlash until the patterns on both drive and coast sides are all but perfect. Then and only then will the diff be quiet. Hope this helps. Good luck.

I’d have take the rear back out and then send it back to GPI if it’s just going to be noisy I think I can deal with it

[Black_SS10]

I hate gear noise. I just had mine rebuilt, new bearings, new trutrac (nothing was wrong with the old one), and a new GM OEM 3.91 gear set. I have the LPW cover, billet caps, and offset bushings; along with solid cradle bushings. It has very little noise. I didn't and don't expect it to be silent.

[IWANTA(ss)]

Originally Posted by Black_SS10

I hate gear noise. I just had mine rebuilt, new bearings, new trutrac (nothing was wrong with the old one), and a new GM OEM 3.91 gear set. I have the LPW cover, billet caps, and offset bushings; along with solid cradle bushings. It has very little noise. I didn't and don't expect it to be silent.

I had the gears in my NBS single cab truck change and they could be whiny. The whining I hear now I’m really starting to think is just a noise that hot rods make I have a video I’ll post to see what y’all think.

[Black_SS10]

Originally Posted by IWANTA(ss)

I had the gears in my NBS single cab truck change and they could be whiny. The whining I hear now I’m really starting to think is just a noise that hot rods make I have a video I’ll post to see what y’all think.

If it is minor whine, I wouldn't worry too much. Especially with a LPW cover and poly bushings. I'm in for a video, I want to hear how much whine you have. Lol

[alice]

Most gear whine occurs between 45-55 MPH, either during slight loading or deceleration. If the whine is outside these limits and sustained, the differential should absolutely be removed and adjusted. Sustained noise/whine is unacceptable and indicates that the tooth patterns are WAY OFF!!! Don't accept this! However, if the whine is only at certain speeds, very minimal and above and below these speeds, noise goes away, then the contact pattern is close, not perfect but close and no damage should occur over high mileage.

If the later is true, one can live with it if they choose. My high ratio gears, (5.36) which you would expect to be very noisy, are all but quiet as stock. The time & effort in achieving correct gear contact patterns will assure you of almost a perfect setup that will have little to no noise, no matter what ratio gears you are installing. THE CONTACT PATTERNS TELL THE STORY.

[IWANTA(ss)]

How can I upload a video without putting it on you tube first

[IWANTA(ss)]

https://youtu.be/OjbsnJGXFbI

[Black_SS10]

Originally Posted by IWANTA(ss)

https://youtu.be/OjbsnJGXFbI

It was hard to tell in the video, but I am guessing that you drove and various speeds. That is a lot on gear whine!!! I find that unacceptable!!! I have very minor whine at higher speeds, I just deal with it. But what I just heard is way too much! I don't care what anyone says!

[IWANTA(ss)]

Originally Posted by Black_SS10

It was hard to tell in the video, but I am guessing that you drove and various speeds. That is a lot on gear whine!!! I find that unacceptable!!! I have very minor whine at higher speeds, I just deal with it. But what I just heard is way too much! I don't care what anyone says!

Yes I was in between 45-60 mph it’s no whine up to 45 and very little after 60. I’m going to have to get with GPI about it.

[oldman14ss]

WOW! that is noisy! I'm no expert but my opinion is that is way to loud. my ring and pinion is set up a little closer to the toe for competition as shown in the truetrac manual at 5k back lash. its still on my blocks waiting for me to finish. I guarantee if mine are singing they are going back to my installer. now there are 5 cut gears and two cut gears. 5 cut so ive read are harder to set up because of the taper in the gears.

[Joe M 2012 2SS]

I'm sure GPI didn't do anything wrong. The problem is Motive, they used to make high quality gears in Italy, they have been bought out a few years back, and now are made in China.

I had Motive 3.91's put in with my tru-trac by someone with 40 years experience, pattern was perfect, backlash spot on, whined like crazy. Poor machining. Switched to AAM, and after many passes at the drag strip it has developed just a little whine, but no where near what the Motive's did.