Gear noise HELP 2005 Tahoe new 4.56 rear gears, .007 pinion shim, back lash .007, pinion preload 23nm, total preload 39nm.

[Erickk120]

Will gears be noisy if the pinion depth is a smidge off? Like .001 to .004?

depends how far off,I know the pinion for motive gear comes stamped with a pinion depth to check with a pinion depth tool, they are expensive and not worth it unless you want to do a lot of them and sometimes might still need adjustment after fact. I know the pinion head comes with a +-.002 thousands of variance from distance marked on the head. What was your factory pinion shim depth, I always start there and its usually pretty close most of the time, For me its usually always too shallow by a few thousands, but its a good starting point.

 

[Mudsport96]

Well, when you get to it let is know.
But, i have done gears before on an 8.8 ford crown vic (3.90 set) a 8.8 (4.56 & 4.88) and a 8.5 chevy (3.73). And no matter what i did even with a perfect pattern, the 3 90s always had some slight whine to them. I just figured maybe it was the way the were cut, maybe an imperfection in the face or something.

 

[Erickk120]

Well, when you get to it let is know.
But, i have done gears before on an 8.8 ford crown vic (3.90 set) a 8.8 (4.56 & 4.88) and a 8.5 chevy (3.73). And no matter what i did even with a perfect pattern, the 3 90s always had some slight whine to them. I just figured maybe it was the way the were cut, maybe an imperfection in the face or something.

For the ford 88 did those happened to be motive gear orange box? I did a set of those 390s and my god, I can feel the hardness of the material in the pedal to this day.

 

[Mudsport96]

Honestly i dont remember, pretty sure it was motive but not 100 percent. It's been the better part of 15 years ago.

 

[WFOALASKA]

Well, when you get to it let is know.
But, i have done gears before on an 8.8 ford crown vic (3.90 set) a 8.8 (4.56 & 4.88) and a 8.5 chevy (3.73). And no matter what i did even with a perfect pattern, the 3 90s always had some slight whine to them. I just figured maybe it was the way the were cut, maybe an imperfection in the face or something.

Definitely will. Its snowed 3 to 4 inches here in Alaska. Had to get outside projects put away. Bought all new berings and seals. Either tonight, or early tomorrow morning will tear it down and start over. Front diff has to be done too. But wanted to get the rear perfect, so the front will be easier. ( i hope ) Just rebuilt the transmission with a bunch of Sunnax goodies. So need to drain/ flush, and new filter it as well. Transfer Case is next for a full rebuild. Then the ole LM7. The wife and I bought this Tahoe, bran new in 2005. 3 sons, so it was the main family daily till 2 years ago. It has 188,920 miles on it now. Didn't even have to do a full brake job until 180,000. We live here in Alaska, interior, so no stop and go city life for it. Grocerie shopping is a 200 mile round trip..LoL ‐60 to 100 degrees and 3 feet of snow.. this Tahoe has never let us down. Its taken care of us.. now its time to take care of it. Die hard GM fan for sure. Will get some pictures up of it. Seriously, thanks for your help with these gears guys.

 

[Mudsport96]

Out of curiosity, why the 4.56s? Lift and tires?

 

[WFOALASKA]

Alright, brought it back in. This is the patterns from just a few min ago. This is how it was while driving.

 

[WFOALASKA]

Alright, brought it back in. This is the patterns from just a few min ago. This is how it was while driving.

The rotational toqure is in inch pounds. I checked it right before doing paint. It was 25 inch pounds. Total for ring and pinion together.

 

[WFOALASKA]

Drive is toe/middle. Coast is mid/heel. Picture is same no change, just after paint. Seem to show a bit better.

 

[WFOALASKA]

No change.. pulling apart.