linegtdt52

iTrader: (12)

Fellas, I have just solved the unanswerable. I had a rear-end that when you drove it it sounded like your ears were on the differential on the drive side. Pulled it and found pinion was too deep. well I was certain this time i wasn't gonna let this ruin my f-body. I WAS RIGHT. I pulled the hog-head and replaced it as well as putting 85w-140 in the rear. NOT A DAMN BIT OF WHINE! DO NOT USE THAT 85w-90. ITS A BUNCH OF CRAP. No way thick enough to tackle the job of deadening the sound in which the gears have the potential to make. The bad thing is that mine were motives! MOTIVE GEARS!! Should never of whined that bad but an idiot set them up. Just wanted to let you guys know that I have not had any problems what so ever and I was cruising around 80!

geovett

iTrader: (53)

dang man, my whine is bad very loud, running 373's on a eaton posi (10bolt) how did u know to change hog??and what gears were u running? u didn't reset gears? tell me again what u did with a little more detail PLEASE......NEED HELP IN THIS AREA..........lol....

linegtdt52

iTrader: (12)

Dude the hog-head is in a 9" not a 10 bolt but regardless I would definitely switch the viscosity of the fluid as it will help keep your oil from breaking down so much when it gets hot in your rear.

thechef

iTrader: (13)

umm i dont see that you cured anything, you swapped one center section for another one and the second one is set up correctly and you used a heavier oil.....

Gary Z

In my experience, switching from 75W-90 to 85W-140 has no effect on whine.

linegtdt52

iTrader: (12)

If I understand you correctly, you dont think oil has any effect on gear whine? Do you work on these cars for a living?

linegtdt52

iTrader: (12)

If you read the quote you would see where I explained the pinion depth was too far and "an Idiot set up the gears", so I wasn't implying it was perfect to begin with but with 99% of all people that put these 9"'s in their vehicles have some sort of whine. And I would have thought that since you are probably with an automobile shop and an LS1tech sponsor that you would know definitely first hand that Gear oil makes a big difference. The dissipation of heat? the thinning of gear oil under heat? I am not a brain surgeon but both of those play a very important role in a gear set. I guess I got my ASE's for nothin

linegtdt52

iTrader: (12)

Gary Z You are right, but using a thick gear oil initially makes the difference because the gearset doesn't get nearly as hot and it is important to do atleast 1 or 2 heat cycles. Kind of like I would never change the fluid at 200 miles either but I know it's all about getting good fluid to help protect the gears from further heat through burnt oil.

thebart455

my car is so loud at the speed when my 4.10's whine i dont notice it

thechef

iTrader: (13)

so you redid the gears and set them correctly and you think its the oil that cured your problem????

ghettocruiser

iTrader: (17)

Meh... Properly set up gears wont whine... Regardless of fluid. you want to use the correct weight, but if they are whining that bad, thare are other issues.

Im confused as to what you did as well.... Did you re-set the gears? Or did you replace the whole third member? If you re-set the gears, did you actually do a set up on it? Or did you just thin out the shim stack and bring the pinion out more..?

Just curious.

J.

GuitsBoy

iTrader: (4)

I always use the heavier gear oil in the rear. I do every little thing you can do to help keep that 10 bolt alive...

linegtdt52

iTrader: (12)

NO SIR! I REPLACED my center section also with NEW gears. I shimmed back the pinion so it wasnt so deeply biting the ring gear and also adjusted the ring with the spanner tool to get a better pattern. I, 100% whole-heartidly, believe that gear oil DOES make a difference. I think the 75w-90 is way too thin and it breaks down way too fast especially with a 9". Let's be honest people that purchase a 9" are doing so to gain strength for the pounding they intend on giving the vehicle at the track or maybe on the streets. My point is with the conjunction of stuff I can see from my previous center section, I can show you where the gear turned colors from getting too hot regardless of pinion depth and the gear oil could no longer do its job. That's why I think the 85w-140 is so much better because when it thins, it is still able to lubricate which I believe will help keep gear whine down. Hey dont get me wrong guys you cant just slap this thing together and put the gear oil in and expect everything to be A OK. Heck no! If you think that please back away from all vehicles. I believe there was a slight miscommunication and I apologize on my behalf. Oh and for whoever said it has to be set up "right", Define "Right". According to some people right is where it doesn't whine, to some right may just be in spec. I want mine to be able to handle ***** to the wall performance and hopefully still have a decently quiet gear, and that is what i got. I can hear my fuel pump over my 9"!

wrd1972

iTrader: (12)

What brand gears, what ratio and what thickness was your pinion shim pack?

linegtdt52

iTrader: (12)

motive 3.89 gears I think it was around .019 but I am not sure if it was for that rear or my 4.10

1BadZ95

Not true. You ever set gears up before? We've installed MANY sets of gears in various cars and you can have the gear set with a perfect backlash and have it make a perfect pattern and the gear will still whine. Install the same set of gears with same backlash and same pattern and no whine. It IS the gears occasionally.

Hawk108

iTrader: (1)

I want you to set up some new gears in my 9"

linegtdt52

iTrader: (12)

I wouldnt mind help setting up gears but I just dont have the time to do it. I think with these they are more trial and error. I 100% agree with even if they are set up perfect they can still whine and that's where I tried to adjust mine off of the specs that were given to me for my new gear set. Guys I have about 1000 miles on my rear now and still no whine. I do have motive's which I love motive gears as they do tend to be the quietest gear set but I think all aspects come into play as well. I think fluid HELPS and never claimed it to be a cure-all. Mine might have done fine with the regular suggested oil but I wont put it in there.

bigblock4-speed

My moser 12 bolt makes makes noice as to where it seems as though there is no fluid in it- but id have to say thats cause all my poly mounts have been removed- and 4.10 gear set.. and ya- i still hear my fuel pump as well as my rearend.. so i must have the best of both worlds.. lol

Gary Z

To amplify my earlier post, my Moser 12-Bolt with 4.11 gears was set up perfectly (by Moser) and it still whined so loudly between 65-75 mph that I drive to and from the track wearing earplugs. Prior to installing 4.33s (after 150 quarter-mile passes, I rechecked the backlash and pinion depth – both were still within 0.002 inch of specifications. Switching from 75W-90 to 85W-140 oil did not affect the whine in this rear. (Marker - My 1000th Post)