8 3/4 stocker rear

gmonde · 02-13-2011, 07:24 PM

well looking to the 2011 season fresh motor ready to dyno ,i pulled the center section to check the ring and pinion and found some fractures on the ring gear along with razor sharp edges on the pinion, there are seveal reasons why this happened and i can list them but want hear from the racers who run a 8 3/4 and what they have run into running this rear thanks gmonde

Phillip marvetz · 02-13-2011, 08:09 PM

Razor sharp pinion? How about a picture of that please. How does the pattern look? How many passes does these gears have on them? What ratio are you running?

jmcarter · 02-13-2011, 08:11 PM

Lots of variables to consider but highly recommend you first call Jim Bailey. Here's his website:

http://www.finishedracing.com/

X-TECH MAN · 02-13-2011, 08:30 PM

Quote:

Originally Posted by gmonde

well looking to the 2011 season fresh motor ready to dyno ,i pulled the center section to check the ring and pinion and found some fractures on the ring gear along with razor sharp edges on the pinion, there are seveal reasons why this happened and i can list them but want hear from the racers who run a 8 3/4 and what they have run into running this rear thanks gmonde

Possably improper set up? Or the thinner weight gear lubes some have been running? Ive set up several 8 3/4 rears in the past and all of them are still together and in good shape today. One was run in an 3730 lb IHRA K/CM MoPar with a 360 crate motor running 11.30's, hi stahl converter and its still good to go after 10 years and lots of runs. These were 4:88's. Im NOT saying Im that good....maybe just lucky? Maybe just the wrong heat treat of the gear set? You should have it rockwell tested if you can to see how hard or soft it is. Just because its new or a major manufacturer dosent mean its always right. I found that GM (Pontiac) screwed up a bunch of new Super Duty 455 rods many years ago and they were to hard from improper heat treating causing breakage. Pontiac recalled them when they rechecked them themselves. Just trying to give you some ideas here.

George Mirza · 02-13-2011, 09:51 PM

Richmond Gears? I have cracked and broken the teeth of a few sets over the years. I think they are to hard and brittle. I have an old set of Zoom gears that have lasted forever.

Check the pinion depth, that could be some of the problem.

I have always run the 742 case with 1 3/4 straight pinion, some have trouble with the 489 case tapered pinions, they want to push back under load and crack the caps.

With the weight you are carrying you are close to the limits of this rear without some upgrades.

I have only heard good things about Jim Bailey's treatment, my next set of gears will be done. Can only help your situation.

George

gmonde · 02-13-2011, 09:56 PM

x tech good answer on two of the counts,,,,,, yes 4:88 and i switched to a synthetic 75/90 half way thru last years season and to add i lost traction on two runs witched caused the car to shake real bad ,,as far as set up these where a set of used gears that i set up and worked to get get the best gear pattern leaning towards the toe of ring gear ,if you look you can see that the drive on the ring gear runs the entire tooth ,i have no idea of time,passes on the set but they didnt have the fractures in the ring or razor sharp edge ,these are just pulled from my car , a g/sa 3650 lbs car tha ran 11:50 to 11:80 depending on air conditions with a 1.529 60 ft ,,i was on the fence about going with the synthetic low weight and it showed that there wasnt enough viscosity witch ended up with metal to metal on hard launch and the tire shake didnt help,,,just asking who runs a 8 3/4 with a heavy car how they are doing with there set up gmonde

gmonde · 02-13-2011, 10:04 PM

Quote:

Originally Posted by George Mirza

Richmond Gears? I have cracked and broken the teeth of a few sets over the years. I think they are to hard and brittle. I have an old set of Zoom gears that have lasted forever.

Check the pinion depth, that could be some of the problem.

I have always run the 742 case with 1 3/4 straight pinion, some have trouble with the 489 case tapered pinions, they want to push back under load and crack the caps.

With the weight you are carrying you are close to the limits of this rear without some upgrades.

I have only heard good things about Jim Bailey's treatment, my next set of gears will be done. Can only help your situation.

George

george:this a 489 case with mark willaims caps,billet spanners,if i stayed with 85/140 i dont think this would of happened but looking for et some time's cost gmonde

Darcy Clarke · 02-13-2011, 10:04 PM

I run a 83/4 in my A stocker and change the gear set every 100 passes max. I as well check it 2 to 3 times during that time as I had one set that was starting to lift the ring gear teeth, very close to disaster. I have a set of gears done by Jim Bailey that I set up and will be using it this year.

Darcy Clarke
AA/SA, A/SA

gmonde · 02-13-2011, 10:09 PM

Quote:

Originally Posted by Darcy Clarke

I run a 83/4 in my A stocker and change the gear set every 100 passes max. I as well check it 2 to 3 times during that time as I had one set that was starting to lift the ring gear teeth, very close to disaster. I have a set of gears done by Jim Bailey that I set up and will be using it this year.

Darcy Clarke
AA/SA, A/SA

whats the gear lube you run,,whats the 60' gmonde

Darcy Clarke · 02-13-2011, 10:16 PM

I have run different lubes but mainly the shockproof 75/90 synthetic. The 60 foots are typically low 1.30's and I weigh 3540 lbs , I foot brake with no 2 step. The housing is back braced and I use Strange spools with ARP Studs. The 83/4 is good but at certain power levels it has a limit and it is just regular maintenance. I am looking forward to seeing how the gears that Jim did for me work out, I have only heard good things about them.

Darcy Clarke
AA/SA, A/SA

02-13-2011, 07:24 PM	#1
gmonde Senior Member Join Date: Nov 2007 Posts: 615 Likes: 56 Liked 166 Times in 59 Posts	8 3/4 stocker rear well looking to the 2011 season fresh motor ready to dyno ,i pulled the center section to check the ring and pinion and found some fractures on the ring gear along with razor sharp edges on the pinion, there are seveal reasons why this happened and i can list them but want hear from the racers who run a 8 3/4 and what they have run into running this rear thanks gmonde Attached Thumbnails

02-13-2011, 08:09 PM	#2
Phillip marvetz Senior Member Join Date: Oct 2008 Location: Lynden ,WA Posts: 820 Likes: 0 Liked 3 Times in 3 Posts	Re: 8 3/4 stocker rear Razor sharp pinion? How about a picture of that please. How does the pattern look? How many passes does these gears have on them? What ratio are you running? __________________ 2009 V/SA Record Holder

02-13-2011, 08:11 PM	#3
jmcarter VIP Member Join Date: Dec 2008 Location: Richmond Hill GA (and Port Ludlow WA) Posts: 4,134 Likes: 2,006 Liked 2,743 Times in 858 Posts	Re: 8 3/4 stocker rear Lots of variables to consider but highly recommend you first call Jim Bailey. Here's his website: http://www.finishedracing.com/ __________________ Jim Carter 2340 Super Stock 2340 SST/2340 Stock

02-13-2011, 09:51 PM	#5
George Mirza Senior Member Join Date: Jan 2002 Location: North Attleborough Ma. Posts: 522 Likes: 0 Liked 0 Times in 0 Posts	Re: 8 3/4 stocker rear Richmond Gears? I have cracked and broken the teeth of a few sets over the years. I think they are to hard and brittle. I have an old set of Zoom gears that have lasted forever. Check the pinion depth, that could be some of the problem. I have always run the 742 case with 1 3/4 straight pinion, some have trouble with the 489 case tapered pinions, they want to push back under load and crack the caps. With the weight you are carrying you are close to the limits of this rear without some upgrades. I have only heard good things about Jim Bailey's treatment, my next set of gears will be done. Can only help your situation. George

02-13-2011, 09:56 PM	#6
gmonde Senior Member Join Date: Nov 2007 Posts: 615 Likes: 56 Liked 166 Times in 59 Posts	Re: 8 3/4 stocker rear x tech good answer on two of the counts,,,,,, yes 4:88 and i switched to a synthetic 75/90 half way thru last years season and to add i lost traction on two runs witched caused the car to shake real bad ,,as far as set up these where a set of used gears that i set up and worked to get get the best gear pattern leaning towards the toe of ring gear ,if you look you can see that the drive on the ring gear runs the entire tooth ,i have no idea of time,passes on the set but they didnt have the fractures in the ring or razor sharp edge ,these are just pulled from my car , a g/sa 3650 lbs car tha ran 11:50 to 11:80 depending on air conditions with a 1.529 60 ft ,,i was on the fence about going with the synthetic low weight and it showed that there wasnt enough viscosity witch ended up with metal to metal on hard launch and the tire shake didnt help,,,just asking who runs a 8 3/4 with a heavy car how they are doing with there set up gmonde

02-13-2011, 10:04 PM	#8
Darcy Clarke Member Join Date: Mar 2008 Posts: 193 Likes: 22 Liked 422 Times in 29 Posts	Re: 8 3/4 stocker rear I run a 83/4 in my A stocker and change the gear set every 100 passes max. I as well check it 2 to 3 times during that time as I had one set that was starting to lift the ring gear teeth, very close to disaster. I have a set of gears done by Jim Bailey that I set up and will be using it this year. Darcy Clarke AA/SA, A/SA

02-13-2011, 10:16 PM	#10
Darcy Clarke Member Join Date: Mar 2008 Posts: 193 Likes: 22 Liked 422 Times in 29 Posts	Re: 8 3/4 stocker rear I have run different lubes but mainly the shockproof 75/90 synthetic. The 60 foots are typically low 1.30's and I weigh 3540 lbs , I foot brake with no 2 step. The housing is back braced and I use Strange spools with ARP Studs. The 83/4 is good but at certain power levels it has a limit and it is just regular maintenance. I am looking forward to seeing how the gears that Jim did for me work out, I have only heard good things about them. Darcy Clarke AA/SA, A/SA