Pro gear life

Dana Fitzpatrick · 12-26-2014, 11:38 PM

I have a 3300lb,9 inch tire 68 Camaro,4-speed, that I shift w/o the clutch.Runs mid to high 9's. It has a complete Strange 12-bolt,spool,pro gears, support cover.I'm looking for estimates on gear life and what to look for when I pull the cover off.As always,thank you.

12-27-2014, 12:14 AM

Quote:

Originally Posted by Dana Fitzpatrick

I have a 3300lb,9 inch tire 68 Camaro,4-speed, that I shift w/o the clutch.Runs mid to high 9's. It has a complete Strange 12-bolt,spool,pro gears, support cover.I'm looking for estimates on gear life and what to look for when I pull the cover off.As always,thank you.

What gear ratio? Big or small block? I ran 4.88's they lasted around 75 runs with the stick. When I pulled the cover, the teeth started developing cracks on the ring gear. 3400 pound car leaving around 5k. Running 10.60's

Don Anderson · 12-27-2014, 01:47 AM

Try these guys for gears:

Dewco

(765) 962-7201

Dana Fitzpatrick · 12-27-2014, 09:46 AM

Quote:

Originally Posted by Todd Hoven

What gear ratio? Big or small block? I ran 4.88's they lasted around 75 runs with the stick. When I pulled the cover, the teeth started developing cracks on the ring gear. 3400 pound car leaving around 5k. Running 10.60's

Big block,4.56's.I leave between 5400 and 5900,soft-loc clutch.

Dwight Southerland · 12-27-2014, 10:25 AM

You might also talk to Tom's Differentials in ID - http://www.tomsdifferentials.com/

HIs heat treating process usually doubles 12 bolt gear life. Cracks on the ring gear teeth are not as much to be concerned about as cracks on the pinion.

Dave Casey · 12-27-2014, 01:13 PM

I just replaced my Richmond 4.56 12 bolt pro gear, 3250 lb bbc stick, no special treating, carefully setup originally. low 10 sec stocker I got over 250 runs out of it. I like to set them up about .001 deep, keep the pinion bearing on the high side preloadwise, and usually .003-.005 lash

hope that helps

Don Anderson · 12-31-2014, 05:43 PM

Try Mach Development for gear coating.
520-568-3511

Larry Hill · 12-31-2014, 09:34 PM

I have a Richmond pro gear I have been running in the Cuda since 1991. I change oil in it every other year and it still looks great. It is the best thing I ever bought for the car.

tj310 · 01-01-2015, 09:24 AM

I use a steel cover and weld a pipe plug in a position where you can see the teeth. They usually give a warning before they fail . ---Trevor

Mike Taylor 3601 · 01-02-2015, 11:02 AM

I had 2900lbs. nova 355 nash 5 speed 3.25 1st 5.57 rear had 12 bolt all MW axles, spool,steel caps, ran 6.12-6.20 1/8 60' 1.26-1.28 usually got about 35-50 runs.
My problem was that the pinion would bend and lose backlash on one side and backlash be loose when pinion was turned 180 degrees. once I figured out what was going on by accident was pushing car and could barely push then would free up then bind again. would keep a check on it by checking backlash on gears just by jacking up and feeling of it at driveshaft.
I believe it did this because 12 bolt not having support on rear of pinion like a 9'' does
I had Mc Leod soft loc and normally ran 300-400lbs base on pressure plate and no counterweight added to levers.
Mike Taylor 3601

12-26-2014, 11:38 PM	#1
Dana Fitzpatrick Member Join Date: May 2009 Posts: 148 Likes: 4 Liked 10 Times in 6 Posts	Pro gear life I have a 3300lb,9 inch tire 68 Camaro,4-speed, that I shift w/o the clutch.Runs mid to high 9's. It has a complete Strange 12-bolt,spool,pro gears, support cover.I'm looking for estimates on gear life and what to look for when I pull the cover off.As always,thank you.

12-27-2014, 01:47 AM	#3
Don Anderson Member Join Date: Dec 2010 Location: Duluth, Mn. Posts: 154 Likes: 2,777 Liked 24 Times in 8 Posts	Re: Pro gear life Try these guys for gears: Dewco (765) 962-7201

12-27-2014, 10:25 AM	#5
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,996 Likes: 63 Liked 756 Times in 189 Posts	Re: Pro gear life You might also talk to Tom's Differentials in ID - http://www.tomsdifferentials.com/ HIs heat treating process usually doubles 12 bolt gear life. Cracks on the ring gear teeth are not as much to be concerned about as cracks on the pinion.

12-27-2014, 01:13 PM	#6
Dave Casey VIP Member Join Date: Dec 2002 Location: Hampden, MA Posts: 1,194 Likes: 233 Liked 758 Times in 160 Posts	Re: Pro gear life I just replaced my Richmond 4.56 12 bolt pro gear, 3250 lb bbc stick, no special treating, carefully setup originally. low 10 sec stocker I got over 250 runs out of it. I like to set them up about .001 deep, keep the pinion bearing on the high side preloadwise, and usually .003-.005 lash hope that helps __________________ Dave Casey 1330 STK

12-31-2014, 05:43 PM	#7
Don Anderson Member Join Date: Dec 2010 Location: Duluth, Mn. Posts: 154 Likes: 2,777 Liked 24 Times in 8 Posts	Re: Pro gear life Try Mach Development for gear coating. 520-568-3511

12-31-2014, 09:34 PM	#8
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,582 Likes: 1,866 Liked 10,582 Times in 2,186 Posts	Re: Pro gear life I have a Richmond pro gear I have been running in the Cuda since 1991. I change oil in it every other year and it still looks great. It is the best thing I ever bought for the car. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

01-01-2015, 09:24 AM	#9
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: Pro gear life I use a steel cover and weld a pipe plug in a position where you can see the teeth. They usually give a warning before they fail . ---Trevor

01-02-2015, 11:02 AM	#10
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,348 Likes: 296 Liked 248 Times in 87 Posts	Re: Pro gear life I had 2900lbs. nova 355 nash 5 speed 3.25 1st 5.57 rear had 12 bolt all MW axles, spool,steel caps, ran 6.12-6.20 1/8 60' 1.26-1.28 usually got about 35-50 runs. My problem was that the pinion would bend and lose backlash on one side and backlash be loose when pinion was turned 180 degrees. once I figured out what was going on by accident was pushing car and could barely push then would free up then bind again. would keep a check on it by checking backlash on gears just by jacking up and feeling of it at driveshaft. I believe it did this because 12 bolt not having support on rear of pinion like a 9'' does I had Mc Leod soft loc and normally ran 300-400lbs base on pressure plate and no counterweight added to levers. Mike Taylor 3601