changing rear gears how hard is it - The 1947 - Present Chevrolet & GMC Truck Message Board Network

merlinman572 · 08-05-2009, 09:53 AM

hi im just getting into drag racing and want to try a new set of gears in my axle its a ford 9 inc with spool and would like to do as much work as poss on my own any advice would be greatfully recieved.

70k52wd · 08-05-2009, 10:13 AM

That's a third member rear. Some drag guys have a couple of centers set up with different ratios for different conditions. I would just get a third member with the ratio you want to try. Keep the set up you have. But then, I don't know how to set a rear up, so for me that is the easy way to get what you want.

red caddy · 08-05-2009, 01:37 PM

For my nickel, the Ford 9 is the easiest chunk to setup. There are several good tutorials availible on the net, just google Ford 9. (check out Pirate 4X4 .com) The first one I did took most of a day, now I do one in less than hour. The only tools required are a mag base dial indicator, a good dial caliper or 0 to 1 micrometer, a torque wrench, and common hand tools.

I built a bench fixture to hold the chunk, much easier than chasing it around the shop floor.

Both my race rig's use the 9, so I've accumulated a dozen or so chunks, from 2.46:1 to 5.12:1, 31 and 35 spline. Plug N' play at it's best. Good luck, Paul

merlinman572 · 08-05-2009, 04:06 PM

thanks for advice will go on line and do some search's have all the tools you described at moment running 3.7-1 on 33 tyres with 572 merlin block kickin 628hp 700lbft on dyno in c30 full size crew cab nearly 3 ton running 13.07 @102mph was thinking of trying 4.3-1 gears

*ImportThis* · 08-05-2009, 09:50 PM

use an impact to tighten the pinion nut, because if you use the old style crush sleeve you wont crush the sleeve by hand. you want to set your backlash at .003-.006 for a drag race application on a 9"(as long as you are using new R&P)

an impact with 9/16", 3/4" and 1 1/16"(im pretty sure for pinion nut) impact sockets should pretty much do ya, except i use a wrench for the keepers. make sure to red locktite the ring gear bolts, and blue locktite all other bolts and torque to proper spec.

i agree red, i have done a hundred or so 9" chunks, mainly for circle track cars, and they are by far the easiest to set up, and being able to swap complete chunk on the go is great.

red caddy · 08-06-2009, 11:54 AM

WOW, that's a helluva rig, COOL.

Are you running 1/8th or full quarter? In the 1/8th, 4.30's should be fine, but unless you are spinning way past 6000 and growing those 33's the MPH will still seem low. What launch and shift RPM work good for you now? RED

08-05-2009, 09:53 AM	#1
merlinman572 Registered User Join Date: Jul 2009 Location: uk Posts: 15	changing rear gears how hard is it hi im just getting into drag racing and want to try a new set of gears in my axle its a ford 9 inc with spool and would like to do as much work as poss on my own any advice would be greatfully recieved.

08-05-2009, 10:13 AM	#2
70k52wd Blaze-Air Join Date: Nov 2008 Location: Virginia Posts: 1,117	Re: changing rear gears how hard is it That's a third member rear. Some drag guys have a couple of centers set up with different ratios for different conditions. I would just get a third member with the ratio you want to try. Keep the set up you have. But then, I don't know how to set a rear up, so for me that is the easy way to get what you want.

08-05-2009, 01:37 PM	#3
red caddy Registered User Join Date: Dec 2008 Location: Venice Florida Posts: 83	Re: changing rear gears how hard is it For my nickel, the Ford 9 is the easiest chunk to setup. There are several good tutorials availible on the net, just google Ford 9. (check out Pirate 4X4 .com) The first one I did took most of a day, now I do one in less than hour. The only tools required are a mag base dial indicator, a good dial caliper or 0 to 1 micrometer, a torque wrench, and common hand tools. I built a bench fixture to hold the chunk, much easier than chasing it around the shop floor. Both my race rig's use the 9, so I've accumulated a dozen or so chunks, from 2.46:1 to 5.12:1, 31 and 35 spline. Plug N' play at it's best. Good luck, Paul

08-05-2009, 04:06 PM	#4
merlinman572 Registered User Join Date: Jul 2009 Location: uk Posts: 15	Re: changing rear gears how hard is it thanks for advice will go on line and do some search's have all the tools you described at moment running 3.7-1 on 33 tyres with 572 merlin block kickin 628hp 700lbft on dyno in c30 full size crew cab nearly 3 ton running 13.07 @102mph was thinking of trying 4.3-1 gears

08-05-2009, 09:50 PM	#5
ImportThis Account Suspended Join Date: Aug 2009 Location: Paris, Tx Posts: 16	Re: changing rear gears how hard is it use an impact to tighten the pinion nut, because if you use the old style crush sleeve you wont crush the sleeve by hand. you want to set your backlash at .003-.006 for a drag race application on a 9"(as long as you are using new R&P) an impact with 9/16", 3/4" and 1 1/16"(im pretty sure for pinion nut) impact sockets should pretty much do ya, except i use a wrench for the keepers. make sure to red locktite the ring gear bolts, and blue locktite all other bolts and torque to proper spec. i agree red, i have done a hundred or so 9" chunks, mainly for circle track cars, and they are by far the easiest to set up, and being able to swap complete chunk on the go is great.

08-06-2009, 11:54 AM	#6
red caddy Registered User Join Date: Dec 2008 Location: Venice Florida Posts: 83	Re: changing rear gears how hard is it WOW, that's a helluva rig, COOL. Are you running 1/8th or full quarter? In the 1/8th, 4.30's should be fine, but unless you are spinning way past 6000 and growing those 33's the MPH will still seem low. What launch and shift RPM work good for you now? RED



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