Pinion preload for Ford 8.8 stick car.

Sean Marconette · 09-09-2010, 11:45 PM

With new bearings is having the pinion preload at 12-15 in/lbs too light? This is without the seal installed yet, and a solid spacer. 25 in/lbs is what is recommended for a street gear with new bearings. Any thoughts or recommendations would be appreciated.

Thanks

Sean

Dragsinger · 09-10-2010, 04:43 AM

Sean,

my method for the pinion is to have almost no preload, just barely have the slack out. Never any problem in a wide range of applications and performance levels.

The side bearings will have slightly more preload, the shims will require a light, tap. tap, tap to install.

When completely assembled the gear set will be very easy to rotate.

Mike Taylor 3601 · 09-10-2010, 05:27 AM

What Dragsinger said, if want to measure most rears factory spec is around 40'' lbs.
I usually go by feel like dragsinger a good example is have slight drag like front wheel does,as long as you have enough preload that you have no slack up& down you should be fine.
Mike Taylor 3601

Sean Marconette · 09-10-2010, 07:54 AM

Thank you, Dragsinger, and Mike.

I am glad I asked.

Sean

buzzinhalfdozen · 09-10-2010, 08:45 AM

!2-15 inch lbs. is fine you absolutely have to have SOME preload on the bearings, without it the pinion is free to move. I try to get 20-35 in. lbs total turning torque on race rears. Joe

Mark Yacavone · 09-10-2010, 11:19 AM

You won't have to worry,Sean. After a few launches with a stick car,it'll be loose anyway

Sean Marconette · 09-11-2010, 10:15 AM

Thanks Joe and Mark. Its done and back in the car.
Much better than what I saw with the gear set I replaced. All of the pinion teeth had stress fractures and were ready to let go!

Sean

09-09-2010, 11:45 PM	#1
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 790 Liked 275 Times in 76 Posts	Pinion preload for Ford 8.8 stick car. With new bearings is having the pinion preload at 12-15 in/lbs too light? This is without the seal installed yet, and a solid spacer. 25 in/lbs is what is recommended for a street gear with new bearings. Any thoughts or recommendations would be appreciated. Thanks Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

09-10-2010, 04:43 AM	#2
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,760 Likes: 5 Liked 99 Times in 60 Posts	Re: Pinion preload for Ford 8.8 stick car. Sean, my method for the pinion is to have almost no preload, just barely have the slack out. Never any problem in a wide range of applications and performance levels. The side bearings will have slightly more preload, the shims will require a light, tap. tap, tap to install. When completely assembled the gear set will be very easy to rotate.

09-10-2010, 05:27 AM	#3
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,364 Likes: 342 Liked 283 Times in 98 Posts	Re: Pinion preload for Ford 8.8 stick car. What Dragsinger said, if want to measure most rears factory spec is around 40'' lbs. I usually go by feel like dragsinger a good example is have slight drag like front wheel does,as long as you have enough preload that you have no slack up& down you should be fine. Mike Taylor 3601

09-10-2010, 07:54 AM	#4
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 790 Liked 275 Times in 76 Posts	Re: Pinion preload for Ford 8.8 stick car. Thank you, Dragsinger, and Mike. I am glad I asked. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

09-10-2010, 08:45 AM	#5
buzzinhalfdozen Senior Member Join Date: Sep 2006 Location: Bellevue Ohio Posts: 984 Likes: 0 Liked 11 Times in 8 Posts	Re: Pinion preload for Ford 8.8 stick car. !2-15 inch lbs. is fine you absolutely have to have SOME preload on the bearings, without it the pinion is free to move. I try to get 20-35 in. lbs total turning torque on race rears. Joe __________________ Joe Buchanan SS/BX 3117

09-10-2010, 11:19 AM	#6
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,803 Likes: 2,892 Liked 5,099 Times in 1,944 Posts	Re: Pinion preload for Ford 8.8 stick car. You won't have to worry,Sean. After a few launches with a stick car,it'll be loose anyway __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

09-11-2010, 10:15 AM	#7
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 790 Liked 275 Times in 76 Posts	Re: Pinion preload for Ford 8.8 stick car. Thanks Joe and Mark. Its done and back in the car. Much better than what I saw with the gear set I replaced. All of the pinion teeth had stress fractures and were ready to let go! Sean __________________ Sean Marconette 84 Mustang 5060 SS/N