pinion bearing initial rotation

9

9050lx

Member

Aug 31, 2006

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Sep 29, 2008

#1

• Sep 29, 2008

• #1

I bought a used 3:73 low miles gearset installed in an 8.8 1989 fox rear to rebuild for my Daily driver.Carrier bearing has pits so i will replace them.The supposedly new pinion bearings are turning at 15 in lbs rotational torque but the initial force required to turn the pinion flange takes two hands to get it to start to rotate.The feel of the bearings are kind of bumpy when rotating the pinion flange.Should I replace them or is this normal?Was told 300 miles total on the gearset and pinion bearings.Also, I have some axles with surface rust on the bearing surface,I polished out with emery cloth. no pitting or grooving ,can I run these without failure?

 

F

Forcedpower

New Member

Mar 1, 2004

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Sep 30, 2008

#2

• Sep 30, 2008

• #2

I'm a little confused is this a complete rear or just the gears? A pinion bearing is around $20 or you can get the whole bearing kit for $100. If you are just going to install the gears in your rear I would get a new bearing so you know its good.

 

9

9050lx

Member

Aug 31, 2006

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Sep 30, 2008

#3

• Sep 30, 2008

• #3

Yes this is a complete rear that has a low-mile 3:73 installed,currently disassembled except for the pinion.

 

NIKwoaC

中國製造

15 Year Member

Oct 31, 2006

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Chengdu Province

Sep 30, 2008

#4

• Sep 30, 2008

• #4

In my opinion, you should ALWAYS change bearings when doing a rebuild on a rear end. If the rear end has seen some driving time, the pinion should spin much more easily than that. Hell, on a fresh rebuild, you should be able to turn the pinion with ONE hand, with just very slight resistance, let alone something that has been driven 300 miles.

I'd say pull the pinion, and rebuild it yourself (or get someone to do it who knows how) with fresh bearings.

I'm curious about the rust issues you are seeing. If the gears have any rust on the teeth, they are likely junk. It sounds to me that this rear was left out in the weather?

 

9

9050lx

Member

Aug 31, 2006

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Sep 30, 2008

#5

• Sep 30, 2008

• #5

No, the axles are from a different purchase.They had light rust on them when I recieved them.No grooves or wear at all.

 

old_blue

15 Year Member

Nov 3, 2003

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Oct 2, 2008

#6

• Oct 2, 2008

• #6

15 in lbs isnt anything. sounds like someone may have torqued them to ft lbs vs in lb or they went a little crazy with a impact wrench when setting the crush collar. should be able to turn with one hand with little effort.

 

9

9050lx

Member

Aug 31, 2006

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Oct 2, 2008

#7

• Oct 2, 2008

• #7

Yeah I figured I better dig deeper.The rear pinion bearing was starting to get slight pits,the race has circular rings in it.I also think someone over-torqued or used an impact.Replacing them now.I will also move the pattern toward the heel while I am in there.