Author Topic: rear end problem  (Read 4759 times)

Offline necromonger

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rear end problem
« on: March 13, 2012, 05:27:02 PM »
Hello.I have been working on my truck, brake shoes wheel cyl em brake cables and so on and i noticed way to much back lash in my rear end.can I adjust the back lash on my ring gear or do i have to buy a new set?
new build,1978 chevy 3/4 ton 2 wheel drive 350 4 speed trans.

Offline zieg85

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Re: rear end problem
« Reply #1 on: March 13, 2012, 05:58:29 PM »
A couple of things could be wrong...  If you are new to the truck and the PO re-geared it they might have not set it up properly.  Indications would be a fairly clean rear end.  If yours is a grease pit caked mess, chances are the pinion bearing is going and it may have been leaking for a while... My $.02
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline necromonger

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Re: rear end problem
« Reply #2 on: March 13, 2012, 06:21:35 PM »
I will check pinon bearing and see if i can move it up and down.
new build,1978 chevy 3/4 ton 2 wheel drive 350 4 speed trans.

Offline zieg85

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Re: rear end problem
« Reply #3 on: March 13, 2012, 06:34:02 PM »
One additional thought is that the PO changed the pinion seal and over-tightened the nut, crushing the sleeve more causing excessive backlash...
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline Engineer

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Re: rear end problem
« Reply #4 on: March 13, 2012, 07:27:51 PM »
Are you sure it is excessive back lash?

There could be many areas of wear that would indicate slop between the pinion, and the wheels.

Some places that wear: differential gears, the cross that the differential gears ride on, axle splines, etc.

There should only be .006" back lash on the ring/pinion. On the GM 14-bolt you can take backlash out by adjusting the spanner nuts that screw into the sides of the housing. Problem with taking lash out of a used set of gears is the fact that the gears have already taken a set to the current backlash.

I have taken backlash out of used gears before without side effects, but you run the risk of making the gear set noisy by changing the mesh of used gears.
2002 Chevy 2500HD 4x4 8.1/ZF6sp RC/LB
2001 Chevy 2500HD 4x4 6.0/4L85E EC/SB
1997 Chevy Blazer 4x4
1994 Chevy K-2500 4x4 C6P 5.7/4L80E
1979 Chevy K-30 4x4 4sp 4.10
1977 Chevy K-30 4x4 4sp 4.10 454

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