Too much diff backlash? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mancad · 02-25-2016, 01:35 PM

I have a 1968 C20 with low miles (57k) and a No Spin axle. It seems like it has a little too much backlash in the differential. The drive shaft will turn a little over 30 degrees one way when turned by hand. Does that sound excessive? I cannot find a spec in the service manual.

Bigdav160 · 02-25-2016, 02:48 PM

I don't think you can accurately determine backlash using that method.

**kwmech** · 02-25-2016, 03:11 PM

What he said^^^. What you are feeling is the slop (for lack of a better term) in the complete set-up, especially with the posi. Totally normal unless you have an unusual noise or something else going on

Mike C · 02-25-2016, 11:45 PM

The "No Spin" and mechanical lockers of that style including the later Detroit Locker and the LockRights are known for driveline backlash. But it's NOT the same as backlash in the gear set.

mancad · 02-26-2016, 12:39 AM

Thanks for your responses. That was a generic use of the term backlash to cover any and all looseness in the differential. Didn't mean to imply the gear backlash used to set up the ring and pinion fit. Maybe hysteresis would have been more appropriate.

02-25-2016, 01:35 PM	#1
mancad Registered User Join Date: Jun 2014 Location: reno nv Posts: 10	Too much diff backlash? I have a 1968 C20 with low miles (57k) and a No Spin axle. It seems like it has a little too much backlash in the differential. The drive shaft will turn a little over 30 degrees one way when turned by hand. Does that sound excessive? I cannot find a spec in the service manual.

02-25-2016, 02:48 PM	#2
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Too much diff backlash? I don't think you can accurately determine backlash using that method. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

02-25-2016, 03:11 PM	#3
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,679	Re: Too much diff backlash? What he said^^^. What you are feeling is the slop (for lack of a better term) in the complete set-up, especially with the posi. Totally normal unless you have an unusual noise or something else going on

02-25-2016, 11:45 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,732	Re: Too much diff backlash? The "No Spin" and mechanical lockers of that style including the later Detroit Locker and the LockRights are known for driveline backlash. But it's NOT the same as backlash in the gear set. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

02-26-2016, 12:39 AM	#5
mancad Registered User Join Date: Jun 2014 Location: reno nv Posts: 10	Re: Too much diff backlash? Thanks for your responses. That was a generic use of the term backlash to cover any and all looseness in the differential. Didn't mean to imply the gear backlash used to set up the ring and pinion fit. Maybe hysteresis would have been more appropriate.



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