8 3/4 Differential lash.

[Encswsm]

This weekend I finally got around to pulling my left rear axle to put Normal left threaded lugs in it (after my Disk Conversion on the front it was a odd man Charlie). anyhow while putting it all back together I notices there's an awful lot of lash when I turn the wheel till I feel the gear teeth engaging They actually clunk when engaging.
What is normal?
Thanks

 

[RemCharger]

You're likely feeling all the slop in the side gears, splines, etc

 

[R413]

It will be always be more with a tire on due to the diameter. But you don't check it at the tire, you check it at the ring gear. The backlash between the ring and pinion gears. Leave the differential out of it. As above.

 

[nitro_rat]

You're likely feeling all the slop in the side gears, splines, etc

It will be always be more with a tire on due to the diameter. But you don't check it at the tire, you check it at the ring gear. The backlash between the ring and pinion gears. Leave the differential out of it. As above.

What they said. Let's just hypothesize that you jack up one side, then you turn that lifted tire. The transmission is in park.

1. Slop in the splines of the elevated wheel's axle
2. backlash in the spider gear set
3. backlash in the ring and pinion
4. lash in the driveshaft/universal joints
5. Lash in the transmission slip yoke splines
6. slop in the transmission's park stop assembly
7. slop in the opposite side's axle shaft splines

Now once you've accumulated ALL of the above slop, the wheel stops turning. At an 8.75" ring gear diameter, 0.010" (ten thousandths of an inch) backlash equals very close to 0.030" at the outside diameter of a 26" tire. That's a 3x increase due to the increased diameter of the tire. So all the accumulated slop in all of the above components is multiplied somewhere around 3x vs. measuring at the ring gear's diametrical pitch, where backlash is actually measured. That's why you get so much more than the 0.030" you would get if you were just measuring backlash at the OD of the tire!

Food for thought...

 

[Encswsm]

It will be always be more with a tire on due to the diameter. But you don't check it at the tire, you check it at the ring gear. The backlash between the ring and pinion gears. Leave the differential out of it. As above.

Thanks I will do that.

 

[Encswsm]

What they said. Let's just hypothesize that you jack up one side, then you turn that lifted tire. The transmission is in park.

1. Slop in the splines of the elevated wheel's axle
2. backlash in the spider gear set
3. backlash in the ring and pinion
4. lash in the driveshaft/universal joints
5. Lash in the transmission slip yoke splines
6. slop in the transmission's park stop assembly
7. slop in the opposite side's axle shaft splines

Now once you've accumulated ALL of the above slop, the wheel stops turning. At an 8.75" ring gear diameter, 0.010" (ten thousandths of an inch) backlash equals very close to 0.030" at the outside diameter of a 26" tire. That's a 3x increase due to the increased diameter of the tire. So all the accumulated slop in all of the above components is multiplied somewhere around 3x vs. measuring at the ring gear's diametrical pitch, where backlash is actually measured. That's why you get so much more than the 0.030" you would get if you were just measuring backlash at the OD of the tire!

View attachment 1785896
Food for thought...

I didn’t think of it that way. Thanks for the explanation!

 

[R413]

Thanks I will do that.

You can't do it with the rear axle together.

Just answer this, did the car drive ok without odd noises? Then keep driving.

 

[Encswsm]

You can't do it with the rear axle together.

Just answer this, did the car drive ok without odd noises? Then keep driving.

I literally drove the car about 15 miles and pulled it into my garage where I have been working on it. The brakes were sketchy and when I pulled them apart both front brakes were barely working and the passenger side back brake was all oil soaked from the seal leaking. When I get that finished I’ll get to drive it more. A new true track chunk is in my future but I just want to drive it for now.