Rear end play

[73pony]

I have noticed that the drivetrain seems a little sloppy lately. Original 2.75 open rear. With the Trans in neutral I have about 20+ degrees of rotation of the drive shaft back and forth. What is normal? I am planning a rebuild of the rear end but was hoping to put it off until I put the car away for winter. Is the rear end shot? How much rotational play is normal? Can I drive it like this for a few more months? Any help is always appreciated. Car has a newly rebuilt T5 conversion and new u-joints. All of the rotation seems to be from the rear end. If I have it in gear it is a lot less. Like closer to 5 degrees.

 

[Bentworker]

Backlash is measured on the ring gear not the pinion. It is hard to correlate pinion rotation into a useful number. 20 degrees seems like a lot, what does your oil look like? Does it make any noises? Any play on the pinion?

 

[Don C]

I agree, 20° is too much, your bearings are likely worn. I would change the gear oil to get rid if as much worn metal as possible, to help slow down further wear. The more metal particles that float around in there the faster the wear will become.

You might be able to make it a few months if you baby it. If it starts making whining or growling noises park it. When the gear mesh gets bad enough the differential can lock up.