Is this normal backlash on rear wheels

Road_Runna

20+ Year Stangneter :roc</strong><span class=
Dec 23, 2002
594
6
39
Ogden, UT
I just finished doing a Differential trak lok install. I reused my old S spring because the new one that was supplied is impossible to install, heck I even had problems reinstalling the old one.

I checked backlash on the big gear once I installed everything except the diff cover, I used a dial indicator and came up with 12 thousanths of an inch (.012) backlash.

I took my digi cam, and recorded the backlash I get when the rims are installed and bolts tightened. Automatic trans, and car is in the Park mode, is this normal?

MVI_1674.mp4 video by car_sand - Photobucket
 
sounds normal to me.... last one I did appeared to have excessive backlash, same as yours is doing, and it was within spec. Long as the backlash at the carrier is .012 I'd say your fine.
 
This question dawned on me last night. What is the correct gear mode to measure backlash? (P) PARK or in (N) Neutral.

I rechecked backlash today, while in the PARK mode I got .008 thousanth's of an inch.
I din't mention on any of my posts, the clutch pak im installing is the Carbon Fiber pak by FRPP?
 
I don't think it matters. You want to measure the backlash without rotating the pinion and drive shaft don't you?

That's what I thought.
I measured backlash again yesterday this time in the Neutral gear selection, I came up with .009, it's not that hard to overturn the pinion gear and easily get more backlash because of the turning of the wheels.
 
I started the car this morning, and took it around the block.

I wasn't too happy witht the ammount of oil I put in the differential, so im going to add more saturday and start peeling the tires.

Also, I ran out of the Permatex thread sealant, and started using nylon tape sealant on the threads. Will that create a problem? I used the tape thread sealer (NYLON) on the pinion bolts, and cap bolts.
 
I started the car this morning, and took it around the block.

I wasn't too happy witht the ammount of oil I put in the differential, so im going to add more saturday and start peeling the tires.

It only takes 3.75 pints and is filled to the bottom of the filler hole. Don't forget to add the friction modifer.

Also, I ran out of the Permatex thread sealant, and started using nylon tape sealant on the threads. Will that create a problem? I used the tape thread sealer (NYLON) on the pinion bolts, and cap bolts.

I assume you mean "Teflon" tape. Teflon tape may not seal the bolt threads. Teflon tape is best used on tapered threads such as NPT nipples and couplers. Was there a reason to use the tape on the pinion bolts and cap bolts. I don't believe that's a good idea when tightening bolts to a specified torque.
 
That's what I thought.
I measured backlash again yesterday this time in the Neutral gear selection, I came up with .009, it's not that hard to overturn the pinion gear and easily get more backlash because of the turning of the wheels.

You have to 'lock down' the pinion, so it can't move, then only move the ring gear when you check lash.