Issues with 8-3/4 489 case gear set-up

[Ben Mowery]

So I am having some issues with setting up the ring and pinion in my center section. The background is my GTX was equipped with a 3.23 open diff. I wanted to convert to sure-grip. I purchased a Yukon sure-grip. This unit uses early style bearings from what I have read. So I removed gear from old carrier and installed with new bolts on sure-grip unit and bearings. I installed a new race in both ends of case and a new front pinion bearing along with a crush sleeve eliminator. I chose to reuse the rear pinion bearing as it didn't look bad. I installed pinion and set preload. I had a pretty steady 15 in. lbs. From there installed the carrier and set backlash. Had about .007" backlash at the tightest spot. So I am thinking I am home free since I am reusing rear bearing and shim that was on the pinion. I go to check the pattern and it appears as if the pinion needs shimmed up more. So my question is if this is possible? If so what may have caused it? Is there a chance the race for the rear bearing in in too far? I did a double check with a T&D set-up too with a new bearing setting in the race I measured that I need 0.031" shim. The gear is a +1 so a 0.030" shim. Out of curiosity today I pressed the bearing off and it has a 0.030" under it. At any rate I am at a loss and was hoping maybe someone might have some insight.

 

[khryslerkid]

Can you possibly take pictures of the pattern (drive side and coast side) and post on here?

 

[5.7 hemi]

If you were just installing a sure-grip, why did you mess with the pinion! All ya needed was to swap over the ring gear, your new bearings on the sure-grip and get to it. After that, just get as close to possible with the backlash to what it was before ya took it apart....you did measure that before hand?

 

[dvw]

Reading a pattern on used gears is iffy at best. If you reestablish the the original pinion depth all seated nice etc. Then copy the original backlash and send it.
Doug

 

[BeepBeepRR]

Not to jack this thread I have a 489 case with a Sure Grip I have been reluctant to setup since I'm a noob in that area.. I bought the Doctor Diff kit and added a crush sleeve eliminator. There are no instructions on how to do this. Hence the reluctance to do it. Anyone near Atlanta that can show a dude how to set it up with the CS eliminator?

 

[5.7 hemi]

Measure the crush sleeve that came out of the pumpkin, let’s say it comes in at 1.550, now measure the eliminator spacer, say that’s 1.350, you’ll need .020 shims to get 1.550. Now set up as per usual, check rotational torque, backlash and pattern. Too deep, take out .005 and try again. Rinse, lather and repeat till it’s right.

 

[BeepBeepRR]

Measure the crush sleeve that came out of the pumpkin, let’s say it comes in at 1.550, now measure the eliminator spacer, say that’s 1.350, you’ll need .020 shims to get 1.550. Now set up as per usual, check rotational torque, backlash and pattern. Too deep, take out .005 and try again. Rinse, lather and repeat till it’s right.

Damn, I bought the sure grip and the other stuff separate. So I have no crush sleeve to go by. But it makes sense.

 

[5.7 hemi]

http://www.ratechmfg.com/chryslerspbs.htm

 

[493 Mike]

Damn, I bought the sure grip and the other stuff separate. So I have no crush sleeve to go by. But it makes sense.

Just put in lots of clearance and remove shims until you get the preload you want, as said above lather-rinse-repeat until done.
Mike

 

[BeepBeepRR]

Just put in lots of clearance and remove shims until you get the preload you want, as said above lather-rinse-repeat until done.
Mike

Thanks sounds pretty simple. I'll mess around with it soon I need to get a set of ring gear bolts. I forgot to add them to my cart.

 

[BeepBeepRR]

http://www.ratechmfg.com/chryslerspbs.htm

Thanks... Good info