88GTA3555SPD

ok first off when i checked the pinion depth i tightened the yoke down until just after it had zero play on the pinion. but i did this without the crush collar in...is this a problem??

next i used a peice of steel bar stock across the bearing cap surfaces and check pinion height down to the face of the pinion and got a measurement of .032 and after i installed this shim i got a depth measurement to the exact number etched on the pinion gear. will this measurement change once the collar is crushed???

then i installed the gears on the carrier along with the proper shims to achieve richmonds .010 desired backlash...after that i check the pattern in four teeth ina row in four different spots....the pattern looks perfect exactly like the picture shows

the directions werent very clear and if i install the crush collar last will it change any of these measurements??? also when crushing the collar my book says crush it until you achieve a turning resistance of 17-22 inch pounds or richmonds 20-25 w/ new bearings...is this accurate? or do you tighten the pinion nut to a certain amount of lb. pounds??

thanks alot

Bones232

I think I can answer a couple of your questions...

The crush collar shouldn't affect your pinion depth. I believe the only purpose of the crush collar is to keep adequate pressure on the pinion assembly so it is less likely to loosen up during operation.

When setting the pinion depth and backlash, I basically went by the contact pattern and then double checked the backlash with a dial indicator.

I also had trouble determining the proper turning resistance. I didn't know if the turning resistance is how much torque is required to start the assembly turning or sustain motion. I ended up using the latter. Using a torque wrench to periodically check tension, I tightened down the pinion until it took around 20 in-lbs to start it moving. It make sense that new bearings would need more torque to account for break in time.

Also when you tighten down the crush ring, be careful, once it starts to crush it gets measurably easier to crush the ring. I wasted a couple of crush rings before i got the resistance where I thought it should be.

88GTA3555SPD

yeah yesterday i got all the measurements done and started to crush the collar but wasnt exactly sure of the procedure so i stopped. the richmond install directions arent very detailed on that.i guess ill continue to crush it tommorow until i get to that inch pound spec.

if this rear works out well i might think about building up my own 12 bolt...anyone know how much cheaper it would be to go this route

how much you think i would pick up goin from 3.23 to 3.73
last time at the track i ran 12.9 at 107mph 1.97 60 foot

dyno pull was 355hp 389trq....needs a better tune w/ dfi...soon

ede

setting the pinion depth by looking at the contact pattern is about the worse way to go about it. measure the pinion depth with a depth mic or gage and the steel bar like you said, without the crush sleeve. lot of people will hone out a bearing so it'll slip on and off to change shims. after you have the correct pinion depth press on the new bearing and install with the crush sleeve. tighten the pinion nut untill you have the correct preload and you're done with the pinion ,however i'd look at and consider a solid spacer instead of the crush sleeve. on the little 10 bolts i tend to over tighten the nut and have to get another crush sleeve. you check the preload on the pinion, you need a dial type wrench, not a set ft/lb torque. after the pinion install the carreir and shim it as needed to get the correct backlash, i go for .008. after you have that check the contact pattern. the contact pattern is very subjective and the least important, sort of a final check sort of thing

88GTA3555SPD

thanks ede. Judging by the picture in the richmond directions they want the pinion face exactly even with the inner edge of the ring gear...thats where the number etched on the pinion comes from. so i knew that just checking a pattern wouldnt be a good way to determine if it was remotely close..someone else told me that as well and when measurements are in .001 of an inch, looking at a pattern by eye is no way to determine anything. so i knew that was a half *** aproach.

but im gonna finish this thing today and install the rear.

anyone know where i can find a banjo bolt for my PBR caliper
??????????lost one, i think im screwed

HalfInchWrench

Not sure if it is the same bolt used on the pre PBR rears but if it is then it's near impossible to find. Dealer doesn't carry them anymore. Rummaged thru every GM car at the wreckers and managed to make one work from the front of a C4 vette. Was not the same but the closest match I could find. What a nightmare. I now have a couple of spares in case this ever happens again.

88GTA3555SPD

well the rear is in the car but i gotta wait til the morning to pick up some synthetic gear oil....

anyway i think these PBR calipers are fuked up which really sucks....i started bleeding the brakes and the one caliper has good movement and locked the rotor tight, but the other barely moves and kinda grabs the rotor and i also cant get a decent pedal out of it. i gravity bled it for a few minutes and then started pumping it to bleed them. after a few pumps the pedal gets pretty good but once i started it the pedal goes right to the floor.

i really dont wanna buy calipers for this thing..im sure they're like 100 bucks a peice. so have any of you guys located a rebuild kit or had any luck overhauling the PBR's

sp63

on a power assisted master cylinder. car running, pedal goes to floor is a sign of leaking primary cup seal - correct?

todd200

Incorrect. Most cars you can push the pedal to the floor with the car running. The reason you can do this is because at idle, with so much vacuum, you have enough assist you can push it to the floor fairly easily.