Installing my posi. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Ron's68 · 11-22-2002, 02:53 AM

Yes, I'm installing my posi carrier and gears. Its taken me a year after I bought it to start, but I started it this weekend and managed to get it apart. The next day I tried to install the pinion shaft but could not get the crush sleve to crush. I was worried about the truck being up on jacks so I pulled the rear end out. Just for info, it is now much easier to work on. I should have done this from the start, I think it would have saved me some time.(duh) Well now I have the correct preload on the pinion shaft (after one broken breaker bar) and I'm ready to install the carrier. I can't wait till tomorrow. One more thing, torqing the ring gear with your seventeen year old daughter as a helper, is not a good thing. She has a wicked slap shot in hockey but could only manage to get to 50ft/lbs. of torque, not the 55 required. I hope its enuff. I will let you all know how the rest goes incase your thinking of trying this yourself. By the way, the local rear end shop here quoated me 400 to 600 dollars, just to install it with my parts. It may be a pain but not that much of a pain, yet.

DanoDMano · 11-22-2002, 03:06 AM

Is it easier to convert than to just buy a rebuilt Posi-rearend??

Ron's68 · 11-22-2002, 03:20 AM

Dan I think I messed up by trying to convert mine. It would have been much easier to just replace the whole rear end with one that already had posi. I have about $400 invested already and still have to do the work. On the bright side, mine will be compleatly rebuilt with new bearings and seals. Plus I get the pleasure of learning how to do it.

alta-aj · 11-22-2002, 03:21 AM

Sorry you had trouble. I'm surprised.

A buddy of mine and I swapped a 3.07:1 non-posi for a posi including changing the pinion in under 3 hours with the aid of air operated tools. The 3 hours was start to finish, with the rear end still in the truck and of course included setting the lash according to spec and torquing appropriately. The hardest part was knocking the pinion out which took about 8 hits with a 7 lb hammer. It was one of the easiest jobs I've done on these old beasts.

**1971Stepside** · 11-22-2002, 10:01 AM

I converted my old 12 bolt 3.07 over to a 3.73 posi. Bought all new seals, bearings, ring and pinion, and Eaton posi. Had the rearend out of the truck and I was charged $70 to have it all put back together by a professional.....sounds like the guy you talked to was trying to screw you.

crazy longhorn · 11-22-2002, 05:51 PM

Im not fast, but im pretty finnicky. I set up the gears in my longhorn with nothing but a magnet base indicator for back lash, & marking compound......& a little good advise from the local driveline shop that does my shafts. take your time, hell i spent a sat afternoon, & a sunday set her up(first 1). 3000 miles later with all the hard abuse that diff has seen, shes stiil goin & the wear pattern on the gears looks like the stockers that came out. good luck, have fun,& abuse those tires!....crazy AL

Ron's68 · 11-23-2002, 02:08 AM

Hay thanks Al. It was just the crush sleeve that gave me problems. Today I got the carrier in and shimned. I'm getting a good pattern with the marking compound. Tomarrow morning I will be chacking backlash. (I had to barrow a dial and base from my brother, AKA tool time Bob ). He has a tool buying addiction. Lucky me.

I havent spent too much time on it so far, mabey 6 or 7 hours. I spend a couple of hours on it per night, It gets too dark and I dont want to mess up. But I'm almost done. I'll let you all know how it runs soon.

11-22-2002, 02:53 AM	#1
Ron's68 Registered User Join Date: Mar 2001 Location: Modesto, ca Posts: 143	Installing my posi. Yes, I'm installing my posi carrier and gears. Its taken me a year after I bought it to start, but I started it this weekend and managed to get it apart. The next day I tried to install the pinion shaft but could not get the crush sleve to crush. I was worried about the truck being up on jacks so I pulled the rear end out. Just for info, it is now much easier to work on. I should have done this from the start, I think it would have saved me some time.(duh) Well now I have the correct preload on the pinion shaft (after one broken breaker bar) and I'm ready to install the carrier. I can't wait till tomorrow. One more thing, torqing the ring gear with your seventeen year old daughter as a helper, is not a good thing. She has a wicked slap shot in hockey but could only manage to get to 50ft/lbs. of torque, not the 55 required. I hope its enuff. I will let you all know how the rest goes incase your thinking of trying this yourself. By the way, the local rear end shop here quoated me 400 to 600 dollars, just to install it with my parts. It may be a pain but not that much of a pain, yet. __________________ 68 LWB, .040 over 350 with 10:1 pistons, balanced, vortec heads,comp 270H cam, air gap RPM manifold, holley 750, 4.10 posi and gear drive to annoy the neighbors.

11-22-2002, 03:06 AM	#2
DanoDMano Pronounced "Pew-al-up" Join Date: Oct 2002 Location: Puyallup, Washington Posts: 845	Is it easier to convert than to just buy a rebuilt Posi-rearend?? __________________ Classic GM Trucks of Washington Club Member 1970 FS chevy,350/350, Edelbrock cam and intake. Holley 650 carb,HEI,AT,Tangier Orange, 18's, Power Locks, Truck Photos

11-22-2002, 03:20 AM	#3
Ron's68 Registered User Join Date: Mar 2001 Location: Modesto, ca Posts: 143	Dan I think I messed up by trying to convert mine. It would have been much easier to just replace the whole rear end with one that already had posi. I have about $400 invested already and still have to do the work. On the bright side, mine will be compleatly rebuilt with new bearings and seals. Plus I get the pleasure of learning how to do it. __________________ 68 LWB, .040 over 350 with 10:1 pistons, balanced, vortec heads,comp 270H cam, air gap RPM manifold, holley 750, 4.10 posi and gear drive to annoy the neighbors.

11-22-2002, 10:01 AM	#5
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	I converted my old 12 bolt 3.07 over to a 3.73 posi. Bought all new seals, bearings, ring and pinion, and Eaton posi. Had the rearend out of the truck and I was charged $70 to have it all put back together by a professional.....sounds like the guy you talked to was trying to screw you. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

11-22-2002, 05:51 PM	#6
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Im not fast, but im pretty finnicky. I set up the gears in my longhorn with nothing but a magnet base indicator for back lash, & marking compound......& a little good advise from the local driveline shop that does my shafts. take your time, hell i spent a sat afternoon, & a sunday set her up(first 1). 3000 miles later with all the hard abuse that diff has seen, shes stiil goin & the wear pattern on the gears looks like the stockers that came out. good luck, have fun,& abuse those tires!....crazy AL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-22-2002, 03:21 AM	#4
alta-aj Registered User Join Date: Aug 2001 Location: Qualicum Beach, B.C>, Canada Posts: 117	Sorry you had trouble. I'm surprised. A buddy of mine and I swapped a 3.07:1 non-posi for a posi including changing the pinion in under 3 hours with the aid of air operated tools. The 3 hours was start to finish, with the rear end still in the truck and of course included setting the lash according to spec and torquing appropriately. The hardest part was knocking the pinion out which took about 8 hits with a 7 lb hammer. It was one of the easiest jobs I've done on these old beasts.

11-23-2002, 02:08 AM	#7
Ron's68 Registered User Join Date: Mar 2001 Location: Modesto, ca Posts: 143	Hay thanks Al. It was just the crush sleeve that gave me problems. Today I got the carrier in and shimned. I'm getting a good pattern with the marking compound. Tomarrow morning I will be chacking backlash. (I had to barrow a dial and base from my brother, AKA tool time Bob ). He has a tool buying addiction. Lucky me. I havent spent too much time on it so far, mabey 6 or 7 hours. I spend a couple of hours on it per night, It gets too dark and I dont want to mess up. But I'm almost done. I'll let you all know how it runs soon. __________________ 68 LWB, .040 over 350 with 10:1 pistons, balanced, vortec heads,comp 270H cam, air gap RPM manifold, holley 750, 4.10 posi and gear drive to annoy the neighbors.



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