Well since the wife told me gas prices were to high to drive the car I figured I would get to work today. I was planning on pulling out the rear to get it ready for some POR-15. Future plans were to paint it, install my TA girdle, and haul it off to have the 3.73s installed by a shop. I frankly want no part in setting gears being my 3 gallon compressor will not run air tools. Before I started anything I went to check the posi. Turns out I can easily spin the tire with one hand. I put a torque wrench on it to measure it takes ~18 ft lbs to spin it. Just need to break loosen some more stuck bolts and I'll have it out of the car so I put it on the bench to check the posi cone windows.

Exactly how difficult is it to rebuild (cones/shim) the posi? I've read the articles and tutorials, but I'm still debating if I want to tackle that myself.

 

Its pretty simple, I did mine with no air tools. Just take your time. I have a couple of spare 10 bolt rears for back-ups. 10 bolts are easy to find, I have 3:08 and a 3:45. 9 bolt posi's are designed to wear out and are expensive to repair and replace. I will eventually replace mine with a modified Ford 9 inch rear.

 

Three day weekend is basically over now and the project is just getting started. After pulling the rear end and carrying it to the bench I drained it and pulled the cover. All teeth on the ring look good no nicks or chips or etc. Not like it matters I have a new set for it anyways.

Cones are bottomed out in the case. I have a feeling I'm going to need the case machined and new cones. There is no gap what so ever in the windows.




That's all the further I got for this weekend. I spent most of it wrestling with bolts and fittings.

 

Bearing caps are off and axles are pulled. I spent most of my time pulling the posi unit out tonight. Finally after a lot of praying, cursing, prying, and pulling on it with a rope I gave up and went to google for ideas. Found a great one! I used an old shirt and folded 3 or 4 times and tucked it under the ring gear and used a 5/8" box end wrench on the ring gear bolt. Slowly cranked it downward pulling the shirt in between the pinion and ring gear. Soon enough it stopped and I gave it one more nudge and pop the carrier moved 1/2" or so, which I used a crowbar to gentle pry each side out. Whole ordeal probably took me 2 minutes.... after 30+ minutes of previous failed attempts. I'm not going to ever try to pry a carrier out again.

 

Don't forget to keep posting pictures....

 

No Problem probably grab some more pictures later this week.

So as of right now I have a TA Performance Girdle and stud kit, Randy's Ring and Pinion 3.73 gear set with install kit, and 2 containers of Amsoil. I called around to a few shops for gear installs. I was quoted everywhere from $308, $425, $500 (gm dealership), and $749 (gm dealership) just for labor and fluids. Before jumping in and spending $300+ I figure I better go through it first and make sure the posi will work.

I was planning on painting the rear and the sway bar along with installing new shocks and springs so it didn't take much more just to pull the rear too. I guess now that I have air in the brake lines I might as well think about upgrading my front end also.

This would have been a lot easier if I had noticed the front of the car against the wall of the garage before I started. I had to put springs back in and wheels back on Saturday to put the car in Neutral and push it back some. That was just a minor set back though.

Anyway to remove the rear end I had to remove the tires, hardline into the brake line junction on the house, hardlines on the housing, pulled the brake hoses off the body clips, unclip the parking brake cables located in the trans tunnel on the equalizer, carrier bolts to the brakes (found it far less work to remove those with the calipers on), Shock bolts, Springs, sway bar end links and bushings, LCA bolts, Torque Arm Bolts, U-joint bolts, and finally I loosened the axle retainer bolts with the rear still in the car. I put a bucket under the driveshaft with a wood block so it didn't pull the transmission tailshaft. I've heard if you leave the driveshaft down for long periods of time it can pull the seal and cause a leak. I also put the torque arm on a bucket so it wasn't pulling the rubber boot again the driveshaft hoop (spohn rod end tq arm). It was about all I could with carrying the rear end with rotors (stuck on) to the bench alone. I have no clue how much that thing weighs but lifting a sbc block out of a Town Car trunk seemed easier.

I knew the posi was a little rough for awhile now. I was just ignoring it, sure it would one wheel peel once and while but most of the time it would work. I guess I'm paying for that now. We'll see how bad it looks once I pull the halves apart. I'm guessing since the cones are all the way at the bottom the case is basically bored out and not going to work long or at all if I have it machined and the cones machined. If I can't get it to work I've pretty much decided not even going to spend the $375 on a rebuilt used posi. I'll probably just tack the cones in take it into the shop to have it MIG'd. I have a new gasless mig welder coming, but I don't think any slag in there would be good.

 

Please forgive grainy quality it's from my old 1 MP cell phone.

Caps and spacers pulled:


Posi up close outside the housing:


Stamped 3.27 gear ratio on the ring:


My poor man's vice (no bench vice) to take apart the case. I loaded it on the axle on the floor with the bolts facing up. I used a ratchet and hit the end of it with my palm (poor man's impact wrench) to break all the casing bolts loose before removing any.


Upper case pulled. I caught the side gear and the cone before they fell out on the trip to the bench.

 

Continued...

I went to turn all the spider gears over to check for broken teeth. I found quite a bit of metal shavings in the case... Soon enough POP!



I'm pretty sure the spiders aren't suppose to be weld solid onto the ring post surface, but I could be wrong.

They also crumbled some of the metal as I pulled the spiders out. It looks like the spiders are locked up solid on the posts and the posts finally snapped at some point during use.

So now I'm looking at $365 for a posi overhaul kit (new spiders and cones) which I still have a heavy worn case or an entire rebuilt carrier for $385 + shipping. I really don't want to spend a lot of money on this rear end. Currently I still have ~$600+ in parts that are still new and ~$300+ shop labor to put new gears in eventually to match my camshaft. Maybe I should just think about selling the parts and parting the rear end and going with a Quick Performance 9" rear eventually. Ideas?


Also looking at my case it is smooth on the inside so it's not like the ones that have to be machined to accept the new flat style posi cones that 9bolt.com is shipping. Course that doesn't help with broken spider shafts and cones already bottomed out.

 

Coming back to this after I've had a few days to think.

My posi must have been machined when I bought it by one the previous owner(s). The case is smooth on the inside where others said there should be raised rings at the end of the casing, unless they made 2 different case designs in the series 3 carriers. It also had 2-4 shims between the side gears and the cones per side. I doubt the factory used that many shims when it was first built. If I did cut the cones, machined the case, shimmed, and bought new spider gears OR just bought a rebuilt posi I would frankly just have too much money in it. I estimate around $1000 to $1200 for parts/labor after I put a new posi in, girdle, and have new 3.70 gears setup by a shop.

I've decided to follow 83 Crossfire TA's Blog Posting and just weld the cones in converting it into a spool. I know it's not the best solution especially on a street car, but that will at least let me make it back into a roller that I can move around easily. I still haven't put insurance on it other than the $12/month I carry over winter so it's not like it's going to see any drive time. Most it will see currently is pulled out of the garage to pull another car in to do work, then it'll go right back in later.

Now it's time to sell some parts and save up for a Quick Performance 9".

 

I know this thread is pretty dead, but I know how annoying it can be to search years later to find an interesting thread with no ending. Another user volunteered his 10 bolt as a replacement in my car if I haul it so I didn't feel to bad about just zapping this one together. Sorry about the grainy pictures my wife has the digital camera so back to the 1.3 MP cell phone.

The is half of the carrier (side without ring gear). Ignore the 2 bolts I just left them in because there was a purple paint mark on the other half between the 2 bolts so it was an easy way for me to make sure I lock the carriers back together correctly again. You might also be able to see a slight blur mark in the upper left corner where the cross shaft would go. That's because the only thing keeping the spider gear on track was the broken shaft as it ate into the inside of the case (theres another one for the other broken one too).




I beveled the edge of the posi cone to allow a good wedge weld between it and the case. I can't remember if this is a picture of the beveled cone in the carrier. I used a bench grinder to bevel it. I also wiped the pieces clean with a paper towel and used denatured alchol on a cloth to make sure all residue was gone.



I then used some lumber I had laying around the garage to wedge it under the carrier so the splines of the axle wasn't showing. I didn't want to get any splatter on those. I used the axles to make sure the cones were still centered correctly.

I know my welds aren't pretty at all, but it was a cheap Chicago Electric $80 flux-core 30 wire welder and I'm a software programmer not a welder. I made 3 to 4 passes on it with the recommended wire speed and current.



Repeated the same process on the other side. This picture was after the initial pass. Like I stated I used a cheap welder (80 amp) and I made more 3-4 passes total.



So there you go I have converted a worn out posi with multiple shims, cones on the end of case, and 2 broken cross shafts to a spool. If I ever want to replace the carrier it'll be as easy as just buying a new rebuilt one from 9bolt.com and throwing it in. The only thing welded are the posi cone to the carrier. The real question is will it work and how much stress will it take.

 

Fireturd350; I have a couple of comments. First, you must be one big software programmer to carry a rear end to a bench. Second, your welding skills are pretty good with a small welder that you used, not bad. The only thing you will notice is some tire skip on real short turns. They will probably shorten your tire's life span, but you will sure get traction now. Too bad the carrier is shot, I've seen some on ebay and in salvage yards, but changing to something different is probably better.