I picked this up at a swap meet and the guy said its a posi unit from a 57-64 pontiac/olds thats not complete. I wanted to know if there are any places I can get parts for this to get the posi unit in my '57 rear end thats under my duece 5 window. All the speed shops around here said that no one carries this stuff anymore. Any ideas? Thanks
there's a thread en***led 57 ponti/olds ratio HELPPP or something along those lines...Blownolds just schooled me on posi carriers on it...damned fine info from him...from what I remember of that schooling (I need to re-read it) it looks to be a '58-'63 Dana/****er power-trak unit...he couldn't remember if it was available for '57...here's a link to the thread... http://www.jalopyjournal.com/forum/showthread.php?t=109006&page=3
rear gasket fel-pro RDS 6431 pinion seal chicago rawhide 19438 axle seal chicago rawhide 15005 carrier race SKF LM104912 carrier bearing SKF LM104949 inner pinion bearing SKF HM804846 inner pinion race SKF HM804810 outer pinion race SKF HM89410 outer pinion bearing SKF HM89446
there are other bearing manufacturers as well, SKF's tend to be the better/more expensive manufacturer...I bought everything I needed at Napa except bearings, all the seals and gaskets cost me about 115 bucks...not bad considering it's gonna last a damned long time... who has the proper friction lube for these posi rearends? are they all about the same?
If your axle is a 1957, you may be looking at some trouble with that posi. 57 and 58 pontiacs and olds used 29 spline axle shafts. Those axles shafts mesh into the side gears of the posi unit. Well, 57's didn't have posi units but they were avaliable in 58. In 1959, Olds and Pontiacs went to a 31 spline axle shaft and kept it until '64. This means if you want to keep your stock 57 axle shafts, your posi needs to be a 1958 only posi. Good luck finding a real, live 1958 Olds/Pontiac 29 spline posi carrier. They were an option and pretty rare. There are a lot more 31 spline posis avaliable. The later 31 spline axle shafts were too long to fit the 57 housing and to compound the problem, in 59 [first year for 31 spline axles] Pontiac went to the "wide track" ride. The 59-60 axles were about 3 inches too long. 61-64's were a little shorter but still too long. 61-64 Olds' were a shorter axle than the pontiacs and they're 31 spline. You can cut off about 7/8ths of an inch from the 61-64 Olds axle shafts and they'll fit the 57 pontiac/olds housings but it doesn't leave very much splined shaft to engage the side gears. Best deal is to use an entire 61-64 Olds housing with a 31 spline posi or have axle shafts made for your 31 spline posi in your 57 housing. I just had a pair of axles made at Dutchman axle company in Portland,Oregon and total cost was a smidgen over 500 bucks with freight. That included new axle bearings and I had the flanges drilled for 3 different wheel bolt patterns.. Hope this helps..
Good lord!! Now I see why everyone just says screw it and goes to a 9"!! Thanks for all the info guys I appreciate it!! Willys426 on here pm'd me so I called him and he said he has a kind of "Posi" unit that you just slide into the existing one legger. Seems pretty cool where it works as a locking device but isnt a total locker. $240 though that I dont have right now and the car runs and drives as it is. Hell I dont know I'll probably just say screw it and stay with the one legger for now. I still dont have all the springs and everything to even complete the posi unit and even after I do that I still probably only have 29 spline axles!
did he say he had a spool or a mini-spool? ****, I wish I could find a spool for those rearends...I could use one for my '57 rear sometime down the road...count the axle splines inside your posi-carrier, if it's a 29 spline carrier it'd be worth selling for some decent cash since they're pretty rare, if it's a 31 spline carrier I'm sure a couple of us could use one for parts if you wanted to part with it...
That posi is the Dana/****er Powerlok posi. It is a good posi, but parts are tough. You can get clutches, but no other parts that I am aware of. The one you show seems to be missing the pinion gears, side cups, side gears, and most of the case bolts. I think that the Olds/Pontiac case bolts are standard RH thread, not LH thread like some of the early Chevy ones. If they are LH thread though, then your only hope is ARP (I almost want to say that they recently added those bolts to their line-up), but if not, then God help you in finding the LH bolts. If yours are RH thread, then that shouldn't be a problem. I understand the pinion gears to be the same as for the other Powerlok posi's, or at least the same as Chevy ones. You can probably dig those up somewhere. But the side gears and side cups, good luck. The few guys I know with partial posi's generally seem to be hanging on to them, waiting for someone else to give up looking for parts, and sell them their spare pieces. One good thing about this posi style here is that you can install either the 29-spline stuff or the 31-spline stuff-- if indeed it is an Olds/Pontiac unit... That then begs the question: what is the number stamped on the side of the posi case? It will look something like 22096X or 22097X or something...
BTW, I forgot to mention--- don't even bother wasting your time calling Dana-- they got rid of all their Powerlok parts years ago.
hahaha, good point, I guess I didn't even look at the pictures that close...there must be some sort of measurement to determine what ring gears fit that carrier, or a stamping/casting...
First off thanks for all the help, you guys kick ***! Alot of good info! Ok so the bolts are all RH threads (on the part in the first picture in the upper right hand corner with the 6 holes and 2 bolts). The numbers on the side of that piece are this. 151A, and 22096X The numbers on the top are C30942, and 2 I'm horrible with rear ends and posi units so I dont know if this helps or not. I havent taken the rear end apart under my deuce yet to check what spline axles are in there either. That might be a winter project when I have time to tear it apart when I'm not driving it.
22096X says that it was originally intended for 31 spline and 2.69-3.23 ratio. But you can install either the 29-spline or 31-spline parts into it. And, that number is stamped on the "****on" half, not the "flange" half... and the "flange" half is what determines the ratio because of the offset of the flange. That can also be switched around.
So this WILL work? I just need to get all the parts for it after I find out if my rear end has a 29 or 31 spline? I guess none of the parts thats in the one legger will work besides the gears? Like I said I'm no good with rear ends and posi's.
No, none of the one-legger differential parts will work--- except for the ring and pinion, pinion bearings/shims, ring gear bolts, and the differential side bearings--- the posi itself is a completely different type of differential than an open differential.
****. O well. Well if anyone has any parts for this let me know, but until then I'll just roll with it the way it is! Thanks for all the help guys!
are you refering to using the bearings and shims and such from either a 29 or 31 spline third member with this posi carrier, or can you actually swap out the splined side gears from a 31 spline to make it into a 29 spline? I was under the impression the splined side gears were of different diameters and wouldn't interchange...
I was talking about the swapping of the side gears and side cups from the insides of the Powerlok-style posi. Should be interchangeable, I have seen one set of splines inside a posi that was stamped with a number that indicated it started life with the other spline. I think that instance was a 29-spline set in a posi that had been 31-spline (diameter of the axle holes in the case were not an issue in this instance). Now, going the other way, I would expect that 31-spline Powerlok posi side gears/cups could be installed inside a 29-spline Powerlok posi case, but I do NOT know if you'd have to enlargen the axle holes in the case for the larger diameter 31-spline axles. I have never measured and compared the axle hole diameters between those two posi's... I have only run across TWO 29-spline pos's over the last 15 years, and one was the aforementioned one that had 29-spline parts inside a case that originally was 31-spline.
hmmm...yeah, the 29 spline versions must be getting hard to find by now, and I'm sure you could make anything fit in those side gear locations if you had the equipment to machine the side gears...I'm very lucky that the posi that someone is selling me is internally complete and just needs the carrier bearings (which should swap out between open and posi carriers, right?)...I'm very grateful to you guys here not only for the killer information, but also for the p***ing on of good deals and such...I'll be sure to try my best to p*** on as much information and good deals as I can to return the favor...
Carrier side bearings and races are the same from '57-64. The only thing you need to watch out with on bearings is the difference in the O.D. of the pinion bearings between '59-62 and '63-4. The pinion seals are different between '59-62 and '63-4 as well.
WoW, U guys seem to be in the know, I'm wondering as I have found a '58 29 Spline Posi, if this could go into a '56 Starchief Convertible? Is the track the same? Can I utilize the Housing on the Starchief or must I change that as well?
The entire 3rd member was changed in '57 so no parts from a 57-64 third member will fit in the earlier 1956 housing. Good news is a complete 1957 Pontiac rearend is a tru bolt-in for 55-56 Pontiacs. A 58 pontiac rear would be except '58s used coil springs but Olds still used leafs, just like your 56 Poncho. In short: a complete 57 Pontiac or a complete 57 or 58 Olds rear end will interchange with your 56 Pontiac rearend.
Well, I have a '57 Olds Housing, would it bolt into that? And would the Olds housing then in turn bolt into the Pontiac Body?
Olds housing will fit the Pontiac springs. Would want to measure the axles to be sure they'd work in the Olds housing.
Talk to Brad Duerst at fabcraft metal works,he's the go to guy when looking for hard to find stuff for these old pontiac/olds rears by most pontiac owners accounts. The number is: 1-800-208-8242 Email: bduerst@verizon.net http://www.fabcraftmetalworks.com/ The website is under construction right now,so dont expect much from that. Hope this helps.
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