i have a 8.5 3.73 rear that came out of a 84 hurst olds that had around 30,000 miles on it, bad news is that it didn't get the G80 option. Anyone here know of a reputable place that is reasonably priced for a stock style posi unit? Im assuming i can re-use the gears as they do not even have any mesh wear marks, but after looking at G body parts they were mentioning about the diff bearings need to be replaced, how true is this?
8.5 3.73 open to posi swap
- Thread starter gp02a0083
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Putting where you located will help if someone knows anything in your area or check the phonebook for offroad and 4wheel drive palces them guys are allways changing gears for pulling or climbing.in my area the price is around 400 for the posi unit then it will be about 200-250 labor..
You could go with a Richmond Powertrax unit :idea: It just replaces the spider gears. You will have to know your axle spline count to order one. It is a special order item for any NAPA store:
28 spline - RIC 9207852805
30 spline - RIC 9207853005
That would be their "NO-SLIP" TRACTION SYSTEM. These are supposed to be very simple installation and don't require special tools. The replacement of bearings is recommended in any rear end job, since you're already in there
28 spline - RIC 9207852805
30 spline - RIC 9207853005
That would be their "NO-SLIP" TRACTION SYSTEM. These are supposed to be very simple installation and don't require special tools. The replacement of bearings is recommended in any rear end job, since you're already in there
sorry, i am located in Central NJ roughly 30 min from Englishtown Raceway park. I hae not removed the axles but i am assuming that they are 28 spline being this was a stock 8.5 rear, but i will check when I take the axles out. Like i mentioned before this rear has about 30,000 miles on it, the gear set does not have any wear marks even from a proper mesh. I want to reuse the 3.73 gears to save a little bit of money, plus i think it would help with my 307/ 200-4r with the stock 7.5 2.5x rear. I probably should have been more specific, I want to replace the open diff with a posi or limited slip unit that was dictated by the G80 RPO code. I do not want a locker system or a conical type, i believe the OEM style is a eaton clutch pack design. Trying to build this with a budget in mind, i saw most rears from summit and jegs are around 450 or so, im just looking to see what is out there and weigh my options. Oh and as for the bearings, i opened the case and even the oil looked brand new, i suppose it would be ok to try using the bearings from the open diff to the limited slip? or is there a size difference ?
If there is actually only 30k miles on the rear end, then your bearings should be fine to reuse. The Powertrax unit is not a locker unit. It is a simpler way to replace the "open" spider gears with a positive traction unit. If you buy an original style Eaton posi unit, there is a lot more labor and tools involved in installing it. The Powertrax unit will run around $450, I believe.
The Powertrax IS a locker, it's just not like a factory gov-lock, it's better but still a locker.
I am looking to add posi to my 8.5" rear end as well… hopefully I will look into it this winter I haven't even started restoring the car yet… Im not sure of mileage on mine buts its a lot higher than 30k… What should I look for when I open it up as far as inspecting it? Its amazing that G80 posi wasn't standard on 442s & Hursts … I pulled out a GM Restoration packet for an 85 Monte & adding Posi was only a few hundred dollars extra…I don't recall the exact # but it wasn't much…
yah i am not looking for a locker type setup or a conical type, just the factory OEM clutch pack type limited slip. Installing it into the rear shouldn't be a problem for me, i have a lot of resources i can use for that. I Checked the rear last night , it is a 28 spline as i thought, so this 8.5 is completely bone stock.
So i suppose i was coreect in saying the OEM style limited slip was a Eaton clutch pack design?
So i suppose i was coreect in saying the OEM style limited slip was a Eaton clutch pack design?
POWERTRAX makes 2 different units :idea: The "Lock-Right Locker" and the "No-Slip Traction System" :wink:jrm81bu said:
I was recommending the "No-Slip Traction System"
The stock style posi is no longer sold. I have one thats in my wagon thinking of going spool it works fine how much you willing to pay i will pull it out for the right price. I also have an extra set of good clutches to go with it as a spare set Also no longer avaliable. I am in sj 10minutes for exit 4 on the tp
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