Easy to Posi?

[MGD72Monte]

I have a stock 2.73 non-locking rear end. I am removing it to change control arms (to boxed) to put in a sway bar. I will be changing all bushings, I want to replace the flexible brake line and metal lines leading to the drums, inspect the rear diff, change oil and detail the diff. To detail the diff, I will likely be pulling the axles out (hopefully not the whole carrier unless I find something wrong or get carried away like usual). I'll have a look at the seals to see if they need changing.

 

I like the 2.73 and I think it is working fine but was wondering if it is easy to convert it to posi while I'm in there, by simply inserting a part??? or do you have to change the whole carrier assembly? Any one done this?

 

Thanks

[monte70car]

Look into a power trax unit it gives you a posi in a straight line and a open rear when making turns. I run one in my Monte with a 2.73 gear and a 700r4 trans and I love it.

[Riznitch]

I wish someone would put a good video of the install out for the power trax. I HEAR its cake but if your not familiar with the rear, the directions seem overwhelming.I have heard some good things about power trax. Been waying my options like MGD and made some phone calls and found that to get a limited slip rear cost about 700.00 installed.

 

MGD, I belive if you put a new carrier in, there re-lashing involved.

[72MC]

MG, if you want the "original style" posi, you will need to change the carrier and "re-set up" the rear. I have an original GM 2 series posi carrier with all new spider, side gears and the original style new steel clutches. I could be persuaded to part with it. The internals are new from Randy's Ring and Pinion, quality stuff.

 

Or you could go with the Power Trax set up. - Dave

[monte70car]

Power trax unit ain't that bad the spider gears that's in the carrier gets thrown out and then the power trax goes in place of the spiders. I just I had pictures of when I did my to help but that was 11 years ago.

[Mike 57]

If I had a choice between a power trax and a posi I would go for the posi I think it is a better setup for your application. I would get in touch with Dave (72MC) and see if a deal could be made.

I run a Detroit locker and I think the power trax is nosier than it.

[Austin90]

I just put in a eaton locking differential in my car yesterday, the hardest part was getting the new bearing races in the housing, and finding the right torque specs for the pinion nut. all in all it took around 5 hours of working slow. If you get an eaton unit you have to get the matching ring and pinion for it or else it wont fit. I think the series 3 differential fits 373 and down, and the series 4 fits 410 and up.

[MGD72Monte]

Thanks for the input guys, I guess you can't just convert without changind the carrier. I'm still undecided, we'll see how the post removal inspection goes before I decide.

[MonteCarLois]

You'll have a good time playing with your rear end.

You asked about adding a part to your carrier for a 'posi'. I'd guess you've considered mini and full spools based on price. Let me tell you right now, stay away from them. Unless it's a full race car, you will surprise yourself one day if you spool it. Unless you're making regular passes at the strip, you don't need a positraction. Yeah it's cool to make two marks on the pavement, but the way to tell when you 'need' a positraction is when you are putting so much power to the ground that you can roast both tires with an open rear end.

If you do decide to go with a positraction unit, I strongly recommend a factory style for the simple ease of replacability and time tested reliability. Also, if you're going to open it for any reason, always replace the seals. It's just cheap insurance.

One other thing... why would you use the boxed control arms? Are they awesome? Totally, but you don't really need them unless you are running a 3500 stall converter or higher.

One other thing... if you do go with another carrier, Trax, stock posi or what-have-you, it is only 'required' to adjust the backlash if you change gears sets. If you use your original ring and pinion, no adjustment is necessary. I know this may sound goofy, but think about it... the carrier centerline is always the centerline and so long as the replacement carrier is machined properly, the geometry is the same.

Oh, and if you do swap the carrier, one piece of advice... red loctite is your friend, but only on the ring gear bolts. And believe it or don't, the bolts do NOT need to be totally free of oil. Just wipe the bolts off, add a couple drops, torque to spec and have a nice day!

[Andy's Auto]

There are no conversions on a rear diff non posi except an air locker. The cost is insane. I would call Summit, get an Eaton coming with an install kit. If you are reusing the original gears things go quick. I have done dozens so far this year from Nissan GTRs to good old 12 bolts. Fairly easy job as long as you are not intimidated.

[DRDIRT11]

i even did one on my 77 pickup. like someone said, dont be intimidated. do a little research. ive always has posi in my monte and wouldnt have it any other way.

[John Burns]

Eaton Truetrac:

 

http://www.eaton.com/EatonCom/ProductsSe...etrac/index.htm

 

I have this in my Camaro in a 9" (I'm sure they make one for the Chevy). Read the description- it is true: no noise, no clunking; acts like it is "open" until you need it. No clutches to wear out

 

I'm not sure how they break- I'm trying- I beat the crap out of mine. Highway, full-throttle blasts with sticky tires... this is in 10-second, 3900lb car with a 540.