Posi question '76 ( and then some ramblings ...)

ttlfailur · Wrench Necoa #: 1724 Joined: Oct 31, 2003 Posts: 21

I would like to know the cast numbers and i d stuff to be able to tell if the parts car that I am getting has posi. Dude says it does but I would like to know before I get into that. Great deal seems either way, the glass is good and has power windows. Would also like to know the ratio of mine too, so any hints on where to look and what was common if it is or isn't an SS, though still unconfirmed as I have yet to have looked for the build sheet. I want to get her off of the jackstands first. Speaking of jackstands while she is up what do I need to check, do or look for on my differential, I plan on an fliud change but, like, I roll the wheel and there is about 3/4 of an inch before the yoke starts to turn and has a slight chink but not real loud, does this mean anything? TIA (Thanks In Advance)
ltr dudes.

And now if there is any interest I have a decent progress report on my ride. Which means that yes there is finally Progress I now sit with a 77 maybe SS med blue solid color w/out side moulding, lt blue interior ( in impecable condition minus major chalking of the pillar moulding) w/ some underside rust of the rear panels and floorpans. She came from the Arlington plant/ and now has an 1974 160 h.p. stock 350/TH400 Q-jet(as it came out of my RV unmolested, from flint plant MI.) after minor fabrication of the trans crossmember, added new flow tech headers. Finally have found the last piece of the puzzle (p.s. pump mount) and after I get the driveshaft cut 4 inches, put on the 15" turbines, check the brakes, pack wheel bearings (not in that order, the other order he he eh) replace some shifter parts and trace some wires she will will be ready to come down off the jackstands. oh and the reason I am writing all of this is I have to stay awake because if I take a nap I will never get back up to take the driveshaft to be cut so please bear with me. I would love to start her tonight if I could. Oh, where is all of this going? So far I have spent ...keeping in mind that I bought her minus motor because I already had a motor with only 6000 mi on it and the space and all of the tools to do this, not to mention another form of transportation... well, two forms if you count the Harley. Not including the extra gas going back and forth for food and eating out while working on it; and shuttlin my ole lady to work....yada yada. Parts included up to the drive shaft which shouldn't be more than about a hundered bucks w/ balancing and new u joints. . Car complete as is now so far under $1100 w/ parts car that I haven't picked up yet!. Not bad eh? And while it may look rough on the outside a bit, the frame is straight and solid, minus surface rust of the usual lower rear panels and floor pans from sittin around not being driven. LIke I said maybe be starting her tonight if I can get it to all go smoothe. Well thanks all, it is now 8 and I am off. Ltr

bgstk · Posted: Wed Nov 19, 2003 8:54 am Post subject:

As to the "chink", that is when the ring gear hits the pinion gear to turn the yolk. There has to be a little play in the gear set, but someone else will have to tell you if that seems like too much. I believe, to check for posi, when you turn one wheel, the other wheel should turn the same direction. With a non-posi, when off the ground, the wheels will turn opposite directions or one will turn and the other won't move. As to gear ratio, put a mark on the drive shaft or the yoke and turn the wheel one revolution while counting how many times the driveshaft turns. If the driveshaft turns a little less than 3 times, you.ve got a 2.73, a little over 3 times, a 3.23, and so on.

ttlfailur · Wrench Necoa #: 1724 Joined: Oct 31, 2003 Posts: 21

You don't happen to know the code that tells, huh? or can anyone help out with that? I would like to know before I buy the parts car but there is no way to really get it of of the ground. Pretty sure the wrecker is just going to drag it up, the undercarrage is pretty bad.

Orfunauto · Posted: Thu Nov 20, 2003 8:18 pm Post subject:

The axel code is usually stamped on the right axel tube (passenger side) between the shock mount and the carrier. Look for it at the front side of the tube just above center. It should have a two or three alpha character code. If you can get that code, I have a book that lists all GM codes/ratios and whether it's a locking or non-locking type.

PS: GM did have a brain fart at one time, they stamped the code on the back side of the left axel tube about three inches from the carrier on a few........... Duh-huh?

ElkyPete · Posted: Fri Nov 21, 2003 11:56 am Post subject:

My 76 came with a 2.73:1 rear end Open face "Limited Slip" which meant if your flat and pulling straight, not cornering, then both wheels get power but on a corner or uneven road all that goes the way of the Doo Doo Bird. I think all "open face, peg legs etc.. non posi) worked that way.

Saturday morning I am putting a rear end out of my 72 El Camino (3.73:1 Posi 12 bolt) in the 76. I did the measurements last night and they are the same width, backing plate to backing plate.

I suppose the only thing I'll miss is the 2100 RPM at 60. That will all be different by Saturday evening. I was running 80 down the interstate last night going home from the shop and I was only turning 3000. But I don't want a 200 MPH truck not without an overdrive. I'll settle for a 8.5 second 1/8th time that is what I want to happen.

With that 2.73:1 my 383 / 350 THD would only push it to the 10s in the 8th. I always loose all my power when it comes out of first. The RPMs drop to basically idle speed in second and again on the third shift. And this B&M Torque master 2100 RPM stall converter is a POS. It seems to flash between 600 and 800 so I'll never again by a B&M torque converter.

From what I can tell the 1976 El Camino was absoultly the heaviest model Elky produced. it Weighed in at between 3800 to about 4000 Lbs GVW and had only about 160 Hp to push it.
_________________
Home Site: http://www.elcaminoplace.com
1972 El Camino Custom 400
1976 El Camino Classic
1980 El Camino Super Sport
E-Mail: engstrvr@sbcglobal.net

ElkyPete · Posted: Tue Nov 25, 2003 11:50 am Post subject:

Look for a small metal tag attached to the rear cover and look into the glove box for an information decal on the Posi.

Axel codes are stamped in a location that is not easy to see under the truck. I use to know what those code were. I could have that info at home. I'll look.
_________________
Home Site: http://www.elcaminoplace.com
1972 El Camino Custom 400
1976 El Camino Classic
1980 El Camino Super Sport
E-Mail: engstrvr@sbcglobal.net