Can someone post a pic of stock 8.5 rear end cover. I have seen some completely round covers and some covers that have a two areas on the sides that turn inward toward the middle. Is it the large corners cast at the bottom of the housing that identify the 8.5 rear over the 8.2 or does the type of cover make any difference? Thanks!
Thanks Bert, I saw that exact picture on another site and my cover looks like the 8.2 in the top picture and my housing has the cast corners in the bottom. Would I be safe to say I have a 8.5 rearend? o No:
The ears is a good telltale. A more definite one if look at where the axle tubes go into the center section. If it's smooth, it's an 8.2. If there are four bumps around the area, like at 12, 3, 6, 9 o'clock, then it's an 8.5. You can see these in the pics of the above link. I was told by two guys who've built rearends for years (since the 60's) that they have seen 8.2's with the lower casting ears, but never with the bumps by the axle tubes.
For the 400th time, one cant identify an 8.5 rearend by the shape of the cover! There were at least 5 different rear covers used on 8.5 rears over the years! Just on the '71-72 8.5 A-body rear, there was the common housing that took the cutout rear cover, & there was the less common housing that took the round style cover! Instead of looking at rear covers, look at the pinion yoke where the u-joint attachs. Does it have U-bolts & nuts ??? U-bolts & straps were on all different forms of 8.2 10 bolts. All 8.5's used straps & 7/16" headed bolts. Got Posi? :3gears: Roger
Below is pic of the factory '71-72 8.5 A-body housing which takes the round rear cover. George's 8.5 pic in his above article is of a '73+ 8.5 A-body housing which uses the smooth round cover. Have several of those housings as well. Compared to the common cut-out rear cover 71-72 8.5 A-body rear, note: -only one large plug weld hole on the flat casting on each side of the cover. -the big square lugs on bottom of the housing do not exist, just "fang" like protrusions similiar to those cast on many 8.2 & 12 bolt housings. -Last, ck out the hole on each side where the r/e grease flows. If one were to bolt on a cut-out style 8.5 rear cover, these holes would still be visible, not under the cover where grease can propperly lube the differential. http://img85.imageshack.us/img85/4002/oldsmobilerearend001ml0.jpg Got Posi? :3gears: Roger
Here is a detailed rear end in the 70 Stg1 conv I just finished. Car has a corporate 8.5" from a 72 Skylark. As Roger states, easiest to ID by pinion yoke with 4 screws and 2 straps.
No problem, am currently working on a sticky on all the 8.5 A-body & 8.2 BUICK 10 bolt questions. Will be linked to pics from web storage. Basically working on multiple view shots of every style of GM A-body r/e ever built. Also pics of all the different pinion flanges. Will make it easy for those to ID what they have. Got Posi? :3gears: Roger
The 8.5 G-body housing is unique in its the the only 8.5 housing with upper & lwr control arm mounts which has 2.6" diam axle tubes. As Runnings pics shows, it also has the square protrusions on the bottom at 8 & 4, & it uses the round style 8.5 cover. Got Posi? :3gears: Roger
This was a Non Posi rear. Although I have a posi in a cardboard box "that will fit", per the last owner. this one is getting ford (not a good word) bolt in axle housing ends, Moser 30 someting splines and a full spool, willwood brakes. Anyone need the posi "in the box" ?
You could be right on the housing ends.. I was told if you run too quick or have a spool you will need c-clip eliminators and or ford bolt in axles (moser) / aftermarket. The posi unit is stock, probably out of another t-type or Grand national. I wont be using it, so its for sale.
To weld on the commonly available ends on the smaller diam axle tube, you will have to cut the c-clip end off & make a sleeve to accept aftermarket hsg end. If car sees street duty, consider the tapered bearing ends over any sealed ball bearing style. Ford Bearing ends are a misnomer, even Ford Motor Division figured out tapered axle bearings were better than sealed ball bearing axle bearings. Not wanting to mess with making pipe sleeves, might ck Mark Williams & Moser Engineering, they might be willing to program their CNC machine to allow for the G-bodys smaller axle tube. Got Posi? :3gears: Roger
I might call those guys. The axle ends with Taperd bearings sounds like a good plan. :TU: Moser is close enough for me to drive, I have considered letting them fix it up..
