Hoping someone has the answer or the significance as to why the rear coil spring seats are different on each side of the axle. there is also a little hole on the right side axle.

 

Whats different? The lil hole is where the axle vent once lived. Highly suggest replacing it.

 

The little hole in the axle tube is where a vent cap should go.
As to the spring seats, it beats me.

 

thanks for the info......and where would one find a replacement vent cap, local parts place, or maybe Rockauto

 

actually found the answer right here on this great forum classicoldsmobile.com/forums/.../43667-issues-axle-vent-tube.htm

 

Ahh I see it now. The center hole is different....sharp as a bowling ball last night. Never noticed this before. Wonder if it has something to do with better spring retention? But that side takes a dip upon drive line torque so you'd think that concern would be on the drivers side?
Is this an 8.5" 10 bolt corporate O style rear or an 8.2" O?

 

I really don't know. But am more than willing to learn how too.
This forum has been my information source and guide and during my continued restoration process.

 

The most obvious is the O-Type has 12 bolts on the cover. The 8.5" corporate and 8.2" rears both have 10 bolts, so a bit more investigating is needed to ID those.

Post up some pictures of the rear cover, the side of the center section, and the pinion yoke and that will help ID which one you have.

 

we just parted out a 69 Grand Prix and it had a 68 ,almost enclosed,
spring perch.... and.... a 69 and newer open spring perch...

out of over 75 a body gms I have parted yours is the only other like this I have seen

Scott

 

Scott, To clarify the info for all: The closed style perch is up to 68 and the open is 69 up? At least from your observations...

 

must be a one of a kind mistake on the spring perches which of coarse makes it priceless Looks like its a 12 bolt Type O, not sure what the M21 means as well as all the other stamped #'s and the P ( posi ? )

 

It was due likely to the manufacturer just phasing out an obsolete design and phasing in the updated design. For whatever reason, the design was updated. It must not have been a flaw so much as a simple part update which allows the vendor to use up their supply of the old then use the new rev design. The line workers didn't care and just did what they were told to do... weld em up... ship em out. Cool oddity.
TO= 391:1, 10 bolt carrier, O style, 8.5" ID ring gear anti-spin axle. At least that's true for 67-69. My data doesn't go past 69. But I do believe this holds true for the early 70 O axle. Late 70 then 71-72 is different. Then you get into the Corporate GM axle years.
Someday someone with time will put a complete spread sheet together showing all the 64-72 Olds (and others) axles. Picture IDs of the housings and covers with corresponding info on each.... Spline counts, bearing sizes and all the other subtleties etc all in one neat sheet. The infos out there just not in one source.

 

thanks for all the info Dr, really appreciate it

 

make sure springs go back in faceing the same way they came out also you should get rubber spring cups for top and bottom of springs keeps them from squeeking

 

I suggested this a while back and got ripped by the fella who runs(?) wild about cars, saying THAT is the site where this info should be and not here on a question/answer forum. I didn't agree but having an argument on the internet is, well you know...