Discussion in 'Got gears?' started by Larryb, Jan 9, 2021.
hi I'm based in the UK can anyone id this axle , i think its a 74 skylark but may be wrong
number on it is 406208
9 3/8 big car rear.. Riverias etc.
can i get a pos1 and 411 gears to fit?
No. No aftermarket support. One of the hardest rear differentials to build.
No, nothing new is made for that rear.
so this may be a stupid question but i have a 411 posi from a chevy with is rebuildable . my shafts are 28 if i change the shaft bearings to take the 28 spline (which i can do ) whats stopping me fitting the hole unit in the casing ?
I don't know enough about that rear to give you an answer, but if there was an easy way to get around the lack of parts for that rear, it would have been done long ago. Monzaz is the expert here. Maybe PM him and ask.
cheers new to the site so don't know anyone but will PM him thanks for advice
I would say for sure no. If there was any parts interchange between a chevy rear, or any other rear, it would be well documented at this point. I'm no expert, but i'm pretty sure Chevy never had a ring gear that was even close to a 9 3/8" ring gear. They had 9.5 in light 3/4 tons for a while, but I doubt anything would cross.
No No and NO....
Nothing interchanges with this 12 bolt Oldsmobile FULL SIZE CAR rear with 31 spline axles.
a 12 bolt Chevy rear will NOT BE 28 spline either ...so who knows what the heck you have in hand there.
ALL Chevy 12 bolt carriers are 30 spline and c-clip
YOU JUST CAN NOT DO IT.
If you could I would be doing it already...trust me i have been experimenting for YEARS every time something new comes out from any company we try to retro fit stuff or see if it can easily be machined to fit.
ALWAYS looking and trying.
Sorry for the bad news.
IF you show pictures of parts you have 4.10 / 4.11 posi unit etc.... will ID the stuff so you now what you have there. 28 spline axles are not 12 bolt chevy car or truck.
Thanks for the reply
So you are saying the axle is a olds i thought it was a buick Regal ? It is a bolt in shaft, Its
2.someting gears open , i need lower gears and a posi , i have a 4,11 chevy rebuildable posi, can i change the import splines to fit the shafts i have or even buy new shafts? then bolt in the whole unit , and change yoke or can i get any thing to bolt in? I’m in the uk so no one can id this axle? so just looking at all options as this axle is in the car which is a hot rod all painted and bracketed would like to keep the axle and do whatever i can with it, i will take some pics of the chevy 411 diff for you and send on thanks again for helping i be guided by your knowledge,the axle number is
It's a 9 3/8" big car rear. There are NO new parts made for it. You cannot use parts from a 12 bolt, it will NOT work. The only parts you will find are used. Back in Post #6, I linked you to the thread discussing that rear and the differences over the years.
9 3/4 buick ,olds ? has anyone know of any parts for it I'm after gears and posi /locker , and yes you did give me a link thank you I'm just exploring all avenues as i want to keep the axle
9 3/8 rear. It came under the biggest GM cars, the Buick Electra, Centurion, Wildcat, Riviera. It also came under the Oldsmobile Delta88/98. There are no new parts for it. If you were here in the states, you could scour the junk yards, but in the UK, I think you are pretty much out of luck. No parts from other rears are usable. You can't Frankenstein it.
ok thanks so i need to put out a advert for a posi/locker /low gears for a 9 3/8 big car rear ? how do i confirm the year of my axle ?
No, you won't find a posi locker that will fit that rear housing.
You need a whole new housing, axle tubes, the works
Look for letter codes on the axle. There is information on that thread about it.
im déterminé to keep this axle so i will find a way something must fit i know its a 9 3/8 still don't know year i thinks a 74 regal but no ones confirmed yet so i keep digging
No, that didn't come out of a 74 Regal if it's a 9 3/8. The 74 Regal came with an 8.5 10 bolt.