Oldsmobile W27 rear end differential housing

[Stefano]

Oldsmobile W27 rear end differential housing. This is the aluminum center section which was available as an option on 1970 W Machines.

Code SZ is 3.91 posi
http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/1970W27Aluminumrear009.jpg

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/1970W27Aluminumrear008.jpg

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/1970W27Aluminumrear006.jpg

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/1970W27Aluminumrear018.jpg

[markjohnson]

That's one of the neatest options that Oldsmobile ever did. I'm pretty sure that the entire aluminum center section was one-year-only (1970) but when it came back in 1971-72, it consisted only of an aluminum rear cover on a standard iron axle.

[SmallHurst]

<<GRAEMLIN_URL>>/drool.gif That is a sick chuck of change there! Love to have one, but worth enough to buy another car with.

[Plowman]

Look's so cool, I know it's rare,is that rear,the aluminum center section,any stronger.

[SmallHurst]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Plowman</div><div class="ubbcode-body">Look's so cool, I know it's rare,is that rear,the aluminum center section,any stronger. </div></div>Actually, it's weaker. It was an idea to reduce unsprung weight. Stress cracks would show up eventually.

[Stefano]

The warranty replacement was the iron Olds 12 bolt, if that says anything. Only approx 355 were ever factory installed on W machines.

[LeeP]

My 1970 olds was ordered with the w-27. During the restoration the expert on this rear end Joe from Texas, restorer and I agreed the differential came with aluminum anodized bolts on the cover. So mine looks like the one in the picture with different bolts. In addition since mine was a California purchased W-30 one of the top fins on the cover was trimmed to allow for the extra fuel line for the California smog. I thought my cover was junk till I found the dealer bulletin on the cover. Huge research required for only one aspect of the restoration, but fun.

Lee

[Stefano]

The bolts on the one I posted pics of are to be original. However, I would not think that the restorer paid that close of attention to the coating. I have a pre resto-photo I'll try to scan.

Cool info!

[LeeP]

I have seen them both ways but Joe worked for Oldsmobile in the day and has two w-27 w-31s and is the most knowledgeable person on the w-27 in the world. Mine was original too when it was restored. During a restoration you have to go with the best information you can get. If I were judging your car I would not take off points for the bolts. My car will be at a few events in November SEMA and Muscle Car Nationals. When it is out I will try to get some nice pictures of the detail of my restoration.

Lee

[Stefano]

Here is the pre restoration pic.

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W31%20Rally%20Red%204%20speed/1970W27Oldsmobilerearorigpics.jpg

[LeeP]

My w-27 restoration can be seen on the link below. You cant really tell the bolts are aluminum plated because they are dirty in the picture. Lee


http://levelonerestoration.com/imageview.aspx?id=27

[Stefano]

The Vintage pics are priceless. Thanks for posting.

[Xplantdad]

Good old Hansel Olds in Fullerton. I used to have about 20 of those plate frames (I worked at Hardin in Anaheim and we did dealer trades with Hansel all the time <<GRAEMLIN_URL>>/smile.gif )

Really cool car!

[LeeP]

Thanks Bruce. I tried to do the car as correct as possible and having the photos one month after it was purchased was a great help. The Original owner (Rug)ordered it side stripe delete but it came with the side stripes so the car conflicts with the original order form from Hansel that he gave me. I am glad olds made the mistake because I like the side stripes better. He also gave me a bunch of other original documents and pictures. Got lucky.

Back to the original discussion on W-27 rear ends.............sorry

Lee

[LeeP]

Bruce you may also enjoy the posts on classic oldsmobile related to old dealership pictures. I included the link. Lee


http://classicoldsmobile.com/forums/gene...html#post335510 (http://classicoldsmobile.com/forums/general-discussion/40052-long-lost-olds-pictures-2.html#post335510)

[Fast67VelleN2O]

The W27 package is just awesome. I have only seen two rears in my life and they were both on ebay. One day, I will find myself a W27 rear end.

[LeeP]

I feel like a w-27 pig. I have had three of them.

Lee

[Stefano]

I believe that is an Anti-Trust violation. You must give one to me immediately!

There are many enthusiasts who have never seen one. Stop by MCACN and you may have a couple to view.

[LeeP]

My car is shipping out today for the trek to MCACN with its w-27 rear end. One stop at CEMA in Vegas then Colorado to the restorer to tidy it up for the show. Hope to meet many of you in a couple weeks.

Lee

[markjohnson]

I was talking to a friend tonight that had a 1970 442 W-30 Convertible that he paid $3000 for in the mid-'80's. It had the W-27 aluminum rear end, red plastic inner fenders and every single option except for power windows. It was a TurboHydro car with the Dual Gate shifter and he told me that it had a very rare auxillary transmission cooler in front of the radiator. Get this, shortly after he bought the car he put a 6-71 Supercharger on it while pretty much leaving the rest of the car stock. It went 12.70's through the original exhaust manifolds in that configuration. I think it went to the Philedelphia area. I'll try and get some pictures if anybody's interested.

[LeeP]

I would love to see the pictures. I may even know the car.

Lee

[Stefano]

Pics for sure.

Only approx 355 of the W27 rear ends were factory installed on any of the 1970 W-Machines. I had always thought this option was only available on W-Machines, W30, W31 and W32?

[Fast67VelleN2O]

How many total aluminum W27 rear ends do you think were built?

[Canuck]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stefano</div><div class="ubbcode-body">Pics for sure.

Only approx 355 of the W27 rear ends were factory installed on any of the 1970 W-Machines. I had always thought this option was only available on W-Machines, W30, W31 and W32? </div></div>

I have also seem them on two of the 1970 442 pace cars which were not W30 cars.

Paul

[Canuck]

Just looked up the option list offering for 1970 and it shows availability of the W27 on F85,Cutlass S with W31 or W45 (rallye) and on the 442 with W30 required. I will assume that the Pace car W27 I saw were not original.

Paul

[Stefano]

Interesting about the pace cars?

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/L88PistonsandW30Stripes023.jpg

http://i9.photobucket.com/albums/a79/StefanoBimbi/71%20W30/1970%20W27%20Rear%20End%20Aluminum/L88PistonsandW30Stripes024.jpg

[Bruce]

pics were taken in 1987 during restoration

http://i478.photobucket.com/albums/rr145/bruwster55/K7A12E4EBED5B7_1000001.jpg

http://i478.photobucket.com/albums/rr145/bruwster55/K7A12E4EBED5B7_1000002.jpg

http://i478.photobucket.com/albums/rr145/bruwster55/K7A12E4EBED5B7_1000009.jpg

[Xplantdad]

Very cool!

[Jeff H]

I just saw an ad on FB Marketplace for a W27 rear in PA for $28K. I guess there aren't too many around and his ad says no codes are stamped in it.

https://www.facebook.com/marketplace/item/297823556560259/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A40de5b4a-78b0-42c6-aec5-37a85a17f194