I'm going to be rebuilding the rearend out of my Cutlass and there are guys in Florida that are supposed to be guru's with the type "O" differentials. The guys are Bruce Ponti and Rick Bedford.
https://www.motortrend.com/how-to/re...-cutlass-w-31/
From reading the article, it sounds like they have started a business and are supplying clutches and kits. I have searched and have come up with zip. Does anyone know of these guys and have contact info for them?
Thanks.

 

Clutches and kits are also available from a couple of members here on C.O. I've had great assistance from both JD Race (member Monzas) and Brian Trick, though Brian hasn't been on in a while, I think.

 

I was looking at JD Race "website", unless I missed it, I didn't see anything for the Anti-Spin components. Such as the clutches and shims. He has alternatives such as carriers modified to work with our "O" differentials. Maybe I missed it.

 

The O-Type uses the same limited slip clutches as the common 8.5" 10 bolt rearends. The bearings and seals are available from auto parts stores, online parts places, etc. (ebay, Rock Auto, Amazon, and others).

Be aware there are 3 versions of the A body O-Type: the early (1966-1969) standard duty 28 spline, the early heavy duty 31 spline, and the later (1970) standard duty 28 spline.
The early versions use a sealed axle bearing and an oil seal pressed into the end of the tube, and the '70 version uses an open bearing with the oil seal sandwiched on the axle shaft between the bearing and the retainer. The '70 uses the same bearing and seals as the '71-up 8.5" 10 bolt rears.

 

Call Jim @ jdrace.com.

 

I don't think that is correct. If it were the case, why would the two guys mentioned have to manufacture their own clutches. I'm not a guru on these, but I think the "O" differentials are their own beast and from what I have been able to gather parts are limited and difficult to come by.

My rear is the 28 spline axles. It is a 1969 3.91 Anti-Spin rear out of my Hurst/Olds.

 

Well, if you discover the GM part number for the O-Type clutches and for the 8.5” 10 bolt clutches is not 231127, let me know. I rebuilt my O-Type 20 years ago and installed 231127 clutches and 231260 300 pound S-spring that was listed for both rearends and all has been well.

As to why some folks are manufacturing clutches, it’s likely because GM discontinued the 231127 clutches a long time ago and there is still a demand for limited slip clutches for these rearends, so enterprising folks have stepped in to provide a product. You’ll note if you search for LSD clutches, you’ll find a few aftermarket options and the GM clutches are essentially unavailable.

The unique parts for the O-Type that are in limited supply and difficult to come by are gears and carriers. Carriers are now available and are Ford 8.8 units machined so the O-Type gears will fit. Gears are the most difficult to find, but there are used GM sets, and some old stock of Richmond Gear and Motive Gear, but in very limited ratios. Everything else is fairly easy to find (bearings, seals, and axle shafts from performance places such as Strange).

 

I second this suggestion. Jim is a fantastic resource.

 

I have some sets of the clutches that Bruce had made , they work very well and can sell you a set if you need them , $200 shipped to you . Thanks Bob

 

If you search for "LSD clutches" you're likely to find all sorts of interesting options.

 

I just read the article linked in the first post and it states the clutches for the O-Type are the same as the 8.5” 10 bolt clutches:

“Ponti and DiBlasi partnered about 10 years ago to launch production of steel posi clutches for 12-bolt O-type rearends and all 1971 and up GM 8.5 corporate S-spring posis.”

 

Correct. Now unless I'm interpreting this incorrectly, it means that they are making clutches for the early "O" type AND the '71 and later corporate diff. I don't interpret that to mean they are the same. Just that they are making clutches for both. I will call Jim at JD Race, but I'd still like to get a line on these guys in Florida. So based on the responses, I'm assuming no none on here has contact info for them.

@Bob Kelso If you have purchased these, do you have contact info for them? Thanks.

 

I think I have Bruce's contact. I'll see if I can find it and send to you.

Don W

 

Thank you very much.

 

Note the same part number for the 8.5” 10 bolt clutches and the O-Type clutches.



https://www.ronsmachiningservice.net/compare/2034/2035

 

69oldsguy, did you get Bruce's contact info? I found his card today.

Don W

 

I think I have about 2 sets left. But they are not 200.00 they are 235.00 a set.
Sorry.
Jim
JD Race