I have a '72 Cutlass Supreme and want to upgrade to 3.42 posi from the one wheel deal 2.73 I have now. I want all new parts, but am a bit clueless as to what I need.

Am I correct in that what I need are a Ring and Pinion gear set, posi unit/carrier, and then the gaskets, seals, etc. rebuild kit? I would like to get a Richmond gear set and an Eaton posi unit, as I have heard they are one of the best. School me otherwise if not. I am assuming 8.5" and 30-spline?

I also want to completely disassemble the rear end, and powder coat it.

 

The 72 Cutlas 8.5" rear that you have,has 28-spline axles,& a 30-spline pinion.The Eaton posi units are one of your better units.They have clutches & are rebuild,if needed.Richmond is a good gear,but I prefer Motive.I think their finish proccess is better,& a little less finicky setting up.You will also need a complete bearing,seal,& install kit,with shims,compound,crush sleeve,etc. I can supply all of this,or you can get everything from a variety of places & suppliers.

 

Thx.

In re to the Eaton posi unit... would this be the one I need below?

http://www.summitracing.com/parts.as...=ETN-19557-010
"Differential, Posi Performance, Limited Slip, 28-Spline, GM, 8.5 in., 3 Series"

Notes: Designed for 2.73 and higher gear ratios. Requires special bearings LM-102949 cone and LM-102911 race.

 

In re to ring and pinion gears, what are the best of the best? Motive? Strange? I prefer North American made stuff.

As for Motive, these ones below appear to be the better (Performance) ones? By better, I read somewhere there are two lines (basic vs performance) from Motive.

http://www.summitracing.com/parts/MGR-G885342/

hmmm... Motive does not seem to have 'Performance' 3.90/1's. I might upgrade to 3.73 or something like 3.91 instead as I considering the 200-4R trans later on when I get to that part of the project. I have a column shift though (with buckets even).

 

and what about this 'corporate' rear end? If I have 30-spline axles, it is corporate?

 

The 8.5" 10-bolt was started in 1971,& later became known as the 10-bolt corporate or 8.5" corporate.They had 28-spline axles untill 1988,when they went to 30-spline axles. The reason that the newer carriers,like the Eaton,need a special carrier bearing is that they made the bearing hub larger/thicker,thus taking a different carrier bearing,compared to the originals of the past.
Motive makes a really nice gear.If you are dead-set on a 3:91,then look for US Gear or Precision Gear,for that ratio.You can get Strange gears,which I believe are still made by US Gear.

 

I don't know much about differentials but thought I would ask about this:

http://www.powertrax.com/powertrax/noslip.html

I believe I saw it in another post you started Brian. Is the Powertrax system another option for "positraction" performance in older cars? I guess Oldszy would have to get gears in addition to this system if he wanted 3.42 gears.

 

I have the no slip. Works, very good traction but clunky around corners.

 

The No-slip is quieter than the Lock-Rite.Both are inserts that install into your exsiting non-posi carrier.These are great for your mild builds & cruisers,but won't last too long in a drag car.If you have the 2:72-up carrier now,then this is an option.These are also a good alternative for the guys with the 12-bolt O-axle rears,that don't have a lot of options,but just want a posi.

 

ok, this is what I want/need so far...

Eaton Differential, Posi Performance, Limited Slip, 28-Spline, GM, 8.5 in., 3 Series
http://www.summitracing.com/parts/ETN-19557-010/
* Requires special bearings LM-102949 cone and LM-102911 race

Richmond Gear 4902781 Gear, Ring and Pinion, 3.42:1 Ratio, GM, 8.5 in., 10-Bolt, 3 Series, Set
http://www.summitracing.com/parts/RMG-4902781/
'Double Diamond' high performance gears

Richmond Gear 8310211 Ring and Pinion Installation Kit, GM, 8.5 in., 10-Bolt, 30-Spline Pinion, Kit
http://www.summitracing.com/parts/RMG-8310211/
* Carrier bearings in this kit will apparently not work will not work with Eaton posi unit (need LM-102949 cones and LM-102911 races instead as above)

In re to LM-102949 and LM-102911, I can get those at Rock Auto. Per member 'monzaz' (thanks), they are the same ones @ http://www.summitracing.com/parts/RMG-29-0013-1/ (Richmond Gear 29-0013-1 Differential Spool Bearing Kit; Fits GM 8.5 in. 10 Bolt; Incl. Bearings/Bearing Races)

That leaves the axle bearings and axle seals. What do I need? I am told they are press on as opposed to the c-clip version (Chevy) offered in the Richmond Gear Mega Ring and Pinion Installation Kit (831021M) which is supposedly the same as 8310211 above with the addition of axle bearings/seals.

I just hope the installer knows what he is doing when I bring in all these parts. I will prob have to write a big black X on the Richmond carrier bearings saying no no no, don't use these... use theeese speciale bearings over here.

 

The axle bearings are SET-9 or A-9,depending on the brand.The seal is # 712146.Make sure the bearings are pressed-on the right direction,not backwards.

 

Brian... with all the parts I listed, what would be your price delivered to 14301? In re to the axle bearings/seals, I don't want any overseas made stuff though, even Timken's if they are (that's the rumor I heard).

Also, what would be your price on a complete drum to drum 8.5" corporate rear end blasted/painted (powder coated preferably) with the same parts above shipped to 14301?

Thx

EDIT: Erie, PA.... that is where I got my NOS 71/72 Olds rear bumper shipped from. I won it on eBay.

 

The price for a complete kit would be $800.00 shipped to 14301.That includes a new Eaton posi,Motive gears(or whatever you want),Timken bearings & seals,installation shims,crush sleeve,marking compound,etc.Everything.The timken bearings are still your best bet.Bower is China,Federal Mogal is China.Timken is spanning out to Mexico & Indonesia,but hasn't gone China yet.

As for a complete rear,with the above parts,WITHOUT brakes,but with backing plates,you are looking at $1100.00 shipped to the ABF dock located in Tonowanda,NY 14150.
If you want a comlplete brake package,with all new wheel cylinders,shoes,drums,hardware,etc.,add $225.00.

I will be traveling through the Buffalo/Rochester area saturday,september 18th,& I could bring it with me,to help save the freight charge.Morning would be better.I could possibly come up another day as well,depending on my schedule.

 

Are you saying I can't get any 100% US or Canadian made rebuild kits?? That is just disgusting if so. What about the Richmond ones I posted that does not have the outer axle bearings/seals?

Richmond Gear 8310211 Ring and Pinion Installation Kit, GM, 8.5 in., 10-Bolt, 30-Spline Pinion, Kit
http://www.summitracing.com/parts/RMG-8310211/

Richmond Gear 29-0013-1 Differential Spool Bearing Kit; Fits GM 8.5 in. 10 Bolt; Incl. Bearings/Bearing Races (includes LM-102949 / LM-102911 apparently)
http://www.summitracing.com/parts/RMG-29-0013-1/

I guess there is no MEGA (which includes outer axle bearing/seals) complete rebuild kit that is 100% US or Canadian made either for the 8.5" corporate? SKF? National? I see them at Rock Auto along with Timken.

thx

EDIT: What about the axles themselves? After 38 years, I wonder how they are. Who makes the best of the best axle replacements? If mine are ok (and I actually decide to rebuild mine rather than get another rear end) is it ok to powder coat the axles? If so, I imagine you can only powder coat from the axle bearing area outward?

 

The "MEGA" kits that are offered with wheel bearings are not the correct wheel bearings for our rears.They are for the c-clip rears,like the 10-bolt & 12-bolt Chevy rears.Summit's kit contains Koyo bearings.Does that sound like US? The only pieces that I have from Timken that are not always US,are the seals.Those are becomming the luck-of-the-draw.The pinion seal,& the axle seals,can come from US,Mexico,or Indonesia.All of the bearings & races are still US.It basicly comes down to Timken trying to hold quality,but at the same time,need to compete with the cheaper Chinesium competitors.The Timken prices have gone up many times in the last 2 years,but that is what I still buy.The machining & finishing is still the best I have found.
Just a tip for some of you do-it-yourselfers: Auto Zone was/is a good place to get Timken bearings,but as of last week,they began an overhaul of the inventory & brands,& will now start carrying a Duralast brand of bearing,& they can't tell me where it's made.Once they get some,I'll just opn a box.They already have ValueCraft,which is obviously Chinesium.It didn't sound like they were going to continue stocking Timken.It's not really a problem for me because I have a place near my work,Erie Bearing,which is a major Timken supplier,& I get everything from them anyway.

 

Definitely Eaton, I just put a 12 Bolt Chevy with an Eaton posi and Richmond 3.73's in mine.

Save yourself some cash and do it yourself.
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