Dana 36?

[rficalora]

I saw an interesting article about C4 automatic rear suspensions being cheap (I'm seeing them for $300-400 with limited slip around here) and easy to modify.  They are similar to the Jag in that the universal joint 1/2 shafts do double duty as the upper control arms so should be similarly easy to fit to a B.  Thoughts on them holding up to a Ford 302/T5 B?  Is the Dana 44 bolt in swap if the 36 breaks?  Thinking about this for Drew's project.

[Spitfire 350]

Rob,
I believe a 36 will hold up if driven in a reasonable manner. I've broken the gears in two of them, but I did a LOT of burn outs and hole shots. The last one broke when I launched it on a road surface that was uneven and traction came, went, and came again. Probably wouldn't have broken if I'd gotten out of it when I first lost traction. It had been in the car about 10 years.
They can have some pretty silly factory gear ratios, my original 36 had a 2.59:1 gear set. I put in a Richmond Gear 3.75:1 gear set. My spare 36 has a factory 3.07:1 gear set. I'm not sure what gear sets are still available for the 36s.
If I remember correctly, the 44 is approximately 3/8" longer from the input flange to the rear surface of the case. I was able to use the same driveshaft for the 36 and 44, the 44 just puts the yoke a little further into the transmission.
The half shafts came in aluminum and steel versions.
I think it'll be worth the extra $ to start with a 44 if you can find one. Hope this helps.

[Jim Stabe]

I originally had a D36 when I got my car running. It had a new set of 3.75 gears in it and the posi was tight so it would paint 2 stripes with the 315 section tires. The tires however, were almost 15 years old and although they had no miles, the rubber had hardened to the point they had vastly reduced traction. I drove it that way with the supercharged engine for 1000 miles trouble free but I tried not to shock the driveline with clutch dumps, power shifts and the like. Send me your email and I'll give you a Word document that you should find interesting about when rear ends fail.

I think the D36 should hold up to the SBF/T10 OK unless you put really sticky tires on it and go drag racing. The D44 is slightly longer than the 36 and the pinion centerline is offset about the same amount to the right. If you get a D36 suspension look for a 1988 or newer because it has the emergency brake integrated in the caliper. You will also have to narrow the track to get it into a stock width MGB. I had to widen my car 11" and flare the wheel wells another couple inches to fit in a stock width suspension. Narrowing necessitates shortening the half shafts, building a new toe rod assembly (I used heim joints) and making new camber rods. You will also have to provide a solid structure in the body to attach the trailing arms because they are what propels the car. I assume you knew that you have to use coilovers since the stock Corvette spring is both too wide and too stiff.

[BlownMGB-V8]

I think you can still pick up an XJ6 axle for under $500 and it comes with the D44 and Chevy lug pattern. Not hard to narrow or mount and can be fitted with the stock fuel tank and battery boxes. Many have the Power-Lok diff. Good for about 500 hp.

Jim

[MGBV8]

Put the 36 in it to keep the driver in check just a bit.  

[rficalora]

I like how you're thinking Carl!

[roverman]

....Or spend much more for Dana 44 Vette.  As said, if you're not into street/drag racing, maybe 36. Clutch selection should help.
                                                              Good Luck, Art.

[BlownMGB-V8]

Didn't some of those early Vettes come with a straight six? I can remember back in the day the D-36 wasn't considered strong enough for a healthy small block.

Jim

[MGBV8]

Yeah, early C1.  

[rficalora]

We'll, we're going to try it.  I just made a deal to buy a complete drop out from a 84 vette (D36) hub to hub, including brakes + a second diff & bat wing for $350.  The guy needs to drop the suspension; targeting to have it ready for pick-up Monday evening or Tuesday.

[Jim Stabe]

The fun begins.

[BlownMGB-V8]

Indeed.

[Scott Costanzo]

Hey Rob, not sure if you saw this but this guy is pretty creative with the C4 rear suspension.

Scott

<iframe width="550" height="400" src="//www.youtube.com/embed/O0dUbfkHQvk" frameborder="0" allowfullscreen></iframe>

[MGBV8]

Please weigh it, Rob.

[rficalora]

Will do Carl.  Not likely we'll do the rear before Auburn.  Goal is simply to have it running with the 302 by then so Drew can drive it there.  So right now we're thinking just the MG rear and do the IRS after.  I could weigh the Vette rear now, but it'll lose weight when narrowed so was planning to weigh it after it's narrowed and with whatever we fabricate to hang it.

And great video Scott.  Thanks!!

[Jim Stabe]

I weighed the components of my D36 when I got it back in the early 2000's.

Center section with batwing                  60 lbs
One half shaft                                        10 lbs
One camber rod                                    3.5 lbs
One side trailing arms                              5 lbs
One side upright with bearing               18 lbs
Toe rods  assy                                        5 lbs                                                
88 and newer Caliper                             7 lbs
88 and newer Rotor                               13 lbs

[BlownMGB-V8]

So 183 lbs not counting springs and shocks, 99.5 lbs unsprung weight. Somewhere in the Roadmaster thread we have the comparable weights for the Jag IRS but I haven't found them.

I think with coilovers it might come out a little lighter than the stock axle but not by much. The unsprung weight will be a good bit less though. The Jag setup has the advantage on unsprung weight due to the inboard brakes.

Jim

[Jim Stabe]

Rob - any progress on the rear end install?

[rficalora]

Just saw this Jim.  I sent you a couple of emails with the progress.  Really just started on it this week.