D36 Durability

I have heard conflicting stories as to the durability of the D36.

I have no dyno on my motor, but it was built by Pat Musi, and on paper we are thinking about 550-600HP.

I put about 1000-2000 miles a year on the car.

I may run on borrowed slicks twice a year.

Should I be keeping an eye out for a D44, or do you guys think the D36 will hold up a bit?

The 36 will NOT hold up with any power. It was not even offered on '84's with a 4+3 manual. All stick 'Vettes got a D-44.

Actually all 84s had the 36, even the manuals. All later manuals got the D44. The 36 is a POS

Twin_Turbo said:

Actually all 84s had the 36, even the manuals. All later manuals got the D44. The 36 is a POS

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I stand corrected. That's what I get for thinking...CRS

Twin_Turbo said:

Actually all 84s had the 36, even the manuals. All later manuals got the D44. The 36 is a POS

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I will agree that the D44 is a heavier duty piece of equipment, and the preferred choice in high perf applications, but I have to disagree with your blanket statement that the D36 is a POS. I have been running the original D36 3.07 in my turbo 355 six speed for years, with no problems. I only do road course stuff with mine (drags hold no interest with me), so the driveline shock loads are modest. Given the outrageous prices guys are asking for D44 setups, I'll just keep on running my (typically 300-400 dollar) D36.

69427 said:

Twin_Turbo said:

Actually all 84s had the 36, even the manuals. All later manuals got the D44. The 36 is a POS

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I have to disagree with your blanket statement that the D36 is a POS..

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There's relatively little scientific argument behind most opinions. Its all old wives tales and internet smarts.

If they were as fragile as everyone says, you'd see tons of pictures of failures around. I've seen only the clutchdust one.

turtlevette said:

69427 said:

Twin_Turbo said:

Actually all 84s had the 36, even the manuals. All later manuals got the D44. The 36 is a POS

Click to expand...

I have to disagree with your blanket statement that the D36 is a POS..

Click to expand...

There's relatively little scientific argument behind most opinions. Its all old wives tales and internet smarts.

If they were as fragile as everyone says, you'd see tons of pictures of failures around. I've seen only the clutchdust one.

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That's what I'm thinking...

Being as most all auto
Vettes had a Dana 36, (except for the wimpy 205 hp '84..which won't break a wet noodle) were behind an auto trans. This is what saved them. That is why G.M. used the Dana 44 in most manual trans applications. Thanks grumpyvette for the following:
grumpyvette
08-31-2007, 08:33 PM
DANA 36 vs DANA 44

The C-4 Dana 36 was the only axle available in 1984 Corvettes. In 1985, Chevrolet brought out the Dana 44 which was similar to the 80-82 Corvette axle, but not interchangeable. The Dana 44 axle is considerably stronger, but not indestructible. The Dana 36 and the Dana 44 (44's in some autos and all manuals) axles were used through 1996.

The Dana 44 is much larger than the D36. The 44 has a larger, "beefier" carrier/components to handle larger (lower) ring and pinions, and increased torque. NOTICE THE LOCATION OF THE TOP CENTER BOLT HOLE ON THE DANA 36 THATS NOT ON THE DANA 44 REAR, thats a QUICK WAY TO TELL THEM APART

603967 GM 44 REAR 1980 CORVETTE
605172 GM 36 REAR 1984 CORVETTE
605180 GM 36 REAR 1984 CORVETTE
605220 GM 44 REAR 1985-87 CORVETTE
605239 GM 36 REAR 1984-86 CORVETTE
605260 GM 36 REAR 1985-87 CORVETTE
605321 GM 36 REAR 1988-90 CORVETTE
605322 GM 44 REAR 1989 1/2-90 CORVETTE
605365 GM 44 REAR 1988-89 CORVETTE
605417 GM 44 REAR 1990-90 1/2 CORVETTE
605490 GM 36 REAR 1990 1/2-96 1/2 CORVETTE
605491 GM 44 REAR 1990-96 1/2 CORVETTE
605492 GM 44 REAR 1990 1/2 CORVETTE


Look at the size difference, especially at the case above the yokes:

http://www.ikerds.com/merchant2/graphics/00000001/photos/d36198496.jpg
Dana 36

http://www.ikerds.com/merchant2/graphics/00000001/photos/d44198596.jpg
Dana 44

And visit

ikerds.com (http://www.ikerds.com/merchant2/mer...e_Code=CP&Product_Code=440-000&Category_Code=)

Who were kind enough to supply the pics...

Maybe the facts will help shed some light, then again...must be internet smarts & old wives tales.

The Dana36 has a Dana44 sized pinion, 26 splines and a 1.375" shaft and a 10 bolt 7.55" ring gear.
The C3 Dana44 has a Dana44 sized pinion, 26 splines and a 1.375" shaft and a 10 bolt 8,5" ring gear.
The C4 (super)Dana44 has a Dana 60 sized pinion, 1.625" shaft, 29 splines and a 10 bolt 8.5" ring gear.

Looking at just the gears, the 36 is the least desirable of all these.

When it comes to the cases, the D36 is a lot less meaty than the 44, and the caps have a similar step in them that the C3 D44 has also, and that is right where they always crack. The C4 44 cap has a sloped section next to the bolt, making it significantly stronger. I think the 36 had smaller cap retaining bolts also but not 100% sure on that. Tracdogg will know the answer to that one. Been a long time since I had my last 36. I never used it because I got the 44.

Joby blew up his rear end with his mighty, although blown, crossfire and an automatic tranny.

I've been reading up a bit on the D36/44 debate.

Seems it goes both ways, and it's all anecdotal evidence. Nothing scientific. That's OK, there can't be anything scientific.

If anyone within 100 miles of NYC has a D44, or just a bat wing, I'd be interested if the prices right. If I can pick something up cheap today, I'll take it and put it aside

I ran and still (at least temporarily)run a DANA 36 in my 1985 vette with a 383 that makes about 475 flywheel hp BEFORE I hit the nitrous....if I don,t use slicks and only street tires the traction (or lack of it) acts like a fuze that tends to prevent the full torque loads from impacting the rear suspension, but I don,t do hard launches either, I baby the car off the line and play catch-up in the mid and far track, the few times Ive run slicks Ive twisted off u-joints and half shafts rather quickly and Im sure the rear is marginal,but the dana 36 has held up so far, but even the dana 44 is MARGINAL (but obviously better) in my opinion.
In my big block 1968 vette I destroyed the stock rear the first time I used slicks, I installed a custom fitted dana 60 live axle and tubbed the rear, adding a 4 link suspension on that car, it cost me a small fortune but with a 13.7:1 cpr 496 BBC I didn,t really have a choice.
Im on a pension so moneys darn tight but evenually Ill install a similar engine and a 4L80E trans in my 1985 vette and a similar rear suspension

you might find HOOVERS MODS INTERESTING

http://www.myphotosonline.biz/album...r/Big+Block+Project/Rear+suspension/Installed

but keep in mind hes using a ford 9" which is lighter in weight and lower in strength than a dana 60

grumpyvette said:

I ran and still (at least temporarily)run a DANA 36 in my 1985 vette with a 383 that makes about 475 flywheel hp BEFORE I hit the nitrous....if I don,t use slicks and only street tires the traction (or lack of it) acts like a fuze that tends to prevent the full torque loads from impacting the rear suspension, but I don,t do hard launches either, I baby the car off the line and play catch-up in the mid and far track, the few times Ive run slicks Ive twisted off u-joints and half shafts rather quickly and Im sure the rear is marginal,but the dana 36 has held up so far, but even the dana 44 is MARGINAL (but obviously better) in my opinion.
In my big block 1968 vette I destroyed the stock rear the first time I used slicks, I installed a custom fitted dana 60 live axle and tubbed the rear, adding a 4 link suspension on that car, it cost me a small fortune but with a 13.7:1 cpr 496 BBC I didn,t really have a choice.
Im on a pension so moneys darn tight but evenually Ill install a similar engine and a 4L80E trans in my 1985 vette and a similar rear suspension

you might find HOOVERS MODS INTERESTING

http://www.myphotosonline.biz/album...r/Big+Block+Project/Rear+suspension/Installed

but keep in mind hes using a ford 9" which is lighter in weight and lower in strength than a dana 60

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So basically, if I don't put slicks on it, should be OK for a while......

Maybe I'll just baby it for a bit, rather than drop $2K, since I'll make some suspension changes too.

Not to sure if this will work but follow me.

the aluminum batwing can have the C3 style iron case bolted to it. The 84 c4 and the 82 vette had the same rearend (I think). So get an 84 batwing, bolt a C3 Iron case to it, and fill it with Toms 12 bolt innards get some custom axles made and goto town.

Take that establishment.

guru said:

Not to sure if this will work but follow me.

the aluminum batwing can have the C3 style iron case bolted to it. The 84 c4 and the 82 vette had the same rearend (I think). So get an 84 batwing, bolt a C3 Iron case to it, and fill it with Toms 12 bolt innards get some custom axles made and goto town.

Take that establishment.

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The 84s were all D36. I'll give you my stuff if you want. I have a lead on a D44 3.08 that I can get at a pretty good price.

Let me know if you want my D36 setup. All yours, complete.

The D36 isn't a bad diff but it is small. It will handle moderate torque loads but it can't handle shock loads. Same as the 80-82 D44. The damage occurs when the gears are unloaded and shock forces are applied. A good example is rolling at 5mph and dumping the clutch. Automatics don't deliver the same shock.
Mike