ItBites01

I exploded my Dana36 C4 rear end and need to upgrade to the Dana44.

I have heard the Dana 44 requires a shorter driveshaft, which I assume means the distance from the stub axle centerlines to the forward u-joint yoke is longer? If so, how much?

Does that also mean the length to the vertical bolt pair on the pumpkin snout are also at a different length from the stub axles?
If so, how much?

For me its not as simple as swapping to the Dana44 torque arm, my rear end is not in a Corvette (sorry). It is in hot rod. So I really need to know dimensions so I can modify my frame where the housing mounts.

If it helps, I do have a 73 big block vette and my wife used to drive a C4 , so I could really use some help here.

Does anyone possibly have drawings or dimensions?

blue94

The ZF/D44 shaft is 26 3/4" center to center of the end yokes. The auto/D36 shaft is slightly longer.

ItBites01

Blue, thanks for the response!

I get that the driveshafts in the C4 are different between the ZF/D44 and the Auto/D36, but is that due to the different transmission lengths or is the D44 itself longer than the D36?

Further, how about the location of the torque arm bolts on the D36 vs D44?

Doug 87L98

I was just about to post the same question, as I grenaded my dana 36 also. I just purchased a dana 44 rear. It also came with the driveshaft, but not the C beam.

I need to know how much shorter the C beam is. I have heard it is 1" shorter AND 15/16" shorter. I have also heard that all that is needed to do is drill two new holes at the transmission end of the beam and the dana 36 C beam will work just fine.

Is it 1'' or 15/16''?
And can new holes be drilled without any complications down the road OR the drag strip!

Doug 87L98

The D44 is longer, the transmissions are the same size.

WVZR-1

How is the D36 mounted to the chassis at the 2 bolts at the nose of the differential? The D44 mounting holes are 24mm forward of those for the D36. The suspension components are all the same.

Are you interested in "new" build? I've all required NOS components for a build.

D44 housing, D44 cover, differential, 3.73 gear, 3.54 gear, short axles, install kit and pinion flange.

I've PM'd you an email address!!

With the new housing and cover from me you could easily handle them assembled to fabricate the required mounts!

vetteoz

http://www.joby.se/corvette/mods/2001-0X11_diff/

vetteoz

Typical method for retro fit apps
Most don't run the C-beam so they need a front support for the diff nose

ItBites01

WVZR-1,

Thanks for the 24mm dimension! Is that also the driveshaft difference?

My forward attach is similar to the one shown, but has flat plate bolted to the housing. The plate is 3/8 steel and hangs off the right side. There is a rubber donut atop the plate that rides against a plate on the frame, with matching donut on top of the frame plate. But similar enough to the photo. No torque arm.

Are the half shafts the same length between the D44 and D36? I was hoping to use my halfshafts, since I just put super u-joints from Denny's in them (plus I have them)...

Also, I need a 3.07 gear in the D44. In my light car, I still run 10.6@130mph with the old D36 with 3.07s, but don't have OD, so I need to match the gears.

LTxDave

Halfshafts are the same. You should be able to find a 3.07 Dana 44 pretty easily--lots of them on eBay.

ItBites01

Just for chuckles, I thought I'd let y'all know my driveshaft is only about 13" long. The engine/transmision is set really far back in my application. My weight balance is 48%front, 52% rear. Looks like I'll shorten the driveshaft to about 12" long. LOL.

ItBites01

gsdave,

Thanks for the halfshaft response, that helps me out. I trust my halfshafts that I have now and want to use them. Also, thanks for the evilbay tip. I didn't even think to look there...

WVZR-1

You're drive-shaft is tailored to your application and I believe I'd do the install measure and then likely do the shaft. The 24 mm dimension is only for the mounting points for the c-beam.

What do you use for a slip-yoke to the transmission presently? If you use a long slip-yoke it's possible you could accomplish the drive-shaft modification with the purchase of a slip-yoke! Maybe just cutting the slip-yoke could also accomplish the fix. Does your drive-shaft use 1310 joints? If yes, post trans type and if it's apart the length of the machined barrel of the slip-yoke. Let's see what's available.

I've a specialty built drive-shaft here that has 1350 end-yokes on it and it broke a 1350 joint demolishing the rear end yoke. You could get two very special shafts from this.

Am I understanding that your using the mounting points on the front of the pinion as only a "so to speak pinion-snubber"?

ItBites01

WVZR-1,

The trans is a TH400 and uses the non-bolted slip yoke (no threads in the output shaft). The u-joints are 1310, as that matches the input on the D36. The driveshaft was built by Denny's Driveshaft. My plan is just to send the driveshaft back to Denny and have him shorten it. But I like the idea of shortening the yoke splines, if it doesnt come too close to bottoming out on the inside against the output shaft. Interesting...

It does have 1310s and they seem enough, since the halfshafts are 1310s as well and they have more torque multiplication than the primary driveshaft, but time will tell. The car is 2600 lb and on street tires, ran 10.6@130, with a 1.7 60' (out of a total of 3 passes), but I mostly road race it. I will never run slicks on this IRS.

Yes, the forward mounting point is like a pinion snubber in both directions, with a 5/8 bolt running thru the assembly, so it snubs in the acceleration and decelleration direction. The rubber donuts are about 1/2 inch thick and something like 3.5inch diameter. I think I will go to harder poly donuts on reinstall to reduce the motion.

vetteoz

C4 halfshafts have 1350 uni's

Doug 87L98

Thank-you.

ItBites01

Thanks to all y'all on the great info. Didn't realize the halfshafts use 1350 u-joints, Thanks vetteoz!

Does the D44 use 1350 u-joints on its input yoke? The D36 had 1310 as I recall. If the D44 uses 1350 u-joints on the input yoke, then I'll get Denny to build an entire new driveshaft with 1350 on both ends or maybe get the driveshaft from WVZR-1 and shorten (thanks for the offer).

vetteoz

All C4's have 1310's on the DS and 1350's on the halfshafts

ItBites01

Thanks a bunch all! Great info.