Drive shaft question
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Le Mans Master
Joined: Jan 2002
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From: Jenison MI
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St. Jude Donor '06
Drive shaft question
I'm putting in my D44 into my 1993 Auto. The rear is for an 85 so I know I need to drill out some holes. My question here is that will the auto drive shaft fit? I thought I read here that it would but the search is not coming up with crap. Oh, and just to make sure, the holes I need to drill out is the 4 on the bottom that the rods bolt to right?
Le Mans Master
Joined: May 2005
Posts: 5,214
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From: Queensland, AUSTRALIA
Have a look here: http://forums.corvetteforum.com/show....php?t=1406371 i just did this job a few weeks ago. Get the C-beam from a manual car, it fits straight in. You can drill new holes, but its not expensive for a C-beam. I also used a manual car drive shaft as you can see in the pics of my thread. The auto shaft may work, but it was also cheap for the used manual drive shaft, so i bought one. The holes that need to be drilled in the auto C-beam are best drilled at the transmission end, and i believe the manual C-beam is about 15/16ths of an inch shorter than the auto C-beam. There is a tech article on here somwhere for that part that shows the holes drilled and gives the measurement. Ill see if can track it down for ya mate. 
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Le Mans Master
Joined: Jan 2002
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From: Jenison MI
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St. Jude Donor '06
Originally Posted by Casethecorvetteman
Have a look here: http://forums.corvetteforum.com/show....php?t=1406371 i just did this job a few weeks ago. Get the C-beam from a manual car, it fits straight in. You can drill new holes, but its not expensive for a C-beam. I also used a manual car drive shaft as you can see in the pics of my thread. The auto shaft may work, but it was also cheap for the used manual drive shaft, so i bought one. The holes that need to be drilled in the auto C-beam are best drilled at the transmission end, and i believe the manual C-beam is about 15/16ths of an inch shorter than the auto C-beam. There is a tech article on here somwhere for that part that shows the holes drilled and gives the measurement. Ill see if can track it down for ya mate.
On the batwing there are some holes that I need to drill out because the later C4's had larger bolts then the yearlier ones. I do have a C-beam from a M6 so I'm all set there, I was looking to see if I had to go to a different drive shaft or if my Auto (stock) one would work. Thanks for the help though.
Race Director
Joined: Oct 2001
Posts: 19,653
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From: Melbourne Florida
Cruise-In IV Veteran
The driveshaft from your D36 set up is too long...some have cut and re-welded them to fit but I would not be comfortable with doing that...picking up a manual (D44) driveshaft is not an expensive proposition and will be a direct fit....
Burning Brakes
Joined: Nov 2005
Posts: 908
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From: Colorado Springs Colorado
I just did the same thing, using an '85 D44, and I know exactly what you are talking about. I didn't drill out the D44 case, I used 3/8-16 all-thread to replace the asymetrically sized studs from the later design, and adjusted the dogbone brackets for the smaller bolt size by centering some 3/8 washers over the 5/16 holes, and welding them in place. I tried using the 85 brackets first, but the geometry was all wrong.
As for the driveshaft, you can use it in a pinch, but it has almost no endplay left. You have to drop the transmission tailshaft a couple of inches to even get it in place. I have to take mine back out soon (out of balance, the balance mark was gone from my D44, and I must have guessed wrong), and I'll be putting the shorter one back in. The difference in lenght is about 3/4 inch.
As for the driveshaft, you can use it in a pinch, but it has almost no endplay left. You have to drop the transmission tailshaft a couple of inches to even get it in place. I have to take mine back out soon (out of balance, the balance mark was gone from my D44, and I must have guessed wrong), and I'll be putting the shorter one back in. The difference in lenght is about 3/4 inch.
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Le Mans Master
Joined: Jan 2002
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From: Jenison MI
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St. Jude Donor '06
Here is a stupid question. You say that you have to pull the drive shaft and reinstall it because it's not lined up with a mark on the pig? I have never had to line any drive shaft up on any car. What mark are you going by and are you setting the weight on the shaft in-line or opp. of the "mark"? Heck I've had my stock one out 4 or 5 times and never put it in using any marks.
Team Owner
Joined: Mar 2000
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From: Boston, MA
I can never remember. Is it the driveshaft itself or the yolk that makes up the difference in length? I remember Fastguy grinding the splines off of his 700R4 yolk about 3/4" and his driveshaft fit fine.
Burning Brakes
Joined: Nov 2005
Posts: 908
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From: Colorado Springs Colorado
The heavy side of the shaft and the diff yoke have marks on them, they should be reinstalled on opposite sides. The guy who sold me my rear did me nice and sandblasted all the parts, they were very clean. So clean, there was no mark left on the D44 yoke. I took a 50/50 chance when putting everything together, but I have a rumble now.
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Burning Brakes
Joined: Nov 2005
Posts: 908
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From: Colorado Springs Colorado
Originally Posted by scorp508
I can never remember. Is it the driveshaft itself or the yolk that makes up the difference in length? I remember Fastguy grinding the splines off of his 700R4 yolk about 3/4" and his driveshaft fit fine.
Burning Brakes
Joined: Nov 2005
Posts: 908
Likes: 1
From: Colorado Springs Colorado
BTW, before you take the drive shaft yoke out, you'll want to have the special tailshaft plug handy (which I don't have) or use your air bleeder (which I do have) to take a tad over 4 qts of ATF off. Otherwise, be prepared for the flood of ATF that washes past the spline.
Le Mans Master
Joined: May 2005
Posts: 5,214
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From: Queensland, AUSTRALIA
Originally Posted by fsr402
Ok sorry I was not clear on what I was looking for.
On the batwing there are some holes that I need to drill out because the later C4's had larger bolts then the yearlier ones. I do have a C-beam from a M6 so I'm all set there, I was looking to see if I had to go to a different drive shaft or if my Auto (stock) one would work. Thanks for the help though.
On the batwing there are some holes that I need to drill out because the later C4's had larger bolts then the yearlier ones. I do have a C-beam from a M6 so I'm all set there, I was looking to see if I had to go to a different drive shaft or if my Auto (stock) one would work. Thanks for the help though.
Originally Posted by scranage
BTW, before you take the drive shaft yoke out, you'll want to have the special tailshaft plug handy (which I don't have) or use your air bleeder (which I do have) to take a tad over 4 qts of ATF off. Otherwise, be prepared for the flood of ATF that washes past the spline.
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Last week I made the swap.
I used a MANUAL driveshaft.
I used the stock AUTO C beam with new holes drilled at the tranmission side.
I Used the stock AUTO yoke.
FYI the DS from the auto was with a label of part #10054289
the manual one with part #10054299
The perfect measurement (center U-joint to center Ujoint) was EXACTLY 19.3 mm (= .76")LESS on the manual shaft. (I was thinking about 1"...)
Probably ALL manual DS are the same or similar (4+3 and 6 speed..) but the code of the manual one (#10054299) if I remember is for 89-91 manual corvettes.
-Beppe-
I used a MANUAL driveshaft.
I used the stock AUTO C beam with new holes drilled at the tranmission side.
I Used the stock AUTO yoke.
FYI the DS from the auto was with a label of part #10054289
the manual one with part #10054299
The perfect measurement (center U-joint to center Ujoint) was EXACTLY 19.3 mm (= .76")LESS on the manual shaft. (I was thinking about 1"...)
Probably ALL manual DS are the same or similar (4+3 and 6 speed..) but the code of the manual one (#10054299) if I remember is for 89-91 manual corvettes.
-Beppe-
