Greetings, Corvette fans;
Technical question regards driveshaft installation in 1980 model. It's my brother's car and we have swapped the L48 for a MAS performance stroker engine. He removed the driveshaft to have it "built" to stand the torque from the new engine. He removed the shaft while the engine and tranny were out of the car. Now that the new engine and tranny are back in - how on earth do we get the driveshaft back in. The car is up on jack-stands and I can't find enough space to put the shaft back in. I forgot about that rear cross-member with the "pinion snubber" on it. Do we have to put weight back on the rear suspension or do I have to lower the tranny cross member? I'm not very familiar with the Corvettes so thought I'd better ask about this.
Thank you all for any help you can provide.
COPCO

 

sounds like the wrong style front yoke may be on the new drive shaft

 

Hmmm, is yours an auto or manual? well the driveshaft, should go right back in. The front yoke that slides into the transmission slides in and out by hand at least on an Auto. So you might have to push it in or pull it out for it to reach the drive shaft flanges and strap clamps. I just removed my drive shaft and installed new ujoints. Mine is an Auto.

Probably need to provide some more info about the engine and if you made any mods to he rearend.

 

Hey, guys,
Thanks for the responses. The car has a turbo 350 which I took to a friend of mine and he built it up to where it will hold about 700 HP. The driveshaft was re-made at a company in Denver that makes drive- shafts for all kinds of racing stuff including the really hot stuff. The old front yoke is exactly the same length, etc. as the new one. There's been no modifications to the car at all, as he's the second owner and the car has 68,000 original miles. I was wondering if maybe the car has to be picked on a drive-on lift and that maybe would take the torque off the "pinion snubber" to where we could pry that thing down atoub 1/4 inch. Right now, with the axles hanging, I'm almost afraid to try to pry the lower part of the differential downward for fear of cracking the casting. Some of the "pinion snubbers" that I've seen in technical bulletins are a bolt-on piece which attaches to the lower, forward portion of the carrier but THIS one is a cast extension of the lower portion of the front of the differential below the pinion input.
Did any of that make any sense to you guys?
Right now I've tried to push the driveshaft forward above and to the side of the tranny and then pull it back alongside the punkin' but I can't get the extra 1/4 of clearance. I think if I could figure out how to get that extra little bit of space I could get the yoke into the tranny and then pull it back into the pinion yoke ( you know, kinda like we do with every other driveshaft in the entire universe.)
Thanks again, for your input. I've been building hot-rods all my life but ain't never seen nothin' like this before and sure-as-heck don't want to break this thing.
COPCO

 

I just went through this myself, rotate the rearend yoke 90 degrees so that you can slip the driveshaft past it slightly, then get the front u joint in the trans yoke, and rotate the rear into proper orientation. It takes a little patience and trial and error.

 

Are you trying to install the shaft with the yoke on the shaft ?

 

Holy-moly,
Nicks79: rotate the rear yoke ........ good grief, that's the only thing I didn't try yet.
I'll sure try that ! We only get to work on the thing every other week-end as I have to drive up to Denver from Colorado Springs. MY only remaining question, then is: did you slide the front up along the tranny and then pull it back over the cross-member to the punkin ? I can't slip this one up and over that rear cross-member because of the "pinion snubber being a cast part of the diff.
Thanks, bunches.
COPCO

 

with DWncchs.. which is what he was probably getting to...it is alot easier to remove the yoke from the driveshaft. Install the yoke in the transmission and push it all the way in ( after making sure you mark the yoke and driveshaft so it is reconnected the SAME WAY as removed) Then install the driveshaft to the rear differential. then CORRECTLY join the yoke and driveshaft. Torque bolts and use removable...not permanent loc-tite is also recommended. In my opinion.

The concern I have, is if you are adding alot more power to this car than the factory had, and have an automatic that is beefed up...I am concerned with the use of the factory side yokes for an automatic which use smaller bolts to secure the u-joint straps to the u-joints and the side yokes. I feel you MAY want to consider installing the manual side yokes which have much larger diameter bolts that secure the straps to the u-joints. And also change out the inner rear wheel bearing flange so those smaller bolts can be replaced with a flange that has the larger bolts. You will also need half shafts due the u-joints are larger. And you can get half shafts for an early Corvette manual trans car that are stouter than leter models. I think it has to do with the wall thickness. Someone may have more info on this. This is just a thought. More work...yes.... but you do not want to have a weak link in the chain...so to speak. If you break a u-joint or one comes apart....the damage it causes is severe to the components that the half shaft comes in contact with. Seen it...repaired that! Also...I would use the solid spicer u-joints WITHOUT zerk fittings for re-greasing.
"DUB"

 

And,DWncchs;
Yes, sir, with the yoke assembled onto the driveshaft. Please don't tell me I have to press it apart and then put it together while it's stuffed into the tranny.

 

And, GRANDMASTERCORVETTE,
Oh, yes, I can see it now. I tried to tell him that we probably needed to beef up more than we have, already. He's not really nuts but this engine DYNO'd at 465HP and 468 Lbs/torque. Also told him to buy a case of new rear tires.
I do notice that the new front yoke and the rear yoke look beefier than the old ones but I don't think we got bigger straps or heavier grade bolts.
Thank you for this additional info. My '39 Chev coupe/327/10 bolt/TH350 is so much simpler.
COPCO

 

Your drive shaft should be made so you can UNBOLT the yoke from the driveshaft. NOT PRESS IT OUT. YOU HAVE A PROBLEM ON YOUR HANDS....IT IS WRONG. I have been through this ONE time in the past and had to drop down...but not out ...the rear differential so I could install the driveshaft. THAT WAS A BEOTCH!!!!!!!!!!!!! TAke it back and have it FIXED.
"DUB"

 

GRANDMASTERCORVETTE'
Well, there we have it ! I just called big-brother in Denver and asked him a few little questions about this new and stronger driveshaft. Yes, indeedy, nice big Spicer front yoke and (OUCH) ain't got no bolts and ain't got no way to come loose from the shaft. And, I'm feeling just a bit stupid since I never even looked at the old shaft before he took it to the shop to get it beefed up. Ain't that the way it goes ! Lesson learned: pay closer attention when working on somethin' I ain't familiar with. Good Grief !
The great part about this whole episode is that maybe there is another guy out there who will get some good old fashioned learnin' from this.
Thank you, thank you to all you guys who responded and, in particular to DWncchs, who initiated this line of thinking and to you, GRANDMASTERCORVETTE, for helping this old feeble brain make sense out of it.
COPCO

 

COPCO,
It still can be used if you want to take teh time to do a bit more dis-assembly....which isn't that bad... The best part is that you can do it laying down on your back....which can often tiimes allow you to take a nap...but...remember to take some wrenches and clank them around from time to time so people think that you are working.

Joking aside...At least the problem is identified. Much better than wondering what the heck is going on and why can't I get this darn thing in. Wish you the best and I hope the rest of the project is less troublesome. REALLY consider upgrading to the manual half shaft parts. I would hate to read that something "snapped".
"DUB"

 

I'd recomend the Manual Trans or any 1982 1/2 Shafts. When you have them out You might as well remove the Rear End as you will have most of it Unbolted anyway. You will have to change the Side Yokes anyway.Then when You re install it you can feed the driveshaft in from the Rear first.

 

Just saw this thread and it just so happens I had my drive sahft out to have it lengthened for my Doug Nash 5 speed and went with bigger front u joint.

You can use almost everything you have except for the correctfront yoke. Get in contact with the drive shaft vendor and see if they will sell you a take a part front yoke at a resonable cost as this is a must have. Hopefully you can press the current one off and maybe they will work out some sort of an exchange of the press fit yoke.

When you have the parts sorted I install the drive shaft first to the rear diff. Tighten the rear strap bolts just snug (1/4 12 point socket on extension works best for this as it fits down the drive shaft tunnel. Once drive shat is bolted to diff push the yoke all the way into the trans. Lift the front to the drive shaft into position and bolt up. You may have to rotate the drive shaft to fit up through front yoke.

The only issue I can think of is the drive shaft possibily being a bit too long to still allow you to fit it in once the yoke is in the trans but you won't know till you get that far. Lucky you have an auto as I had to pull my back out to grind clearance on the yoke for the Long 1st gear shifter rail which sits right next to the tail housing as the rail moves to the rear when in first just clipping the bigger yoke.

Good luck