I'm swaping out my 198 v6 and 2 speed trans with a 65 buick 300 v8 and a th-350 trans in my 62 buick special, and i'm not sure what to do with the double drive shaft, should I use a single drive shaft or keep the carreir bearing two piece shaft ? any advice would be appreciated
The V8 cars had a two piece driveshaft too. Because of how the frame is made and how the pinion is pointed somewhat to the ground, you will need to stay with a shaft that has double-cardan constant velocity joints. If the factory shaft is in good shape, you are a huge step ahead. If it has wear problems, it will become a money burden because the parts to repair what you have are scarce to non-existant. That's what I figured out 15 years ago. The carrier bearing housings are hard to come by. X908CC replacement bearings don't lie around in the Dollar Store. It also seems like the u-joints are small in both applications. They're similar, but smaller diameter caps and cross dimensions. IIRC, 2.5RL series designation. If need be, a guy can modify to use some later model stuff to come up with a new answer that mimics the old design. FINAL PROBLEM with that is the bolt circle on the pinion companion flange is 4" centers instead of the more standard 4 1/4" centers. The pilot is standard 3 1/8" along with 7/16" bolt size. I haven't had to tackle the entire project, but have had my hands in the metal that makes it happen.
Those driveshafts were barely adequate with the original engine, and the center bearing is a common failure point. A friend of mine put a bigger engine in one of these cars. After breaking a couple stock driveshafts he came up with a one piece replacement that worked fine. Sorry I can't provide any details.
...or adapt a more modern Rzeppa-type ball-and-cage CV as used on most late-model product (BMWs, Chrysler 300s, Jeeps, Mustangs, etc.)
Junk the 2 pc. won't hold up and check with your local drive shaft/transmission shop, they will come up with something.
I replaced the two piece with a one piece tube in my 62 Skylark. Course I also got rid of the stock rear end and put a leaf spring Chevy 11 housing under it. The one piece tube will work just fine as long as you dont haul any fat girls in the rear seat. Oldmics
I'll be going through the same issue as well. Think I may just cut and clearance the fire wall (planning on Th350) and raise the drive shaft tunnel to make a one piece drive shaft fit nicely. It's gonna be on bags to so really doing it out of necessity. I've tried to find center bearing parts yeah good luck not many around, only ones I found were on ebay and not complete. Good Luck let us know what you come up with.
I'm thinking on cutting the tunnel and raising it up and putting a one piece shaft in, I didn't want to change out the rear end if possible
Here's a good measuring stick for how to modify a driveshaft tunnel on a car like that---Use a 2x4 as a driveshaft mimic in size. Make sure you have more than 1" of clearance all the way around the 2x4 as you move it around as much as suspension movement will cause. Last dose, make sure your driveline angles are correct when changing from 2pc CV shafts to a 1 pc shaft. It will make a difference in the long run.
Go to a local driveline specialty shop..... They'll fix you up with the right items. Well worth the cost. 4TTRUK
Duchan, I know this is an old thread but what did you end up doing for this configuration? I am in the process of doing this as well and want to do minimal ****** tunnel work. Any help would be greatly appreciated! Chris
I ended up useing a 65 Buick 300 bolted right up to the v6 motor mounts and used a th350 trans I cut the floor about to the tail shaft and up to the heater box made the floor around it, built a crossmember and put the trans as close to the floor as I could, the drive shaft I used the original one because I still have the stock rear axle in it, I got a u joint and a shaft end from northern driveline and shorted it and welded the end back on, it works but I have a slight vibration I'm thinking its the bearing in the drive shaft, I want to put a different rear end in it and then use a one piece shaft but haven't got to that. Any other questions let me know, Bob
Bob, Ok. That's what I am running into now. TH350 is in but of course, the floor needs cut. :-( I am planning on doing that so I can get the running gear in. Do you happen to know about how much you had to raise the trans tunnel? I am ***uming that you didn't do anything to the drive shaft tunnel since you used the stock shaft. With using the TH350, it has the slip yoke design on the tail shaft where the Dual Path didn't. The slip was built into the rear shaft by the carrier bearing. Did you do any mods to that slip joint? If not, then you have a double slip and that could be causing vibration. Another Y-body guy did a power train swap like we did and he put slip yoke on front shaft and then put a small weld on the slip part of the rear shaft and had it re-balanced. I wanted to do a 1-piece shaft but my concern would be that the drive shaft tunnel is too shallow; just like the trans tunnel. Thanks so much for getting back to me Bob. It is much appreciated! Hope to hear from you! Chris
Chris, I'm not really sure on the exact measurements I know that its right under the heater core and then I cut the width to the transmission and rolled sheetmetal to form the tunnel, with the front seat in its right at the edge. The drive shaft I just shorted and welded a new end to go with the th-350 and didn't do anything with the slip joint or the rest of it, I bet that's where it vibrates , the vibration starts at about 50 mph to 55 not real major but drives me nuts, my plan is to change the rear end to a gm 7.5 (79 monte) cut the tunnel out raise it and use a 1 peice shaft.
Ok. So you cut from the heater core to the front edge of the seat then? I am probably going to cut the tunnel out and just space it up to where I need it. I think I am going to stick with the 2 piece shaft, unless my buddy talks me out of it and I decide to cut the DS tunnel. Lot more work than I wanted to get into.
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