2 piece driveline upgrade options

[cortcomp]

Sorry if this has been covered, i didn't see anything searching that answered:

I have the small, 2 piece drive shaft. The mount for the carrier bearing is the kind where the bolts are in-line with the driveshaft. I am swapping in an NP440 trans which is pretty close as i recall to the 3 speed, so i may not need a new driveshaft. However, if it's too long or short, i've read the smaller driveshafts aren't that desirable. Add in that i have OD and 3.73 gears, and that tiny shaft will be spinning away.

I know a larger diameter shaft resists failure from the "jump rope" effect, and i do have a 327 albeit it's stock rebuilt and won't be a performance truck, so i'm wondering if i shouldn't just go to a larger all new driveshaft and be done. However, i see the larger diameter carrier bearings mount with bolts side to side, not front to back, and i'd have to check again but don't think my chassis would accept that...

So what do you guys do? It's a LWB and with OD i think 2 piece is still safest here, and i don't mind buying a new shaft balanced and new joints, etc, but not sure what sizes i can go to because of the bearing. It's the standard 1" drop in front and 3" drop in rear with CPP springs, everything else stock suspension.

[jayoldschool]

Go to your local truck driveline shop and have them make you a one piece shaft, 3.5" or 4" inches. If your shop can shorten aluminum shafts, you can grab one of the beautiful aluminum big diameter shafts from under a late model long GM truck. The shop will shorten, and put the correct yokes on it for your trans and rear. If you don't have a good local shop, Denny's will make you whatever you need (and they probably have the specs you need in their data already).

http://www.dennysdriveshaft.com/

I'm sticking with the stock set up, new U joints and center bearing, but with stock trans/230. With any more power, and definitely with OD, I would be going one piece.

[Captainfab]

I would stay with a 2 piece driveshaft, but upgrade to the HD carrier bearing and larger shafts. I do make the mounting bracket for the HD carrier bearing, but I don't have a for sale thread for them yet.

[jayoldschool]

If you compare the price of a good one piece shaft to new larger 2PC, larger carrier bearing, mounting bracket... I'm betting the one piece will win.

[mixermike]

Swapped in a np440 in my 63 a few months ago. My truck is a lwb with a one piece driveline.my original driveline had issues so I had a new one built and balanced. 4" tube,new joints,new yolk $500 out the door. The new tranny is GREAT!!!!

[cortcomp]

I'm sure the one piece price will win, i'm worried about going 85-90mph in OD spinning that shaft...once it starts to rope, it's over. I doubt it would happen, but still, that's why there are two piece shafts, way safer the longer distance you go.

Mixermike: did you have to change driveshafts because of length? It really seemed it would line up fine, i just don't have the tranny in to check, and i'm trying to predict any setbacks i may have in the next month.

Captainfab: So you make a bracket that will change my longitude bolt pattern to lattitude, and i can use a standard bigger OD carrier bearing for these trucks, and have a driveshaft to match made up and be good to go just like this truck had come with the bigger shafts from the factory?

[mixermike]

The length of the original shaft would have worked just fine. Mine was bent!!

[cortcomp]

Good to know! So i should be able to get cptns bracket, take my driveshaft to the shop and say "make me a driveshaft same as this one but in a diameter to work with this heavier duty bearing."

Of course i'll check first, but that takes some measurement/chance to screw up out of it!

[66Submarine]

Considering that most of the 20-30 series and larger trucks are not particularly desirable, you might also check out junkyard driveshafts; most of those came with SM420 ("granny") 4-speeds, and those all have the HD driveshaft. A LWB C10 with the SM420 4-speed would just need the front driveshaft shortened (AFAIK) if you find one. They will have the slip joint in the second (axle end) shaft that you don't need, though. Not sure if that would bother you or not.

The same setup was also used in larger trucks AFAIK, and the same type of setup is still used today in box trucks and the like with long wheelbases. Considering that 3/4-ton-and-up stuff also interchanges really well between decades and manufacturers, you may find something that would work with just a little shortening out of something like that, too. Might be worth a look if you have any decent junkyards where you're at.

AFAIK, the NP440 is longer than your current three speed. I'm not sure what year Mike's truck is, but 67-72's like in his picture used the longer Saginaw 3-speed with a synchronized first gear (the same length as a Saginaw or Muncie 4-speed, etc). 60-66 used the SM318 Muncie 3-speed, which was shorter than all of those.

[Captainfab]

Yes that is exactly why I am making these brackets. Here is the first one I made:

http://www.67-72chevytrucks.com/vboa...d.php?t=620312

I am really not a fan of those light duty drivechafts like you have. I believe those are the reason everyone is so down on 2 piece driveshafts. They just don't hold up.

Before you go and have both new shafts made, I would check your area for used ones that if not the correct length, could be shortened. That is much less $$ than having complete new shafts made. Even driveshafts from a squarebody may work.

Here is a pic of what an original HD driveshaft looks like.






.

Originally Posted by cortcomp

Captainfab: So you make a bracket that will change my longitude bolt pattern to lattitude, and i can use a standard bigger OD carrier bearing for these trucks, and have a driveshaft to match made up and be good to go just like this truck had come with the bigger shafts from the factory?

[66Submarine]

Hey, this time I beat you! I guess we're even...

[Captainfab]

Yeah, but I gots pictures in mine

Originally Posted by 66Submarine

Hey, this time I beat you! I guess we're even...

[66Submarine]

Originally Posted by Captainfab

Yeah, but I gots pictures in mine

But I'm 2,500 miles from my truck on a laptop without my picture collection! No fair!

[cortcomp]

To follow up on the above, i put my driveshaft in today to test and see where things lined up. The tranny can take the entire 4" of the yoke. 3/4" from bottom out is the rule of thumb i've always used. If you went 1" from bottom out, and the yoke at current length is just shy of 2" on the shaft, this driveshaft is 1" short. Looking at the marks on the tailshaft, that's as far as it was in with the 3 spd though, and that got me home almost 2K miles.

I'm not 100% what i'll do yet, big show is two weeks away now and still have work to do, may not have time to chase driveshafts and may rebuild this one and put new carrier bearing on and a 1" longer yoke for safety. See what craigslist turns up.

[cortcomp]

Or just get this and refurb it:

http://cleveland.craigslist.org/pts/4540691198.html

Imagine it would fit from the looks of it, no measurements

[earl84]

I just finished replacing the entire driveline from a 79 LB C20 into my 66 LB C20. Got the measurements I needed and took to a driveshaft place for shortening and balancing. Both shafts needed to be shortened, but I also replace the SM 420 with a TH400. Took them about 2 hours to shorten, balance and paint, cost $100. They even took out my new U-joints I had on the older, smaller driveshafts and installed into the new driveshaft, as well as the newer carrier bearing. I think it would be easiest, quickest, and cheapest if you got that CL setup and had it shortened.

[cortcomp]

According to NAPA, this bearing (PGB PHB88107A):

http://www.napaonline.com/Catalog/Ca...07A_0329212836

Fits C10 60-86 and C1500 88-99. So, that shaft being from a half ton 8ft bed regular cab, should take the same carrier bearing, and would probably work, at least as a base to get started from. I'll see if i can snag it and run all the parts down to the driveline shop. Ordering a bracket from Captainfab, if it comes in in time, i'll swap to that shaft (i think it'll make it.)

[Bigdock]

I'm kinda in the same boat I'm putting full Porterbuilt suspension under mine right now and have a one piece driveshaft that's going to have to convert over to a 2 piece shaft

[cortcomp]

It seems at least that the shafts from a HUGE array of trucks will work...at least up to 99 it seems? Trying to snag this one and a new carrier bearing tonight or tomorrow and take down to driveline shop to move my yoke over, shorten or lengthen, balance, new joints, etc, maybe put in this weekend or early next week.

[cortcomp]

Hit a minor snag or two...the placement of the carrier bearing is more forward on an HD driveshaft than the smaller one, it's hard to measure to tell the driveshaft shop where to put it without a reference. Second snag, the later driveshaft i grabbed has the carrier bearing WAY further back, so one shaft is too long (which is ok, can be cut) but the forward one is way too short. Again, could have it fixed, but wouldn't know where to tell them to put the carrier bearing.

Going to return this carrier bearing, get the one for my truck. Have a yoke that leaves about 1-1.25 inches of slip in it vs about 1 7/8. Going to have new ujoints put on mine, new carrier bearing, balanced and painted and throw it in. Will keep captains bracket and an eye out for a larger driveshaft at swapmeets, craigslist, etc.

[kevinjr]

Originally Posted by Captainfab

I would stay with a 2 piece driveshaft, but upgrade to the HD carrier bearing and larger shafts. I do make the mounting bracket for the HD carrier bearing, but I don't have a for sale thread for them yet.

Hello Cap i'm new guy old guy i need a new carrier bearing for my 64 2wd long bed i would like to buy one from you .Its a 327 3 on the tree nothing but a good looking driver.
I here tell your the go to for these trucks so that why i'm reaching out .Another question i have is do you know anybody in the chicago area that could put this in for me .Its past my ability (fused) Back .
My Favorite Clint Eastwood line is A Man Must know his limitations.
Well any way Thanks for your time any help would very much appreciated
Kevin 708-222-3500

[LostMy65]

Originally Posted by jayoldschool

Go to your local truck driveline shop and have them make you a one piece shaft, 3.5" or 4" inches. If your shop can shorten aluminum shafts, you can grab one of the beautiful aluminum big diameter shafts from under a late model long GM truck. The shop will shorten, and put the correct yokes on it for your trans and rear. If you don't have a good local shop, Denny's will make you whatever you need (and they probably have the specs you need in their data already).

http://www.dennysdriveshaft.com/

I'm sticking with the stock set up, new U joints and center bearing, but with stock trans/230. With any more power, and definitely with OD, I would be going one piece.

.
When I went to pick-n-pull, they were all destroyed by the forklifts.
I could watch the local ads for trucks being parted. What years should I keep an eye out for?

[DonLeverton]

Originally Posted by Captainfab

Yes that is exactly why I am making these brackets. Here is the first one I made:

http://www.67-72chevytrucks.com/vboa...d.php?t=620312

I am really not a fan of those light duty drivechafts like you have. I believe those are the reason everyone is so down on 2 piece driveshafts. They just don't hold up.

Before you go and have both new shafts made, I would check your area for used ones that if not the correct length, could be shortened. That is much less $$ than having complete new shafts made. Even driveshafts from a squarebody may work.

Here is a pic of what an original HD driveshaft looks like.






.

My truck has coil springs. It looks like NAPA/SKF is saying that is the determining factor?

Inland Empire Driveline does make a HD billet pedestal style support with a polyurethane bushing. The “standard” one has the 1.181” ID bearing, but they do supply a 1.375” version. I’m going to try that one, and use 1350 series u-joints on my 66 GMC long Fleetside with a blown BBC and TH400.

Wish me luck?🤷*♂️
Posted via Mobile Device

[pdxhall]

I have a 66 longbed with an aftermarket center crossmember. I bought a heavy duty 2 piece out of a 2000 chevy long bed and had it shortened where needed to get it to fit. Sorry I can't find a better picture right now.

[DonLeverton]

Originally Posted by pdxhall

I have a 66 longbed with an aftermarket center crossmember. I bought a heavy duty 2 piece out of a 2000 chevy long bed and had it shortened where needed to get it to fit. Sorry I can't find a better picture right now.

Thanks
Posted via Mobile Device