Driveshaft Question: 1 piece or 2 piece?

[ChumBucket]

'69 SWB 1/2 ton

Just got through with the c-notch and front/back airbag install. With the standard crossmember, do I need to be thinking about a 1-piece driveshaft or can I just stay with the stock 2-piece setup? Worried about the pinion angle geometry?

Anybody think this is a concern? Obviously hoping the stock setup will be OK, an all new 1-piece is going to be $$$$

Thanks guys.

[Jeffs70]

I have two trucks
1st with c-notch, bags and a 2 piece drive shaft
2nd with c-notch, bags, and a 1 piece drive shaft and both work just fine with out any problems. but maybe im lucky?

[RenoKeene]

We have a guy in town that builds drivelines for a living and he recommended I stick with the 2 piece on my big block short stepper. I wanted him to make me a one piece, he had been down that road many times and thinks the stock setup is a better design for my truck.
This advice cost him money so I have to believe he knows what he is talking about.

[57larry]

on a short wheelbase, I'd go with the 1 piece driveshaft

[ol_skool_chevy]

Originally Posted by 57larry

on a short wheelbase, I'd go with the 1 piece driveshaft

WHY..................can you give a Good Reason?

[crazy longhorn]

The swb truck has a short enough shaft, to run a 1 pc unit....& as long as you have the room for a larger tube shaft(you need that on a 1 pc), I would agree with Larry. My reasoning is that you have less parts, & less ANGLES to play with(less headache to setup) If the truck is "layin rail", you might be better off with a 2 pc (for clearance through the crossmember). Personally, I would run a 1 pc shaft in my longhorn....if I could (no go due to lenght tho). crazyL

[BB72CHEVKT]

I have changed all my trucks to a one piece shaft.

[Keith Seymore]

Originally Posted by ol_skool_chevy

WHY..................can you give a Good Reason?

There's a dozen good reasons, some of which are presented above.

I'd use a one piece any time I could get away with it. Less complexity, fewer moving parts, fewer angles, less mass, usually less cost (from an OE perspective) etc.

The factory did a two piece in some applications to keep the prop rpms below the prop critical speed - the speed at which the drive shaft begins to bend and swing like a jump rope. It is determined by vehicle top speed capability, shaft material, tire size, rear axle ratio, overall system resonances - and the availability of pre-existing parts. Use of a two piece design was a compromise (ie, suboptimization) right from the drawing board.

In the aftermarket you/we don't have the same constraints relative to material and diameter, so - if it was me - I'd have a one piece shaft made using whatever it takes. Steel, composite, aluminum, metal matrix - whatever - and at whatever diameter was required to cover my anticipated vehicle top speed.

K

[Keith Seymore]

Originally Posted by ChumBucket

'69 SWB 1/2 ton

Just got through with the c-notch and front/back airbag install. With the standard crossmember, do I need to be thinking about a 1-piece driveshaft or can I just stay with the stock 2-piece setup? Worried about the pinion angle geometry?

Anybody think this is a concern? Obviously hoping the stock setup will be OK, an all new 1-piece is going to be $$$$

Thanks guys.

I have a question, and it's not directed specifically at you, but perhaps you could help me understand:

I see this all the time on the boards, where guys will go to all kinds of modifications (engine transplants, trans swaps, frame modifications, suspension reworks) and then ask: "what driveshafts are out there that will fit?".

Any shaft I've ever had made was two or three hundred bucks, to make one from scratch. Why would a person do all that work, spend all that money on high tech modifications, and then want to use a shaft that they found buried in the dirt somewhere or out of somebody's beater?

Really? Spend the incrementally few more bucks and have a new shaft made.

Sorry if this sounds curmudgeonly - a stage I am looking forward to, btw - but I'm being sincere here.

K

[ol_skool_chevy]

Originally Posted by Keith Seymore

There's a dozen good reasons, some of which are presented above.

I'd use a one piece any time I could get away with it. Less complexity, fewer moving parts, fewer angles, less mass, usually less cost (from an OE perspective) etc.

The factory did a two piece in some applications to keep the prop rpms below the prop critical speed - the speed at which the drive shaft begins to bend and swing like a jump rope. It is determined by vehicle top speed capability, shaft material, tire size and rear axle ratio - and the availability of pre-existing parts. Use of a two piece design was a compromise right from the drawing board.

In the aftermarket you/we don't have the same constraints relative to material and diameter, so - if it was me - I'd have a one piece shaft made using whatever it takes. Steel, composite, aluminum, metal matrix - whatever - and at whatever diameter was required to cover my anticipated vehicle top speed.

K

I fully agree with most Everything you said above. I was only asking to give a GOOD REASON because as the thread states. One piece drive line or 2, Anybody think this is a concern?"
Larry Only said "on a short wheelbase, I'd go with the 1 piece drive-shaft"
He never state any concern as to why.
I'm always Entertained by statements with no reason....
I'm actually Entertaining the Idea of having one made for my truck.

[trev1]

I have been watching this thread. I am at an impass. I have a 69 c-10 cst that was originally a BB truck. I bought it without a motor or tranny. I put a 350 in it with a NP833 4 speed trans. I am down to the driveshaft. I found one, and went to se what needed to be done to make it fit. The wheel base on the truck is 127in. It came up bout two in short. I the started looking for a longer slip yolk. Could not find one. So I went to a Driveshaft Shop. He had a longer slip yolk. While talking to him I priced a new Carrier baring....ie.. all to have him rebuild it and balance it. Well he pulled out the carrier bearing, and it had a different mount than the truck had. He looked further and couldn't find anything different to match what I described. So I know I have to have a 2 piece driveshaft, I need a carrier bearing, and will have to have a front driveshaft made to fit. All that does not bother me. But.... The mount on my cross member bothers me. I took some pics. and if someone could identify exactly what I have. Are the carrier bearing mounts different for a 1/2 ton than a 3/4 ton? The pic shows that the Factory rivets are still in place, the carrier braring mounting bracket doesnt appear to be hackd on in any way. I'm darn confused.

[helldiablo]

Originally Posted by trev1

I have been watching this thread. I am at an impass. I have a 69 c-10 cst that was originally a BB truck. I bought it without a motor or tranny. I put a 350 in it with a NP833 4 speed trans. I am down to the driveshaft. I found one, and went to se what needed to be done to make it fit. The wheel base on the truck is 127in. It came up bout two in short. I the started looking for a longer slip yolk. Could not find one. So I went to a Driveshaft Shop. He had a longer slip yolk. While talking to him I priced a new Carrier baring....ie.. all to have him rebuild it and balance it. Well he pulled out the carrier bearing, and it had a different mount than the truck had. He looked further and couldn't find anything different to match what I described. So I know I have to have a 2 piece driveshaft, I need a carrier bearing, and will have to have a front driveshaft made to fit. All that does not bother me. But.... The mount on my cross member bothers me. I took some pics. and if someone could identify exactly what I have. Are the carrier bearing mounts different for a 1/2 ton than a 3/4 ton? The pic shows that the Factory rivets are still in place, the carrier braring mounting bracket doesnt appear to be hackd on in any way. I'm darn confused.

theres 2 kind of carrier berings "round type" and "horseshoe type" i belive
it looks like to me you have a "horseshoe" type carrier, my 69 has the other kind the "round" type..

[trev1]

Cool... anyone got any pics of the "horseshoe" type and thier bracket?

[helldiablo]

here is a pic i hijacked from autozone website horseshoe type


the other is the round type im not sure whats better but im sure someone will chime in..

[helldiablo]

part numbers from autozone...

Part Number: HB88107A



Alternate Part Number: HB-88107-A

Application: Horseshoe type

-----------------------------
Part Number: HB206FF



Alternate Part Number: HB-206-FF

Application: Round type

[66skylarkpost]

i just took a couple quick pics my '72 short step i'm restoring here at home. it has been lowered with 3" springs and a 1" block , ece delux track bar that give ya another 1/4" and i run a one piece driveshaft , without any issues oh , ive got a 400 short tail trans , which i see is leaking out of the yokes weep hole again ...

[BLK96]

I tried to have a 1-piece shaft built for mine (72 lwb 350/350 C10 leaf rear), driveline shop thought they could do it. On lift at full droop driveshaft hit bottom of crossmember it goes thru. My options at that point were modify crossmember or stay with 2-piece shaft, I stayed with 2-piece. Apparently some of these trucks they were able to convert to 1-piece without mods, not mine.

[trev1]

Thats great information. I looked up the carrier bearings, both are available at Autozone. Does anyone have pics available that are using the Horseshoe type bearing? It just looks like something is missing. I know on the later Chevy trucks. Ie..75.... have a bracket that attaches to the crossmember that the carrier bearing bolts to. I guess what I am asking, does the 69 model use the same type mounting bracket?

[trev1]

Anyone with any pics? I went to ORileys and bought both kinds of carrier brarings. The Horseshoe one did not fit the driveshaft. The round type did. The only problem is that it does not fit my bracket.....Any ideas?

[jonzcustomshop]

I thought the 2 piece design was due to wheelbase length more than anything else...at a certian point 1 piece wont work? -or is not optimum?

that said if you have to get one made anyway, (shorten your existing) I think a 2 piece would be a good idea on a lowered vehicle, it would solve any clearance problems with the rear x member...

I was thinking of using one on my lowered 50 chev convertible , so I wouldnt have to cut up the rear driveshaft floor tunnel