Thoughts on one piece drive shaft

The carrier bearing went out on my '65 Riviera and left me stranded on the way to Roundup. I saw one of my friends up there who was a previous owner of the car and he said he has replaced it before, it's probably wearing out prematurely because of the up and down of the air bag suspension. I talked to another guy with a '63-'65 and he had the same problem, so he just had a custom one piece driveshaft put in and has had no problems since. The bearing is nearly $200, a driveshaft won't be much more than that, they can probably just weld a tube in the middle of my existing two piece unit. I wonder why GM screwed around with the two piece in the first place? Anyone forsee any problems?

 

Critical speed.

How long is that driveshaft?

My guess is that with a one-piece steel shaft of typical 3in diameter circa 1965 and, say, a 3.25 rearend you'd have a top speed of not much over 100mph before the shaft reached critical RPM and came apart.

Just as a metric - Crown Vic P71 cop cars have a shaft 55-and-change long c/c on the U-joints, most run 3.27 gears and a 3.66in aluminum one-piece shaft which hits critical RPM somewhere short of 140mph. When Ford briefly tried to sell 3.55s in the CV they had to use a MMC (metal-matrix composite) shaft to avoid speed-limiting the car below 130mph. And if you try running a CV 130mph for as long as, say, a bone-stock 525i or Camry could, you stand a chance of seizing the tailshaft bushing anyway unless you've retrofitted it for pressure lubrication...

Some useful data out there for a little googling, example: http://www.pstds.com/driveshaft_critical_speed_chart.htm

Of course, if you're going low and slow forevermore, it might not matter to you. And there's various ways of making a one-piece shaft stay together to higher RPMs - larger-diameter aluminum tubes, MMC, carbon fiber or carbon-fiber-wrapped aluminum, etc. depending on budget and need.

 

Might try a long tailshaft tranny and a shorter overall driveshaft.

This is what I SHOULD have done on my Lincoln but didn't.

IMO the longer arc on a one piece will produce better angles considering the variety of ride heights you are likely seeing with your bags.

In my view, a longer shaft will provide more flexibility... Split the difference with a long tailshaft tranny and you might be better off.

 

Welding a tube in the middle is asking for more problems. One long uninterrupted straight tubing welded to front yoke and rear yoke is the correct way to go.

 

A lot of newer cars (Germans for the past eon or so, more recently some Detroiters) are now using CV joints (not double-Cardan rock-crawler type, real Rzeppa ball-and-cage CV joints) at various points in the driveshafts to deal with driveline-angularity and smoothness issues.

I've got a cute little shaft, a takeoff from a late GT500 out in the shop, it's a two-piece shaft with a 1330 at the trans yoke, a big CV joint behind the center bearing, and another CV at the diff input. The drag guys rip 'em out and stick in big single-piece shafts with 1350s on them because even these CVs are marginal at 550HP but you won't run 160mph with a one-piece shaft.

With luck this or something like it goes into my '64 Galaxie wagon. The CVs also seem to me to be a good solution for the uneven-driveline-angles problems with truckarm rear suspensions...you could run a CV in the middle to accommodate the changing shaft angularity and Cardans front and rear at minimal fixed angles (or a CV at the rear, doesn't much matter, but diff flanges for the CVs are not that common...)

 

I'm on a real tight budget so a trans swap is not an option. One long tube does sound better.

 

Also, I mostly just cruise, do a little freeway driving, rarely over 70 or so, rarely over 50-100 miles from home, except to Roundup once a year, so high speed driving is not a factor. I do plan to pull a popup or teardrop size trailer next year to Roundup, however, if that is a factor.

 

You might want to take your trans output stub with you to a junkyard & find the longest one piece shaft from a large sedan or pick up.

Just welding two shafts together will be a balance problem at any speed & may ruin your trans or rear not to mention other damage as it comes apart & flails away at the bottom of your car.

 

I was running into similar issues on my 59 ElCamino.
Had my local 4 wheel drive shop add a slip joint to the rear driveshaft, no problems since.

The slip joint is a common solution for 58-64 Chevy X-Chassis with the 2pc driveshaft.

 

fwiw, i picked up a olds 98 driveshaft with a th400 yoke for $25 + shipping. you could have one shortened and balanced and still be cheaper than that carrier. but the frame might force you to have a small diameter tube, which is a problem. 2wd 1/2 t suburbans have a long 1 piece that has a larger diameter, and reduces at the ends.

 

I'll have a driveshaft shop build it for me and balance it

 

The slip joint is also a good thing to consider; the stock two-piece shaft has one in the middle. All y'all have given me a lot of ideas, thanks.

 

Good info. I don't miss the old center support,but I've wondered about the vibration when I'm really scootting.

 

Exactly.
I just sent the shaft for my 62 out yesterday to have it rebuilt and add a slip joint to the rear shaft 'cause i have bags in it.
The one upgrade i did make was the billet carrier bearing though. We have broken the stock style ones in cars without bags and i didn't want to have any problems later.
The carrier was 105.00 and well worth the money.

Tony

 

Obviously you're not very familiar with the Rivi's and Nailheads.

Two piece driveshafts can be a royal PITA. Don't skimp on it, get the quality stuff and don't cheap out and fix all of it, not just the obvious failed piece. But I agree the increased movement from the bags may be an issue. Is there adequate room for full travel up and down with a one piece? IF so then that may be the way to go...

 

Who makes the billet carrier bearing and is it a direct bolt in?

 

You are right, even though I (usually) baby this thing, it makes a LOT of torque, and I do like to have fun on occasion. Plus my friends drive her as well, and who knows what they do when I'm not around. My buddy just got the car to my house this morning while I'm here at work, I'll have to get under there with a tape and do some measuring with the suspension both up and down. I need to put some bumpstops in there anyway to keep her off the ground in case of a bag or line failure.

 

Inland Empire
www.iedls.com

they should have everything you need

 

The Inland Empire stuff is nice, but expensive! May be overkill. I've done some shopping around and found the bearing and support for about $125. The last one went five or six years, a few of those as a daily driver(before I owned it). At 1000 miles a year, I think I'll just spend the buck and a quarter and take my chances, she may go ten years the way I drive.
On another note, Danny of Bruce's rod shop said he did a lowered car and slottedthe holes to slide the bearing forward a bit, maybe something down there is putting thrust load when raised or lowered?

 

A word of advice, the carrier bearing on my Impala got knocked loose and I thought it was a goner, when I pulled it out the housing itself got separated from it's "base". Apparently it was just spot welded in two spots. I ran a bead around the housing, popped her back in and called it done. Whenever it goes, I'll make sure to run a bead on the new one as well. So, I guess check your new one too!

 

Richard you may actually need to shorten your rear shaft. What may be happening is that when you lower it the drive shaft is hitting the end of the slip joint. That would happen when the drive shaft is about level or running straight back to the rear end.

Running a drive shaft long isn't the problem you would run into. I have a couple in the garage right now that run in the 70-80" range. Your problem is going to be what in the world that long bugger is going to run into. GM run the two piece shaft in a lot of them to overcome problems with a long straight line hitting either the floor or the chassis.

Snyway before you run your new bearing check and see of your slip joint is bottoming out.

 

Will do.

 

Will do that too.

 

this, but remember that if you run a 2 piece shaft it allows flex in the middle is you are lifted front dropped rear...

chances are you need to put a slip in the back or atleast that is by far the best option.. .i run one in my 63 along with a solid carrier bearing... no issues, and i can drive at some F'd up angles.. plus it was $225 for the bearing and the rear section with a slip in it (new rear section is also made a little beefier)

i wouldnt go solid driveshaft on a car with bags, you need that flex

 

I don't think they have a location near you but whatever you do don't use Midwest Wheel/Precision Bilt! Terrible customer service and a shoddy job to boot!!

 

As the rest have said, your problem is that you need a rear sliding shaft. This will keep the fore and aft movement of the carrier bearing to a minimum, which is what is making it fail; the root cause of the problem. The problem with one-piece conversion is that the driveshaft will not have enough clearance inside the X-member frame.

Just take your existing driveshaft, front and rear, to the driveshaft shop and have them make a sliding rear section. You need to keep the two-piece shaft. Weld around the foot of the new carrier bearing to reinforce the spot welds if not using the heavy duty one from Inland. You should have no problems once you fix the cause of the problem. You can make the rubber stronger on a stock carrier bearing by filling the rubber with urethane like windows use for sealing. Especially since your rear sliding shaft now takes the requirement for fore and aft movement away from the carrier bearing.

 

Definately keep us informed on what you do. I considered a one piece drive shaft on my Riv. at one time but based on looks alone (I didn't measure) it looks like a one piece would hit the top of the part of the frame that the driveshaft itself runs through, before the rearend would bottom out when all the way down (aired out).


If you Riv. is as low as mine is (I'm sure it is) when all the way down I'm not sure if a one piece driveshaft is the best option. The slip joint sounds better to me, either way definately let us know what you find out ,and decide.

BTW nice meeting you at the LSRU.

 

don't do a one piece shaft, you'll have to tunnel out the floor if you want to keep the air ride.

they do sell a billet carrier bearing with a urethane bushing, way better than the original. it won't go out as fast as the rubber ones.

the carrier bearing will go out eventually, even the more expensive ones. it's just part of the maintainence of a car with air ride.

 

it should be the same as 63-64 impala. these guys have them in stock. they are off of the beltway and I-10 east, channelview area.

http://www.lastminutecustoms.com/

(832) 487-9773

 

This is where I got in trouble with my Lincoln, I had taken out the stock long tailshaft tranny and went in with a short THM 350, a long shaft wouldn't make it through the X member and hook everything else. I ended up using a two piece from a 62 Bel Aire, shortened 2" and it works good except I can occasionally feel the U-joint a little when starting up a steep hill, (when the axle wraps up) I think a longer shaft would have helped here.

I regret not getting a long tailshaft thm 350, it wouldn't have cost me much more than the short one.