One Piece Drive Shaft? experiences? - Page 2

carl johansson · 10-06-2011, 07:49 PM

I'm not sure what would be the issue causing this vibration many of you speak of. Most vehicles have one piece drive shafts, and do not suffer from excessive vibration, so I am wondering what is it specifically that makes the Supra more prone to vibratioin, so much so that engineers went to a 2 piece drive shaft to reduce the vibration - which in actuality would not eliminate the source of the vibration, just mask it.

So I guess I am, looking for more than -" well it vibrates more!"

We have no problem with the 2 piece, other than excessive maintanence costs, and more "complexity" which typically ends up being less reliable.

We never plan on changing a drive shaft or U joints at a race, but you never know - and seeing as how you spend alot of money to prep a car, and alot more money to get to the race, once you are there, you want to maximize your racing dollar. Our primary goal is always to finish the 15 - 18 hours of racing - still running! (even though this is "cheap racing" a weekend of racing costs us about 2500 bucks, entry, tires 75 - 100 gallons of fuel , hotels etc, not including transportation to and from the track, and not including the car prep, which typically is 2 - 3 K after all of the safety stuff you have to have, and all of the systems you have to repair)
So we figure if we went with a 1 piece, it would change out easier in an emergency, the Ujoints could be changed in 15 minutes at the track, instead of finding someone to press those things out and screw with the carrier bearing!

I plan on having the one piece professionally built, and balanced, Don't know if that would eliminate some of the "vibrations" many of you speak of.

Anyone know or have an idea why the one piece is creating the reported vibrations (other than a misfit drive shaft, bad ujoints, or incorrect installation?

Rana, Google up 24 hours of LeMons to see the kind of racing we do!
in our opinion the supra is pretty well suited for this race series!

87 hilux, just saw your response - most is accurate, but the races are on road tracks, so 2 - 3.5 miles long, left, right, up down, we run on some of the best tracks in the country. We will be running at Infineon in 2 weeks, same course as the NasCar boys, with some added pieces those nascar guys whine about (so no carousel for them - cause they wear ballerina tutus!)
we often hit speeds of 120 - 130 at the end of the longest straights, followed by panic breaking down to 35 mph to make the next corner. We shift 20 - 35 times per lap, so you better know how to heal and toe!

Good place to learn to become a road racer, great place to have fun!

Carl Johansson

Ranma · 10-06-2011, 10:46 PM

Well Carl,

When I first bought my Supra brought him down to the toyota dealer. The U joints in him were bad, so sent the drive shaft down to the shop. So the U joints were changed in a professional shop and it was balanced. Well that did not eliminate the vibrations. Sent it back to the shop while replacing an axle and rebuilding the differential and the other axle. Put it back tougher and still had the vibration. At this time "genius" realized it was the drive shaft when I saw Ford on it. Got a replacement 2 piece, sent it to the shop. Put him back tougher and the drive is as smooth as smooth itself.
What you do does sound like fun, but not sure if I could take the g forces on the sharp turns. Do be careful Carl and enjoy your racing time

You are right a sitting car is so much decoration.

El Supracabras · 10-06-2011, 10:57 PM

The excessive vibrations are probably from a poorly executed conversion. If you plan on using a professional service to build a driveshaft I would think (hope) you wouldn't have any problems. In Ranmas case, it sounds like the kid she bought the car from didn't care about or more likely didn't know what he was doing. The 2 piece is pretty stout, but ripping the rubber out of the center bearing in the middle of a good race would suck. Race cars are supposed to rattle, right?

carl johansson · 10-07-2011, 05:51 PM

Quote:

Originally Posted by worm611

http://shaftmasters.com/toyota-supra...iveshaft3.html

Read some posts on forums about guys running this shaft, I purchased one, but did not install it yet, quality looks great!

anybody have any other sources they like? i gotta pull the trigger on this ASAP!

cre · 10-08-2011, 04:53 PM

Actually, the two piece is more to do with longevity and preventing the DS from grenading on you (and yes, it helps with vibrations but don't put it past Toyota to know how to build a balanced drive shaft... They would have if not for other factors , I'm sure, they're MUCH cheaper). You can find a LOT of information on this already online including a lot of wonderful pictures of exploded one-piece DS'd sticking out rear seats or gas tanks or taking out cars behind the vehicle it was installed in. It's the whole reason DS loops/cages are required at tracks. It's all about elasticity, centrifugal force and the outward fatigue it causes. Aluminum is the most susceptible (also the worst for vibration), steel is less susceptible and CF the least (although I believe CF may have more vibration tendency than steel).

I'll see if I can find a calculator for critical rotation speeds (this is just the speed at which the most stress is seen, it doesn't mean that if you drive at that speed one you're dead... I think on the 4.30:1 it was something low like 80MPH with a one-piece aluminum DS and stock size tires).

Bah, I don't have time today to dig for all the fun pictures Google image search used to show, they've changed the sorting priorities of something. Anyway, from what I've seen with fatigue the metal shafts will spiderweb and tear in multiple places. From too much power it usually looks more like a torn paper towel roll or crumpled. Carbon fiber looks like an expensive broom when it goes (not a lot of damage potential other than the spline and forward U-joint).

The Stock two piece has a critical rotation speed about three times that of a one piece. The two piece also serves to dampen shock through the drivetrain. You can get a lighter two piece made for little money and retrofit a more common carrier bearing OR have a one piece with a thicker center sleeve welded in essentially shortening the drive shaft into two and thus raising the ceiling a bit.

Vibration will kill seals, bearings and U-joints but the DS isn't going to just pop like a cartoon gun with a finger in it.

Of a final note a lot of drive shaft shops will tell you you need to check the DS every few thousand miles for signs of spider webbing or cracking (especially one this long)... do it; It's cheap insurance and really beats having the ass of the car try to pole vault on the highway. I've only known a couple people who've had trouble with their on-piece DSs on MKIIIs, those were aluminum. I've always run steal (on various cars) and never had a problem.

10-06-2011, 07:49 PM	#1
carl johansson 3" Exhaust Join Date: Nov 2007 Location: Auberry, California Posts: 141	excess vibrations? why? how? I'm not sure what would be the issue causing this vibration many of you speak of. Most vehicles have one piece drive shafts, and do not suffer from excessive vibration, so I am wondering what is it specifically that makes the Supra more prone to vibratioin, so much so that engineers went to a 2 piece drive shaft to reduce the vibration - which in actuality would not eliminate the source of the vibration, just mask it. So I guess I am, looking for more than -" well it vibrates more!" We have no problem with the 2 piece, other than excessive maintanence costs, and more "complexity" which typically ends up being less reliable. We never plan on changing a drive shaft or U joints at a race, but you never know - and seeing as how you spend alot of money to prep a car, and alot more money to get to the race, once you are there, you want to maximize your racing dollar. Our primary goal is always to finish the 15 - 18 hours of racing - still running! (even though this is "cheap racing" a weekend of racing costs us about 2500 bucks, entry, tires 75 - 100 gallons of fuel , hotels etc, not including transportation to and from the track, and not including the car prep, which typically is 2 - 3 K after all of the safety stuff you have to have, and all of the systems you have to repair) So we figure if we went with a 1 piece, it would change out easier in an emergency, the Ujoints could be changed in 15 minutes at the track, instead of finding someone to press those things out and screw with the carrier bearing! I plan on having the one piece professionally built, and balanced, Don't know if that would eliminate some of the "vibrations" many of you speak of. Anyone know or have an idea why the one piece is creating the reported vibrations (other than a misfit drive shaft, bad ujoints, or incorrect installation? Rana, Google up 24 hours of LeMons to see the kind of racing we do! in our opinion the supra is pretty well suited for this race series! 87 hilux, just saw your response - most is accurate, but the races are on road tracks, so 2 - 3.5 miles long, left, right, up down, we run on some of the best tracks in the country. We will be running at Infineon in 2 weeks, same course as the NasCar boys, with some added pieces those nascar guys whine about (so no carousel for them - cause they wear ballerina tutus!) we often hit speeds of 120 - 130 at the end of the longest straights, followed by panic breaking down to 35 mph to make the next corner. We shift 20 - 35 times per lap, so you better know how to heal and toe! Good place to learn to become a road racer, great place to have fun! Carl Johansson Last edited by carl johansson; 10-06-2011 at 08:00 PM.

10-06-2011, 10:46 PM	#2
Ranma 12psi boost Join Date: Jun 2010 Location: Claremore, OK Posts: 326 Blog Entries: 10	Well Carl, When I first bought my Supra brought him down to the toyota dealer. The U joints in him were bad, so sent the drive shaft down to the shop. So the U joints were changed in a professional shop and it was balanced. Well that did not eliminate the vibrations. Sent it back to the shop while replacing an axle and rebuilding the differential and the other axle. Put it back tougher and still had the vibration. At this time "genius" realized it was the drive shaft when I saw Ford on it. Got a replacement 2 piece, sent it to the shop. Put him back tougher and the drive is as smooth as smooth itself. What you do does sound like fun, but not sure if I could take the g forces on the sharp turns. Do be careful Carl and enjoy your racing time You are right a sitting car is so much decoration. __________________ 1986 Mk III MA70 7MGE Targa Top 5 Speed Stock Exhaust

10-08-2011, 04:53 PM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Actually, the two piece is more to do with longevity and preventing the DS from grenading on you (and yes, it helps with vibrations but don't put it past Toyota to know how to build a balanced drive shaft... They would have if not for other factors , I'm sure, they're MUCH cheaper). You can find a LOT of information on this already online including a lot of wonderful pictures of exploded one-piece DS'd sticking out rear seats or gas tanks or taking out cars behind the vehicle it was installed in. It's the whole reason DS loops/cages are required at tracks. It's all about elasticity, centrifugal force and the outward fatigue it causes. Aluminum is the most susceptible (also the worst for vibration), steel is less susceptible and CF the least (although I believe CF may have more vibration tendency than steel). I'll see if I can find a calculator for critical rotation speeds (this is just the speed at which the most stress is seen, it doesn't mean that if you drive at that speed one you're dead... I think on the 4.30:1 it was something low like 80MPH with a one-piece aluminum DS and stock size tires). Bah, I don't have time today to dig for all the fun pictures Google image search used to show, they've changed the sorting priorities of something. Anyway, from what I've seen with fatigue the metal shafts will spiderweb and tear in multiple places. From too much power it usually looks more like a torn paper towel roll or crumpled. Carbon fiber looks like an expensive broom when it goes (not a lot of damage potential other than the spline and forward U-joint). The Stock two piece has a critical rotation speed about three times that of a one piece. The two piece also serves to dampen shock through the drivetrain. You can get a lighter two piece made for little money and retrofit a more common carrier bearing OR have a one piece with a thicker center sleeve welded in essentially shortening the drive shaft into two and thus raising the ceiling a bit. Vibration will kill seals, bearings and U-joints but the DS isn't going to just pop like a cartoon gun with a finger in it. Of a final note a lot of drive shaft shops will tell you you need to check the DS every few thousand miles for signs of spider webbing or cracking (especially one this long)... do it; It's cheap insurance and really beats having the ass of the car try to pole vault on the highway. I've only known a couple people who've had trouble with their on-piece DSs on MKIIIs, those were aluminum. I've always run steal (on various cars) and never had a problem. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 10-08-2011 at 05:34 PM.

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10-06-2011, 10:57 PM	#3
El Supracabras 3" Exhaust Join Date: Feb 2010 Location: Chicago Posts: 240	The excessive vibrations are probably from a poorly executed conversion. If you plan on using a professional service to build a driveshaft I would think (hope) you wouldn't have any problems. In Ranmas case, it sounds like the kid she bought the car from didn't care about or more likely didn't know what he was doing. The 2 piece is pretty stout, but ripping the rubber out of the center bearing in the middle of a good race would suck. Race cars are supposed to rattle, right?