Carrier bearing or 1-piece driveshaft?

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soulrebelz

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May 4, 2011
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Just bought an '87 Supra Turbo on Saturday. By Sunday afternoon, it was clattering as I shifted through the gears. From everything I have read, I am guessing the carrier bearing needs to be replaced. Should I replace it or should I just replace the driveshaft with a 1-piece??? I know that there is tons of info on this already, but I am a newbie here and I need to post... :icon_bigg Thanks!
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
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GrimJack;1709527 said:
Before you do anything else, jack up the car, slide under there, and make sure the bolts from the driveshaft to the rear diff are on tight. And present, for that matter.

Agreed. I've experienced loose drive shaft bolts and it shudders and chatters just like you might expect the carrier to do.

A quick check and wrench may solve your problem.

Sent from my ADR6400L using Tapatalk
 

Enraged

A HG job took HOW long??
Mar 30, 2005
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search for the ford ranger center carrier bearing thread. you can find them for $40-75, so if you are on a budget, it is quite a bit cheaper than a one piece driveshaft.
 

tsupranami

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Mar 11, 2006
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#1 advantage is never having to replace that carrier bearing again.

Other advantages include: better tourque dampening during launch and shifts; lightweight benefits include less rotational mass, easier to balance and maintains balance better, less wear on bearings in tranny and rear end and u-joint.
 

Poodles

I play with fire
Jul 22, 2006
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tsupranami;1710159 said:
#1 advantage is never having to replace that carrier bearing again.

Other advantages include: better tourque dampening during launch and shifts; lightweight benefits include less rotational mass, easier to balance and maintains balance better, less wear on bearings in tranny and rear end and u-joint.

- Stock 2 piece is dampened, 1-piece is not. Dunno where you're getting that part...
- Not easier to balance as it's common to have issues with a 1-piece's balance.
- More wear on the bearings because it's not supported.

Also raises the risk of catastrophic failure on high speed runs. There's a lot of reasons Toyota went with a 2-piece...
 

tsupranami

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Mar 11, 2006
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AFAIK, #1 reason Toyota uses a 2 piece shaft is for comfort. Same reason the subframes are rubber mounted; not for increased performance, but for smoother passenger car operation (isolation from vibration).

Unless my engineering books are incorrect, less mass = easier to balance and maintain balance.

Simple engineering principles and basic physics can quantify the actual rotational inertia potential and vector load anaylsisi will show that as we haven't changed the distance the unit spans, the loads are still carried in the same general locations. However, the lighter unit exerts less force at any given angle of deflection. The center bearing disrupts the linear rotational load vector to provide better frequency dampening, and combined with the center bearing rubber isolator, provide superior vibration isolation. Note that the 2pc does not balance better, but is better dampened to reduce the transmission ot the ever present vibrations from reaching the passenger compartment (comfort).

Try getting a two piece balanced at a local shop. Many can't, and those that can charge much more for a 2 pc vs 1 pc.So, assuming someone has 1pc DS balance issues, at least they can affordably rectify it instead of forking over tons of money on new Toyota parts and/or an expensive 2pc balance job.

Stock DS =100+lbs. AL DS = <40 lbs. 100/3=33lbs static average supported by each bearing. 40/2=20lbs. static average supported by bearings. Get out the engineering handbooks on vector load analysis and see where the loads are carried, and you will see clearly that the bearings holding the heavy 2 piece DS have more loads to manage.

Granted, catastrophic failure of the 1 piece at high speeds is a serious concern.

However, a driveshaft hoop is a simple and effective solution for this problem. They are required by many race sanctioning organizations, regardless of whether you are using a 1 pc or 2 pc ds. The hoops for a 2 pc are also more expensive and complex because of the extra ujoint at the carrier.
 

Nick M

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Sep 9, 2005
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Koenigturbo;1709766 said:
What are the avantanges for a one piece besides weight?

No other advantage. Two pieces handle the speed better. If your unit is damaged, including the bearing, then you could have a vibration that will go away with the new u-joints and balanced shaft.
 

Poodles

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Jul 22, 2006
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100+ lbs for a 2 piece? :rofl: Apparently you've never removed yours. The support bearing is holding most of the load, hence it's name.

Catastrophic failure is the main reason the 2-piece was used. The bonded rear section and dampening around the center support bearing are for comfort. And it's easy to balance a 2 piece as they can balance both parts individually (how it was done from the factory).

You can argue all you want on this, but I'll take Toyota's millions of dollars worth of engineering of your opinion any day.
 

joel903

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Apr 6, 2005
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Poodles;1710302 said:
- Stock 2 piece is dampened, 1-piece is not. Dunno where you're getting that part...
- Not easier to balance as it's common to have issues with a 1-piece's balance.
- More wear on the bearings because it's not supported.

Also raises the risk of catastrophic failure on high speed runs. There's a lot of reasons Toyota went with a 2-piece...

This post is very true!
 

CyFi6

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1 piece is a good option because of price... You get a brand new shaft as well as new joints for a little over $300, whereas with stock you are almost at that price point just replacing the center support bearing, then you have to hope your rear bonded section has not shifted, that your u joints are good, and that the shaft is in balance. So depending on the previous condition of the stock shaft you could be paying well over the price of a 1 piece. As far as comfort is concerned, most of that goes out the window when you start modifying it, I can almost bet driving a lightly modified supra with a one piece is not going to have a sensible difference than one with a two piece, at least not a big enough difference for the majority of us to give a hoot.
 

tsupranami

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Mar 11, 2006
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Poodles;1710302 said:
- Stock 2 piece is dampened, 1-piece is not. Dunno where you're getting that part...
- Not easier to balance as it's common to have issues with a 1-piece's balance.
- More wear on the bearings because it's not supported.

Also raises the risk of catastrophic failure on high speed runs. There's a lot of reasons Toyota went with a 2-piece...


My bad...2 people on the internet say it's true, so therefore it is a fact....

Unfortunately I don't know it all like others here, so I can't quote weights and figures from the top of my head, nor can I give a general recommendation or subjective dissent without giving the basis of my opinion and the sources of my research...

So I do research and share it with others...And while I don't accurately recall the weights of the parts I replace, I do recal the general ratios, such as the 1pc AL is less than half the weight of the 2pc stocker...

My condolences to all here, including Poodles, who knows someone who has died or been severely injured as a result of a catastrophic 1pc driveshaft failure. My freinds and I have apparently been very very lucky according to the "truth" posted here....

Poodles;1710302 said:
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"Not easier to balance as it's common to have issues with a 1-piece's balance."

"Also raises the risk of catastrophic failure on high speed runs. " ...

Perhaps someone could direct me to the controlled study that supports these statement, otherwise, these types of statements are purely speculative and hyperbole. Maybe an article somewhere, some trade journal, something?

Because I don't see how balancing a lighter 1 piece shaft can be harder than balancing a heavier two-piece shaft? Can anyone explain? How is one "more" or "better" balanced than the other? Is this "common " balance problem related most to improper manufacturing, shipping damage, or improper installation?

I do research and can't kind the failures and balance problems you have identified on such a frequent basis...

The things I have researched show that the carrier bearing and its rubber support do an excellent job at transferring some of the load and vibration to the chassis, and the rubber effectively isolates the vibration when working properly. The increased mass of the steel 2pc also helps dampen vibrations transmitted longitudally to the transmission where it could be felt through the shift lever.

Conversely, a lightweight 1pc can transmit more energy directly from the engine/transmission to the rear differential, therefore, it can also transmit vibration from either of those sources more effectively as well. Many confuse this increased "buzzy-ness" felt through the shifter with a driveshaft balance issue.

As Poodles pointed out, the stock two piece is a model of reliability and smoothness, agreed, but at stock power levels.

That is why they are used in many passenger car applications. "The street driveshaft is constructed of robust thick tubing and is capable of handling occasional massive loads at low shaft speeds. But most of its life is spent with little stress just going to the grocery store. It's unlikely to ever need full replacement...."

"The driveshaft in (a) race car is also built to give dependable service in its normal application, but its design criteria are entirely different. The racing driveshaft is constructed of thin wall tubing and each component is carefully selected for light weight. This combination of features is better for smooth and efficient high-speed operation." http://www.circletrack.com/drivetraintech/ctrp_0902_formula_1_nascar_driveshafts/index.html

2pc Driveshafts are rarely used in high-speed applications, factory produced or race engineered. Expensive torque-tubes and rear-mounted transaxles, and more budget friendly 1 piece aluminum or carbon fiber are more commonly preferred or used on high hp street cars, race cars, and exotic sports cars.

Although Toyota is a fine company with brilliant engineers, the engineers at Aston Martin, Lotus, Ferrarri, Lamborghini, Bugatti and many, many others, know the benefits of a simple yet effective design. Bonneville Land Speed Record Holders, NHRA drag racers, Nascar stockers, Grand Am road racers, etc. ad nauseum, have used one piece driveshafts at much higher speeds than our cars are even capable of for more years than I've been alive (and I'm getting old...and grumpy...lol).

A well built, properly intalled 1 piece driveshaft with safety loop is far simpler and far more efficient at putting power to the ground as safely as any unhooped, dampened 2 piecer. At any speed. Head to a racetrack near you for living proof.

Granted, it might not be as smooth, or as reliable in the long run, especially if the loads have been increased beyond the design criteria (re: BHP+ upgrades). But none of the parts will last as long if they are subjected to loads above what the engineers designed (wider tires, HP+, big brakes, etc.).

So it depends on what you intend to do with your car, really. Drag race, autocross, stock street cruiser, dyno queen, etc...

Street car with close to stock power levels, stick with the 2pcs.

If it's gonna be a high hp or high speed car, then a high quality 1pc w/hoop would be more likely beneficial.

Need more twist for hard launches with slicks at the strip? AL and carbon arguably work best here.

Need more durability for impacts (rally, trucks, etc.) steel is usually recommended.

Need superior high speed stability? Carbon fiber driveshafts are designed for just such applicaions.

What it really boils down to is this, AFAIK: What do you intend to do with the car? That should answer which type of DS you should consider.
 

tsupranami

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Mar 11, 2006
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CyFi6;1711411 said:
1 piece is a good option because of price... You get a brand new shaft as well as new joints for a little over $300, whereas with stock you are almost at that price point just replacing the center support bearing, then you have to hope your rear bonded section has not shifted, that your u joints are good, and that the shaft is in balance. So depending on the previous condition of the stock shaft you could be paying well over the price of a 1 piece. As far as comfort is concerned, most of that goes out the window when you start modifying it, I can almost bet driving a lightly modified supra with a one piece is not going to have a sensible difference than one with a two piece, at least not a big enough difference for the majority of us to give a hoot.

Good points! I have a one piece in my 89 and a two piece in the wife's 89. I have driven many other freinds Supras (1 piecers and stockers) and the difference is, IMHO, imperceptible. You have to drive them back to back over the same roads at the same speeds (ours both have the same tires, wheels, swaybars, but different struts.) to tell the difference, and even that difference could be attributed to the different tranny's (hers is a brand new OEM Toyota unit, mine a rebuilt original), different struts (coilovers on mine, tems compatible Illuminas on Eibach SS on hers). or condition of the suspension and subframe bushings, etc.
 

Poodles

I play with fire
Jul 22, 2006
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Funny, most of the high end cars and race cars you mentioned use torque tubes, which is an entirely different animal... Heavy trucks run multi piece driveshafts, so your point about power has zero merit.

I wish I could find the thread on here where the guy had a catastophic failure at speed. He's very lucky he didn't wreck, and it tore a nice hole in the bottom of his car and severed all the lines under the car.
 
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