Installing used driveshafts

[alphaeighteen]

Hi All,

I have some used driveshafts. My current driveshafts probably have bad ujoints causing some vibrations when putting throttle on the freeway and also pinging when switching from reverse to drive.

How do I make sure that these are installed correctly? I've seen and read about in phase and out of phase but not sure I understand these fully.

Thanks

 

[ZackR]

Hi All,

I have some used driveshafts. My current driveshafts probably have bad ujoints causing some vibrations when putting throttle on the freeway and also pinging when switching from reverse to drive.

How do I make sure that these are installed correctly? I've seen and read about in phase and out of phase but not sure I understand these fully.

Thanks

Have you greased your existing U joints?

 

[alphaeighteen]

Have you greased your existing U joints?

Yes, didn't do anything.

 

[greentruck]

Phasing refers to the position of the yokes with respect to each other once the drivehsaft is installed. They are idyllically either matched up if in phase or 180 degrees (or maybe it's 90 degrees?) out of phase if not.

 

[alphaeighteen]

Phasing refers to the position of the yokes with respect to each other once the drivehsaft is installed. They are idyllically either matched up if in phase or 180 degrees (or maybe it's 90 degrees?) out of phase if not.

Does that mean that someone would have removed the yoke from the drive shaft during installation? I haven't removed the yoke so it should still be in The same position as installed

 

[Box Rocket]

Here ya go.

 

[ProjectsNMotion]

This post has the image you want

80 Series Rear Drive Shaft Phase

Cheers

 

[greentruck]

Does that mean that someone would have removed the yoke from the drive shaft during installation? I haven't removed the yoke so it should still be in The same position as installed

The DS is a slip shaft, two pieces that slide together. It's possible for it to be reassembled incorrectly per the helpful illustration from Adam.

 

[alphaeighteen]

The DS is a slip shaft, two pieces that slide together. It's possible for it to be reassembled incorrectly per the helpful illustration from Adam.

Great. I did not think that the orientation matters when mounting it to the flanges if the DS is assembled properly? I have seen videos where people mark the orientation of the shaft relative to the flanges with markers

 

[greentruck]

Great. I did not think that the orientation matters when mounting it to the flanges if the DS is assembled properly? I have seen videos where people mark the orientation of the shaft relative to the flanges with markers

Yes, once you get it right and no bad vibes, you want to mark it so all you need to do is match things up to be right again.

 

[alphaeighteen]

Yes, once you get it right and no bad vibes, you want to mark it so all you need to do is match things up to be right again.

Thanks for this, so I may need to rotate the DS on the flanges to get it correct? I believe the current used drive shafts are already balanced since it was on a wrecked daily driver which was not lifted or wheeled.

 

[greentruck]

Yeah, don't take them apart, check that they're in phase and run them and you should be good, assuming nothing got bent on the way to the junkyard. But also don't be afraid to revisit balance if the U-joints seem good and you're getting vibes. Balance is usually achieved by welding small tabs of metal on the shaft and sometimes these loosen and fall off, for instance. Another possibility is a yoke that has been twisted or otherwise is no longer straight, as this won't allow even a good u-joint to turn properly. A heavy truck garage will have contacts for driveline repairs if new parts are too dear or used are unavailable.

 

[BILT4ME]

Yeah, don't take them apart, check that they're in phase and run them and you should be good, assuming nothing got bent on the way to the junkyard. But also don't be afraid to revisit balance if the U-joints seem good and you're getting vibes. Balance is usually achieved by welding small tabs of metal on the shaft and sometimes these loosen and fall off, for instance. Another possibility is a yoke that has been twisted or otherwise is no longer straight, as this won't allow even a good u-joint to turn properly. A heavy truck garage will have contacts for driveline repairs if new parts are too dear or used are unavailable.

Also, there was a service bulletin put out by Toyota that changed the front shaft from being in-phase to being 90' out of phase.

The slip yoke goes to the FRONT of the vehicle on both DS.

And you do NOT need to mark the diff flange or tcase flange in relation to the DS. They don't care. Only what is part of the DS.

 

[alphaeighteen]

Also, there was a service bulletin put out by Toyota that changed the front shaft from being in-phase to being 90' out of phase.

The slip yoke goes to the FRONT of the vehicle on both DS.

And you do NOT need to mark the diff flange or tcase flange in relation to the DS. They don't care. Only what is part of the DS.

I have a 92. The front ds is currently out of phase. Should I move the slip yoke so that they are both in phase?

 

[BILT4ME]

I have a 92. The front ds is currently out of phase. Should I move the slip yoke so that they are both in phase?

Only if you are having vibration issues. Then move only the front DS to in phase.

 

[-Spike-]

Scary info in this thread.

The graphic above that claims one orientation is 'incorrect' is, well, incorrect. Either in or out of phase can be correct. Phasing depends on what configuration the driveshaft is used in. The front driveshaft on the 80 series was intended to be out of phase, because at stock height it's in what's called 'broken back' configuration, meaning the u-joints are at equal angles instead of opposing angles like most driveshafts are. Lifting the truck screws up the angles, but the truck would have to be lifted something like 10-12 inches (warning: wild-ass guess) before the driveshaft angles were 'correct' for an in-phase orientation. People have run them in-phase with no apparent issues, especially after adding a suspension lift, but in order to be 'correct' you need to lift the truck 4-6 inches and add a double-cardan (cardon? No one seems to know the correct spelling wikipedia says 'cardan', good enough for me) joint. If you have a lift and no DC (also referred to as a CV, or constant velocity) joint, you can pretty much do whatever you want with phasing- it's wrong either way. Driveshafts with two u-joints are intended to be run at equal or equally opposing angles, and you can't do either on the 80 at anything other than stock height (unless you want to get crazy). I've never heard of the Toyota TSB referred to by @BILT4ME but that doesn't mean much, I don't keep up on those things. And when I do I forget them quickly. The angles are fairly small, so it probably works either way. If you do some research you'll find that there doesn't even seem to be a consensus on phasing in the real world, but the geometry and math dictated that Toyota put the front shaft out of phase.

Also, and arguably more importantly, driveshafts are spinning assemblies, and are balanced. As assemblies. You can't just pull the slip yoke apart and reposition it and expect it to be balanced- it won't be. If you change the orientation of any part of a driveshaft, or have any doubt about whether or not it has been changed, you should have it balanced at a driveline shop. It's not very expensive.

 

[greentruck]

Scary info in this thread.

The graphic above that claims one orientation is 'incorrect' is, well, incorrect. Either in or out of phase can be correct. SNIP

Also, and arguably more importantly, driveshafts are spinning assemblies, and are balanced. As assemblies. You can't just pull the slip yoke apart and reposition it and expect it to be balanced- it won't be. If you change the orientation of any part of a driveshaft, or have any doubt about whether or not it has been changed, you should have it balanced at a driveline shop. It's not very expensive.

Yeah, it's true it can be either way. There is some difference of opinion on which way the factory did things during certain years that I didn't want to get into myself, since I don't know the definitive answer to that. If you're at Square One, best to leave things as you find them until you're certain there's a reason to change them IMO and that will usually become clear with patience and some due diligence to be sure everyone is on the same page in describing things which can take some work, too. It's hard to tell what a truck has been through by just looking at things. People do strange or incompetent things with trucks, but if it's running OK, you should generally let sleeping dogs lie until you're sure what you're doing will solve your problem.

 

[Box Rocket]

Scary info in this thread.

The graphic above that claims one orientation is 'incorrect' is, well, incorrect. Either in or out of phase can be correct. Phasing depends on what configuration the driveshaft is used in. The front driveshaft on the 80 series was intended to be out of phase, because at stock height it's in what's called 'broken back' configuration, meaning the u-joints are at equal angles instead of opposing angles like most driveshafts are. Lifting the truck screws up the angles, but the truck would have to be lifted something like 10-12 inches (warning: wild-ass guess) before the driveshaft angles were 'correct' for an in-phase orientation. People have run them in-phase with no apparent issues, especially after adding a suspension lift, but in order to be 'correct' you need to lift the truck 4-6 inches and add a double-cardan (cardon? No one seems to know the correct spelling wikipedia says 'cardan', good enough for me) joint. If you have a lift and no DC (also referred to as a CV, or constant velocity) joint, you can pretty much do whatever you want with phasing- it's wrong either way. Driveshafts with two u-joints are intended to be run at equal or equally opposing angles, and you can't do either on the 80 at anything other than stock height (unless you want to get crazy). I've never heard of the Toyota TSB referred to by @BILT4ME but that doesn't mean much, I don't keep up on those things. And when I do I forget them quickly. The angles are fairly small, so it probably works either way. If you do some research you'll find that there doesn't even seem to be a consensus on phasing in the real world, but the geometry and math dictated that Toyota put the front shaft out of phase.

Also, and arguably more importantly, driveshafts are spinning assemblies, and are balanced. As assemblies. You can't just pull the slip yoke apart and reposition it and expect it to be balanced- it won't be. If you change the orientation of any part of a driveshaft, or have any doubt about whether or not it has been changed, you should have it balanced at a driveline shop. It's not very expensive.

While this might be technically true, I think it muddies the waters a bit. An 80 at stock height that has a front drive shaft out of phase *could* have issues once the truck is lifted. Generally speaking, running the driveshaft *in-phase* will rarely cause any issues since the joints are not fighting against each other in their rotation. So, I believe the safest route, particularly on lifted trucks, would be to run the driveshaft *in-phase* regardless. And calling it "scary info" to say running drive shafts in phase is a bit extreme.

 

[-Spike-]

While this might be technically true, I think it muddies the waters a bit. An 80 at stock height that has a front drive shaft out of phase *could* have issues once the truck is lifted. Generally speaking, running the driveshaft *in-phase* will rarely cause any issues since the joints are not fighting against each other in their rotation. So, I believe the safest route, particularly on lifted trucks, would be to run the driveshaft *in-phase* regardless. And calling it "scary info" to say running drive shafts in phase is a bit extreme.

I think a graphic categorically saying that running any driveshaft out of phase is wrong is muddying the waters. Well, it's actually more than that, but whatever.

The scary part is the amount of misinformation happening, not any particular bit of it.

 

[BILT4ME]

Scary info in this thread.

The graphic above that claims one orientation is 'incorrect' is, well, incorrect. Either in or out of phase can be correct. Phasing depends on what configuration the driveshaft is used in. The front driveshaft on the 80 series was intended to be out of phase, because at stock height it's in what's called 'broken back' configuration, meaning the u-joints are at equal angles instead of opposing angles like most driveshafts are. Lifting the truck screws up the angles, but the truck would have to be lifted something like 10-12 inches (warning: wild-ass guess) before the driveshaft angles were 'correct' for an in-phase orientation. People have run them in-phase with no apparent issues, especially after adding a suspension lift, but in order to be 'correct' you need to lift the truck 4-6 inches and add a double-cardan (cardon? No one seems to know the correct spelling wikipedia says 'cardan', good enough for me) joint. If you have a lift and no DC (also referred to as a CV, or constant velocity) joint, you can pretty much do whatever you want with phasing- it's wrong either way. Driveshafts with two u-joints are intended to be run at equal or equally opposing angles, and you can't do either on the 80 at anything other than stock height (unless you want to get crazy). I've never heard of the Toyota TSB referred to by @BILT4ME but that doesn't mean much, I don't keep up on those things. And when I do I forget them quickly. The angles are fairly small, so it probably works either way. If you do some research you'll find that there doesn't even seem to be a consensus on phasing in the real world, but the geometry and math dictated that Toyota put the front shaft out of phase.

Also, and arguably more importantly, driveshafts are spinning assemblies, and are balanced. As assemblies. You can't just pull the slip yoke apart and reposition it and expect it to be balanced- it won't be. If you change the orientation of any part of a driveshaft, or have any doubt about whether or not it has been changed, you should have it balanced at a driveline shop. It's not very expensive.

See the attached thread with @cruiserdan as well as Onur information confirming what things started and how they changed.

I do not take responsibility, but I know who knows their stuff on these trucks.

In phase or out of phase?

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