Driveshaft Yoke and a Tail of 3 Tail Housing Seals

[scootermcrad]

UHG! I hate to start another thread on driveshafts when there is so many out there for 4th gens. I feel like I've been reading them for hours without seeing what I'm looking for... so... I'll ask. If I'm just missing the answer, please feel free to post me a link.

2007,2WD SR5 V6. I have been experiencing all kinds of wonderful things with this vehicle, as it's approaching 190K. The latest battle with Toyota has been tail housing/drive shaft yoke seals. In 2014 they replaced the defective factory seal with a redesigned seal free of charge (never thought I would be offered something like that out of warranty! Huh. ) In 2016 the new one failed and I negotiated the replacement cost down. Well, guess what... that one has failed also. They REALLY don't want to replace this one without charging me a whole bunch of money and on top of that they said the drive shaft yoke is "porous" and tends to cause these failures so it will keep happening unless I replace the whole drive shaft. HUH? I debated with them for awhile and they stood their ground on that. Anyway, their solution is to sell me a nice new crappy original style drive shaft assembly and won't replace just the yoke (of course not), so that will cost me around $1000. Of COURSE I'm not going to spend that, but I just think the whole thing sounds ridiculous.

Has anyone else run into a yoke and seal issue like this??

That being said, I still have the original drive shaft (integral yoke up front, companion flange at rear end) and of course the lovely "clunk" that goes along with it, so maybe it's time to just replace that drive shaft and be done with all this B.S.

So is the Lexus drive shaft still the thing to get? Can anyone share a year, model, or even just a part number and source? Or is there an even better option now? I have no problem taking it to our local drive line shop to be balanced. Or can I really buy just the yoke? Yoke part number?

Any feedback on this whole thing would be appreciated.

Thanks everyone!
Scott

 

[gaber6]

Sounds insane. I thought the part that rides in the seal presses/bolts onto the driveshaft anyhow so no need for an entire new driveshaft. I've removed it once before when I replaced it.. I'm talking differential seal side, though.

 

[ZiaMan]

Easy - You’re in NC and the first place I would call is is east coast gear supply

https://eastcoastgearsupply.com/contact.html

 

[scootermcrad]

Easy - You’re in NC and the first place I would call is is east coast gear supply

https://eastcoastgearsupply.com/contact.html

Thanks man! I'll check into them. Local-ish is always good!

 

[scootermcrad]

Anyone else had or even heard of this issue?

Is the Lexus driveshaft what I'm after if I'm going to replace it?

Sounds insane. I thought the part that rides in the seal presses/bolts onto the driveshaft anyhow so no need for an entire new driveshaft. I've removed it once before when I replaced it.. I'm talking differential seal side, though.

Agreed! Very strange! Seems more like the stealership just doesn't know exactly what the problem is, so just leave it up to the customer to just buy a bunch of parts to cover their rears.

 

[scootermcrad]

Anyone else had or even heard of this issue?

So, looking at my driveshaft and looking at everything else I see on these threads, mine is different. It really does have a standard yoke up front and a companion flange mount on the rear differential end. Sooooo.... I guess the Lexus double companion flange style drive shaft isn't going to work. I also don't have zerk fittings at either end. Basically non-serviceable.

I still don't buy their excuse that it's the yoke causing the issue.

Sounds insane. I thought the part that rides in the seal presses/bolts onto the driveshaft anyhow so no need for an entire new driveshaft. I've removed it once before when I replaced it.. I'm talking differential seal side, though.

Agreed! Very strange!

 

[scootermcrad]

Pictures are worth a 1000 words, right?

 

[TechWrench]

Anyone else had or even heard of this issue?

So, looking at my driveshaft and looking at everything else I see on these threads, mine is different. It really does have a standard yoke up front and a companion flange mount on the rear differential end. Sooooo.... I guess the Lexus double companion flange style drive shaft isn't going to work. I also don't have zerk fittings at either end. Basically non-serviceable.

I still don't buy their excuse that it's the yoke causing the issue.



Agreed! Very strange!

The reason the Lexus shaft wont work is because you have a 2wd, not 4wd. The two driveshafts are very different. Your slip joint, if you can call it that is the front yoke that plugs into the rear transmission housing. While on the 4wd, the slip joint is integral to the driveshaft, and located near the rear differential.


And you mention the 'clunk', which surprises me, since I have not heard of anyone with a 2wd with that problem, only 4wd models.


As for the rear seal issue. There are really only a few things that will cause a seal to fail repeatedly. The seal could have been installed incorrectly, the bushing that centers the driveshaft yoke in the rear transmission housing is worn and allowing the yoke to wobble around and damage the seal, or the outer surface of the yoke has damage or is worn and causing the seal lip to wear, or the front u-joint is worn and causing the driveshaft to be out of balance and the vibration will cause the seal to fail.

You need a competent technician to figure out which is the culprit.

Good luck.

 

[scootermcrad]

The reason the Lexus shaft wont work is because you have a 2wd, not 4wd. The two driveshafts are very different. Your slip joint, if you can call it that is the front yoke that plugs into the rear transmission housing. While on the 4wd, the slip joint is integral to the driveshaft, and located near the rear differential.


And you mention the 'clunk', which surprises me, since I have not heard of anyone with a 2wd with that problem, only 4wd models.


As for the rear seal issue. There are really only a few things that will cause a seal to fail repeatedly. The seal could have been installed incorrectly, the bushing that centers the driveshaft yoke in the rear transmission housing is worn and allowing the yoke to wobble around and damage the seal, or the outer surface of the yoke has damage or is worn and causing the seal lip to wear, or the front u-joint is worn and causing the driveshaft to be out of balance and the vibration will cause the seal to fail.

You need a competent technician to figure out which is the culprit.

Good luck.

I knew the driveshafts were different between 2wd and 4wd. Just couldn't find any clarification on what the Lexus driveshaft was for, since I've never laid eyes on one. But that all makes sense.

I indeed have the clunk. Not all the time, but on occasion. It usually happens when I come to a quick stop. Immediately following the stop, I get the "bump", like someone tapped me. It's been happening for several years.

Nothing they said about the yoke causing the seal failure made any sense at all. My money has been bad installation...

...OR, we can have a really scary conversation about the concept that the "bump/clunk" is related to the transmission and causing the seal to fail.

 

[TechWrench]

I knew the driveshafts were different between 2wd and 4wd. Just couldn't find any clarification on what the Lexus driveshaft was for, since I've never laid eyes on one. But that all makes sense.

I indeed have the clunk. Not all the time, but on occasion. It usually happens when I come to a quick stop. Immediately following the stop, I get the "bump", like someone tapped me. It's been happening for several years.

Nothing they said about the yoke causing the seal failure made any sense at all. My money has been bad installation...

...OR, we can have a really scary conversation about the concept that the "bump/clunk" is related to the transmission and causing the seal to fail.

There are several theories about the 4wd clunk cause, but IMHO, it is a clearance issue in the driveshaft slip joint. Way back when I first started experiencing the 'clunk' on my 1st '03 V6, I tried most of the suggested remedies, and as others have noted, greasing the slip joint would 'fix' the clunk for a while but it would usually come back within a year or so. After several years of this, I finally removed the driveshaft and disassembled the slip joint for a look see. What I found was after cleaning all the old/new grease from the joint, the fit between the splines of the joint were very tight. I could barely get the splined joint of move in/out when dry. This lead me to conclude that the machining specs for the splines were a bit to tight. I only had this one driveshaft to inspect, so I can't speak to all of them, but given the widespread problem, I suspect most are like that. While I had the driveshaft on the bench, I decided to try an experiment. I made up a mixture of grease and valve lapping compound, and applied it to the splines and then worked the joint back and forth for about an hour (with beer breaks of course). When I separated the joint and thoroughly cleaned my compound from the splines, the joint fit together a bit easier, with less binding. I pumped the joint full of Mobile 1 Synthetic grease, and reinstalled the driveshaft. From that day forward, I never had the clunk again. I did grease the slip joint about once a year from then on, but I suspect the lapping compound polished the splines just enough to allow them to move a bit easier.

Now to your 2wd 'clunk'. If the cause is the same as the 4wd models, the slip joint splines between the yoke and the output shaft on the transmission may also be clearance a bit too tight and causing the joint to bind when braking hard. The other possibility is that the bushing in the rear extension housing of the transmission, that is supposed to center and support the driveshaft yoke is damaged or the clearance too tight and causing it to bind. The only way to tell for sure, is to have a technician, who knows what he is doing, remove the driveshaft and check for how the yoke fits into the extension housing. It should slip in and out of the housing easily, with no binding, and there should be very little lateral movement when it is inserted.

Without being there, that is about all I can suggest to look at.

 

[scootermcrad]

There are several theories about the 4wd clunk cause, but IMHO, it is a clearance issue in the driveshaft slip joint. Way back when I first started experiencing the 'clunk' on my 1st '03 V6, I tried most of the suggested remedies, and as others have noted, greasing the slip joint would 'fix' the clunk for a while but it would usually come back within a year or so. After several years of this, I finally removed the driveshaft and disassembled the slip joint for a look see. What I found was after cleaning all the old/new grease from the joint, the fit between the splines of the joint were very tight. I could barely get the splined joint of move in/out when dry. This lead me to conclude that the machining specs for the splines were a bit to tight. I only had this one driveshaft to inspect, so I can't speak to all of them, but given the widespread problem, I suspect most are like that. While I had the driveshaft on the bench, I decided to try an experiment. I made up a mixture of grease and valve lapping compound, and applied it to the splines and then worked the joint back and forth for about an hour (with beer breaks of course). When I separated the joint and thoroughly cleaned my compound from the splines, the joint fit together a bit easier, with less binding. I pumped the joint full of Mobile 1 Synthetic grease, and reinstalled the driveshaft. From that day forward, I never had the clunk again. I did grease the slip joint about once a year from then on, but I suspect the lapping compound polished the splines just enough to allow them to move a bit easier.

Now to your 2wd 'clunk'. If the cause is the same as the 4wd models, the slip joint splines between the yoke and the output shaft on the transmission may also be clearance a bit too tight and causing the joint to bind when braking hard. The other possibility is that the bushing in the rear extension housing of the transmission, that is supposed to center and support the driveshaft yoke is damaged or the clearance too tight and causing it to bind. The only way to tell for sure, is to have a technician, who knows what he is doing, remove the driveshaft and check for how the yoke fits into the extension housing. It should slip in and out of the housing easily, with no binding, and there should be very little lateral movement when it is inserted.

Without being there, that is about all I can suggest to look at.

Hey man! Thanks for putting all that time into that answer and that is REALLY interesting! I can totally see how that would help. Awesome that you took the time to do that (with beer breaks, as expected) and science it out.

I've reached out to Toyota and I'm getting it in to a technician first thing in the morning to see what we can figure out about this issue. When talking to the service manager he said they went through a phase with the 2wd Tacomas and drive shafts. He said it sounds like possibly a similar issue.

Anyway, I'll be working a little closer with them on this tomorrow and hope to learn something. I'll have them check for the DS yoke fitment on the trans output shaft. Maybe that is the source of my clunk. Doesn't happen often, but it still catches me off guard when it does. I'm nervous the seal is an output shaft bushing/bearing going bad. Fingers are crossed that it's just the seal being installed wrong. Guess we'll see where my cards fall.

Thanks for all the great input!

 

[scootermcrad]

Update...

After getting the service manager's undivided attention, we put it up on a lift this morning and took a closer look with a technician that at least seemed to know what he was doing. Turns out it's not actually the SEAL that's leaking. HA!

Turns out the leak (more like a weep) is coming from the butt end of the slip yoke. On the butt end of the yoke, inside the "U" portion, there is a pressed in plug, of sorts. Sort of like a freeze plug, for lack of a better description. Fluid is just getting pushed around the plug.

They told me they won't service the yoke or U-joint, only option with them is to replace the drive shaft or take the drive shaft to someone who can repair the plug.

So, that gives me some more realistic options. And far cheaper! I'll pull the drive shaft and clean up the slip yoke and see about just getting some high temp epoxy or sealer down around the wet side of the plug. The other option is to pop the plug out and see what diameter Dorman plugs I can find to replace it, but that might be a little more risky. I would also assume it's probably a metric plug. Maybe not, though.

So have any of you other 2WD folks out there had to address this??

 

[TechWrench]

Update...

After getting the service manager's undivided attention, we put it up on a lift this morning and took a closer look with a technician that at least seemed to know what he was doing. Turns out it's not actually the SEAL that's leaking. HA!

Turns out the leak (more like a weep) is coming from the butt end of the slip yoke. On the butt end of the yoke, inside the "U" portion, there is a pressed in plug, of sorts. Sort of like a freeze plug, for lack of a better description. Fluid is just getting pushed around the plug.

They told me they won't service the yoke or U-joint, only option with them is to replace the drive shaft or take the drive shaft to someone who can repair the plug.

So, that gives me some more realistic options. And far cheaper! I'll pull the drive shaft and clean up the slip yoke and see about just getting some high temp epoxy or sealer down around the wet side of the plug. The other option is to pop the plug out and see what diameter Dorman plugs I can find to replace it, but that might be a little more risky. I would also assume it's probably a metric plug. Maybe not, though.

So have any of you other 2WD folks out there had to address this??

I would suggest that you tread lightly with this. I am pretty sure that that plug in the rear of the yoke is designed to act as a relief 'valve'. When the yoke moves in and out on the transmission output shaft, the transmission fluid that fills the splined joint can act as an airtight seal between the two moving parts. When the yoke has to slide in or out on the output shaft, and if this vent does not work, it will cause the pressure buildup in the cavity between the end of the output shaft and the bottom of the yoke to force the output shaft to move with it. This could cause internal pressure from the output shaft to possibly damage other internal components of the transmission.

How much fluid is actually leaking from this plug? If it is only an occasional drop or so, I would consider letting it be. If it is a lot more, than maybe the plug is not fitting in the yoke properly, and needs to be replaced. I know you were told that they will not service the driveshaft, and if their only remedy is to replace the entire driveshaft, you will have to decide if the cost is worth it. Also, I would have the level of the transmission fluid checked carefully. If the level is too high, that could be the cause for excess fluid in the tail housing extension and that could aggravate the leak from this vent.

 

[scootermcrad]

I would suggest that you tread lightly with this. I am pretty sure that that plug in the rear of the yoke is designed to act as a relief 'valve'. When the yoke moves in and out on the transmission output shaft, the transmission fluid that fills the splined joint can act as an airtight seal between the two moving parts. When the yoke has to slide in or out on the output shaft, and if this vent does not work, it will cause the pressure buildup in the cavity between the end of the output shaft and the bottom of the yoke to force the output shaft to move with it. This could cause internal pressure from the output shaft to possibly damage other internal components of the transmission.

How much fluid is actually leaking from this plug? If it is only an occasional drop or so, I would consider letting it be. If it is a lot more, than maybe the plug is not fitting in the yoke properly, and needs to be replaced. I know you were told that they will not service the driveshaft, and if their only remedy is to replace the entire driveshaft, you will have to decide if the cost is worth it. Also, I would have the level of the transmission fluid checked carefully. If the level is too high, that could be the cause for excess fluid in the tail housing extension and that could aggravate the leak from this vent.

Aaaaa... This is a very good point. I believe it's non-vented, though. Appears to be solid and sealed. It doesn't appear to vent.

I'm honestly not sure how much it's leaking. Now that I know it's leaking, I'm going to pay closer attention.

There's an overflow drain tube, of sorts, so it can't be overfilled. The transmission is one of those lovely "sealed" transmission. Fluid is topped off at the side plug towards the back and filled until it drips out the overflow. I had a complete fluid change done while they had it up on the lift.

 

[AuSeeker]

Aaaaa... This is a very good point. I believe it's non-vented, though. Appears to be solid and sealed. It doesn't appear to vent.

I'm honestly not sure how much it's leaking. Now that I know it's leaking, I'm going to pay closer attention.

There's an overflow drain tube, of sorts, so it can't be overfilled. The transmission is one of those lovely "sealed" transmission. Fluid is topped off at the side plug towards the back and filled until it drips out the overflow. I had a complete fluid change done while they had it up on the lift.

Good to read it just a more or less simple fix.

But I beg to differ on your statement, these sealed transmissions can definitely be overfilled or underfilled if the proper procedure is not followed when checking the fluid level or if the fluid level is not check at all and they just assume how much fluid needs to be put in after a fluid exchanged is done.

I know this was done at a dealer so I feel the level was most likely done correctly, but I just don't want someone who may change their own fluid or have someone else do it that doesn't know how to check the level correctly to come across your post, read what you wrote and assume these trasmissions can't be overfilled or underfilled.

 

[TechWrench]

Aaaaa... This is a very good point. I believe it's non-vented, though. Appears to be solid and sealed. It doesn't appear to vent.

I'm honestly not sure how much it's leaking. Now that I know it's leaking, I'm going to pay closer attention.

There's an overflow drain tube, of sorts, so it can't be overfilled. The transmission is one of those lovely "sealed" transmission. Fluid is topped off at the side plug towards the back and filled until it drips out the overflow. I had a complete fluid change done while they had it up on the lift.

I am somewhat surprised that it isn't vented, but then I am not a Toyota engineer. But, I will have to take you up on your feeling that the trans "can't be overfilled" because it has an overflow drain tube. AuSeeker was right in that if the proper procedure is not followed, an over or under filled transmission can result. I don't know the specific temp off the top of my head, but the transmission has to be brought to the correct fluid temperature, to set the final fluid level properly. If this procedure was not followed, you may well have an over filled transmission and not know it. Just because a 'trained' Toyota technician did the fluid change, doesn't necessarily mean he knew, let alone followed the procedure properly.

 

[scootermcrad]

Good to read it just a more or less simple fix.

But I beg to differ on your statement, these sealed transmissions can definitely be overfilled or underfilled if the proper procedure is not followed when checking the fluid level or if the fluid level is not check at all and they just assume how much fluid needs to be put in after a fluid exchanged is done.

I know this was done at a dealer so I feel the level was most likely done correctly, but I just don't want someone who may change their own fluid or have someone else do it that doesn't know how to check the level correctly to come across your post, read what you wrote and assume these trasmissions can't be overfilled or underfilled.

Ah! Yes! Sorry. Didn't mean to be misleading. I'm not a Toyota service pro, by any means. I don't mess with transmissions anymore than I have to, and I have let the dealer handle basically everything with this vehicle (except for brakes and simple maintenance stuff), mostly for the sake of how many irons I have in the fire at one time.

I get involved as much as I can with my daily drive (the 4Runner in subject), simply to keep from getting ripped off and over-charged by a dealership or anyone else I might have do the work for me. I unfortunately just don't have the time to do as much as I would like with my vehicle, so I have to depend on others, sometimes. Which I HATE.

I do feel the transmission was serviced properly in this last visit.

 

[scootermcrad]

I am somewhat surprised that it isn't vented, but then I am not a Toyota engineer. But, I will have to take you up on your feeling that the trans "can't be overfilled" because it has an overflow drain tube. AuSeeker was right in that if the proper procedure is not followed, an over or under filled transmission can result. I don't know the specific temp off the top of my head, but the transmission has to be brought to the correct fluid temperature, to set the final fluid level properly. If this procedure was not followed, you may well have an over filled transmission and not know it. Just because a 'trained' Toyota technician did the fluid change, doesn't necessarily mean he knew, let alone followed the procedure properly.

I certainly won't argue with that. IN FACT, I tested him on that. I asked him about his procedure, since I wasn't familiar with how this transmission is serviced. He said all the right stuff. Now, hopefully he DID all the right stuff. I guess that remains to be seen.

This is why I hate not doing stuff myself and I hate owning vehicles I don't have time to work on myself. I feel like if I'm going to own a vehicle that's going to start needing repairs, I better know how to do them, have someone I know I can 100% trust to do the work correctly, or get rid of the vehicle. So far, I don't like my options.

To reiterate both of your points, I'm not implying I know how to service the transmission or that I've even serviced the transmission myself. So hopefully that didn't come across wrong. Just reporting back what I know about the situation.

OH! The yoke thing. On other transmissions I actually HAVE worked around, I have seen several that don't have vented caps. In fact, most of them didn't. So there must be provisions in the transmission design somewhere to allow for any pressure build up during the small amount of linear travel of the yoke while the suspension is traveling.