Toyota Sienna Forum - siennachat.com banner
1 - 14 of 14 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 · (Edited)
Hi all,



Our 2008 Toyota Sienna with 170K miles started leaving a small drip on parking strip. Soon after noticing the drip, noticed bad smells in the van when warming up or stopped in traffic, not moving, engine running.


Mechanic's diagnostic noted that fluid is leaking from the transfer case directly onto the exhaust pipe (see photo) under the passenger's front seat causing the bad smell to enter the car when running, but not moving. The mechanic asked if they could drain the fluid to see how much metal was in it. No metal chunks came out, but when stirred the fluid is “sparkly” (photo attached), which to the mechanic indicated a complete failure of the transfer box. They didn’t clean up seeping transfer case or try to determine where the leak was coming from. They said the leaks weren’t worth sealing because the transfer case had completely failed as evidenced by the “sparkles” in the fluid.


The mechanic said the new transfer case would cost about $3800 just for the part, plus about 16 hours of labor, because both the engine and transmission would first have to be removed to replace the transmission case. They said our van wasn't worth fixing, as the fix exceeded $6000.


My brother, an airplane mechanic did a little thinking outside the box. He hypothesized that 170K of AWD miles could’ve added fine metals to the fluid transfer case fluid and might not indicate a failure. And he said, because the transfer case is leaking, but not low on fluids, it might be worth trying to replace the axle seal on the transfer case if that appears to be the source of leakage, or fixing other leaks. But, the car mechanic said if the transfer case valve was the source of the leakage, then engine and transmission would still need to be removed in order to fix the leakage.

Does anyone have recommendations? If the fluid is slowly leaking, is it worth trying to reseal things? Do the fine metal flecks really indicate the transfer case has failed even though it doesn’t make sounds and only has a slow leak? Has anyone had luck figuring out where the leak is actually comes from? If yes, how did you figure it out? Has anyone had luck adding sealant products to the fluid?


I really want to fix our van! I just put brand new tires on it, replaced the alternator and the tie rods ☹
 

Attachments

·
Registered
Joined
·
1,269 Posts
Wow, that is REALLY "sparkly" fluid! Just to say that everyone is "correct" in their advice to you here. That much metal flake probably indicates total failure is imminent. Trying to fix the seal is probably not worth it for a mechanic. Replacing the seal may fix the leak. Fresh fluid plus fixing the leak may keep the van running another 20k miles. Using some kind of stop-leak product may fix the leak or, at least, slow it down and, if the choice is between that and scrapping the van, would be your best hope. So the real choice is, do you want to take the risk/expense of fixing the leak or go all-in and drop a low-mileage trans/transfer case into the van or just trade it in on a push/pull/tow deal. That really just depends on you and your objectives. You might be able to sell the tires online to someone, especially if you send the van to a junkyard, but I would expect to get far less than retail price for them. In general, you don't want to get stuck in the sunk cost fallacy, though, so I would just consider the value of the van currently, the cost of any repair, the value of the van after any repair and the cost of a replacement vehicle which meets your needs.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #3 ·
Wow, that is REALLY "sparkly" fluid! Just to say that everyone is "correct" in their advice to you here. That much metal flake probably indicates total failure is imminent. Trying to fix the seal is probably not worth it for a mechanic. Replacing the seal may fix the leak. Fresh fluid plus fixing the leak may keep the van running another 20k miles. Using some kind of stop-leak product may fix the leak or, at least, slow it down and, if the choice is between that and scrapping the van, would be your best hope. So the real choice is, do you want to take the risk/expense of fixing the leak or go all-in and drop a low-mileage trans/transfer case into the van or just trade it in on a push/pull/tow deal. That really just depends on you and your objectives. You might be able to sell the tires online to someone, especially if you send the van to a junkyard, but I would expect to get far less than retail price for them. In general, you don't want to get stuck in the sunk cost fallacy, though, so I would just consider the value of the van currently, the cost of any repair, the value of the van after any repair and the cost of a replacement vehicle which meets your needs.
So you don't think there is any possibility that 170K of AWD use could cause that much sparkly in and of itself? Or do the sparkles just flat out mean the gears are grinding down to non-functional status?
 

·
Registered
2009 le awd
Joined
·
439 Posts
So you don't think there is any possibility that 170K of AWD use could cause that much sparkly in and of itself? Or do the sparkles just flat out mean the gears are grinding down to non-functional status?
It would seem possable if it were low and or had never been changed to have some particles in it.
I will admit I just drain it into a black oil pan and might miss this.
Mine is leaking slightly too at 121,000, not on the exhaust yet. I just decided to keep a closer eye on the level. I have changed it twice so far. That and the rear diff are probably one of the most neglected items on a vehicle.

I would do everything within reason to try and save it. If it really is "fried" I would expect it to be making some audible noise.
This seems to be a common leak on the AWD versions, not sure from where though.
 

·
Registered
2014 Sienna LE
Joined
·
568 Posts
My brother, an airplane mechanic did a little thinking outside the box. He hypothesized that 170K of AWD miles could’ve added fine metals to the fluid transfer case fluid and might not indicate a failure. And he said, because the transfer case is leaking, but not low on fluids, it might be worth trying to replace the axle seal on the transfer case if that appears to be the source of leakage, or fixing other leaks. But, the car mechanic said if the transfer case valve was the source of the leakage, then engine and transmission would still need to be removed in order to fix the leakage.
So you don't think there is any possibility that 170K of AWD use could cause that much sparkly in and of itself? Or do the sparkles just flat out mean the gears are grinding down to non-functional status?
I don't think so. You don't get glitter oil from normal wear, even if the fluid has never been changed. There is serious metal wear to cause that. Not changing the fluid may have contributed to the failure, but something is massive wearing to cause that much metal.

My brother bought a tiller without a complete check, or that the owner had changed the oil immediately before the sale, and the oil was glittery each time. He got a few years out of it with frequent oil changes, but they all had glitter. Eventually it died. A small, well maintained small engine should run for decades. So yeah, it's on the way out.

@BillG has good advice.
 

·
Registered
Joined
·
329 Posts
Hello, it's a real drag to encounter problems like this with your vehicle! A leaking transfer case requires that the case be dropped to repair the leak. That much metal in the fluid indicates that a bearing has failed, and I would guess that the entire transfer case will have to be rebuilt to ensure confidence in the bearings and seals that have been running in fluid contaminated with metal particles. Having rebuilt a transfer case in good condition, I would say that it should be done by someone that has rebuilt many of them or it should be replaced. I did it incorrectly the first time, and had to remove it again to fix my mistake.

If you're able to find someone trustworthy to remove, rebuild (or find a replacement transfer case) for a satisfactory price, I'd go that route. That's a lot of ifs. Our '08 AWD has 180k, and I've changed the engine myself and then R&R'd the transfer case on a separate occasion (my therapist promises the nightmares will stop eventually).

If you're not able to find someone you trust to do the work at a reasonable price (less than $2,000 inc. transfer case), I would sell the van "as-is" listing it as being in good condition but needing a transfer case.

I believe the practical life of a Gen 2 (2007-2010) AWD Sienna is right around 180k. The 2004-2006 3MZ Gen 2s seem to last longer. The frequency of repairs and issues with our 185k van has been increasing, and were I not able to handle them myself would be by now prohibitively expensive. Add in the uncertainty involved in having someone else repair the vehicle (repairs done incorrectly or damaging other vehicle systems). The Gen 2 AWD Sienna is not easy to work on - the powertrain is packed densely and access is not good.

I believe your best bet on finding a transfer case is LKQOnline.com. I have used them for parts and been very happy. Salvage yards are notoriously dishonest, and I have found LKQonline to be reliable, honest, and providing good parts at very good prices.

Low mileage compatible transfer cases start at $800 (LKQ Online), and will often be delivered free to your closest LKQ yard.

I hope my experience is of some benefit to you and those that come after us.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #8 ·
It would seem possable if it were low and or had never been changed to have some particles in it.
I will admit I just drain it into a black oil pan and might miss this.
Mine is leaking slightly too at 121,000, not on the exhaust yet. I just decided to keep a closer eye on the level. I have changed it twice so far. That and the rear diff are probably one of the most neglected items on a vehicle.

I would do everything within reason to try and save it. If it really is "fried" I would expect it to be making some audible noise.
This seems to be a common leak on the AWD versions, not sure from where though.
I agree! We are going to replace the axel seal and hope it stops the leak onto the exhaust pipe. Even though it is still just a slow leak, once that leak hits the exhaust pipe, it creates a super nasty odor which is hard to live with and probably unhealthy. I'm hopeful now about replacing the axel seal, but in general I don't have good experiences with stopping leaks- so hard to truly find the source. I sure hope to keep it going and maybe buy a low mileage case from LKQ, like someone else suggested and find a creative mechanic willing to work by the hour.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #9 ·
Hello, it's a real drag to encounter problems like this with your vehicle! A leaking transfer case requires that the case be dropped to repair the leak. That much metal in the fluid indicates that a bearing has failed, and I would guess that the entire transfer case will have to be rebuilt to ensure confidence in the bearings and seals that have been running in fluid contaminated with metal particles. Having rebuilt a transfer case in good condition, I would say that it should be done by someone that has rebuilt many of them or it should be replaced. I did it incorrectly the first time, and had to remove it again to fix my mistake.

If you're able to find someone trustworthy to remove, rebuild (or find a replacement transfer case) for a satisfactory price, I'd go that route. That's a lot of ifs. Our '08 AWD has 180k, and I've changed the engine myself and then R&R'd the transfer case on a separate occasion (my therapist promises the nightmares will stop eventually).

If you're not able to find someone you trust to do the work at a reasonable price (less than $2,000 inc. transfer case), I would sell the van "as-is" listing it as being in good condition but needing a transfer case.

I believe the practical life of a Gen 2 (2007-2010) AWD Sienna is right around 180k. The 2004-2006 3MZ Gen 2s seem to last longer. The frequency of repairs and issues with our 185k van has been increasing, and were I not able to handle them myself would be by now prohibitively expensive. Add in the uncertainty involved in having someone else repair the vehicle (repairs done incorrectly or damaging other vehicle systems). The Gen 2 AWD Sienna is not easy to work on - the powertrain is packed densely and access is not good.

I believe your best bet on finding a transfer case is LKQOnline.com. I have used them for parts and been very happy. Salvage yards are notoriously dishonest, and I have found LKQonline to be reliable, honest, and providing good parts at very good prices.

Low mileage compatible transfer cases start at $800 (LKQ Online), and will often be delivered free to your closest LKQ yard.

I hope my experience is of some benefit to you and those that come after us.
Hi, I really appreciate your detailed and thoughtful input. Yes, such a drag! Especially because we bought ours used from a family member who had zero problems up to 130K. I bought it for 5K and have put 8K into it within just 3 years (I can't believe how many expensive things have broken!). Because I really like the vehicle and it is in good condition, I kept telling myself the repairs were worth it, until this shocking design flaw whopper! Enough to drive any sane person to therapy o_O

I'm tempted to get the part from LKQ and then do what my brother said- do the TSB on the unit (replacing a few seals on the inside) before having it installed. But...then comes the wild card you mention, finding someone to work on it. And....if the engine and transmission must be dropped, maybe I should replace the transmission at the same time. UGH?!?! As in, what if the lifespan really is only 180K and I'm dangerously close to that number. I want to fix this vehicle- I don't want to walk away from it, but maybe I'm just in denial.

In the short-term, if fixing the transfer case axel seal stops the toxic fumes and the leak remains slow, I plan to just see how many miles I can get out of the transfer case before it fails. So far, it has never run low on fluid and makes no sound. An unknowing driver would think there was nothing wrong with it because it still operates perfectly- ah, sweet denial.

Anyway, thanks for the input! Maureen
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #10 ·
I don't think so. You don't get glitter oil from normal wear, even if the fluid has never been changed. There is serious metal wear to cause that. Not changing the fluid may have contributed to the failure, but something is massive wearing to cause that much metal.

My brother bought a tiller without a complete check, or that the owner had changed the oil immediately before the sale, and the oil was glittery each time. He got a few years out of it with frequent oil changes, but they all had glitter. Eventually it died. A small, well maintained small engine should run for decades. So yeah, it's on the way out.

@BillG has good advice.
That makes sense. Wondering, should it have been part of routine maintenance to change out the transfer case fluid? If yes, seems like something the dealer would've initiated. Anyway, thanks for the insight!
 

·
Registered
2014 Sienna LE
Joined
·
568 Posts
That makes sense. Wondering, should it have been part of routine maintenance to change out the transfer case fluid? If yes, seems like something the dealer would've initiated. Anyway, thanks for the insight!
Hmm. According to the 2008 Maintenance Guide, for normal driving it doesn't say to replace the transfer case oil. However if towing it says to replace it every 15,000 miles. That seems to be somewhat similar to how it never says to change the transmission fluid, unless towing (then at 60k). Most here, myself included, think that never changing the transmission oil is a bad idea.

That said, it does mention to inspect the transfer case oil every 15,000 miles, but I'm unsure what this inspection entails, specifically.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #14 ·
Hmm. According to the 2008 Maintenance Guide, for normal driving it doesn't say to replace the transfer case oil. However if towing it says to replace it every 15,000 miles. That seems to be somewhat similar to how it never says to change the transmission fluid, unless towing (then at 60k). Most here, myself included, think that never changing the transmission oil is a bad idea.

That said, it does mention to inspect the transfer case oil every 15,000 miles, but I'm unsure what this inspection entails, specifically.
Hmmm...to my knowledge ours was never once used to tow. But our family of 4 has taken it on lots of trips fully loaded with bikes and gear etc. Good to have a link to the maintenance guide, thanks!
 
1 - 14 of 14 Posts
Top