2005 Sienna leaking ATF from case

[Siennadriver2005]

I have a 2005 Sienna LE FWD with 160,000 miles. About 2 months ago or 3,000 miles, I noticed a few drops of ATF on my driveway. I cleaned everything up from underneath the van and figured out that the leak was coming from the portion of the transmission where the two halves are bolted together. I put the van in a transmission shop and they took out the two bolts and cleaned everything up. They then applied a sealant to both the inside and outside of the transmission halves and installed the two bolts and tightened everything up. After picking the van up and driving it for 40 miles, I noticed the leak had started again. It only leaks about 2-3 drops every 24-36 hours. Any suggestions on what I could do to seal this part of the trans?



The first photo is when the van came back from the shop and the next photo is after driving the van and letting it sit overnight. Also any ideas on why this leak would start after 157,000 miles? The ATF is changed annually and the fluid is sent out to Blackstone for analysis. All reports on the ATF have come back extremely positive, so the fluid is in great shape. The ATF is Amsoil.

 

[DoubleWasp]

A larger picture would give better perspective, but if the leak is actually coming from the pump seal or shafts seal, then nothing short of a rebuild will fix it.

Why is it leaking? Seals harden with age. Then they don't seal anymore.

I might be tempted to throw in some ATP205 to stop the leak, but I'm very hesitant to put sealers into what is pretty much a good transmission with a nuisance leak.

 

[slacktide_bitog]

The ATP 205 is a good idea and seems like the best solution for now.

 

[Trav]

Do not use a sealer of any sort on that if it is an anaerobic seal, ATP-205 is for rubber seals and is solvent based, by all accounts effective but that joint just from looking at the lack of gasket between the halves is probably an anaerobic sealer, don't use anything on that it could dissolve the seal all over the place than you will have more than a few drops. Check with the dealer parts dept and see if there is a gasket or if it is an anaerobic.
You will never get that dry enough to use a sealer internally or externally, it needs to be taken apart, cleaned and prepped and new sealer used.
Either live with it and keep it full or have it redone if no gasket is used.

 

[Siennadriver2005]

Yeah I don't have the ability to remove the trans and two transmission shops that I talked to, both refused to remove the transmission and split the case. They told me that those Toyota transmissions are not meant to be rebuilt and I would be better off with a remanufactored one instead of rebuilding my current trans. So I guess I will have to live with the drips and just monitor it daily.

 

[Trav]

Check with Toyota parts and find out if there is a gasket used before deciding to live with it. If it uses case gaskets then try the AT-205, being a solvent based sealer it has a very short lifespan in the fluid so it wont continue swelling seals and gaskets Ad infinitum.

 

[Siennadriver2005]

Ok I will check with Toyota tomorrow and see what type of gasket material if any is used on that part of the trans. Thanks for the responses

 

[Ursatdx]

Looking at the pics I doubt taking 2 bolts out would allow anyone to apply
any kind of sealant to the "inside of the trans halves".

Looks like someone tried to simply smear some type of sealer on the outside of the trans.

The drain plug on the pan is not OEM (not that it matters).

 

[Siennadriver2005]

I replaced the drain plug this past Spring. The trans shop that did the work informed me that they put some sealant on both the inside and outside of the trans halves but I agree, I don't know how much sealant you could possibly get on the inside of that trans by removing only two bolts. Plus that portion of the trans would have to be bone dry and cleaned out to allow the proper sealant to work.

 

[clinebarger]

Rebuilding & Resealing are 2 different things, All Aisin/Toyota Transmissions can be rebuilt.

The Sealant (Three Bond 1281/1281B Silicone Based) that Aisin uses to seal the Case Halves is VERY good, I have my doubts it's coming from between the Halves, ATF can easily track from other locations & settle/pool in that area.

 

[mehullica]

The red FIPG (form in place gasket) is prone to leak on that transmission & on the Lexus RX330/ES330. I've sealed many of them. There's no other way to stop the leak. The very bottom of that case has about 5mm of sealing surface & it had not enough sealant from the factory in most cases. You have to remove the trans, split the case, & reseal it. Out where I worked it was 12-14 hours labor & about $150 in FIPG, pump seals, fluid. You don't need a rebuild. I worked a 2 different Toyota dealers & we resealed them all the time

 

[andyd]

Paper train it with box cardboard or a baking pan. Total wild guess, 2 actually. That ATF looks fresh. Did you over fill and it is blowing the excess out of the vent? OR, the seal around what ever selector there is, is worn out. The main deal is to keep ahead of the consumption. Do that and it you can manage fine.

 

[Siennadriver2005]

The ATF is replaced every year (between 8-10 qts of Amsoil ATF) and the level is checked frequently and it is not overfilled. The van has had no other issues except replacing the power steering rack about 20K miles ago. The van also has a Magnafine inline filter on the return trans line from the radiator and that is changed every year also.

 

[Rolla07]

Changing ATF yearly? How much do you drive? Not necessary...

Id bring your car to dealer to see what they say. Dealer will be much more aware of how to fix. Worst case just get a quote first.

 

[Siennadriver2005]

The minivan is my wife's mode of transportation and she is driving around 5 kids so we are very careful with this car. I would rather err on the side of caution and changing out the ATF is very simple in this van.