2006 Sienna AWD transmission r&r

Hello GRM family, How hard is it to remove and replace the transmission above. I have hand tools and a couple of hydraulic jacks and some Jack stands as well as about 3 days to spend on it. I have replaced a transmission in an 85 camry as well as a few other car maintenance projects. Is it something simple. The AWD is what is the unknown. Any insight will be appreciated.

Also I read that this uses the same transmission as the 04-07 Highlander. The Highlander transmission for some reason is cheaper. Are they the exact same or are there some minor differences? Trying to get it done for $1k or less. Thanks in advance guys.

I've done Lexus RX's. Very similar.

Getting it out will be the hard part. I'm pretty confident engine/trans/subframe assembly drops out the bottom. No room to get it out the top. Getting the body of the car out of the way enough to roll (makeshift dolly) the assembly out from under it will require some creativity.

Aside from that, the front diff/trasnfer unit is simply bolted to the side of the transmission. Its easiest to remove the engine, set it off to the side, then lift the trans off. the transfer unit sits in a recess section of the engine block and tight tolerances make it way harder to get the trans off the engine rather than the engine off the trans. If my memory is correct, I think there is a small O-ring sandwiched in between the cases, as well as a little bit of sealant. Don't forget them or you'll have to do it all again due to a significant trans leak. I would also reccomend replacing both the outer and inner axle seals on the transfer unit while you have it apart. You'll have to remove the bolted on flange to access the axle seal. replace the large O-ring on the flange as well.

Thank you. This is helpful. If I decide to go ahead with it I know I have you all here for support and pointers.

Second question: I read that the sienna uses the same transmission as the 04-07 Highlander. The Highlander transmission for some reason is cheaper. Are they the exact same or are there some minor differences? Thank you.

Though these models sharing transmissions makes sense to me, I cannot verify with certainty.

I am in the same boat. I have a 2006 Sienna that needs a trans. I am researching Highlander transmissions as well, there are a lot more of those out there. If you come across anything, or install a Highlander trans, please post your results. TIA!

racinjason wrote: I am in the same boat. I have a 2006 Sienna that needs a trans. I am researching Highlander transmissions as well, there are a lot more of those out there. If you come across anything, or install a Highlander trans, please post your results. TIA!

If I am brave enough to do that I will keep you posted.

Found out that transmission has P0796 code. Shift solenoid needs fixing.

My plan now is to drop the pan and replace the solenoid-- If I can find one. Replace the fluid add lucas and see if it fixes it. If not then weigh my options; replacement or part out.

Anyone know where to buy Shift solenoid valve sl3 (pressure control solenoid "c"? Already called the dealer the parts guy seemed almost as overwhelmed as me.

I don't know if the awd is different from the 2wd, but my trans has no "pan". 2004 Sienna

Fueled by Caffeine wrote: I don't know if the awd is different from the 2wd, but my trans has no "pan". 2004 Sienna

Good to know. I just need to get "in there". I am trusting you all will be my support group.

Figured it is about time to update this thread.

I chickened out. Did not want the project to go on for months plus the cost of an engine hoist and miscellaneous tools I would most certainly need. I Found a used transmission for 350 and a shade tree mechanic willing to do it $40/hr. It was a risk, but so far so good. We have put on about 5k miles so far including a few road trips. It did what we wanted it to do; make as figure out if we want a van. We do. We will now be saving up for a better one.

I also had to replace the power steering pump, transfer case output seal and rear differential.

Now that I have done all that, I am confident i can replace the transmission on a non-rusty one. So if you have the time and patience, go for it.