All I know about automatic transmissions is I'm better off with used.

 

I don’t think I would try to rebuild an automatic. Just buy used like @circus mentioned above.

 

If your desire is to learn how to rebuild automatic transmissions this would be a perfect opportunity. Your only risking time, parts and relative low value of the vehicle. If successful you'll be our transmission guru. At least our U151E guru.

 

If you plan to rebuild a transmission to have a like-new transmission and/or learn, I would pick up a junkyard transmission, rebuild that, then install it in your van and see how she runs. If you fail, you have the second transmission to rebuild. If you succeed, you can rebuild your original transmission and sell it.

 

Are you absolutely positive it needs rebuilding? All the solenoids, sensors, valves and TCM's nowadays make diagnosis dicey at best. With my luck after rebuilding it perfectly, it does the same thing. Never knowing what happened.
Wonder how much a shop charges to use their test stand (dyno)?

 

Does Toyota sell remans? Is there a reputable third-party reman supplier? What does a reman cost compared to all the solenoids, bands, frictions, steels and whatever else goes into a rebuild? What’s the objective of a rebuild?

Sixto
04 LE FWD 240k miles

 

Does Toyota sell remans?

Toyota 30510-08010-84 REMAN Atm is for my 2006
The -84 suggests remanufactured.

There is a core charge of $1000

 

Eight years ago my brother gave me a Sienna with a bad transmission. I looked around but couldn't fine a trustworthy transmission for less than buying a different van, not to mention all the work swapping trany's. So that's what I did. Found a beat up Sienna with 60,000 fewer miles and fixed it up with part from the gift Sienna. Only thing I had to buy new was a windshield, both were cracked.

 

$3000 taxes in is reasonable if I can collect the reman and drop off the core at a local dealership; no shipping charges.

Did I hear right that they test solenoids? Why would they reuse a component with unknown cycle count?

@vans4adventure , check out the kits offered by Sonax to address specific transmission behaviors.

Sixto
04 LE FWD 240k miles

 

We used to rebuild them way back when. They were way easier to get out with the rear wheel drive vehicles. Rebuild kits were around ( maybe still are?) so parts were easy to get.
These were only 3 speed automatics, the newer ones are 6,8 even 10 speed now. The valve bodies were and probable still are real particular. You had to keep them very clean. Dirt in there could cause many problems.
It seemed to me you could get rebuilt certified one from a trans shop. That was the one thing i left to the pros. At least you swap them out just by dropping the pan.
After the transverse mounted engines came out (front wheel drive) this practice faded off or maybe it was because i haven't had a trans failure since. Probably will now since i mentioned it.

 

You're a lot braver than I am. I have rebuild an engine, a manual transmission, replaced bearings, and most other parts. I once took the pan off an automatic and put it on quickly. There's a lot to learn about automatic trannys. Let us know how it works out for you. I too would be looking at the sensors, etc. The tranny speed sensor is a definite place to check ...

 

Thanks for all the responses. I’m leaning towards just getting a new used Sienna as the whole process is not my idea of fun, although this guy makes it look easy:

 

I’m leaning towards just getting a new used Sienna as the whole process is not my idea of fun

Unfortunately, that "fun" is part of owning an older vehicle. The 2nd gen Sienna came out when I was in middle school, and the absolute newest 2nd gen is nearly 16 years old.

I always tell people that if they want to buy an older car, they better be good with a wrench, because even Toyotas and Hondas eventually break. It's so much cheaper to DIY things.

 

the whole process is not my idea of fun, although this guy makes it look easy:

Ha Ha Ha... you skipped part 2.

leaning towards just getting a new used Sienna

I figured the transmission isn't the only thing that wears out. Knowing how to do body work kept the cost to about four new tires. Which coincidentally I then had eight.