Replaced the trannies. Going forward in reverse now..

[zz_denis]

Hi guys.

I recently bought another 4runner for my wife with a blown auto tranny. It milkshaked a year ago, the guy flushed it, and it died a year later (really bad slippage in first, not shifting properly, etc). I had a spare good tranny from a parts truck, so I swapped it in.

The truck is 1999 Limited, and the tranny came out of 1996 Limited.
I kept the original x-case (obviously).

I fired her up, everything seemed fine - no noises/leaks etc...

The problem is that the truck is going forward in both forward and reverse gears. When I put it in the reverse, the light on the dash indicates "R".
It also seems to slip when going forward (requiring 20-30% throttle to start going forward. The tranny worked perfect on the truck that it came out of.
Another weird thing is that the 4x4 light is flashing (in any gear/transfer case position). 4wd was working perfect before swapping the trannies..

It sounds like some sort of electrical issue to me.. Is it possible that I damaged one of the sensors during installation? Forgot to plug something in?
Any ideas what could be causing this?
Thanks!

 

[T4R2014]

I am pretty sure that a 1999 transmission has a different valve body from a 1996 unit. You need to get a 1999 replacement.

 

[zz_denis]

Thanks for the reply.

This is a bummer. I spend my whole weekend pulling/installing transmissions and turns out it was probably all for nothing...

I didn't open up both transmissions to look inside, because I assumed that if they are identical outside, and both are A340F, they would be the same.

Well, after your response I found this thread:
http://www.toyota-4runner.org/3rd-gen-t4rs/148888-2000-02-a340f-vs-pre-00-a.html , which clearly shows the differences. Why would Toyota do this?! Why not give transmissions a different model number if they are significantly different?!

Are there any workarounds in my situation that would allow me to use this transmission? Would I be able to use the TCU from 1996 on this truck (1999)? Probably not due to transfer case differences..
Would I be able to swap valve bodies somehow? (probably not, because they look way different in the thread above)
Finally, would I be able to modify the TCU somehow to work with this tranny?

Any help much appreciated!

EDIT: After some more research, I found out that there is no "TCU" on these trucks (unlike 2nd gens) and the tranny is controlled by ECU. ECU's between 1996 and 1999 are completely different, so swapping them is not an option.

After hours of searching online, I couldn't find any info about using 96-98 tranny in 99-00 trucks. If anybody could point me in the right direction, i'd really appreciate it. The transmissions cant be THAT different... There must be something that can be done to make it work...