I have a LS400 transmission on a SC400 motor, swapped into an 86 Toyota 4Runner. Yes, it’s complicated but it works. It runs just like an SC400.

My problem, I blew up the original SC400 tranny due to leaking fluid on an 8 hour drive. Anyhow, I swap in a LS400 transmission. Now the LS400 transmission will not shift from 2nd to 3rd. After a long drive, maybe 15 minutes, when I turn the ignition OFF and then ON, it will then shift correctly. I think it’s in this “safe mode”.. NO trouble codes were founds during diagnostic test. I am assuming it may be related to shift solenoids. FSM is telling me to take out shift solenoid to test. Is there any other test I can perform to confirm before tearing it down? Thank you in advance.

 

it probably is related to the shift solenoids, I would take them off the good shifting ones from the sc trans and then put them on the ls transmission. a worth mention since you did not specify years is that some ls400 transmissions had a separate transmission ecu from the main ecu (I am not sure why I researched this but I did at one point), so I am not sure how compatible that version of trans is with the sc ecu. if the trans part numbers and plugs were the same it should likely work then its probably just the solenoids. you have pics?

according to the solenoid diagram found here for es300 (couldn;t find for sc400 that fast), I would guess your solenoid 1 is stuck "on", not letting transmission shift to 3rd or o/d, but really with these things its hard to say I would swap over the known working ones if you still have them from the sc400.
https://www.clublexus.com/forums/es3...ontroller.html

 

Thanks for the reply! Yes i still have the SC400 tranny, and its all taken apart. i've been actually disecting it for the past 2 days. I also found my lost shift solenoid kit i apparently bought a while back for the sc400. so i'll just put those in. its started to make sense, i saw that ON and OFF grid for the shift valve but didnt understand how to read it, i assumed but didnt know for sure if solenoid # 1 was at fualt. btw, tranny plugs fits right in, i beleive it was a 94 ls400 tranny into my 92 sc400.

 

yeah that should really do it. whenever you hear someone lost 2 of the 4 gears its usually 1 of the 2 solenoids.
believe it or not you lost the better one, if you lost the other one, you would be stuck starting off in 3rd and then 4th, which sort of makes it not want to move very much at all. at least you can use 1-2 now.

I would say you should just do both when you are in there, if that trans was in the condition to have 1 go bad, likely the other one isn't far behind.

really fun sounding swap though but why not bolt up a r150f and be done with it =)
I almost did this with a 2jz in a 85 solid axle pickup, but got tired of collecting and being surrounded by rusty objects and moved on.
maybe some day in like a 98-2000 4runner I always had a soft spot for those.

 

cool , thanks for confirming! 2jzgte was my goal for a swap, but california smog law sucks here! i wanted a r150 too, but it was easier with this method. cost, time, accessibility played a major role..and again califorina laws really sucks, lol. the trans is mated onto dual transfer case and on SAS w/ 35s..

 

^ that is nice and clean! very sharp!

 

wow I think I just had a 1uz toyota gazm. Looks sharp glad its a 4x4 must be a beast with the dual cases. 1uz should turn those 35's much better than before. good luck hope it works out report back and let us know!

 

1uz move this thing just right, with a lot of gear and another spare tire in the back, this things just goes and it doesnt lagg like the old 22re motor. so its really fun with the 1uz. thanks again and will def report back.

 

**REPORTING BACK**Pulled the old solenoids out and test them like the FSM recommended. They both turn out good. I end up using the Rostra kit anyway since I bought it a while back. I drove it for 15 mins and its seems to have fix the problem. Will do more stopping and going testing in the city soon.