Transfer Case Tuneup and Fix (7 Viewers)

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I’m convinced this is a self test that is failing, and need to go read up on the self test conditions. I also suspect the test can fail silently and only start to flash if you try to use the differential.
Agreed. I’m not even sure it’s a test so much as a circuit failing to complete. It happens instantly in start
 
So.. after doing this fix about 8 months ago I did not weekly go into 4lo and lock the center diff. Guess what? As soon as I wanted it on the trail I got the 4lo blinking light lol. Luckily I made it through everything easily in high. Going to try the fix again but man this is annoying
 
So.. after doing this fix about 8 months ago I did not weekly go into 4lo and lock the center diff. Guess what? As soon as I wanted it on the trail I got the 4lo blinking light lol. Luckily I made it through everything easily in high. Going to try the fix again but man this is annoying
Just do some periodic exercise and you’ll be good to go. It took mine a few days of trying every day, and if I use it for a few seconds 2x a week stays functional. I just have to remember to do it.

Not as good as a manual shifter would be though.
 
Just do some periodic exercise and you’ll be good to go. It took mine a few days of trying every day, and if I use it for a few seconds 2x a week stays functional. I just have to remember to do it.

Not as good as a manual shifter would be though.
Do you just do it while stationary? Thats what I was doing before.
 
Oh man you guys are killing my enthusiasm for this fix 🤣 WTF Toyota! This is supposed to be the pinnacle of reliability!
But I've already ordered the Aisin part and will go through with the replacement. Heck I don't even exercise twice a week myself, let alone my CDL! This thing needs a personal trainer.
 
Do you just do it while stationary? Thats what I was doing before.
Oh I do it every way. If it’s failing, try on a warm transfer case. Then after it works repeatedly in that scenario, move to colder days and colder transfer cases.
When it’s working in all situations it then is just a matter of running in 4lo and diff locked every three or four days for a block
 
Oh man you guys are killing my enthusiasm for this fix 🤣 WTF Toyota! This is supposed to be the pinnacle of reliability!
But I've already ordered the Aisin part and will go through with the replacement. Heck I don't even exercise twice a week myself, let alone my CDL! This thing needs a personal trainer.
Electronic will never be as reliable as a manual transfer case. It's very unfortunate.
Oh I do it every way. If it’s failing, try on a warm transfer case. Then after it works repeatedly in that scenario, move to colder days and colder transfer cases.
When it’s working in all situations it then is just a matter of running in 4lo and diff locked every three or four days for a block
Will do, no cold weather for me tho
:cool:
 
I messed up!!!

So I received my Aisin SAT-015 unit today and swapped out the bottom and the top part of the unit. I left the middle part and the rods on the car and took care not to move them. I also double checked the clocking with the pictures shared here on page 6 and what came in the new unit.
After putting everything together and starting the car, I now have a blinking 4Low light. Car does not go into 4Low and the CDL doesn't work either.
Any ideas?

I think I'm going to open it up tomorrow and try pushing the rods in and see if that does the trick.
 
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I messed up!!!

So I received my Aisin SAT-015 unit today and swapped out the bottom and the top part of the unit. I left the middle part and the rods on the car and took care not to move them. I also double checked the clocking with the pictures shared here on page 6 and what came in the new unit.
After putting everything together and starting the car, I now have a blinking 4Low light. Car does not go into 4Low and the CDL doesn't work either.
Any ideas?

I think I'm going to open it up tomorrow and try pushing the rods in and see if that does the trick.
Hmm. Did you pull the battery positive for 15 min?
 
I messed up!!!

So I received my Aisin SAT-015 unit today and swapped out the bottom and the top part of the unit. I left the middle part and the rods on the car and took care not to move them. I also double checked the clocking with the pictures shared here on page 6 and what came in the new unit.
After putting everything together and starting the car, I now have a blinking 4Low light. Car does not go into 4Low and the CDL doesn't work either.
Any ideas?

I think I'm going to open it up tomorrow and try pushing the rods in and see if that does the trick.

Watch the videos linked in this thread. It does a really good job of showing you how to clock both the bottom (4lo) and top (center diff locker) and also how far to push the rods in. It's finicky to get them to mate up properly. Might take you a a couple tries.
 
I took them out, watched the videos and pictures again and adjusted the clocking. The bottom one was definitely off, so I readjusted it.

As for the rods. I was able to move them in and out about 1/2" or slightly less then that. I could definitely feel the weight of the gears moving with the rods. Nevertheless, I sprayed PB blaster and moved them in and out for good measure just like the guy in the video!

I assembled everything back with the rods pushed all the way in. When I start the car there is no blinking 4Low and drives fine.

However, neither the CDL nor the 4Low engages. I can hear the motors turning and the rods clunking into position but the lights just keep on blinking forever and there is no engagement. I tested this warmed up, playing with the steering, driving back and forth etc. Nothing worked!
 
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Update

I kept fiddling with it, turning the car on/off in N and P and trying the 4Low. Unfortunately in one of these cycles there was a really bad grinding sound when going from N to R (the car was stationary, I was just moving the lever with my foot on the brake). I have no idea what happened but somehow I managed to create a bigger problem :frown:
I disconnected the battery, took the whole unit out again and reassembled it...The problem seems to be with reverse. There are no more 4WD related errors but the car does not want to go into reverse :bang:
If I can't figure this out by Monday, I would have to tow it to the shop.
 
Update

I kept fiddling with it, turning the car on/off in N and P and trying the 4Low. Unfortunately in one of these cycles there was a really bad grinding sound when going from N to R (the car was stationary, I was just moving the lever with my foot on the brake). I have no idea what happened but somehow I managed to create a bigger problem :frown:
I disconnected the battery, took the whole unit out again and reassembled it...The problem seems to be with reverse. There are no more 4WD related errors but the car does not want to go into reverse :bang:
If I can't figure this out by Monday, I would have to tow it to the shop.

That's an issue with the 4lo actuator. You may think you had it clocked right but I can guarantee it's not. Same thing happened to me during the course of my troubleshooting. The 4lo actuator rod needs to be set perfectly or it will cause the grinding sound you hear. The rod for the 4lo shouldn't be in all the way. It needs to be out just a tad or it won't actuate properly. That's why you see the guy in the video counting the teeth on that bottom one. The top rod, for the CDL, that one can be pushed all the way in. Right now, the grinding you are hearing is because the transfer case isn't fully engaging either of the gears for lo/hi. So when you try to put it in gear and the output shaft on the trans starts spinning, it's not engaging fully. Just need to keep tweaking and testing until you get it right.
 
That's an issue with the 4lo actuator. You may think you had it clocked right but I can guarantee it's not. Same thing happened to me during the course of my troubleshooting. The 4lo actuator rod needs to be set perfectly or it will cause the grinding sound you hear. The rod for the 4lo shouldn't be in all the way. It needs to be out just a tad or it won't actuate properly. That's why you see the guy in the video counting the teeth on that bottom one. The top rod, for the CDL, that one can be pushed all the way in. Right now, the grinding you are hearing is because the transfer case isn't fully engaging either of the gears for lo/hi. So when you try to put it in gear and the output shaft on the trans starts spinning, it's not engaging fully. Just need to keep tweaking and testing until you get it right.
Thanks for the information. That is actually very reassuring! I was worried that I might have caused a bigger issue. The CDL is actually engaging very quickly, so I guess I got that one right.
So are you suggesting to pull out the 4low rod a bit? How do I know how much? I saw how the Filipino guy was counting the teeth to 9 but I couldn't figure out how to position it. On my first try the rod was a bit out but it wasn't engaging either. Also, I took the car for a drive and it was going into reverse fine but this happened when I started messing with on/off cycles on N and P.
 
I’ve had mine get stuck in neutral when ‘exercising 4lo’. It usually happens when I try to shift in at a stoplight or stop sign. So I’ll be stuck at the intersection. I should stop testing it in traffic. Anyhow, in those cases I’ve been able to get going again by turning the rig off and on.
Sounds like a power cycle isn’t fixing this issue.
 
I’ve had mine get stuck in neutral when ‘exercising 4lo’. It usually happens when I try to shift in at a stoplight or stop sign. So I’ll be stuck at the intersection. I should stop testing it in traffic. Anyhow, in those cases I’ve been able to get going again by turning the rig off and on.
Sounds like a power cycle isn’t fixing this issue.
Yeah, do at home on the drive way or when you return before shutting down (probably nicer as engine warm and revving less)…
 
So today I did several more tries on the 4H-4L actuator part and finally resorted to putting on the old part.
AND.... It worked like a charm!!! :cheers:
I still have no idea what is the difference between the Aisin SAT-015 part and my OEM, as they look identical but somehow I could not get the Aisin part to work. The car was fully drivable in 4Hi when I corrected the rod position but I could not put in low gear. The 4Lo kept blinking and not engaging. I compared the traces that the limit switch was leaving on the contacts and it seems like the Aisin part was indeed completing it's movement and the rod position was also the same but yet the 4low never fully engaged. Could this be an electronic communication problem? If the the actuator is making the full correct movement, the rod should be in the right position so what can possibly cause it to not go into 4Low? For now I am just going to use the old OEM 4low part and the new Aisin CDL part. And of course fix the breather as that was the cause of the issues. Mine was actually attached, but cracked, and water had gotten in and sat there in the housing.

4low.jpg



The top part (CDL) which was my actual problem in the beginning has been fully compatible.
The Aisin part has been working there like it should.

CDL.jpg



A note about the bottom rod position... When you play with that rod :eek: sometimes it likes to stop at a different location and if the housing is completely off there is nothing to compare it against and so it is hard to tell if it is fully inserted.. sorry this sounds really dirty but it's the best description I can give you :hillbilly:
This was the cause of the problem I was having yesterday. The rod was at the red line and so it never reached the full seated position for 4Hi and thus I couldn't put into reverse.
rod.jpg
 
Quick update: The limp mode, VSC, and 4Lo flashing upon startup came from a secondary air pump code. I just went ahead and ordered the Hewitt Gen 2 bypass. Didn’t feel like trying to locate the exact issue and still face issues in the future, so thought best to eliminate. Also the same cost as the air pumps so no additional cost.


I also ordered the actuator from Amayama for $642 shipped vs the $2,756 from Lexus. That said I do have to wait until December 13 to December 26 for it to arrive.

ACTUATOR ASSY, TRANSFER SHIFT​

Genuine Toyota (3641060102)​


Looking forward to getting both of these things done and hopefully back out on the trail.
 
I'm still not comfortable with the noises when shifting to 4lo, can anyone shoot a quick video of the engagement sounds?
 
Just wanted to update this thread. Appreciate everyone’s help. I ordered from Amayama via this link. Shop had to drill out the screws to get the old actuator off, but got this one on and clocked with relative ease.

Lexus quoted $2,7XX, while Amayama got it to my door for $788. First order out of Japan was cancelled, but order from Dubai took 3 weeks. Great communication on all of it from Amayama and well worth the wait.

I have an 09 LX.
Link: Toyota 36410-60102 (3641060102) ACTUATOR ASSY, TRANSFER SHIFT - https://www.amayama.com/en/part/toyota/3641060102

Also, the VSC and all that was a secondary air pump issue. Have the Hewitt kit to install to remove that bs
 

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