Help 4hi Troubleshooting with videos

08 Sequoia 4wd
4wd "worked" but not great when i bought it. Opened up the 4hi actuator to inspect everything and had broke the 4hi little switch inside the actuator.

so i bought another complete actuator on ebay and stripped the 4hi from it and replaced it. Heres where im at now:

i switch to 4hi and 4hi just blinks. The transfer case whirs and engages - the front driveshaft spins with the rear - the front diff SEEMS to engage but doesnt complete the 4hi cycle. Video of truck in air here:
https://youtu.be/Yy_eg9Y0gwI?si=Yy11SKSwOmEVnlAU
-note when 4hi engaged up in air it clunked hard so i stopped it abruptly, which is seen in video after front tire started to spin.

4hi will continue to blink and a noise can be heard coming from the transfer case actuator here:
https://youtube.com/shorts/wN0-ssOHNFo?si=HxI-tYBbIUNX9BcA

this is kind of a complete sequence on road in neutral:
https://youtube.com/shorts/Fr8mlK4-GHA?si=SixpTRuPapLd7Qfz

At this point idk what the issue is, the front diff actuator? It seems like something is kicking the "cycle" back to the transfer case telling it it cant complete and thats why it just makes noise. But it will go back to 2wd fine.

 

When you try to go from 2wd to 4wd you get a slow flashing 4HI light for awhile then it starts flashing fast? If yes, my guess is that you timing of the 4hi actuator is off a little. It doesn't take much. I would pull it off and recheck.

If it was in drive and the back wheels were turning I would guess that the weird clunking when shifting 2WD/4WD with it up in the air is because all the tires are not already spinning at the same speed.

 

This. Hold the brake, or put it in neutral when attempting the shit. The front and rear wheels / drivelines need to be in general sync with each other to prevent the abrupt clunk you heard. This was like trying to engage 4wd while your rear wheels were still spinning on the mud.

 

I figured thats why it clunked hard. My question though since seeing the front tire did start to spin was does that eliminate my ADD as being part of the problem?
What i have a hunch is happening is my TC goes into 4hi, the front driveshaft spins, my front diff engages but then spazzes out and backs out, but my front driveshaft is still engaged...and then i can disengage the driveshaft back into 2wd but it just never fully completes the front diff portion

 

No fast flash just same normal blinking speed the whole time

 

Have you tried it on the ground?

 

Yeah on the ground the TC engages, front driveshaft moves in sync with rear but i cant 100% tell if the front diff is engaged. Sometimes i think the steering feel gets firmer like in my 4wd 4Runner, but im still not sure if its in 4hi because the light continues to blink

 

If it’s still blinking, then it doesn’t “think” it’s in 4hi.

 

Correct. Ill have to test to make sure but im almost positive last time i switched to 4hi then turned truck off, started it back up and it was solid 4hi. I had issues getting it back in 2wd doing it that way but for the heck of it i will try it again. Honestly if i could ghetto get it into 4hi that way just for offroad driving and reliable get it into 2wd, id be happy. I dont wanna disassemble the actuator again and risk breaking the plastic switch again

 

Tried engaging turning off again but didnt seem to be in 4hi. So dont think that trick is gonna work again for me. Might have to risk popping open the transfer case again at this point or screwing with the add