95.5 Taco 4 wheel drive doesn't work

Hello to all,
Very aggravating issue with 4 wheel drive. This is my 4th toyota, but the first with IFS. I've replaced both cv axles and seals, cleaned the mud out of the vacuum lines and my vacuum actuator is working flawlessly. The 4x4 light comes on and the front drive shaft locks in and spins. There is no noise coming from the front differential assembly and while on jack stands I spin one wheel and the other wont move. Same effect spinning the other wheel. It feels like its engaging but obviously no 4 wheel drive... I put the axles in last night. Both are locked in with the clips but the driver's side has an 8th inch of play. Any ideas before I replace the differential?

 

I don't understand your testing conditions. What you describe is normal for an open differential, front or rear, assuming the transmission is in neutral and the transfer case is in 2H. Under what conditions are you testing (transmission gear, transfer case selection, etc.)


Since you mention a vacuum actuator, I'm guessing this is a truck with the J-pattern transfer case shifter, ADD and not manual hubs.

 

Do you have manual hubs? It sounds like you have add and the actuator is not working. Are you sure the actuator is engaging the front diff?

 

Yes it's a add. The actuator works when I apply direct vacuum. I pulled it off to verify action. And the 4x4 light comes on. Would it not if the actuator wasnt working?
The front was on jack stands in 4lo neutral. ..

 

I'm going try and get it up on 4 jack stands( if I can get enough blocks)
Lord I miss my late 80s 4 runners

 

Sorry, yes it's j action add

 

This is a good troubleshooting article for ADD systems.


http://www.off-road.com/trucks-4x4/tech/the-automatic-disconnecting-differential-system-19259.html


I haven't had a Tacoma like yours in 9 years, so my personal memory is fuzzy. However, you can set the truck in 4WD (high or low) and pull the differential actuator and inspect the sleeve to see if it actually moved. I think the actuator has a switch though, and unless it moves and locks in, that light should not come on in the first place.


However, I'm wondering if I'm over thinking this. The front ADD system isn't like a true locker - it just connects one shaft to the other with a sliding sleeve. Even in that case, it's an open differential still, so putting the truck in the air means one side would spin and the other would sit still (just like with an open rear diff).


It's too early and I'm on zero coffee. Ergo, I'm useless.

 

Ok... 4 wheels off the ground(4lo neutral) front wheels did not spin.

Shut off engine...
The passenger wheel catches sometimes and turns the driveshafts and back wheels (driver's side doesn't spin) engine off 4lo neutral.
The passenger wheel will only catch something after moving it back and forth a bit, but when it does catch it will eventually let go if I dont keep momentum up by spinning it with my hand...

Are teeth missing in my diff?

 

Thanks for the link... after reading it, i am 100% certain the actuator is working... the puzzling part is the passenger wheel will catch if i rotate it by hand...(every now and then).

 

I suppose I'll just get a used axle assembly... $400 is worth not having to guess... Hubs are good...new cv axles...good actuator... it has to be the differential...

 

Good luck let us know what happened

 

Just my .02 here but what you are describing is how an open diff operates. I think your 4x4 is fine. ADD is not a locking differential as was stated above.

Jack the front end up again and have a buddy spin the other side same time as you same direction and you should see the driveshaft spin.

Or better yet, you live in Alabama, find some mud and give her hell, you'll know right away if it's working.

Edit: without the engine running I'm not sure you'll have enough residual vacuum to keep the ADD engaged, something to consider while testing.

 

lol... yes we have plenty of mud! and I've found out quick I have NO 4 wheel drive...

I've also had it running while on the jack stands. Every gear and neutral. I bought the Taco from a young kid who obviously didn't take care of her. It had a broken cv axle, and the passenger side CV was cut off (still attached at the hub) but not the differential. I'm sure he went wheeling with it like that because I've found a front diff full of water. The fill nut is notoriously stripped so I doubt he attempted to change the fluids. I suppose I paid for a rough truck with good tires, rims, lift, tranny, and transfer case. Well the 270hp v6 helped It will white smoke my 35's!. only paid $3400 so $500 for the diff and new CV axles isn't bad.... just have to wait 2 weeks to go back to the river:-( waiting on the diff before really testing it...

 

Ok... in conclusion. .. the re manufactured differential made all the difference. .. four wheel drive working flawlessly now. Now time to waterproof and home snorkel... thanks everyone

 

Glad to hear that it all worked out! Now, time for some pics!

 

Before any negative comments are posted....

This is a RIVER truck. Its purpose is to traverse the woods, travel through the creeks eek:which can be quite deep here in Alabama), run through the mud and red clay, to get to the sand bars on the banks of the Alabama river.

Oh, and make it to the beer store for Bud Lights and Jack Daniels!

Thanks for everyone's input

 

your CV angle is horrendous.

 

I know, but the differential drop kit seems to catch every stump under water! I'll deal with new CV's every year...

 

not saying get that.

But you should lower your lift. You have no down travel as it sits i bet and your just binding your CVs all the time practically.

You need bigger tires. If you can weld, look up fitting 35s on 2'' of lift. You'll have more clearance the you do now with 35s and smaller lift and it'll ride better.

 

I have 35s... It rarely sees asphalt so the ride is irrelevant... but it surprisingly rides great... like I said... It's built for our mud-holes, not rocks or pavement...
Thanks though