mysubaruimp

I grenaded my ring gear a little while ago. I just replaced the front diff and now I have some of the same symptons as before I replaced it.

When I go forward or backward while turning I get a very loud and strong pop. The front end is binding then releasing. This only happens in 4wd or AWD mode. I can drive in 2wd all day with not one issue. It also takes a very long time to get it out of 4wd/AWD once it is in, the truck didnt do this before, but it did do it the day I busted the front diff.

I dont know whats wrong with it.

2002 4runner, OEM lift, 33s.

crbocaj125

I have to assume that because you have "subaru" in your sig, you are used to an AWD system, and your runner is part time 4wd. In that case, you should read this thread https://www.yotatech.com/forums/f123/getting-ready-04-tundra-112279/

Hope that helps.

mysubaruimp

Thanks, but I am used to the 4wd system in the 4runner. Before I blew the front diff, things were happy. I have an 02 qith the "multimode" 4wd where I can drive it in a kind of AWD mode where the center diff is unlocked, allowing use on dry pavement, or I can lock the center diff for 4WD mode that cant be used on pavement.

My problem happens in either AWD or 4WD. It happens on snow, dirt, or pavement (I havent tried the 4wd on pavement).

etan

i wouldn't use 4wd daily driven unless youre stuck in some snow. because it seem that surfaces youre driving on are rather flat????


https://www.yotatech.com/forums/showthread.php?t=112277


this might help

DeathCougar

iTrader: (23)

sounds to me like your diff ratios are not the same. Where did you get the front diff from? Did you veryify the ratio, and match axles codes?

crbocaj125

Good advice etan! lol

mysubaruimp

I dont use 4wd daily driven. I dont even use AWD daily. I am well aware of what hapens when you drive a 4wd vehicle on a dry road when there is no slip between the wheels. This is not the issue I am having. I know when to use each 4wd mode, and I dont use 4wd on dry pavement. I use my 4wd all the time, in the correct situations, and I know what it normally acts like. This is a new issue that was caused by me busting up my front diff and then putting a new one in.

For some backstory on what happened: https://www.yotatech.com/forums/f2/carnage-my-truck-lots-pics-no-56k-110590/

Some other pics of me using 4wd, properly: https://www.yotatech.com/forums/f2/just-introducing-myself-pics-101575/

mysubaruimp

I didnt verify the ratios, or match axle codes actually. I was in such a hurry to get it in that I didnt even think to do that. I got the diff out of a 2001 Tacoma. I was told that it was a 4.10 diff, but maybe it wasnt. I will check that tomorrow.

DeathCougar

iTrader: (23)

Thats a pretty big problem, if they are not matching up properly. If you had a 4.30, and put a 4.10 in, there is 100% of your problem.

pepsibluefloat

u could raise one side of ur truck and see if your front spins faster/slower than the rear if u cant figure it out with axle codes....assuming you're not locked

that'd work right?

rocktown

Just to be safe, he'd probably want to lift the entire truck off the ground. But yes, theoretically, if the front and rear dont match then the front and rear tires would spin at different speeds. How easy is it to tell the difference in speeds by just putting it in gear and let the tires spin at idle? I have no idea, i would imagine if the gear ratios are close (say a 4.10 and a 4.30) that it would be difficult to tell just by looking at it. But, who knows, it may be worth a shot. Anyways sube, i wish you luck in figuring it out.

MTL_4runner

Ditto, this should be the first thing to check on your list and if you find out you do have different ratios front and rear, don't use 4WD until you correct the situation.

mysubaruimp

I just lifted the truck up off the ground and spun the wheels. They spin the same amount front to rear. I went about 12 revolutions and they ended up at the same spot they started in.

I can spin both front wheels in the same direction and have the rear wheels spin. This leads me to believe that there is nothing wrong with the drivetrain or I would get binding when I did this by hand. It does the same in 4low or 4high.

I am thinking maybe its the actuator that is having issues? Thats really the only thing I can think of that would be causing it to not come out of 4wd at this point. The lights are flashing, but it wont disengage.

MTL_4runner

That's where I would look next.

mysubaruimp

I pulled the actuator off of the diff. I have the electrical connector plugged in to the truck still. The actuator is just hanging there. I press the 4wd button in the truck and it does nothing. No change in state, no noise.

I believe that it is stuck partially engaged. When I am driving straight there is just enough space for the teeth to miss eachother in the diff. Once i turn, it shifts things and grabs it a bit, creating the sudden bind and pop. This is just a guess on my part, but its the best explanation I can come up with.

I am going to search to figure out a better way to test it, but I think this might be my problem.

mysubaruimp

I also have an extra vacuum actuator out of a Tacoma that I could use instead, if it can be used. Mine is electrical. I dont know if I can swap the two out. The vacuum one works fine.