toybota

I have a 94 4runner that is a v6 auto. I had it in 4wd and was on a snow pile. After backing down off of it i heard some popping noises. I know that I had bad CV boots but I have spare axles so I was not to worried about them braking. So after assuming it was an axle I wanted to try it in 4wd again just to make sure. Turns out 4wd isn't engaging. There are crunching noises so is the diff prob broken? The noises are in 2wd or 4 doesnt matter. Any help in this matter will be greatly appreciated

Derek Csengeri

Strap22

The 94 4runners have the larger diameter inner shaft. I broke mine on my 92 but it was the smaller shaft. The only replacement they make is the larger one now. Not saying that is what your problem is but mine made a lot of noise. I would start with the wires in the add unit and make sure you didn't pull them off. I assume you have auto hubs? Someone else may have a better suggestion. Let me know if we can help.

tc

How do you know it wasn't in 4WD?

Does the 4WD light come on? If so, it's not an ADD issue, as that light only comes on after the collar slides over.

Strap22

TC is correct about the light.

Come on someone has to know what is wrong with this.

tc

One other question - manual hubs?

Assuming not, and an open diff, the problem could very well be the CV's. If one of them is broken enough to not hold power, the open diff will just spin that side and you won't transfer any power. You hear it in 2WD because the CV's always spin unless you have manual hubs.

leebee

x3 with tc & phil .

lee

toybota

OK sorry it took me so long to reply I was stuck at work. The truck is not engaging in 4wd. I know this because I can pull up to a hill at a angle and get the rear diff to open. After I get the rear diff to open I engage 4wd and still cannot advance further. The light does illuminate if that information is of help. Also I can make locked turns with no wheel hop or resistance. The truck just rolls freely. The truck is equipped with auto hubs too if this helps. Has anyone broken a diff and would draining fluid to check for metallic particles be a good way to see if it was indeed some carnage done to the diff. Another thing I can say is for a week I have noticed a small shimmy in my wheel. It comes and goes and has no pattern of repetition, always pulls a bit left on the jerks. I thought it was the idler arm so I changed it. That didn't help. I then inspected everything from pitman arm to tie rod ends to ball joints without noticing any play in anything. Would I be able to notice this broken shaft and which side of the vehicle would it be on? Thanks a lot for the help guys I LOVE YOTATECH.

toybota

Bump???????????/

Matt16

If you wrecked your diff, I'm sure metal particles would be in the oil- maybe even a couple gear teeth.

Brenjen

Well from what I'm reading you're still not sure if it's engaging. If I pull up to a hill at an angle the front lifts a wheel at nearly the exact same time as the rear....in other words it can't climb any further in four wheel drive than in two wheel drive because of the lifted wheels & open diffs. I think you have a CV problem, as TC mentioned at least one of the CV's turn all the time even in two wheel drive...passenger side iirc. You have A.D.D. not automatic hubs; ADD stands for automatic differential disconnect (or something like that)

toybota

Yea but the trucks both front wheels where on the ground. Also it power brakes
the same as it used to. I don't think it should power brake in 4wd. Also my truck used to need gas or application of throttle to roll when in 4wd.

toybota

So the passenger side one is the one that locks up and the other is always correct? The passenger one is the one that has the smaller diam shaft? I'm not asking if I have 4wd. I know that I do not. But if you break one axle does the other still work if the dash indicates 4wd? I can not imagine that one cv is spinning and the diff being open and I do not hear the noises I do while driving down the road. I would at least expect to hear these noises if it was a broken cv and I attempted to climb a hill. Noises started and the 4wd quit working. What could the issue be, and what is the likeliness it is the front diff?

Brenjen

The dash light comes on when the ADD sleeve moves onto the axle shaft. If that sleeve isn't engaging completely or if you have a broken CV then it may be tricking the open diff into thinking the other wheel isn't getting traction & putting all the power to the side that's not engaged.

Personally I think you have a busted CV as I said before. The diff just doesn't know it's broke & thinks it's slipping. If I were you, I'd just go jack the front up & check the CV's; I bet one is busted.

tc

Toybota - you don't appear to be willing to help us diagnose. If the 4WD light is coming on, the ADD is working properly, but maybe you should just pull the diff and replace it. It's only several hundred dollars. :confused:

Seriously - you say in the first post that your CV boots are bad. Search around - you will see that generally, your CV's are not long for this world once the boots are ripped. If grease can get out, dirt can get in.

Check, or hell, just replace, the CV's (at $70/ea with lifetime warranty after core refund) and get back to us.

rowdy235

I will throw my wrench into the works here. The way a differential works, simply, is it will provide power to one wheel, whereas the other wheel can spin freely. On corners, this is great because it allows the wheels to spin at different speeds, but off-road its a pain, because the wheel with less resistance (traction) will spin. A locker solves this problem.

That said, I think you busted a CV joint. In this case, the differential always gives power to the busted CV cause it has the least resistance (eg doesn't spin a tire/move truck). That makes the clicking sound. The light still comes on because the 4wd is still functioning, its just not giving power to the wheels due to the busted CV.

I hope this helps in some way.

toybota

I was just saying for those who have experienced a broken inner shaft cv joint, which seems to be the general consensus that I am gathering from this is. I do understand by the information that all of you have shared with me that my dash indicator light which seems to me operated by a position switch is telling me that my differential is physically attempting to connect the front differentials. The problem I am saying that I see with this diagnosis is that if I can position the truck on an incline as to flex so one rear and one both front diffs are on the ground causing a situaton where the broken shaft would spin more freely than the opposing front shaft thus should emit a sound or noise of some sort. In the instance that this broken shaft is spinning with the axle at a stand still(tire not moving) then i should def be hearing the two pieces of shaft grinding together like a trains brake(metal on metal) or maybe worn brakes. Instead i get no increase in noise. If there is some other way without disassembly I can help this out let me know. Tomorrow I am getting the socket and we just got 8in of snow here and the truck is unfortunately outside. Maybe Monday I can get out to look at some stuff but I know that shaft is inside the tube right?

toybota

I was just saying for those who have experienced a broken inner shaft cv joint, which seems to be the general consensus that I am gathering from this is. I do understand by the information that all of you have shared with me that my dash indicator light which seems to me operated by a position switch is telling me that my differential is physically attempting to connect the front differentials. The problem I am saying that I see with this diagnosis is that if I can position the truck on an incline as to flex so one rear and one both front diffs are on the ground causing a situation where the broken shaft would spin more freely than the opposing front shaft thus should emit a sound or noise of some sort. In the instance that this broken shaft is spinning with the axle at a stand still(tire not moving) then i should def be hearing the two pieces of shaft grinding together like a trains brake(metal on metal) or maybe worn brakes. Instead i get no increase in noise. If there is some other way without disassembly I can help this out let me know. Tomorrow I am getting the socket and we just got 8in of snow here and the truck is unfortunately outside. Maybe Monday I can get out to look at some stuff but I know that shaft is inside the tube right?

Brenjen

Now I'm confused.

Try to separate each of your concerns & label them #1 - #2 - etc. & see if that clears up the issue. It may be that we're just not getting the point because of the "long way around the barn" approach it's being presented in.

I'm sure someone here could help to guide you to the right spot if they could understand the problem....believe me I understand that part of it because I tend to ramble too.

tc

So, the wheel is not turning.

Have you looked inside to see if the inner half of the CV (where it bolts to the diff) is turning?

You only need 10mm, 12mm, and 17mm sockets to remove a CV from our rigs.

toybota

I thought that I would need to take off the 54mm nut. Do I need to do this? That has been the only reason I have yet to dig into it. That socket is hard to come by in a 3/4 in drive for me. I got a 1in drive but come on who has a ratchet for that.