View Full Version : Wicked 4 Wheel Drive!

12-06-2008, 01:38 PM
My truck:
IFS, manual lockout hubs but with ADD, no locker.

The trouble:
I put it in 4 wheel drive on Thursday. The street was snowy and icy. When I gave it any gas, the truck shot to the left.:eek: The front right tire was getting no power. Almost like the 4 wheel drive was not engaging. So I put it back in 2 wheel drive and drove it like a man!:D Today, I started the truck and put it in 4 wheel drive then lifted one front tire at a time. Both hubs were locking. Is it possible that I have water in the diff that may have been frozen? Could that have prevented the ADD to work? Or is it just a little slow?:D What else should I look for? All the vacuum lines look good.

12-06-2008, 02:08 PM
Behavior is consistent for an unlocked axle. Power will always be sent to the wheel with LESS traction. That's what a standard diff does. Without lockers, you get power to one wheel on each axle in extremely slippery situations. That's better than 2WD, where you get power to a single wheel only in extremely slippery situations.

To get equal power to all 4 wheels, you'd need 4WD + 2 lockers.

Uncle Ben
12-06-2008, 02:19 PM
Behavior is very typical for Attention Deficit Disorder! Try to narrow the command to be very specific and it's possible that drugs might be needed! :eek: ;):lmao::lmao:

12-06-2008, 10:06 PM
You are absolutely correct, but this was like nothing I have ever experienced before. I know that with ADD there is a "shaft" that slides into the diff to connect the one side. Which side does that "shaft" control? If it is the passenger side, then I know it was not working because the passenger side was getting no power at all.

I am on them! It is not helping!:D

12-07-2008, 12:58 AM
Assuming you are driving a pre-95 minitruck with ADD, the Collar is on the driver side stub shaft.

There is a collar, that, when ADD is engaged, slides over and "connects" the driver side axle to the diff.

What you are describing is the ADD side working, the other side not.

Couple of things to check:

Are you POSITIVE both hubs were locked? I am ashamed to admit it, but I've had similar situations where I locked one side, had something else on my mind completely, got back in the truck, and tried to go. It was a "DUH" moment, I turned red, fixed the issue, and went along my way.

Check the ol' CV's. Its possible that you have a broken one, especially in one of the joints themselves. Testing with a tire in the air, the axle can still sometimes turn the wheel, since there is very little resistance, but, once on the ground, and the resistance increases, it'll just spin inside the joint, and give no power to the wheel.

12-08-2008, 10:29 AM

12-08-2008, 11:30 AM
Automatic Disconnecting Differential.

Hey Carey, it could be.... stiff and cold grease in the hub. Been known to happen. Pull it apart and have a look-see.

What's curious however is that an unlocked hub would (should?) have the effect of being the path of least resistance. In other words, you would still have the normal one-wheel drive of a 2WD unlocked truck, it wouldn't pull to one side. The unlocked axle would spin freely.

12-08-2008, 12:11 PM
I remember back in the IFS days, my worn out front end allowed an awful lot of toe change in 4x4. One side changed a lot more than the other. I think the left front stayed fairly straight and the worn out linkage going across to the right let the right front toe in a bunch in forward 4x4. (This also resulted in a lot of right front tire wear.)

Result: Strong left pull.

Check for worn out suspension/steering joints.

12-08-2008, 12:24 PM
I remember back in the IFS days, my worn out front end allowed an awful lot of toe change in 4x4. One side changed a lot more than the other. I think the left front stayed fairly straight and the worn out linkage going across to the right let the right front toe in a bunch in forward 4x4. (This also resulted in a lot of right front tire wear.)

Result: Strong left pull.

You have simple chronic worn out IFS.

Excellent point, Mine did that too when it was worn out.

Time to cut it all off and go solid axle. It'll be cheaper than replacing all of your ball joints, a-arm bushings, idler arms, and tie rod ends.

Errr???? I replaced all of that stuff on mine. Cost 500 bucks.

You can't even get long fields for that much.

12-08-2008, 12:38 PM
You *can* get the axle under there and operational for a little more than that*. Longfields are a luxury for some.

*caveat: it wouldn't be my ideal system (rear springs up front, no Longs, no locker, no gears, cheapest high steer you can find...). But you do have to weigh putting money toward IFS when it could go directly to a SAS.

12-08-2008, 02:03 PM
Check the front end parts, that can make a weird pull under power in my experience as well. Also the cold grease idea has merit. I've had times where the grease in the hub is thick on a really cold morning and they are slow to engage. This can be bad if the hub engages while you are moving, so if that happens I unlock the hub and make due for a couple of miles or use something to warm up the hub (momma's old hair dryer). Or remember to lock the hubs when you get home from work the night before a storm is predicted...

12-09-2008, 12:38 AM
Thanks for all the tips! I know the hubs are locking, I can hear them click into place. My truck does have ball joint spacers so the axles are at a steep angle. Combine the angle with some massive IFS flex:lmao: could the axle have pulled apart? Since it is snowing now, I will probably give it a shot tomorrow and see what happens.

Sorry guys, no SAS for me. If Peggy's health let her do the harder trails and if she enjoyed them... Besides, our Packard has needs too!;)


12-09-2008, 06:13 AM
Hubs. It's pretty easy to tell if they are locked in or not on IFS. Turn the dial, reach behind the wheel and grab the axle between the CV joints. If the axle turns, the hub is not locked.

I put BJ spacers on this past summer, too. Do you have additional lift cranked into the torsion bars beyond the 1.5" that the spacers provide? People have said that the way the BJ spacers change the geometry of the front end will make your truck sketchy on snow. I haven't noticed much of a difference either way, but I also have old style BFG M/T tires and so wet and snowy road stability is sort of relative. Not to mention that my truck has a constantly growing list of issues that's kept it parked a lot this fall, so snow time is very minimal.

Keep in mind that with unlocked diffs only one wheel will spin if both wheels per axle are on slick surfaces. IIRC normally my truck spins the right rear and left front on ice, but it just depends on which wheel gets a touch more traction than the other. So it's possible that nothing is mechanically wrong in the driveline of your truck and you're just seeing the way BJ spacers or worn front end parts changed your suspension.

12-10-2008, 12:27 AM
I installed my spacers May 23rd, 2004! No additional lift except 1" body lift, so that doesn't count.Today, we had no issues on the way to work.:confused: I may just have to wait until the next snow fall to see if it does it again.

12-10-2008, 08:48 AM
Or you could... WHEEL THAT SUCKER!

12-11-2008, 01:03 AM
Or you could... WHEEL THAT SUCKER!

You are right! The Westminster Mall parking lot is usually empty....:D