is there anything good about having your front and rear wheels locked together, as far as offroading goes? why don't they put in a diff, like in all time 4wd vehicles?

as far as the torque unloading, is that really bad? like WATRD was saying, i dont think it is extremely harmful. maybe if you put it in 4wd and started doing slow circles in reverse for a long time, something could snap. also, think of this - any torque is bad, because it creates stress... stress = weakness = something breaking. eh?

i dont want to get in argument though. just saying what i think.

 

Yes, with stock part-time 4wd you have at least 2 wheels driving you at all times, 1 front and 1 rear. Full-time 4wd systems with no way of locking or no limited slip device can get stuck with just one wheel spinning. Add in a locker to a part-time system and you have at least 3 wheels pushing you, a second locker and all 4 wheels have power 100% of the time.
Sudden loading and unloading (aka shock loading) can be very bad and that's where most breakage occurs. For example, spinning up a wheel in the air and slamming it down on a high-traction surface suddenly stopping it. The torque has to go somewhere and the weakest link is where it goes, which is not always the tire's contact to the driving surface. Likewise slow torque loading can also break parts. I know of at least one guy who has broken a birfield in a parking lot and all he was doing was coming out of a drive-through and didn't realize he was in 4wd.

 

I KNOW it's not the steering stop issue. I've taken care of that with some wheel bearing grease and check those all the time. Besides, it's not that steering-stop rub-squeak noise. This is a heavy pop that resonates throughout the car.

Anyway, I took the truck offroad just a few minutes ago and did some circles. Seems as though if the sound occurs offroad, it only occurs when turning left. This has also been the case on the pavement. Furthermore, the pop is felt in the steering wheel as well, if that makes sense. It's almost as if it fights me when turning left, then "gives in" and pops and continues the turn if I give it more gas. Otherwise it just stops.

If this is a normal occurence, then that's fine. I'll just keep that in mind when driving in 4WD. However, if anyone thinks there's some kind of structural damage, I definately want to know so I can get it fixed. Can't live without 4WD.

 

No, that's not normal at all. Sounds kinda like a bad CV to me... Ok, what hub type do you have? Auto, manual, or ADD? How often is this pop, every revolution of the tires, multiple times per revolution, or once every so often?

To rule out the front CVs and differential, get the front end up off the ground and on jackstands. Put the tranny in 4wd and lock the hubs if they're manual. If you have ADD run the engine for a few moments while spinning one of the front wheels to ensure the collar locks properly. Now, with the wheels straight spin one side. It should turn smoothly with no binding and the other wheel should turn the opposite direction (given a stock front diff), repeat with the other side. Crank the wheel to full lock either direction and repeat the same test.

To check the front ring and pinion, put the truck in 2wd and still on jackstands. Get underneath and turn the front driveshaft by hand while feeling for any resistance or spots where it turns easily and the front wheels dont. Make sure the front wheels complete at least a few full revolutions while doing this to be sure you don't miss a pair of bad teeth that only match up every few revolutions. You may have as much as 1/16th (rough estimate) revolution of the driveshaft worth of play, that's normal as long as it's consistent.

Start out with this and let us know what you find.

 

for more info on 4wd systems and differentials check out the 4runner FAQ.

rpeAMP, did you get your truck used, or new? do you know if you have a detroit locker in the front?

I never get any pops other than the steering stops and my sway bar QDs.

Steve

 

I have ADD hubs (will probably replace these in the next few months with some manuals). The pop occurs mostly when I make a left turn, basically what will happen is I will feel alot of "tension" on the steering wheel fighting my to correct my turn, then the loud pop, then the tension is relieved. Usually after the pop happens, the truck comes to a slow slow crawl if it doesn't completely stop. Then, I give the engine some gas with the clutch partially in to get it going, then another loud pop, and it frees up.

Does this help any?

 

My '90 truck did the same exact thing with a stick.
However it did it a lot more than my Runner does.
It will do it on the pave, but not like the stick shift did.
Corey

 

I'm going offroad again tonight, and I will try some tight turns on loose gravel/mud and see what happens.