chizzlebuns

Ok so i have heard you can put it in 4wd lo with only being in 2wd, well isnt this bad for it? the way i picture it is the cv axles sit in the transfer case and the grooves are always together so if its in 4lo wont the transfer case in the front be rotating making it grind against the cvs that arent free??? idk i just want to clear this up because i have never thought of it until today. any feed back with explaining this to me would be helpful thanks!

baddest94

I lock my hubs in before i start wheeling everytime and leave it in 2wd untill i need 4wd so that i aint gota get in and out a thousand times durning my ride. I aint ever had any problems, nosies or any other things happen. Heck sometimes if i need to get some extra bit without 4wd ill throw it over in lo with the hubs free just so i get the lo gear ratio that i need. With the putin it in low with the hubs in free postion it lets the tcase ingage but the front tires not turn everything else is moving. And with the hubs locked in and in 2wd i think its just reversed everything is spinning but the tcase. If im wrong someone will correct me but i do it all the time without probs.

83

Year and make of your truck?..

But on my truck, absolutely the axles in no way are anywhere near the t-case. The t-case is behind the transmission, and even the trasmission doesn't touch the axles.

There is not t-case in the front. That's your front differential. No grinding, the xles and wheels are free of each other until you lock them together with the hubs.

Somewhat of a tutorial to help you understand what's actually going on:

The t-case has an input shaft right into the transmission. All power goes through the t-case. If you're moving, the t-case is spinning. The rear driveshaft comes out of the t-case.

What happens when you put the t-case in 4high or low, is that the t-case then is also spinning the front driveshaft. And the front driveshaft is spinning the front differential and axles.

When you lock in the hubs, you are connecting the wheels to the front axles, and therefore the front differential, and therefore to the t-case.

SO....when the hubs are locked but you're in 2wd, you are pushing the front axle and differential. Worse gas mileage, more drag etc. The front differential is spinning the front driveshaft, but the front driveshaft isn't engaged at all to the t-case (to kind of oversimplify things). It's spinning the first bearing in the front output of the t-case, but not spinning any of the 4wd gears.

When you are in 4wd but the hubs are not locked, you are moving more gears in the t-case, and you are getting the "benefit" of the gear ratios in the t-case. You are spinning the front driveshaft and front diff and axles, but no power is going to the front wheels because they aren't locked in to the axles. There is no grinding. The axles are only connected to the hubs when you've locked them. This may be different on your IFS, but I doubt it. And I may have things slightly off there, but the idea is the same. There is no grinding.

So no it's not a good idea to just drive all over with the hubs unlocked but the t-case in 4wd. However you can use it for the gear ratio, like pulling a boat up a ramp, or climbing a steep hill (slowly) when you're sure you have enough traction, you just want lower gearing. Not good for long distances or high speeds on pavement because of gear binding, but I haven't had a problem.

In rare situations, like say you break a u-joint on the rear driveshaft and are stranded, you can remove the rear shaft, lock the front hubs and put it in 4wd, and now you have a front wheel drive vehicle. This is not all that great for it, especially on pavement, but it can get you out of a pickle.

baddest94

Thanks 83 for further exsplaining what i said i aint real good at going in to details bout everything LOL. hope between our explanations he gets the answer he was looking for. I use the low range with 2wd when im out trail riding and just want to go nice and easy and take in the scenery.

chizzlebuns

oooooooh now i get it!!! i thought that the cv's couldnt move freely unless it turns with the tires ya its a 1990 ext cab . im going to have to try it out now thanks a ton guys I am pretty new so thanks for not making fun of me....ahaha off to go wheelin seeee ya

4Crawler

iTrader: (3)

In your case ('90 pickup), if you have manual locking hubs, then yes, you can do 2L by shifting to 4L and leaving the front hubs unlocked. However, if you don't have manual locking hubs up front and have the automatic diff. disconnect (ADD), then you will be in 4WD if you shift to 4L as the front end will lock up automatically.

83

No you did pretty good. I didn't really read your post before I posted mine...