when not using the 4 wheel drive does it make a difference on weather or not you keep the hubs locked v.s unlocked? Gas milage, wear and tear?

 

If you leave your hubs locked your front wheels will drive your front axles which will drive your front differential which will drive your front driveshaft which will drive your tranfercase. Thus more wear on all these components and worse gas milage.

 

I know a lot of people who do it during bad weather so they can shift on the fly but I saw a stack of SD front driveshaft's at the local driveshaft shop when I was having mine lengthened. I asked what the deal was and the guy told me they were all from the power company's rigs because their drivers leave the hubs locked and it wears out the DC joints. Just what he told me. take it or leave it.

 

What's a 'DC joint'?

 

double u-joint set up. correct term is something like double cardigan. may be spelled wrong sorry.

 

I agree that it will cause alot of extra wear and tear on the front end. I personally see about a 2 mpg difference with them locked in too.

 

I think he meant CV joints, which stands for Constant Velocity. A single cross u-joint when operating at any angle other than straight, will produce a jerky output (sppeds up and slows down each revolution) from a constant input. Putting two crosses in close proximity (and timing/aligning them correctly) produces the same smooth and constant ouput as the input shaft.

 

I lock mine when the weather warrants. It's not the wear, it's the fuel I am concerned with..

 

My brothers older (early 90's) dodge cummins 2500 does not have hubs which can be locked or unlocked. The axles and other associated parts are always rotataing. He has 220,000 miles with no work to the 4wd system, and he is not one for maintenance. Philip.

 

I was referring to the dual cardan joint located at the top of a SD front driveline. Constant velocity is a generic term that is used to cover dual cardan, birfield and various other types of joints used to make a shaft deliver power at an angle at a constant velocity. I was just being more specific.

 

I don't believe that's correct. I think on dodges they use an axle disconnect. The outer axles may be turning but I don't think the front driveline is until it's put into 4wd. At least that's how it's been explained to me. I'm not intimately familliar with Dodges though so I won't swear by it. You may be right. Go have a look and let me know if the front shaft turns when the truck is driven in 2wd. Then we'll both know for sure

 

Are you guys talking about the auto hubs or a Warn type manual hub?

If you are referring to the auto hubs, why lock 'em? The auto hubs on my 2001 ESOF system have never failed me, will lock in at a moments notice, and have never given me any problems.

If it looks like I will be in a sticky situation I switch over to 4 wheel drive early for 2 reasons... 1) to keep my momentum in the goo, 2) to take any opportunity I can to keep my 4x4 parts moving and lubed...

Edmo

 

I think we're talking about the stock Ford manual hubs. At least I am.

 

This is only for manual hubs...

My 94 F250 manual and the Ford Truck Bible recommend locking the front hubs at least once a month for at least 10 miles or so. They also say you can leave the hubs locked if you expect bad weather. If you do not need 4WD just lock the hubs and leave the shifter in 2WD. You can shift into 4WD at speeds under 35mph if the road conditions warrant.

When the hubs are locked but shifter in 2WD, the differential is not being driven. Only the axles and hubs are driven. You will get a little more road noise(Sounds like California Rain Grooves), a little more wear, and a little less mileage. But you will also circulate some of the fluid in the diff, which is why it is recommend once a month.

I have read that some members of this list run all winter with hubs locked in 2WD with no problems. But the manual and Bible don't recommend this due to the noise, wear, mileage mentioned.

You can also be in 4WD and hubs unlocked but I am guessing that the drive train will be driven and just the hubs won't be. So this is not as good, nor as convenient as hubs locked 2WD.

Just my opinion based on what I have read and a little experience doing this.

Jim Henderson

 

If your hubs are locked in, the front wheels WILL drive your front differential, your front driveshaft, and the front output shaft of your transfer case. They will not be under power of the engine but they will be rotating just the same. Check your bible, if it is correct, or just go lock in your hubs have someone drive and you watch the front driveshaft or try to turn it with the truck sitting still. If both hubs are locked its not gonna budge except for slack.
I do agree with the rest of your post 100%.