The 4.10LS option was available for manual transmission equipped F150 trucks- in high altitude areas-such as the Denver area. And my truck has the factory towing option. I have the five speed manual and the 5.0 V8. This is a good combination. The 3.93 first gear of the M5R2 x the 4.10LS rear axle ratio makes for a low combination. Almost granny geared! And it is possible to make a left thru a urban intersection in overdrive -without down shifting. The 4.10LS really wakes up that 5.0-believe me!

The front limited slip was only permitted with 3.54 front axle ratio and only with manual front hubs. This is the reason that the original owner of my truck didnt order it on my truck-he wanted the 4.09/4.10LS gearing to pull his horse trailer.

I looked at dozens of F150s of this vintage-I wanted front limited slip-couldn't ever find one! A three digit code, on the VIN sticker,under "axle", will signify a front limited slip-I believe it is "2xx"-if I remember correctly .

Since the OP lives in Cali-I suspect that he hasn't driven this front limited slip in snow. It would make a difference in traction-I bet!

 

3 digit AXLE code printed on the Certification Label (1980 to date); stamped on the Warranty Plate (1961/79); stamped on the Rating Plate (1959/60):

The first 2 digits refer to the rear axle, the 3rd digit refers to the front axle.

 

Yep. This is what my truck has. I'm still on the original hubs. And yes, I sure am glad they're not the auto-lockers!


The axle code is H9B. I kow H9=3.55 rear but can only assume the B=3.54 up front.


Interesting. As mentioned earlier in this thread, this truck has been in snow every year since new; granted it's only for a week or two at a time. I do notice a "wheel hop" during slow speed turns, particularly when nearing the max of each turn to the lock. I've always considered this normal when in 4WD. Otherwise, I have nothing to compare the handling to...this is the only 4WD truck I've driven in the snow. Seems all good to me.

 

I've never driven a limited slip front in snow, but I've driven a truck with front and rear automatic lockers. A locker in the rear is OK, but in the front is scary dangerous on snowy freeways. When one front tire loses traction (like when it hits the snow between lanes as you are changing lanes) you get VIOLENT torque steer toward that tire. All of the power goes to the front tire that has traction and it tries to pivot around the ball joints, whipping the steering wheel over pretty hard. The first time I changed lanes like that the truck SUDDENLY moved over 10 feet before I could catch it (luckily I wanted to make that lane change!). The second time I was ready for it and it only jumped over about 5 feet. I shifted out of 4WD and had the locker removed as soon as I could!

A limited slip would do the same thing, but to a limited extent. Limited slips won't put all of the power to the side with traction like a locker will. They'll still put more power to that side than an open diff (that puts all of the power to the slipping tire) so they'll still pull some. How hard they'll pull will depend on how aggressively they are set up.

 

Great explanation Bob. I've often wondered how the design and physics of a 4WD work when driving in the snow...particularly on freeways like you described. I've had that torque pull when changing lanes. I guess we get used to it after a while, but the feeling of unpredictability is always there.

 

I know that a locker is the harshest, but after my experience with that I'll never have anything other than an open diff (or a selectable locker that's open when unlocked) in the front axle of a truck I expect to drive at any speed in 4WD. I could maybe see going a different route in a dedicated rock crawler or mudder. But even there I think I'd go with a selectable locker.

 

I missed the posting of yours stating that the truck had been in snow. The wheel hop that you refer to in the above post-is that on snow ? Is this wheel hop felt in the steering wheel? Does the truck tend to understeer (make turns wider than desired) when making turns in 4x4 in snow and other low traction surfaces ?

 

The hop is not really felt in the steering wheel so much. There is a some predictable understeer when turning slowly in snow and 4x4. It's always been a handling feature that I've learned to deal with. Seems normal to me. But then again, I haven't much to compare it with...other than driving a 2WD car with chains.

 

I dont know how rare this truck is i bought its a 2006 ford fx4 stepside with a small rear back window but no seats in the rear. If you know can you tell me thanks im new just joined the forum. My stupid mac computer wont let me upload it either.

 

Would be better off in the SuperDuty forum!