Winter Driving

[Fageol]

They've never hassled me about putting them on the rears. I don't think they give a crap as long as they're on. California cops (in my experience) are not as a**l about stupid s*** as Oregon. Even Oregon doesn't care, as long as you're wearin' shoes in the snow.

I don't think it's for us to keep from sliding so much as it's to break up the hard-pack so the scrapers can move it off the road.

In most instances chaining the rear drive tires is certainly the practical thing to do unless one has little tire-fender clearance or if one has some of those fancy fenders or flap mounts that don't allow one to remove the flaps. Then it's pick your poison. Look through a place filled with 3-axle tractors and one tends to find the rear drivers worn more than the front drivers. I am told that the forward drive axle receives more power than the rear drive axle but have not seen the physics, mechanics, or math that says so. Perhaps that's the rationale for the California chart.

On a similar note, last year I was returning from Fairbanks. The first hill one climbs was Ester. It was plowed and sanded. Not once did I wipe my feet. Then came the next big climb, Skinny Dicks (named after the old roadhouse, Skinny Dick's Halfway Inn -- google it). The Alaska DOT didn't do a thing to it so it was slicker than snot. But I was rolling and there's not much of a place to throw iron. Got near the top, burned out, and slid backwards the length of the rig (120'). I succeeded (or maybe I was just lucky) in getting the the tail trailer (a 45' can) into the ditch stopping the slide. The tractor and the lead trailer (a 45' reefer) remained in the southbound lane. The dolly was about halfway into ditch. I hung 8mm 3-railers on the drivers and yanked the trailer out of the ditch (I was already locked up) and returned to Anchorage with no further excitement. From this and at least one other burn-out, those 8mm chains are the way to go. But I'm guessing that they're pretty spendy.

 

[Injun]

Unless the PDL is locked, my rears do not receive power. All I have to do to test this is back into my driveway. There's a little dip at the street end about an inch deep at its deepest and about 18 inches wide. It tapers down from the sides.

I go really slow into my driveway because I don't want to tear up the gravel. If I don't lock my PDL, I'll get the rears pushed into the driveway and the front drives will be lifted off the ground. Remember those sit-n-spin toys from the late 70s? Well, that's what I do: Sit n Spin.

 

[Rigjockey]

This sucks! they gave me an automagic. I have never thrown the iron but, then again I have never been stuck in a standard transmission truck, That I could not get out of. Automagic trucks, When you are stuck, You are stuck! And nobody wants to pull you out with a chain!

 

[Duck]

Remember those sit-n-spin toys from the late 70s? Well, that's what I do: Sit n Spin.

I had 2 of them.



I guess they still make 'em.

 

[Rigjockey]

I had 2 of them.

View attachment 23328

I guess they still make 'em.

I had one of those too! Best toy ever! i am still spun! LOL

 

[Fageol]

Unless the PDL is locked, my rears do not receive power. All I have to do to test this is back into my driveway. There's a little dip at the street end about an inch deep at its deepest and about 18 inches wide. It tapers down from the sides.

I go really slow into my driveway because I don't want to tear up the gravel. If I don't lock my PDL, I'll get the rears pushed into the driveway and the front drives will be lifted off the ground. Remember those sit-n-spin toys from the late 70s? Well, that's what I do: Sit n Spin.

Can't you lock up the interaxle differential (and axles if necessary) and just back on out?

 

[Injun]

Can't you lock up the interaxle differential (and axles if necessary) and just back on out?

I believe that's what I said:

Unless the PDL is locked, my rears do not receive power. All I have to do to test this is back into my driveway. There's a little dip at the street end about an inch deep at its deepest and about 18 inches wide. It tapers down from the sides.

I go really slow into my driveway because I don't want to tear up the gravel. If I don't lock my PDL, I'll get the rears pushed into the driveway and the front drives will be lifted off the ground. Remember those sit-n-spin toys from the late 70s? Well, that's what I do: Sit n Spin.

PDL=Power Divider Lock.

 

[Hammer166]

Unless the PDL is locked, my rears do not receive power. All I have to do to test this is back into my driveway. There's a little dip at the street end about an inch deep at its deepest and about 18 inches wide. It tapers down from the sides.

I go really slow into my driveway because I don't want to tear up the gravel. If I don't lock my PDL, I'll get the rears pushed into the driveway and the front drives will be lifted off the ground. Remember those sit-n-spin toys from the late 70s? Well, that's what I do: Sit n Spin.

Actually they do. The torque is divided equally among the 4 corners until one of them loses traction, and then all the torque is directed to the spinning wheel. It has to do with the fact that the spinning wheel's effective gear ratio changes when it starts to slip. I had a really good article on it posted on the dark side somewhere, but I'm too brain dead to go look it up right now. I'll try after dinner.

The greater wear on the rear drive is because it is further from the center of gravity (which is where the truck wants to pivot) and so has more scrub in cornering.

 

[Fageol]

I believe that's what I said:

PDL=Power Divider Lock.

Sorry, didn't know the acronym. Probably a product of old age.

 

[Fageol]

Actually they do. The torque is divided equally among the 4 corners until one of them loses traction, and then all the torque is directed to the spinning wheel. It has to do with the fact that the spinning wheel's effective gear ratio changes when it starts to slip. I had a really good article on it posted on the dark side somewhere, but I'm too brain dead to go look it up right now. I'll try after dinner.

The greater wear on the rear drive is because it is further from the center of gravity (which is where the truck wants to pivot) and so has more scrub in cornering.

I thought that correcting for the different radii was the purpose of a differential and the interaxle differential accounted for the distance between the drive axles. Guess some research is in order. Been too busy with reviewing a friend's book and household projects for thinking about physics/nechanics etc.

 

[Hammer166]

I thought that correcting for the different radii was the purpose of a differential and the interaxle differential accounted for the distance between the drive axles. Guess some research is in order. Been too busy with reviewing a friend's book and household projects for thinking about physics/nechanics etc.

That is the 'why' for the diffs. But because they act like locked differentials when everything is turning equally, they are quite effective at torque distribution.

 

[Fageol]

That is the 'why' for the diffs. But because they act like locked differentials when everything is turning equally, they are quite effective at torque distribution.

From your comment can I then infer that some other force is scrubbing rubber off the rear duals although the interaxle differential along with each differential is accounting for the changes in radii? Or does the interaxle differential have a different function or insufficiently corrects for the changing radii?

 

[Duck]

The drive axles are parallel to each other, so when you turn, one of them has to side-slip. He says the tractor will typically pivot on the front drive axle, so the rear is the one that side-slips.

 

[wogelsby]

Drove lots of Eastern snow. While a newbie I slipped into a worsening lock-t0-lock fishtale climbing a bridge in Toledo, light load... suddenly hit a dry patch and straightened out. The guy behind me made my day. Said on the CB, "Congratulations, I've never seen anybody catch a jacknife". Took me a few miles before I could breath again.

 

[Duck]

Drove lots of Eastern snow. While a newbie I slipped into a worsening lock-t0-lock fishtale climbing a bridge in Toledo, light load... suddenly hit a dry patch and straightened out. The guy behind me made my day. Said on the CB, "Congratulations, I've never seen anybody catch a jacknife". Took me a few miles before I could breath again.

That happened to me on the Dan Ryan expressway in downtown Chicago one morning. It caught me completely & totally off-guard since it happened to be the middle of summer & I had almost 30k on my drive axles. I must've hit an oil slick or something. I just stepped on the clutch & counter-steered a bit, fishtailing back & forth until I eventually decided I wasn't gonna pull out of it until I applied some trailer brake. That pulled me right out of it, since I had probably 35-36k on the trailer axles. (I'd been legal the whole way from Iowa but ran my trailer axles all the way forward once I got past the last DOT scale, because of the tight area I was headed into.)

After the truck was completely back under control, the adrenaline rush made it hard to breathe.

 

[krelithous]

when the weather outside is frightfull the only judgement that matters is the DRIVER'S!!! Use it responsibly and don't delegate it to anyone else such as a travel agent in an office hundreds of miles away. If you don't feel safe to drive then park it until you do!!
how hard is that

 

[Savpete]

I love driving in the snow! I'm just weird like that though!

 

[krelithous]

I love driving in the snow! I'm just weird like that though!

not me .