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Discussion Starter · #1 ·
Help! My Jeep won\'t go in the snow

I've been bummed out for a week about this. On Super bowl Sunday during halftime the lure of the unblemished snow in the south fourty was just to great for the collection of Yahoos at my house so we went out to play. The capability of the participants ranks as follows;
1st 99 Ford Explorer (Yuppie SUV) Totally stock w/31" tire package
2nd 85 1 ton Chevy longbed 454 open rears approx. 31" all terrain tires
3rd 83 CJ7 NEW BFG 31-10.50 All-Terrains on 8" wheels open rears
4th My 81 CJ7 New 31-10.50 Safari RVR's on 10" Rims ($50.00 for all4)open rears
5th 94 S-10 Blazer 40K miles on 235-75-15" BFG All-Terrains
The only reason the Blazer ranks behind my CJ is it took longer to dig out. This was in 8 - 24" of fresh powder. I was severly dismayed to watch that yuppie explorer doing donuts around me while I was just trying to move. The only thing that seemed effective was 4-low and lots of wheelspeed. All of my previous off-road snow experience was in a variety of full-size Dodges. Those suckers never stopped for anything but gas. I was thinking that maybe skinnier tires would help but I am hate to give up on those 50$ RVR's (they are fairly aggressive)Do I need to add some weight to the rear or what?Am I just expecting too much from a CJ? Does anyone know where I can buy a decent 1980 or earlier small-block Ramcharger?

jay2jeeps, and a well worn towstrap
 
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Discussion Starter · #2 ·
Re: Help! My Jeep won\'t go in the snow

Your jeep is not all that different than mine other than mine is a 83 CJ7 and has the LSD in the rear AMC 20. Last March we had some 20" of snow and mine was unstoppable. I used 4H most of the time and didn't have a bit of trouble even in 3 to 4 foot drifts. In and out of every ditch and creek I could find. Even pulled a few people out, including a 96 Z71 Chevy. OH was that fun!! It was great until I spun a hub on the AMC 20 going up a huge hill. Oh well that will never happen again. I put in the Moser 1-piece kit and have been runing strong ever since. BTW Stock 15X8 waggon wheels with Grabber 31X10.50's.
 
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Discussion Starter · #3 ·
Re: Help! My Jeep won\'t go in the snow

I think that the tires we all use are way to wide.
In this part of the world you are not going to drive
ontop of the snow. You are going to have to get your tires
to the ground and push your way thru./wwwthreads_images/icons/smile.gif
Back in the olden days when i was a kid the farmers
and as I got older at work we and them what ever was
running 7:50X16 and they would go thru snow like crazy>/wwwthreads_images/icons/crazy.gif
 

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Re: Help! My Jeep won\'t go in the snow

it's all about contact pressure. if you have two vehicles with identical tires but one heavier than the other, the heavier one will have more pressure on the ground. traction = friction coefficient times the weight.

79/CJ-7/AMC360/TH400/Q-TRAC/d30/d44/33's/RS9000s/Herculiner
 

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Re: Help! My Jeep won\'t go in the snow

I agree with the tire responses. The open diff's are a major factor in snow on a light vehicle. With big tires you are not getting the bite you need on top of the snow, and with open diff's you have two wheels (one front, one rear) that are basicly rolling resistance that you have to drag through the snow. With lockers or limited slips, all the tires would be pushing you around.
Just my $.02

Mike H.
1983 CJ-7 Laredo
1999 Dakota 4x4
/wwwthreads_images/icons/cool.gifo[[[[o
 
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Discussion Starter · #6 ·
Re: Help! My Jeep won\'t go in the snow

i used to get laughed at for running "pizza cutters" until they were on the end of the strap i was pulling them with. 34x9.5 swamps rock in the snow. they dont like the ice as well, but a little center siping helped with that.

dan

/wwwthreads_images/icons/smile.giflet it snow/wwwthreads_images/icons/smile.gif
 
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Discussion Starter · #7 ·
Re: Help! My Jeep won\'t go in the snow

I'll add my vote to those who point to the tire width as a key factor here. The wider tires are very nice under most circumstances, but snow isn't one of them. The width just tends to stay on top of the surfact rather than bite into it.

Bone stock rigs: '81 CJ7, '96 ZJ. Moab every summer!
 

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Re: Help! My Jeep won\'t go in the snow

/wwwthreads_images/icons/smile.gif Well J-2, if I had been there in my ZJ, I can TELL YOU who would have finished first. The ZJ with the 242 transfer case running open center FWD will drive circles around any yuppie, nipponeze, german, or US army conveyance. Using the factory-optional 225 75R Cooper Discoverers, on the '97 and later slightly-spaced-out wheels, nobody....I mean NO body....drives by our 4.0 ZJ with a full fuel tank for bite. We are BUILDING the ultimate SNOJEEP, and one which will run right with if not better than the ZJ, and that is a CJ 304 TH400 Quadra-Trac with the clutches disabled to get "open center" drive. Our snow shoes for the SNOJEEP will be Cooper Discoverer LT235/85 R16's on 16 X 7 wheels. In snow you need DIAMETER, not width. Our summer shoes for the CJ are 31 X 10.50 Goodyears, on 15 X 10 wheels, and it won't go ten feet in snow with that combination on it.

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 
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Discussion Starter · #9 ·
Re: Help! My Jeep won\'t go in the snow

i run super swammpers and some others in the past, i found that they all do well in about all the snow upper michigan can dish out, the only thing i do is air down to about 6-8 psi and i just float on top of it , no wheel speed and don't spin a wheel. for what it's worth
 

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Re: Help! My Jeep won\'t go in the snow

I have been preaching narrow tires for snow for quite some time. The wider the tire, the more weight and power required to get down to traction. This is why I leave my Jeep with 33x12.50 muds in the garage and take the truck with 10.50 muds for hunting and other snow adventures. If I lived in the Pacific NW, I would probably have a different point of view however, as the snow conditions are quite different.

Enjoying Montana's Big Sky (& rocks & rivers & mountians etc, You get the picture.)
 
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Discussion Starter · #11 ·
Re: Help! My Jeep won\'t go in the snow

My Coopers in 255/85R16 were the best snow tires I ever had - just a bit better than the 265/75's. Tall & skinny is where it's at unless it's unbelievably deep & you can somehow stay on top (like they do in Iceland). Then, & only then, do the rules change.

TEX

/wwwthreads_images/icons/wink.gif Got Mud?
G.U.M.B.O. Mud Racing
 

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Re: Help! My Jeep won\'t go in the snow

Hey CJDave,
I was wondering if you could explain why an open center 4wd is better for snow than a locked part time system, like a NP207 or 231. My XJ does good in the snow with the NP 207 t'case and the stock P215/75R15 tires. I was thinking it might have something to do with the weight distribution between the axles. My Cherokee has the lightweight 2.8L V-6 and the weight distribution front to rear is very close to 50%-50%.

TIA /wwwthreads_images/icons/smile.gif
xjy173
 

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Re: Help! My Jeep won\'t go in the snow

here's my understanding of why the open center is better. when turning a corner, all of the tires follow a different radius. if you add the distance covered by both front tires, it is farther than the distance covered by both rear tires. if the shafts are locked together, the axles are forced to turn the same number of revolutions (and travel the same distance). in conditions like snow and ice, with the tires turning the same revolutions, the steering becomes less effective and the vehicle resists turning. with the open center diff, all the tires are still driven but none of them are locked together.

this is similar to an open diff versus a spool in the rear. with the open diff, the tires can travel the different distances in a turn. with a spool, either the inside tire must slip faster than the ground it's covering or the outside tire must drag slower. with the weight transfer in a turn, the inside tire usually spins faster. maybe dave can explain this a little clearer. two weeks ago we got about six inches of snow here and i was having a much easier time turning than most of the other four wheel drive vehicles. they just wanted to keep plowing straight ahead.

my clutches are worn to the point that i have an open center diff too. i had another transfer case for a while last year that the clutch was so tight on it i could drive around without a front driveshaft and the transfer case unlocked.

79/CJ-7/AMC360/TH400/Q-TRAC/d30/d44/33's/RS9000s/Herculiner
 
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Discussion Starter · #14 ·
Re: Help! My Jeep won\'t go in the snow

disabling the clutches? are these the same clutches that drive the front end? if so how are you disabling them?Ive never been into a Q track but have been into the 128/129 cases and found if i disable (lock) the clutch pack,it acts like a part time case,both ends solidly locked together
are they different than what you are doing to the Q track?
 

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Re: Help! My Jeep won\'t go in the snow

Well, if the axle diffs. are open, wouldn't the tires be turning at different speeds (and thus the axle shafts) during a vehicle turn? From what I can see, that will allow the necessary slippage to relieve any driveline bind. What advantage is it to have the driveshafts turnig at different speeds during a vehicle turn on a lower than normal traction surface? It seems to me that with an open center, it would be possible to have the rear axle tires spinning away from a no traction situation but the front receiving no power at all. With a locked center, some power to the front axle would then pull you out of being stuck. Am I seeing this correctly???/wwwthreads_images/icons/tongue.gif
 

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Re: Help! My Jeep won\'t go in the snow

/wwwthreads_images/icons/smile.gif WILL's response is EXACTLY right, and there is ONE MORE aspect to it even yet. Here it is......now pay attention: The MODERN snow tires.....that is the Goodyear Wranglers, the Cooper Discoverers, the XYZs and the ABCs work on a COMPLETELY different principle than mud lugs do, or the old style snow grips. The rubber compound (invented by Goodyear and eventually pirated by others) allows a CERTAIN KIND of flexure at the tread level. As the small tread pattern gathers snow, and rolls to the road surface, the flexure DOES "WORK" ON THE SNOW.....that is it adds energy via the flexure and the squeezing action. That work input energy MELTS the snow momentarily, and the snow becomes liquid. The liquid quickly re-freezes to the ground, FORMING A REVERSE-PATTERN of the tire tread frozen to the ground....which the vehicle uses to push on and threrby gain traction. Two things are critical: ONE...speed; it takes TIME for this process to work, so high speeds don't get it. TWO...no spinning; there can be no churning from the effects of transfer case lock as the vehicle makes a corner, or it foils the melt-freeze process. Unless you can feed the front and rear axles with an open differential, SOME CHURNING HAS TO OCCUR.....which foils the process. Quadra-Trac cases(the original ones) have a barrel differential which is driven by a chain on the outside. The front and rear outputs are sticking out of the differential just as in an axle differential, with the spider gears inside. Two big cones are also hooked to the output shafts, and the cones "wring" into the barrel of the differential and try to prevent the output shafts from turning different speeds. (that was so you don't spin one front wheel on take off if you happen to be on gravel....the cones are totally unnecessary and a real nusiance). The cones will also push you around on snow, acting like a regular transfer case (as in a 231) exactly what you do not want. By filling the fuel tank in my ZJ, I can get very favorable weight distribution front-rear, and I tell ya folks....NO BODY drives by me when I'm in FWD open center./wwwthreads_images/icons/smile.gif The CJ we are building will be even better with a V8 sitting back from the front axle, a heavy automatic amidships, and a hardtop. I am going to be real interested to see how the weight comes out./wwwthreads_images/icons/crazy.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 

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Re: Help! My Jeep won\'t go in the snow

CJDave, I highly respect your ideas and your knowledge, I look forward to your input on these posts. On this subject, I do need to add my input. I have been driving in snow since before I could drive. Montana snow is on average much dryer than the snow the Coastal Mtn. get. Thus, what I may add here may be of no consequence to your conditions. I must add here that some of the information I will divulge is from my experience studying snow science from the perspective of the Skiing community, under the direction of a Phd in physics, whose specialty is snow science. First, anytime you have movement in the snow pack, you increase the amount of free water through friction. The free water is tractions enemy. I know nothing about what you mentioned about the technology of flexure you spoke, but from all I have learned, it seems just the opposite. When it is 30 degrees below zero F. here on a ski slope, skis don't slide well because of their inability to produce quantities of free water. Water IS formed however. to make skis slide, you polish the bases to reduce the surface area the water needs to act on. Note, a perfectly smooth surface is just as bad, in conjunction with the water, it will form a suction on the surface. Now remember, this is water forming at way below zero between a snow pack that is at the same temp. as the ski, way below zero. Because of this, I need to question the hypothesis that traction is gained by the refreeze of the water under the tire. My understanding is that a dynamic load will continue to produce stresses in the snow pack, and will continue to degrade traction through the production of free water. I fimly believe the ability of the tire to shed the water, remain flexible in the temp. at which it must operate, and have edges for the compacted snow to push against, and the ability of the tread to clean itself and remove those quantities of snow that it cannot compress, determine the quality of snow tire.

Enjoying Montana's Big Sky (& rocks & rivers & mountians etc, You get the picture.)
 

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Re: Help! My Jeep won\'t go in the snow

/wwwthreads_images/icons/tongue.gif Outdoor Life Magazine had an article about the squish-melt-freeze process about 1991 or '92. I had just bought some new Wranglers for my 2WD Suburban and could not, for the life of me, figure out why they hung on, AND they seemed to come up completely clean each revolution. When I read the article, I began looking at the tracks made by that style of Goodyear, and sure enough, it was a frozen tread. The coldest I've ever had them was seven over, which is, I'm sure, a summer day to you guys. The dynamics of the process MAY be changed once you get in the minus-minus part of the thermometer, but I don't know personally. I do know this, if the snow squeaks, I can darn near climb straight up with my ZJ, if I am careful not to use too much power and spin the tires./wwwthreads_images/icons/wink.gif I got my butt snowed on in late June [6/20/68]when I was working on a project near Deerlodge(stayed there...the work was in Gold Creek). Also found a buffalo rifle buried in the dirt out on the plains where we were working. I left it in John Hollenbeck's garage because I was going on to Denver. Whenever I talk to that Montana bunch (really GREAT people), they ask me when I'm coming back for my rifle./wwwthreads_images/icons/smile.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 

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Re: Help! My Jeep won\'t go in the snow

Thanks, Dave, Will, LE and JFR for your responses. /wwwthreads_images/icons/smile.gif

What got me thinking about this was something I saw just the other day. Here in Philly, the most difficult manuver for a vehicle, 4x4 or otherwise, is to extract itself from a parallel parking spot that is full of snow and ice. I came upon(I was on foot at the time) this late model ZJ Limited with the full time 4wd, trying to do just that. I stopped to render assistance and found out that the lady driving the Jeep was in the full time 4wd mode. Her front axle was just sitting there while the rear passenger tire was spinning away with no traction whatever. I suggested to shift the transfer case into the part time mode High Range and the Jeep came to life and extracted itself easily, with the front axle doing a good share of the work. Now, it could be that there was something mechanically wrong with her full time 4wd, I don't know. /wwwthreads_images/icons/smile.gif
 

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Re: Help! My Jeep won\'t go in the snow

/wwwthreads_images/icons/tongue.gif When we ordered our ZJ in the fall of '96, I took a good look at the viscous coupling transfer case that was offered as an alternative to the 242 Select-Trac, and the thought that came to mind was: "How do I control what the case DOES?" In slippery stuff there isn't enough power being used to make it lock up and serve the front drive, and if it does serve the front drive, it will be as locked up as a WWII Jeep. That system didn't impress me. There HAVE been times when I have had to reach down and "Yolk 'em up" to get all four pulling (Like-it-or-not, you're pulling!), but it is rare. Of course in Low Range, the center diffeential is locked up./wwwthreads_images/icons/smile.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 
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