Rear gearing and snow

[crw]

BOF... I believe means body on frame.

Sometimes (well, almost all the time) it's better to write things like this out. If your reader needs to stop and ponder what BOF means, they will likely tune out on you.

 

[supton]

BOF = Body On Frame. Sorry, figured it fit in with a 4WD, AWD, RWD, FWD, V8 discussion...

Haven't owned an automatic yet, my prior RWD's were 4 cylinder manual transmission. And my parents Astro was an old-school 4.3L TBI, not exactly a tire burner either. I do recall that being tricky to module the throttle in, due to the mechanical throttle linkage.

 

[rslifkin]

I generally leave the Jeep in 2wd until I really need extra drive traction, so it's effectively RWD in up to 4 - 6" of snow. The rear diff has a clutch type limited slip in it. It's also got a 2300 stall converter and 3.73 gears stock (although it has a tall 2.45 1st in the trans), and more than stock power.

It definitely requires some care in the snow, considering it'll spin up all 4 and get sideways in 4wd without breaking 2500 rpm (and punching it at 30 in the rain lights 'em i up on the 1st gear kickdown in 2wd). However, if you're gentle with the throttle and aware of what gear it's in (no way to force it to take off in a gear higher than 1st), it's pretty easy to handle.

I find lower (numerically higher) gearing better, as it gives more control (although you have to be more careful not to juice the throttle too hard to avoid snapping the tail loose).

 

[AuthorEditor]

Another data point on this. I once had a Rabbit diesel with very low HP, but decent torque. She was amazing in snow. I could just click it into gear and it would roll forward slowly with almost no throttle and no wheel spin, sometimes pushing a huge mound of snow ahead of the car like a plow.

 

[The_Jeff]

Originally Posted By: AuthorEditor
Another data point on this. I once had a Rabbit diesel with very low HP, but decent torque. She was amazing in snow. I could just click it into gear and it would roll forward slowly with almost no throttle and no wheel spin, sometimes pushing a huge mound of snow ahead of the car like a plow.


I'd have to imagine. Didn't they roll on skinny 155/80/13s or something? A heavy diesel on a 1980's front wheel drive would be heavenly.

In a simple answer to OPs question, what does one do most in the snow? Drive slow. Shorter gearing moves more choices lower in the speed band.

 

[supton]

You're right, one is usually moving slow in snow. I'm more concerned about when I'm not moving at all.

 

[AuthorEditor]

From a Wikipedia article on automatic transmissions:

Quote:
Second (2 or S)
This mode limits the transmission to the first two gear ratios, or locks the transmission in second gear on Ford, Kia, and Honda models. This can be used to drive in adverse conditions such as snow and ice, as well as climbing or going down hills in the winter time. It is usually recommended to use second gear for starting on snow and ice, and use of this position enables this with an automatic transmission. Some vehicles will automatically shift up out of second gear in this mode if a certain RPM range is reached in order to prevent engine damage.
Although traditionally considered second gear, there are other names used. Chrysler models with a three-speed automatic since the late 1980s have called this gear 3 while using the traditional names for Drive and Low. Oldsmobile has called second gear as the 'Super' range — which was first used on their 4-speed Hydramatic transmissions although the use of the term continued until the early 1980s when GM's Turbo Hydramatic automatic transmissions were standardized by all of their divisions years after the 4-speed Hydramatic was discontinued.

 

[SteveSRT8]

Typical Wiki, 'mostly accurate'.

Our GM vans and trucks all do this, put them in second gear and they stay there. Floor it and they will downshift to first, rev them too high and they will upshift to 3rd.

My Chrysler has full manual control of all gears with NO auto shifting if I desire.

 

[supton]

I had a rental Camry a bit back, but didn't test this feature. I know it would still downshift if I got on it, but I didn't try to take off in 2nd. Will have to test out in future rental/loaners.

I want to say I've read GM and Dodge manuals that stated, if put into 2nd gear (traditional 3 and 4 speed autos, none of the electronic controlled ones) it would start in 1st, and go into 2nd if the speed was high enough; but no further.

 

[hypervish]

My RX300 has a snow button that will let me start off in 2nd gear. I never need it though as I have full time AWD and never really lose traction, even in the middle of winter in Michigan. I also have a power mode, which changes the throttle mapping.

 

[itguy08]

Originally Posted By: Garak

My old 1983 LTD with the 2.3 was absolutely gutless. I have no idea what its gear ratio was, but due to its absolute lack of power and its decent balance, I never got the thing stuck no matter what I threw it into. While that car had its share of faults, an ability to carefully modulate the throttle in poor traction conditions was not one of them.

Sounds like my first car - 86 Mustang with that same 2.3. Also gutless but I found with snows and 100lbs in the trunk and snows it was nearly unstoppable. That and a healthy dose of wheelspin. I remember running up some hills in 2nd (it was a 4 speed stick) with the engine screaming at 3-4k. Never an issue getting up and a lot of fun in an empty parking lot.

Definitely love RWD in the winter!!!

 

[Garak]

Originally Posted By: itguy08
Sounds like my first car - 86 Mustang with that same 2.3.


If I ever got into any extra trouble, I could start in second, since the automatic allowed the override. Yes, it was terribly gutless, but I drove in a lot of bad weather without issues.