Using 4wd Low for braking while towing?????
Thread Starter
|
More Turbo
Joined: Nov 2005
Posts: 687
Likes: 0
From: Prosper, TX
Using 4wd Low for braking while towing?????
So I was thinking about using 4wd low for braking while towing a heavy load going downhill (very steep hill) there are a few small turns. It is a side road that is not used much so I am not worried about people waiting for me while I stop to put it in 4wd Low. Is this a good idea? Had someone tell me that the front and rear gears are like .01% different front to rear? I had never heard that!
I know you are not suppose to use 4wd while on dry pavement thought maybe you could in this instance or maybe if the road is at least wet from rain. Any thoughts? Will I hurt the system by using it as braking? Is there a .01% difference front to rear? Yes I have trailer brakes just thought this might help save on brakes and 4wd low is barely used so I thought that might help.
I know you are not suppose to use 4wd while on dry pavement thought maybe you could in this instance or maybe if the road is at least wet from rain. Any thoughts? Will I hurt the system by using it as braking? Is there a .01% difference front to rear? Yes I have trailer brakes just thought this might help save on brakes and 4wd low is barely used so I thought that might help.
Cargo Master
Joined: Feb 2011
Posts: 3,450
Likes: 13
From: Forest lake minnesota
As long as its on gravel you will be fine doing it , it will definatly help with braking and it wont cause any damage to the truck so I say go for it. Just make sure you put it back it 2wd before you hit the pavement.
Laughing Gas
Joined: May 2008
Posts: 939
Likes: 1
From: Central Kansas
I think my main concern would be the increased turning radius, especially if the turns you mentioned are very sharp. With a lot of weight pushing you down the hill and not being able to turn very sharp, I think I would be nervous.
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
Not a good idea. Better than dry pavement, but still hard on the transfer case and front drive train. If you need low range on pavement, better to unlock your front hubs and run in 2WD low range. If you have ESOF you will need to turn off the vacuum to the locking hubs to accomplish that. With manual hubs, just turn them to FREE.
What reduced turning radius? It is the same in 2 or 4WD. Yes, it binds a little at full lock, but that is not a problem.
What reduced turning radius? It is the same in 2 or 4WD. Yes, it binds a little at full lock, but that is not a problem.
Laughing Gas
Joined: May 2008
Posts: 939
Likes: 1
From: Central Kansas
Maybe it's just my perception then. Whenever I'm in 4wd it just seems like I can't turn as sharp, even before full lock. Of course I've never used it on a paved road so that's probably the variance.
Trending Topics
Cargo Master
Joined: Jun 2008
Posts: 2,752
Likes: 5
From: Stillwater, OK
I believe the .01 difference is no longer an option...
I'm not an expert on Ford history, but it was something that GM did in the 1970's...
3.08 rear ratio and a 3.07 front ratio.
I'm not an expert on Ford history, but it was something that GM did in the 1970's...
3.08 rear ratio and a 3.07 front ratio.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Thread Starter
|
More Turbo
Joined: Nov 2005
Posts: 687
Likes: 0
From: Prosper, TX
HOw is this possible and why would you want that?
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
The specs for my '88 F150 listed a front ratio of 4:10 and a rear of 4:11 (or vice versa, can't remember) I always assumed that was just a rounding off error. But I don't really know.
But even if the ratios are in fact a tiny bit different, it won't make any difference because your front diff and rear diff already turn at different speeds all the time. That is due to the track of the tire when turning. Front tires follow a different track than the rear tires, and therefore a different arc distance. This is why you don't use 4WD on hard surfaces. The tires MUST slip a little bit, or something metal will break.
Not that I am aware of on a Superduty.
But even if the ratios are in fact a tiny bit different, it won't make any difference because your front diff and rear diff already turn at different speeds all the time. That is due to the track of the tire when turning. Front tires follow a different track than the rear tires, and therefore a different arc distance. This is why you don't use 4WD on hard surfaces. The tires MUST slip a little bit, or something metal will break.
Not that I am aware of on a Superduty.
Postmaster
Joined: Jun 2008
Posts: 2,564
Likes: 11
From: Wayyy NoCal, USA
My experience:
2WD low is the best option, and works quite well if you need to hold speed way down. Usually holding in 1st gear in 2wd is slow enough, but if you wanna go real slow, 2 lo is an option.
4wd on dry pavement: Never a great idea, but the drivetrains in these things are really stout. As long as you're not making tightish turns, it should be OK. Turning the steering wheel more than 1/2 rotation on dry will make for drivetrain binding and a lot of tire chirping and/or hopping. But I have not seen or heard of an SD actually breaking anything.
2WD low is the best option, and works quite well if you need to hold speed way down. Usually holding in 1st gear in 2wd is slow enough, but if you wanna go real slow, 2 lo is an option.
4wd on dry pavement: Never a great idea, but the drivetrains in these things are really stout. As long as you're not making tightish turns, it should be OK. Turning the steering wheel more than 1/2 rotation on dry will make for drivetrain binding and a lot of tire chirping and/or hopping. But I have not seen or heard of an SD actually breaking anything.
Cargo Master
Joined: Jun 2008
Posts: 2,752
Likes: 5
From: Stillwater, OK
Different ring & pinion setups.
If your front tires turn a little faster it is supposed to aid in steering traction... Does it work? ...sometimes.
If your front tires turn a little faster it is supposed to aid in steering traction... Does it work? ...sometimes.
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
It is worth adding a caution - if you are using the transfer case to control heavy downhill loads, be very careful. If you accidentally hit neutral on the t-case, you will be freewheeling. No front OR rear drive. The synchros are not great on these t-cases, either the manual or ESOF versions.
More Turbo
Joined: Feb 2011
Posts: 719
Likes: 17
Great thread. I have sort of the same question...
I had an 03 Expedition towing a 9500 pound travel trailer. Several times over the years, we came upon steep and long downgrades. The trailer has brakes, but the Expedition just didn't want to hold it back and by the time we got to the bottom of the hill, all four wheels were smoking.
So what is the proper method for braking when towing on a major, long, sometimes twisting hill?
I had an 03 Expedition towing a 9500 pound travel trailer. Several times over the years, we came upon steep and long downgrades. The trailer has brakes, but the Expedition just didn't want to hold it back and by the time we got to the bottom of the hill, all four wheels were smoking.
So what is the proper method for braking when towing on a major, long, sometimes twisting hill?