Being pushed down a steep gravel driveway

Here's my quandary. The maiden voyage mating my new 21 SR5 4x4 CM to the ~5000# TT will start by going down my 17% grade, 450' long gravel driveway. I have little room up here to do any meaningful test and adjustments to the trailer brake gain.

Here's my plan: Scrape excess gravel to the side of the drive first. Cross fingers. 4lo in S1 or 2 and T/H.
My fears are the TT brakes locking up and creating one helluva mess.
Do you think the Tundra will hold it back enough to keep it under 25MPH? There is a gentle 20* turn at the bottom but no then flat with no stopping for 500'. Can the OEM controller be adjusted in a way to prevent locking up the wheels on the way down? Some reading says to set the gain, manually apply the TT brakes and attempt to pull from a stop. If skidding occurs, reduce gain.
Thoughts on my predicament?

 

Uye. The trailer weighs almost as much as the truck - I’d think it wouldn’t take much for it to push the truck if it’s brakes aren’t set properly.

Backing the gain off 1 when the tires lock up sounds like the right thing to do, but I’ve never heard of setting the gain from a stop - only when rolling. Not much exp with this though, so that really doesn’t mean anything.

Sorry, can’t really answer your questions, but if I were me, and you were you, I’d consider getting the driveway paved.

 

Yeah, asphalt would be nice but for the distance the cost would be rather salty. I pulled the TT up here with the neighbor's old POS Dodge Ram 2500 in 4lo and it sound second gear and up we went without a problem. That was without the driveway having the loose gravel scraped off. As far as weight goes, the SR5 will be very close to gross. Fingers crossed there too.

 

That's one hell of a steep grade.

I've found the gain on my stock trailer brake controller to be a bit week, so a middle setting should keep it from locking up. Cannot guarantee it.

You're on the right track with 4Lo and S1, I think. Doing that, and then stab breaking as needed to keep your speeds as low as possible would be your best bet IMO. To figure your ideal speed, put the Tundra at the top WITHOUT hooking up, and cruise down the driveway. See what speed feels ok for that downhill and the turn, and then cut it in half for the tow. Again, just my opinion.


Chris @ColoradoTJ, you towed with your Tundra more than most, and you tow heavy in your diesel. What would your suggestions be? (I know, I tag you for all the towing posts. )

 

Can you back down, like launching a boat off a ramp? The turn at the bottom might be an issue. But it seems like it would be more controlled backing down.

 

On my Tekonsha control there is also a manual lever that I can use in situations like this to feather the trailer brakes as needed to slow the whole train down.
Is there a lever on the built in control like this too?

I would be a little slow to put in in 4Lo myself as sometimes when being pushed that can cause breaking loose in gravel too.

 

Sounds like a job for that POS Ram!

 

That looks like childs play. When I figured my grade I included the taper in and taper off so the quoted figure may be a wee bit conservative.
A normal FWD vehicle has a real problem coming up unless they get a run for it. My little 124 has a LSD and is RWD and walks right up. The Element has AWD and does well to. All bets are off when freezing rain hits. We park the Element at the bottom and take the 4wheelers through the woods to another road then to the car before the ice storms hit.

 

Oh my!

 

Not really other than take the old Wheelhorse with a blade and scrape off the loose stones. It's got a very good base than gives good traction if the loose stones are pushed aside.

 

Quick video

https://youtu.be/7fWKstqQfNE

 

Maybe that Carport at the bottom should give you another idea?

That does not look too bad to me though either.

Also good to see you are a man of good taste all around in vehicles!

I love my Toaster too!

 

The carport was the winter home for my little boat for a few years. The widow that owned it was my gray haired girlfriend, as my wife called her. I took care of her as if she was my mother. She passed away three years ago and the new owners brought with them the Class C. To be honest the carport is starting to get the leans and I wouldn't trust it much longer. Right before Betty died I was planning to add some diagonal bracing to extend the life a few years. I may end up building one up here if we decide to stay here.

 

I might try a 2nd truck behind the trailer in low range using it as extra braking down the grade?

 

I’d be afraid of losing steering in 4lo. Where are old school manual locking hubs… I’d probably creep in S1 2WD, not getting over 1-2mph, that way I keep steering. Maybe air down some for better braking traction? Good luck.

 

Why would you lose steering in 4lo?

 

4Lo, S1/S2. The video doesn't seem bad to me. You have a LOT of slowing/stopping room at the bottom of that hill.

Maybe hit S3 and ease up on the brakes gently if you start to feel like your tires are sliding down the grade rather than rolling...

You're more likely to maintain enough traction to steer without the tires locked up. But you know that.

Might be worth airing down your front tires on the Tundra for more traction into that turn? I'd definitely clear some of those rocks aside until I got a good feel for it.

Edit: Love your property!

 

We love the seclusion and the wildlife. Had a mature Bald Eagle perched in a tree at the edge of the yard a few years back. Less than a mile from the Tuscarawas river so they are a plenty here. The driveway has its pluses and minuses. Keeps the Jehovah's Witnesses away but takes work after a gully washer rain or heavy snow.

 

If the gravel is loose and the trailer brakes are not helping, one could get pushed. In 4lo, that can result in a front tire getting pushed in low traction substrate, starts skidding, no bueno. There have been plenty of times I’ve descended where it was in 2WD for that very reason. I can have the back skid some with a free front and steer. YMMV.

 

That makes sense. Thank you.

 

We have some real steep & loose stuff in Central and SE OR where I’ve played/hunted, let’s just say I learned some hard lessons fast. Actually got pretty dang lucky before I figured it out. It’s the gravel in this case, it can be like marbles. Why is why he is very savvy to talk about moving it out of the way, but it does not take much if being pushed by 5k.

 

At least it's limestone and not river gravel. Riding a motorcycle on river gravel akin to riding on geased marbles. It will definitely get the loose stuff plowed aside first. That's as simple and blowing the mice out of the Kohler cooling fins and one pass down and back. That cooling fan flywheel just does the number on mice.

 

Work harder, not smarter. Throw 1000 lbs in the bed before you head down.

When the truck picks up too much speed, just run along side it and drag your feet.

 

After watching that, I think that you will be fine. I tow a 8k tt and have seen my fair share of gravel roads. Only had to use 4wd once, backing up a very steep hill. Use a WDH set your trailer brake at about 7 to start, and shift down to s1. Then just go slow. If you keep the brakes on most of the way down you will be fine. If you try to coast down the hill and only brake when you feel like you are going to fast, that's when trouble will start.

 

Good point. No way the brakes will get much past warm in that short of a distance.
My last company vehicle was a 2009 F150 4x4 with the extra payload package. I got caught with it up here after a freezing rain once. Can you imagine my excitement when lifting off the throttle and seeing the tach and speedo needles dive down with the truck accelerating? The only thing I could do was to add throttle to get the tires rotating at the proper speed and hope and pray I could make the turn at the bottom. My experience is that it's easier to turn than stop under those types of situations.

 

Well we made down just fine. 4lo in S3. Made it to Cabelas in Louisville Kentucky for the night. CAT Scale said 40# over on the truck GVWR so simply moved a 40# grill and a 5# tackle box from the bed to the trailer. Axles on the trailer are rated at 5600# so I'm good to go. Trip after filling up before the scale averaging 11.8 S4-5, 65 MPH. TC temps ran around 215-225 and peaked at 240 on and entrance ramp. S5 works well but watch the RPM for the TC unlock and go to S4.