Yes, Black Bear Road is dangerous

I had seen that footage as well.  Still very scary.

But what do you mean about the Sterling's park brake being marginal?  The one on Big Blue is binary - it is either on or off, and you are NOT going to rotate the tires when it is on.  I know that because of my first test with the new winch a couple of years ago.  The instructions on the synthetic line said to install it the first time with 2000 lbs of force.  So I put Blue at the end of the driveway with its park brake on and in Park and put the park brake on Big Blue on with a few clicks - and the winch drug Blue w/o BB moving.  So I played with it and it is either on or off, there is no in between.  

As for what gear, I can see what you are saying.  But I think it is the fact that in the lowest of gears it would have to spin the engine at high RPM to move the truck at much speed.  Think of it this way - what gear do you go into for compression braking going down a hill?  Low.  And Blue's auto tranny does the same thing in Tow/Haul mode - a tap on the brakes and it downshifts.  Hit them again and it shifts down again.

That is good to hear about the Sterling parking brake Gary. I was going by my experience with the old axle that I removed from the crew cab. I fiddled with the adjustment but could never get it to hold worth a darn. I assumed that was just the way they were... I will, of course, be putting all new shoes, hardware and cables on the upgraded long yoke axle that is under it now. Hopefully it will hold as you describe.

Thanks for the explanation on the holding gear. I guess that’s my compartmentalized thinking for a non-running engine. Automatic transmissions don’t win many points in my book, but the “park”
position is one good advantage.

Yes, the Park pawl is an advantage for an auto.  As is the fact that you can ease into things and add just a bit more throttle to get over them.  But the 5.76:1 first in a wide ratio ZF5 is a bit better than the 2.46:1 of a C6.  Coupled to the t-case low and 3.55 gearing that gives 55.64 vs 23.93.  

Ford F834 wrote

....  I have heard about line locks not being an acceptable parking brake alternative in states that require vehicle safety inspections. There are many discussions around this in connection with rear disc brake conversion kits and the need for an alternative parking brake....

My understanding is that where vehicle inspections are required they are looking for an emergency brake that can be used to stop the vehicle if the regular service brakes fail.  A line lock uses the regular service brakes and won't help you at all if the service brakes fail, so it's useless as an emergency brake.  But that doesn't mean it's not a good parking brake.

Gary Lewis wrote

....  But what do you mean about the Sterling's park brake being marginal?  The one on Big Blue is binary - it is either on or off, and you are NOT going to rotate the tires when it is on....

Gary, I'm glad Big Blue's emergency brake works well, but the one in my '97 F-250 is TERRIBLE.  I've driven a few hundred feet with it engaged a few times.  It works well enough that I can tell something's wrong and I eventually figure out what it is.  But I'd never count on it for anything.

For what it's worth, it's so bad that a couple weeks ago I broke the cable trying to get it to hold just a little.  I haven't got around to replacing the cable yet, but I'm hoping that I can go through the whole linkage and get it working acceptably.  But at least as I got the truck it was pretty useless.

edit to add 2 Feb 2023:

Ford F834 wrote

....  This brings up another question... it was mentioned here that leaving a manual in gear is more effective in low range? Wouldn’t that ratio make it easier for the kinetic vehicle energy to overcome the engine’s compression and allow it to creep? Intuitively I would pick the highest gear to hold it instead of the lowest. What am I missing?

Going through this thread a few years later I saw this and didn't see that I responded to it.  If I did and I'm repeating myself here, sorry.  And if I didn't respond until now, then I'm sorry about that!

In lower gears the engine has an easier time turning the wheels.  Otherwise you could start in high gear.  But with low gearing the engine has more "leverage" on the tires, so it can turn them easier.

But when you go the other way through the drivetrain it's just the opposite effect.  For instance, if your manual trans has a 4:1 first gear, that means the engine turns 4 times for each time the driveshaft turns once.  But going through it the other way, the driveshaft sees it as a 0.25:1 overdrive.  Think of how much trouble your engine would have starting out in a 75% overdrive instead of 1st gear.

So that's what your wheels see when they try to spin an engine that's shut off.  The lower the gearing the harder it is for the tires to turn the engine, so the better the engine works as a parking brake.

Gary Lewis wrote

Yes, the Park pawl is an advantage for an auto.  As is the fact that you can ease into things and add just a bit more throttle to get over them.  But the 5.76:1 first in a wide ratio ZF5 is a bit better than the 2.46:1 of a C6.  Coupled to the t-case low and 3.55 gearing that gives 55.64 vs 23.93.  

"They say" (but who are they and what do they know?) that a torque converter gives about another 2:1 advantage in crawl ratio, so the 2.46 of a C6 is effectively a 4.92, which isn't much worse than a ZF5.

But that said, I really prefer low manual gears over the supposed advantage of an auto letting you ease into things.  Think of putting a front tire against a ROCK (not a grapefruit ).  With an auto you ease into the throttle and the engine makes more noise but nothing happens.  So you ease in a bit more.  Still just more noise.  So a bit more.  Now the tire climbs the rock and suddenly there's no ROCK slowing you down but you're still deep into the throttle and the engine is still turning 3000 rpm.  So you lift off the throttle, stab the brake, and maybe stop before you slam into something else.

On the other hand, with a manual trans you ease up to the ROCK and the engine stalls.  Bummer, but you haven't hurt anything.  So you do it again with a little more throttle.  OK, sure you might stall the engine one or two times, but eventually the tire climbs.  When that happens, like with the auto the ROCK is gone and you're still deep in the throttle.  But unlike the auto, now the engine is only at 600 rpm, so it's easy to lift your foot (or better yet, release the hand throttle) before the engine accelerates.  So you just smoothly go over the top of the rock.

Or with old-school trucks it's better yet.  When the engine stalls the first time you just restart it without pushing in the clutch.  In low gear low range the truck climbs the rock on the starter (and with the help of the engine at idle as soon as it fires up).  As it starts you let off the starter and you are idling over the top of the rock.

I know that hard core competition rock crawlers all use autos, so they have to be better.  But that doesn't mean they are necessarily easier.  And I really like rock crawling with a stick.

True, I'd forgotten about the torque converter.  But I'm with you, I think I like the manual.  However, I've not had the chance to try Big Blue yet, so how well he works remains to be determined.

By the way, Bob, your Bronco is carb'd.  Right?  Any issues in the San Juans?  Just wondering how important it is to get the EFI on BB.

What axle is in your '97?  I've not looked at BB's rear brakes so don't really know what I have.  In fact, the whole rear axle is pretty much as it was when I got the truck.  All else I've had apart, but the axle and brakes seem to be working, so....

My '97 has the Sterling 10.25".  My old '85 (which was built in Nov '84, so early in the model year) had a Dana 60.  I remember hearing that the Sterling 10.25" came in part way through the '85 model year.  If I'm remembering right, Big Blue could have either the Dana 60 or the Sterling 10.25".  If I recall correctly, the Dana has the fill plug in the cover and the Sterling has it in the casting in front.  If I'm right that would be an easy way to tell which you have.

And for what it's worth, the e.brake in the Dana 60 in my '85 would lock the tires.  It wasn't binary, you could feather it in if you wanted to.  But overall it worked well.

That makes me think, if Big Blue's e.brake is binary, could it be that the brake shoes are reversed?  I think brakes are a lot grabbier of you put the front shoe in back and the back in front.

Yes I'm carbed.  All of the 'wheeling I've ever done ('75 CJ5, '85 F-250, '71 Bronco) has been with a carb.

On the Jeep I had a set of smaller jets and a different power valve for the Holley.  I don't know if that was needed, but it ran great in Colorado like that (7000 ~ 14000 feet).

IF I recall correctly in the F-250 I leaned out the idle mixture (which was done with a needle valve) but left the jets alone.  It's been a while so I don't remember clearly how well that worked, but I know it wasn't a big problem.  Maybe just a little trouble starting at times?

I haven't done anything with the Bronco to go up to ~13,000 feet.  I can't say that it works well like that, but it's not really a problem.  The exhaust stinks pretty bad, I have to hold the throttle open to clear a flood every time I'm trying to start it, and it's pretty down on power (most, if not all, of that is due to the altitude, but some might be due to the rich mixture).

So would it be nice to have EFI?  Sure.  My EFI tow vehicles start and run as good as ever up there (but with less power of course).  But it's certainly not a requirement.


Having said that, there are people who say that EFI is almost a requirement for rock crawling at any elevation.  When you hit rocks fuel in a carb sloshes, which can flood out the engine.  And at severe angles you can starve a carb for fuel.  None of that is an issue with EFI.

That was an issue with the Holley in my Jeep.  Over the years I made a few modifications (vent baffles at least, I don't recall what else) to make it go from terrible to pretty good.  But the Autolite / Motorcraft 2 barrel is widely considered the best carb for rock crawling, and that's what my F-250 and Bronco both had/have.  So I haven't had any issues with them.

For what I think you'll be doing, at least at first, I don't think you'll have much trouble with that.  If you do, lowering the float level while you're in the rocks makes it a lot more tolerable.  Just remember to turn it back up when you get back to the highway or your carb won't be tuned how you think it is.

Ford F834 wrote

....  There is a line lock installed on my F-Superduty because the Cummins swap/Getrag 360 eliminated the Ford driveline brake. I feel comfortable enough with it on relatively flat ground where I will be using it (mostly to leave it running while I open and close our gate) but I wouldn’t care to use this on a backcountry vehicle. I like the driveline brake idea, but unfortunately there isn’t anything that will work with a GearVendors OD that I will have in my crew cab. I guess I will be stuck shutting the engine off and leaving it in gear since the Sterling parking brake is marginal at best....

I forgot to respond to this.  Driveline brakes have good and bad points.  A good point is that since it has the axle gears between it and the tires it's ~4 times stronger than it would be at the end of the axles.  The minus of that is that it turns about 4 times faster, so if you use it as an emergency brake you can cook it pretty quick.

But a big disadvantage off road is that it only stops the driveshaft.  If the vehicle is a little crossed up an open diff or TrueTrac will let the planted tire roll while the tire in the air spins backward.  A clutch-type limited slip helps this a little, and a locker solves it.

Of course if you are in 4WD a single driveline brake holds both driveshafts, so you'd need to be able to spin one front and one back tire to have this problem.  But being crossed up like that isn't that unusual.

Good to know about the carb.  I'll keep the EFI bit until last, and if all else is done and there's gobs of time I'll think about it.  But, I'll take a strip kit for the Eddy with me.  I have the AFR meter on it, so tuning should be easy.  Might even be able to do it with the metering needles, meaning the top of the carb wouldn't have to come off.

On the rear axle, I'd bet the shoes are in correctly 'cause now that the load proportioning valve is out the rear brakes work well.  On our 360 mile jaunt I told Janey to "hold on" and set it down QUICKLY.  No squalls and it stopped NOW!

And I'm pretty sure it is the Sterling.  It even has the long-pinion upgrade on it.

Well, ABC just aired a snippet of that video on World News Tonight.  And they said "Telluride".  

Janey caught it, of course, and she asked where - Ophir Pass?  Nope, Black Bear.  When?  A few days after we were there.  How close?  4.2 miles.  Are you going on Black Bear?  Probably.

But I took the opportunity to explain what we suspect happened, and she is ... ok.  

Yeah, Lesley saw it on the news tonight too and looked it up on YouTube to show me.  I said "yeah, I saw that a few days ago, I wasn't sure if I was going to show you."  

A friend of hers was chatting with her about it and Lesley said "we took our kids over that when they were 5 and 6.  But Bob's a better driver than that guy was."  So I guess Lesley is OK too!

Thanks for the insight on driveline brakes Bob. Those are some very good points that I hadn’t thought of.

Janey said she hopes our friends see it and ask us about it so I have the oppo to tell them more.  Given that, I think she understands that guy messed up.

Ford F834 wrote

Thanks for the insight on driveline brakes Bob. Those are some very good points that I hadn’t thought of.

Of course those same issues also affect leaving a manual trans in gear with the engine off, or putting an auto trans in park.  Another argument for lockers.

Wouldn't a Trutrac cause the other wheel to spin or slide as well?

Gary, here's a video of an F-250 going down Black Bear!

From 1:06 to about 2:45 he's on "the Steps."  That's the most difficult part of the trail.  It's a series of bumps and holes.  I guess people have rolled on this part, so it's not to be taken too lightly.  But it's not that hard either, and no one really remembers it after driving the rest of the road!  And the key to getting down it pretty easily is just to do your best to go straight down hills rather than straight down the trail.  In other words, don't get into the situation where you are dropping one front tire in a hole when the other is climbing something.  Turn so you go as straight into the holes as possible.

From 3:10 to 4:15 he's going around Adios Curve.  No one forgets Adios Curve!  This is where you first get out on the cliff wall.  It's actually very easy in a narrow vehicle, but the 1500 foot drop RIGHT THERE makes it seem nearly impossible.  But it wouldn't be a cake walk getting a full size truck around it without some body damage.

From 4:20 to 4:35 he's going down from Adios Curve to the first switchback (which you can see in the background).  This is a very steep section, but compared to Adios Curve it's straight and wide, so it's where you can start to breathe again.  However, from the full video that Ford F834 posted my best guess is that that Jeep went off the road along here, so while you can breathe here, don't get too relaxed.  Again my best guess, he was going to spot someone around Adios Curve.

At that point the video ends.  The first switchback that you just saw isn't bad.  Even a short wheelbase Jeep almost always has to back up once, so it might take a few with a full size.  But it's a pretty big, pretty level area.

The next section, from the first switchback to the second, isn't shown at all in this video, but the last part is shown from 1:00 to 1:50 of the video Ford F834 posted (how I know the Jeep fell from above this point).  It's a lot more level, but with some very narrow spots, and the cliff is still RIGHT THERE so it deserves your full attention.  It's possible that the Jeep fall started from this section as well (the Jeep that videoed it was on the next section of road, so at had to be here or above that it started).  But this section isn't steep enough for me to think it happened here.  And there's nothing here that I think he'd need to spot for.  This is a good place to stop, get out and take pictures, but don't take it for granted either.

From 4:39 to 5:37 of the fullsize video there are still pictures of a Ford Ranger on the second switchback.  And from 1:50 to 2:20 of the other video the Jeep is making a 5 point turn here.  That is the tightest switchback and the one that will be the hardest in a full-size.  It's also the one that freaks people out the most (well, after Adios Curve) because even Wranglers and early Broncos need to hang their front bumper off the cliff, and you usually end up with your left front driving right on the soft edge as you come off it.  The rock wall behind you and the big rock you are turning around is what makes this tough.  There's just no room.

After that the road is still narrow and shelfy, but if you haven't soiled your armor yet you won't be too concerned (still pay attention though!).  And there are a few more switchbacks that are 3 point turns in a smallish vehicle like an early Bronco.  But you're past the hardest and scariest parts by this point.

And I'll wrap this up with my same broken record.  This trail isn't for everyone.  Don't feel that you have to do it.  If you want to, sure go ahead.  It's not that hard.  But it's not a cake walk, it's scary, and it's dangerous.  That's all what makes it worth doing for some people, but it's also what makes it not worth doing for others.

Gary Lewis wrote

Wouldn't a Trutrac cause the other wheel to spin or slide as well?

I believe a TrueTrac will work just like an open diff in this situation.

A clutch-type limited slip will offer some braking (the torque it takes to slip the diff), but I wouldn't count on it.

Only a locker (or spool) will prevent either tire from rolling if the other loses traction.

Bob - Janey is sitting beside me so I'll watch the videos later when I get to the shop.  

But thanks for the commentary.  And the cautions.  They will be heeded.

What I'm thinking we may do is to run Last Dollar Road and then Ophir Pass on Day one with our wives.  Then on Day Two take them up to Animas Forks and do the Alpine Loop, although the last/north west section of that may be too much for them.  Then on Day Three they may stay in town or rent a car and drive down to Durango for the day, and my brother and I'll tackle something like Poughkeepsie Gulch.

Then, depending on how confident we are, we MIGHT go for Black Bear the next day.  Or, maybe not.  By then we'll know something about ourselves and our machines, and can make a better decision.