Raften
Northern Calfornia
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Joined: 01/27/2003
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Thats interesting INSAYN but I don't know what to make of it. As I read it you were coasting downhill but a manual would not allow you to coast like that without the rpm going up. I am the first to admit I know nothing about transfer cases hooked to autos and how that affects rpm. If you were going 25 and the rpm's were staying low that would seem to indicate a lot of converter slipage going on.
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jsmmv
California
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Joined: 06/16/2005
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Mooney wrote:DonCurley wrote:Mooney wrote:What does an automatic have to do with it? I can select almost any gear just the manual. How does the manual create more braking power?
When downshifting in the lower gears, many manual transmissions can often provide greater engine breaking power due to lower ratio gears as compared with an automatic transmission. Additionally, with a manual transmission, you don't have the typical slippage associated with a torque converter's "fluid connection" found in an automatic transmission, and you instead have direct clutch plate/pressure plate/flywheel contact.
Guess I'm still not buying it. Hit the tow/haul button and converter is locked. I can drop down to a gear that will take the engine all the way up to redline. If all that doesn't work and your still riding the brakes hard, then you're going too fast to begin with . . . regardless of the transmission.
I just finished a 4,000+ mile trip across 7 Western states with camper and trailer in tow. Never found a hill or grade the tranny wouldn't hold. I'm with you Mooney. A stick is fine if you want to be shifting all the time, I have had both. Take the exhaust break out of the equation and there isn't much of a difference. When you put it in 2nd or 1st the torque converter is locked up, no different than stick.
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Matthew_B
The boonies near Dallas, Oregon
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Joined: 08/18/2005
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btggraphix wrote:INSAYN wrote:If you have 4WD and the option of manual hubs, just leave the hubs unlocked, shift into Low gear, and crawl down as slow as you like, and probably never need to touch the brakes.
That's the best suggestion yet. I have been a fan of autohubs/push button on the dash (I am lazy at heart) but now that I have the manual hubs, that is a great option for steep downhills
I have heard of people that put a switch in the line to the hubs to enable 2 LO from the drivers seat.
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Raften
Northern Calfornia
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"I have heard of people that put a switch in the line to the hubs to enable 2 LO from the drivers seat."
That works if you have a vacuum actuated CAD or you can get a kit that does it with a push pull cable or you can do it the cheapest way, just plug the vacuum line when you need to.
* This post was
edited 05/15/08 10:16pm by Raften *
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palmwhit
Wisconsin
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Joined: 09/24/2005
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Okay I'll bite, where is the Sonora Pass, now that I know I need to go see/do it? Lot's of good ideas and thoughts on going downhill from y'all. I've always found that if you start out slow and don't get going to fast before you gear down further you'll be passed by most, till you get to the Midas store that is.
Again, lot's of good techniques for really getting things slow, and slower. Thanks guys.
Regards,
palmwhit
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kcabpilot
CA
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Joined: 04/07/2008
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Sonora Pass is Hwy 108 north of Yosemite runs basically from Modesto Ca to Bridgeport on Hwy 395.
On compression braking - there really isn't any such thing. A gas engine creates a vacuum when the throttle is closed. A diesel has no throttle so on every intake it takes in a full charge of air (actually more than a full charge if it's a turbo) when it compresses that charge it acts just like a big spring and pushes the piston right back down again so no braking effect whatsoever. A Jake Brake is actually a compression RELEASE that dumps the compression with an extra set of valves in the head. An exhaust brake acts similarly to what a closed throttle on a gas engine would do but does it on the other end by restricting the outflow and creating pressure on the exhaust stroke.
1994 Lance 990 on 1997 F350 PSD Dually
We also have a 'truck' that FLYS
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Shearwater
NE Ohio
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Joined: 12/23/2004
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We did Sonora pass west to east and several other passes including Ebbett's past last fall in our Sprinter van (small diesel, 5 speed auto with driver selectable gears, and probably about 8500 lbs total weight.)
We had no problems going up or down - just used the gears to slow down on the downhill side.
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