| I love 2nd gear (with one question) [message #305456] |
Mon, 15 August 2016 20:15  |
DavidJForjan
Messages: 65
Registered: August 2016
Location: Tularosa New Mexico
Karma: 2
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FWIW, I did my first mountain driving today in the 1977 403ci 3.70 final drive 26' Palm Beach (maybe 250lbs extra weight total including me and my Dog). From Tularosa NM (altitude 4571) north on route 70 through Bent, through Mescalero Apache Reservation (up to Apache Peak alt. 7591) down into Ruidoso (alt. about 6600). And first I want to say I read all the posts here I could find for advice for this first drive in mountains. Thank you all very much for sharing your advice.
And I love second gear. While the inclines and declines were not REAL steep, not 6% for sure, it was a real test for me and the beast. I was very pleasantly surprised to learn how strong 2nd gear is. Going out of Mescalero town up to Apache Peak, I kept it in 2nd. The incline coming into Mescalero was too much for 3rd, and as many of you have pointed out, one cannot rely on the tranny downshifting by itself into 2nd, so I did all the shifting manually, which is always preferable anyway. And that 2nd gear took me right up to 7591 altitude Apache Peak very strongly. It's fairly steep, and I was even able to ACCELERATE going up the mountain, from 52mph up to 55mph, but since it held strong at 52-53mph, I held it there. No sense overworking the machine if not necessary. Just put on the flashers and let people pass (2 lanes each way). One aside, 45mph was not enough RPMs to maintain speed so I accelerated to 52 as soon as there was a little leveling off of the incline (had to find that RPM sweet spot). Coming downhill off Apache Peak was an even better surprise. At the top, I slowed down, cuz I didn't know whether 2nd gear would be strong enough to hold it back from taking off on me, and lo and behold, 2nd gear is so strong that it even slowed the machine down going down what on an even steeper decline than coming up. I didn't want to try 3rd gear; it's all downhill into Ruidoso (albeit it leveled off somewhat), kept it in second and had complete control over the speed without using the brakes once. 2nd gear in these THM trannys is a marvel. I love that gear. Coming back out of Ruidoso back home was just as easy, didn't slip into 3rd until the speed limit went back up to 65mph coming out of Bent. Except, and this is my question, I heard a 4 second squeal coming up to the top of Apache Peak, have to check belts? or could that be the Turbo Hydro-Matic?
Like I said, this is all for what it's worth to others. Thought I'd need 1st gear, but didn't, not for going up or down. And this ESPECIALLY I want to say. Thank you all for sharing all your very valuable advice about driving in the mountains with these motorhomes. It's accurate to say I couldn't, or wouldn't, have done it without you all. Thank you all very very much. Dave
David J. Forjan, 1977 403 26' Palm Beach, glad to have the 3.70 Final Drive and pork chop for level front end, Tularosa New Mexico
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| Re: I love 2nd gear (with one question) [message #305470 is a reply to message #305456] |
Tue, 16 August 2016 06:38  |
Chris Tyler
Messages: 458
Registered: September 2013
Location: Odessa FL
Karma: 7
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The squeel is not likely to be the tranny. Hard to say without hearing it. Also since it was transient, most likely a belt slipping.
When transmissions squeal they usually keep it up, and it ususally means Very Bad Things.
N/D will not hurt a healthy transmission as long as your foot is off the gas.
Going into reverse? Not so much.
Dont ask me how I know this.
76 Glenbrook
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| Re: [GMCnet] I love 2nd gear (with one question) [message #305488 is a reply to message #305483] |
Tue, 16 August 2016 21:50 |
DavidJForjan
Messages: 65
Registered: August 2016
Location: Tularosa New Mexico
Karma: 2
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Thank you A. Hamilto. That write-up you referenced in that link was one of my sources of advice. But, it also makes sense. I've only driven manual transmissions in my life. I've always used a lower gear to go down steep hills slowly. One just cannot hope the brakes will last when riding the brakes down a steep hill. And just intuitively, since brake failure is so possible in those situations, and so dangerous, one can surely rely on the fact that engineers have already realized that, and built in the ability to use lower gears to go down steep hills. It just makes sense that transmissions, for probably a very long time, have had this capability built into them. Seems almost a "given" to me. Thanks again.
David J. Forjan, 1977 403 26' Palm Beach, glad to have the 3.70 Final Drive and pork chop for level front end, Tularosa New Mexico
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| Re: I love 2nd gear (with one question) [message #305503 is a reply to message #305456] |
Wed, 17 August 2016 00:15 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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When using 2nd gear I would limit the rpm to a max of 4000 rpm with the 403 or 3500 with a 455. Going down you would likely be shifting from 2nd to 3 and back to 2nd on some grades. This type of driving makes it important to have a tachometer so you don't damage your engine by over reving it.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] I love 2nd gear (with one question) [message #305687 is a reply to message #305684] |
Sat, 20 August 2016 21:22 |
Hal StClair
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
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Senior Member |
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184 mph @ 6000 in high (no slip).
Hal 
"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane."
1977 Royale 101348,
1977 Royale 101586, Diesel powered,
1974 Eagle Bus 45',w/slideout,
Rio Rancho, NM
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