Mike and Paula
Palatine IL
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Joined: 07/10/2007
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I just acquired a Doug Nash DNE2 overdrive. It is a gear splitter that will give a 20% overdrive in 3 gear. I think DNE2 turn into the US Gear Dual Range units. Anyone ever install on there motorhome? Looking for real world results on an 8-10k Lbs., 25- 28’ers on a 460 c6 combo? I will have less than $500 into it so I will defiantly not get hurt on it.
84 Class C Holiday Rambler
Mike - PDM Navistar(International Truck and Engine)
Paula - Medical Transcriptionist
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DaCarmack
Murrieta ca
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Joined: 06/09/2005
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I have a Gear Vendor's in my 85 Lazy Daze with a 350 th400 and a 4.10axle. at 65mph my tach show 3300RPM to 3500RPM. When you shift in to Over 3rd it drop to 2600ish RPM. Much nicer. The best thing about the GV is the Over 2nd gear. To me that is the pass, power and hill pull gear. You can run Over 2nd to 65mph that's about 4000RPMs.
I tow a Carson trailer called an ATV 2 twin axle trailer and I am so happy I have the GV On CA 79 there is a hill I have to go into Over 1st if I have the trailer with the ATV on it. It would be no fun if I only had 3 gear's to chose from.
It was not cheep to have done, about $4500 all said and done but well worth it if you are going to keep the RV for some time
Rv'less for now 
2005 Honda TRX 400 ATV
1983 Honda 185s ATC
2004 Saturn Ion Redline (can you say sleeper)
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Mike and Paula
Palatine IL
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How about fuel economy? Did it improve?
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pauldub
North of Seattle
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Joined: 11/01/2005
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Usually an auxiliary overdrive is used on a vehicle that alternates between being heavily loaded or lightly loaded. This isn't often the case with a motorhome, un less you're pulling a heavy trailer at times.
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DaCarmack
Murrieta ca
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No the MPG did not change, but were I live you can't blink with out going up a hill. Just the fact that i could pull hill 5 to 10mph faster was well worth it. Not only that just having the engine run at a lower RPM was all so very nice. I got any were from 7.5mpg( with trailer and lots of genset time) to the 9's doing 60-65MPH. I got 10mpg once but that was a fluke.
My Lazy Daze was 22ft with a 10,500 GVWR and a 13,500 GCWR.
With full LPG(10gal) full gas(50gal) full water(50gal) it weighed 9200ish. I would go out to the Ocotillo Wells State Vehicular Recreation Area to ride my ATV, with the trailer I have, a Carson ATV 2 twin axle, it weight 1560lbs with a 7000GVWR, 1 ATV, 1 ATC 800lbs total, and two 5gal gas can's. So let call it 2500lbs for the trailer.
I also traveled light when I would camp. You know hamburgers, hot dog, you know cheap. So with a total wight of around 11,700lbs I got in the high 7's, but I ran the genset a lot.
It would do 65 on the flat's, but on a incline I would have to take it out of Over3rd and go into direct 3rd. Going up the Grapevine on I5 here in Cal, I could keep my speed up farther up the hill because of Over 2nd, but in the end I would still be a tick over 40MPH in direct 2nd.
If you need more info just asked away and I will try to help.
DaCarmack
P.S.
Sense you a 460BB I am sure you will be in better shape then me with a 350SB
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Dusty R
Charlotte Michigan 48813
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Joined: 04/05/2003
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Along the same line, most stake rack's used on farm's in the past had two speed rear/drive axels. I've often wondered why that type axel could have been used on MH before the over drive transmissions came out.
Dusty
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j-d
Sunny Florida USA
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Joined: 09/04/2003
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I don't think buying a new OD box and paying labor to install will ever pay off. If you can get yours running under $500 I think it'll help you. We had an 84 Holiday Ambassador 24, similar to yours without the tag, and it had enough power to handle 20% OD a lot of the time.
If you get into climbing hills, what I think you'll really like is Second Over. In the steeps, we either revved in Second or bogged in Third. The split should get you out of that.
God Bless, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100
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Mike and Paula
Palatine IL
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j-d wrote:I don't think buying a new OD box and paying labor to install will ever pay off. If you can get yours running under $500 I think it'll help you. We had an 84 Holiday Ambassador 24, similar to yours without the tag, and it had enough power to handle 20% OD a lot of the time.
If you get into climbing hills, what I think you'll really like is Second Over. In the steeps, we either revved in Second or bogged in Third. The split should get you out of that.
Pay labor......I have not paid for labor in 30+ years...lol I am a PDM for Navistar (instructor). You should see the toys I have access to at work. The only thing I will have to pay for is to balance the drive shaft after I shorten it. But your right I could not justify the 2k+ for a new unit.
I had this thing on a cat scale a few weeks ago and it is a tick over 8500LBS. If I run it at 60 It pulls 8MPG it I just run up another 5 mph the mileage falls way off also you can hear the secondary's opening on the carb as the rpms wind up. I would love another mile or two out of it before I dig into the tune up- I know it is running rich. If I can run 65 and pull 8 I will be happy. I am hopping the keeping r's down that will happen.
Long term goal is to keep the trans with the OD unit with a 4bt or a Fiat NEF 4.5 Diesel. the NEF can be set up for about 250 hp 400 ft of torque. This engine is pretty much a Cummins 6.7 missing 2 cyl. Mileage should be in the upper teens.
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