under/over drive

[WMonroe]

anyone here running one of the underdrive/overdrive units? How do you like it? How expensive are they? I really like my 4. 10 gears except for running out of tach on the top end.

thanks

Will

 

[JWChessell]

Over/Under drive

Do a search in "3rd Generation" for "gear vender. " There is a thread with four posts. I copied it and will try to paste it here as an addition to this post:





OK, it worked. Here's the thread.





ckusy





Registered: Jan 2003

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gear vender

newbee-would like to know if anyone has installed gear vendor,if so what do you think of it. thanks







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10-23-2003 04:07 AM







wsurf





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Just had one installed. Have not run it long enough to know durability but the double over really lowers the RPM (2100 to 1650 at about 65mph, auto trans) and noise. I hear that they are good units from everyone I know that has them, they shift real smooth.





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03 QC 4X4, SO, 48RE, all white, stock so far







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10-23-2003 11:15 AM







JWChessell





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I owned a '81 Chev 454 cu in GAS 1-ton 4-dr crew-cab DRW 4. 10 RAxR 3-spd Turbo 400 auto trans from '89 to '03. In '92 I purchased, repaired an installed a used Mitchell two-speed overdrive -- gear ratios were 1:1 and 28% OD. Total installation cost was about $1350. 00 (cost new and installed from a Mitchell dealer was about $2800. 00 at that time). The Mitchell raised gas mileage about 10%, which in the gas truck was an increase from approx 10. 5 mpg to 11. 5 mpg, although from time-to-time, especially with a tailwind and a long level drive with cruise control, I got as much as 13. 5 mpg.



Some quick math with the desk calculator indicates that during those 11 years PERHAPS I saved between $350 and $450 in fuel costs, meaning it would have taken around 30 years to recover my installation costs. What the Mitchell OD did do, however, was allow me to run lightly loaded on long trips at 65 to 70 mph without high engine noise, and still get about 10. 5 mpg, rather than the 9. 5 mpg we had been getting at those speeds before installing the Mitchell. It was the TIME element that the Mitchell affected, as opposed to driving range or cost -- we could make a 400 mile trip in 6-1/4 hrs rather than 8 hrs, and still remain within fuel budget for the trip (not counting the cost of the overdrive itself, of course).







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10-23-2003 06:20 PM







wsurf





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I agree with JW. I got one for towing (my 4 speed auto now has more gears) and the lower RPM and noise at cruse. I can now do 65 to 75 without high RPM's. You cannot make the mileage increase pay, but what is a couple of thousand when you spend 30 to 40K on a truck !!







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10-23-2003 11:10 PM







Khood





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The guys at GV told me once I switch that gear to OD I'd be hooked. I WAS! I've got the 4. 10 axles,at 70 mph 2400+ rpm.

With GV shift,I'm running 1650 rpm at 70 mph. Its smooth too.

Call the guys they'll tell you all you need to know. I believe they like the calls. Its not cheap ,but it will give you more gear options

other wise you'd never have. Installation was easy if you are some what mechanical. The biggest problem is having someone to do the driveshaft shortening. Mine was $115. 00.

As for economy it can only be better. As for payback,it would be a long run for the cost. For me and now,with the 6 speed run-

ning 70+ mph for hours on end ,its good to have.







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11-05-2003 01:18 AM







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[Turbo Thom]

Will:

Just remember the e-brake will not work with the GV unit. It operates much the same as the auto transmission. Also unless they have fixed the flaw, 4X4 is out also. The overdrive unit mounts behind the transferr case.



My US Gear unit goes in between the t/f case and the transmission. It being a direct shift unit the e-brake works fine also. I put about 82K miles on my first one before I burned it up. I had to much oil in it. It takes one quart. no more. I don't think I could tow without it again. I lost the transmission in my truck 2 weeks ago and had to tow my work trailer to Savannah with the wife's 2500 5 speed. After 6 years with the US Gear over-drive, what an experence. I made it but never felt I was in the right gear. I like mine. It has done a great job for me. The US Gear e-brake I think is the best, too. Two things I just can't leave home with out.



. . Preston. .

 

[4xquadrod]

Gear Vendors

I installed a unit on my truck last week. My purpose was for lowering rpms on the freeways to get rid of the drone at 70 - 75 mph. It worked perfect for this plus my top end is huge with lower rpms. Pricey but with the other mods I had to get rid of that drone at 70. I have been running one on my motor-home for 3 years now with no problems. Just have to remember not to use the unit to slow yourself down on the grades.

 

[Doubleclutch]

Hey Will- I'm glad to see you're getting some good feed-back on your question. You have the CC truck and 4x4 so you could go with either GV or USG. The GV is all hydraulic, the USG mechanical. I would suggest that you visit both websites and read the information offered. You'll get some good info here but some of the answers will be written by a bruised keyboard. Like almost everything else we do with our trucks, we feel that our way is best, and why do others think their's is?

I went with GV because I have a standard cab 4x4. There is a relay to prevent operation of the GV in 4x4. I use an exhaust brake. I've made a simple relay to prevent it's operation while the GV is engaged (exhaust brakes need rpm to operate, higher the better). When the GV is 'IN", the only way you can tell is by the green light or checking the switch on the stick. Quiet! The USG has 4x4 capability at the expense of modifying 2 drive shafts. You don't need a relay to prevent an exhaust brake but as mentioned, more RPM make for a better retardation. I looked at both units, just as you should. I'm happy with the GV, but could be just as happy with a USG were it not for my standard cab. This will be a functional addition to your truck, especially when driving roads too slow for 4th, and too fast for 3rd.

Greg

 

[rweis]

The USG will take an ebrake.



I have a USG ebrake and love it. With an ETC have to lock up the T/C.



I have 3. 54 and run 65 @2400 O/D out. Great torque, and 65 is fast enough with the 5er for me. I like 2400 also because the air flow is great and the EGT's stay lower.



Bob Weis

 

[WMonroe]

Thanks for all of the replies everyone. Thats a lot of great info. I'll have to check out the websites and do a little research. They both sound like great products.

Thanks again

Will

 

[Mopar Man]

Overdrives

I have a GV in a 97 5 speed and love it. It got rid of the big gap between 3rd and 4th as I use 3OD, then 4 direct, then 4OD when towing. The difference between 4OD and 5 direct is about 200 rpm (and 5od is too tall when towing) so I tow in 4od all the time and when you come to a hill that needs a lower gear, it is click, fast clutch, and you are in 4 direct. I also have a exhaust brake, but stock 30 Lb valve springs and I just don't use the exhaust brake in od. Not a problem as I see it.

 

[Loren]

Will,



These units are expensive, but I think they are worth it. Unless you drive about 100,000 mile a year, though, they will not pay for themselves in fuel savings.



I have a U. S. Gear because I have a 4x4 and wanted to be able to use overdrive in 4WD.



Some trucks with six speed transmissions require shortening the fuel tank to use the U. S. Gear unit. It's a lot of trouble and can be expensive.



You will like the additional top gear. With the U. S. Gear overdrive, you will have the equivalent of a 3. 28 axle ratio. I think that splitting the gears is more of an advantage, though.



I am hoping that Robert will publish in the next TDR my article I submitted. I covered the pros and cons of the U. S. Gear and Gear Vendors transmissions, as well as what you can expect after installing either one of them. Look for it.



PM me with specific questions if I can help, but I check e-mail and this web site only about once each week.



Good luck.



Loren