I'd like to hear form anyone using the "Gear Vendor" overdrive.
What kind of experiance have you had? How fast does it shift in/out of overdrive? Any change in gas mileage? Thanks, Deen

Deen Hylton
Ford F250 460 C-6, K&N, Headers, Dual Exh.,Comp. Cams,Shift Kit
Pioneer CD w/Bose Speakers.
Other Passion: Blown 77 Corvette (Sorry Guys/Gals)
How I can afford to Drive the above: 93 GEO Metro

 

Deen,

I thought of installing an over-drive unit in the quest for some better mileage. I brought the subject up in the course of changing out the tranny fluid at a local transmission shop (one of the largest in our large metropolitan area), and the mechanics there told me they have a strong business in removing old over-drive units restoring vehicles to their original configuration. But, .... they put'em on too.

In my situation, for the type and amount of driving I use the truck for, coupled with the cost of the unit and the miniscule improvement in mpg, they recommended that I just use the C6 and live with the mileage.

I typically get 7'ish mpg (mostly highway) towing the boat to the ramp, and last Saturday in gridlocked, stop and go traffic, I think I managed about 4 mpg. Still WAY better than the boat.

Your mileage my vary..... (pun intended).

After my fill up following Saturday's experience, I too would be interested in some real life over-drive unit mpg stories....

Chris
'88 F350 XLT Lariat CC DRW/7.5l/C6/4.10
'93 Mustang LX 5.0l/T-5/3.55's/Flo's/pulleys/K&N/Synthetics
Nissan p/u (DC commuter)
Volvo 940

 

Chris, what kind of mileage do you get when your empty? I have 3:55 gearing and average 7.5 MPG towing 9,000 lbs. and get 11.5 running empty. I have a set of used 4.11's on the shelf but have not installed them yet as they would only come in handy on the steepest grades when towing. I can excellerate up a steep grade when towing my 20' boat but can only maintain 45 MPH in high gear on the same grade when towing 9,000 lb....hence the thought of purchasing the "Gear Vendor" for the additional split gearing.
I will post in another area to see if anyone else is running an overdrive.

Deen Hylton
Ford F250 460 C-6, K&N, Headers, Dual Exh.,Comp. Cams,Shift Kit
Pioneer CD w/Bose Speakers.
Other Passion: Blown 77 Corvette (Sorry Guys/Gals)
How I can afford to Drive the above: 93 GEO Metro

 

Deen,

I get 10-11 mpg empty, and that's mostly city driving. I only use the truck to haul the family&pull the boat and rarely get any "highway mileage" time. Its just too big a gas hog and PIA to find decent parking spots at the grocery store/Wal-Mart. But I wouldn't expect to get too much better mileage on the road.

My entire rig (truck, boat, trailer, people, fully fueled, pop/beer, etc.) weighed 15,500 lbs at the truck stop scales. Based on the printout of steering wheels, drive wheels, trailer wheels weight, and factoring in tongue weight distribution, I figure the boat/trailer around 8600 lbs. I've got 4.10's in it and run around 3000 @ 60 mph. 4.10's pull the boat up the ramp easily. I normally get 7 mpg during "normal towing" (20 miles one way to the ramp - mostly highway). I had thought about putting in 3.73's to reduce rpm's a bit, but have been convinced that the mpg improvement won't be all that great. I was thinking that 3.55's would be too tall pulling the boat up the ramp. I have seen trucks that can pull a heavy trailer smartly down the road fail to pull a heavy boat out of the water.

I can run 65-70 easy but it is spinning the engine more than I am comfortable with, so I normally run around 60. I am able to pass slower vehicles from 60, but if I'm running 65 or more, passing takes some planning. The terrain here in MD is pretty smooth so I don't have much experience in the hills, but I don't think I'd be comfortable running with 3.55's pulling my load on long grades up hill.

About swapping gears, it's rare (in my experience) to have the new gears run as silently as they come from the factory. I don't do that kind of work - I'll pay for it and demand that its done right. That was another reason I shy'd away from doing a gear change.

I think the bottom line is that we both get pretty much the same mileage with significantly different gearing - both lousy.

I was thinking with your gears, and you really felt the need, is it possible to turn that over-drive around and run it as an under-drive when needed, and keep your current gears?

Chris
'88 F350 XLT Lariat CC DRW/7.5l/C6/4.10
'93 Mustang LX 5.0l/T-5/3.55's/Flo's/pulleys/K&N/Synthetics
Nissan p/u (DC commuter)
Volvo 940

 

Chris, that's one heavy boat you got there! I don't believe mine weighs more than 2,800 lbs. with another 1200 lbs. thrown in for the trailer. I also only use my truck for heavy haulin. My 3:55's work great for everthing other than towing up the steepest hills. I should be happy that it's only underpowered for about 1% of my three times a month drive to the drag strip (320 miles round trip each time). The drag strip is at 100 foot elevation, I live at 2,500 foot elevation and there is a 4,900 foot mountain pass in between. Anyway you look at it a change would be expensive and probably would never pay for itself...purchase a turbo-diesel...Gear Vendor Overdrive and a gearing change...supercharger....maybe 45 MPH for 5 minutes isn't so bad afterall

Deen Hylton
Ford F250 460 C-6, K&N, Headers, Dual Exh.,Comp. Cams,Shift Kit
Pioneer CD w/Bose Speakers.
Other Passion: Blown 77 Corvette (Sorry Guys/Gals)
How I can afford to Drive the above: 93 GEO Metro

 

[font size="1" color="#FF0000"]LAST EDITED ON 18-Jul-01 AT 02:01 PM (EST)[/font][p][font size="1" color="#FF0000"]LAST EDITED ON 18-Jul-01 AT 01:58 PM (EST)[/font]

I just finished up replacing a Mazda M5OD in my '91 F-150 with an Advanced Adaptors Ranger III Overdrive unit/'78 NP435 4-spd. for a 27% OD vs. the original's 20%.

This OD has a separate shift lever of its own, and sandwiches in between bellhousing and 4-spd. The case length is 7.5", and lemme tell ya, there is A LOT of shift lever heating and rebending.

I haven't yet dragged my circa 6,000-lb. (loaded) travel trailer around with it, so I don't know what that mileage will be.

I ran up and back from Houston to Dallas last weekend (solo), and got mid-15mpg (300 engine, 4.10). 2,600rpm@70 (down from 2800-2900)highway. I haven't compared this gearbox setup's mileage to the original's yet, but I have this awful feeling that the cast iron gearbox weight increase over the original aluminum will offset the 7% increase in OD ratio and RPM drop for a net wash--same MPG, I think I was getting 15 before!

I have an idea that I may yet add on a GV for a double-overdrive if we end up moving out of town and I have a long enough commute to justify it.

Eddie

 

I have a US Gear overdrive unit (very similar to the gear vendor unit). It is on my 76 F-350 Crew Cab Dually. It is powered by a 93 460, bone stock internals, older (1986) exhuast manifolds, opened up intake track, and true duals. I hual a 9000 lb box trailer over the eastern part of the US. 4th gear (overdrive) can be used on flat grounds, but you really need 3rd for the hills. I left the truck in 3rd for my trip across PA on I-76. There are some 5 mile hills on I-76. In third, I hold about 50mph. No way would I pull the hills in overdrive.

The unit does not shift into and out of overdrive instantly (something I really don't like). It is like shifting a 2spd rearend. You need to hold the rpms constant, and it needs to be between power and coast. It sometimes is a pretty hard shift, if not careful.

As for milage, I get about 8 mpg while towing (with or without OD). As for everyday driving, I get 14 in town, and 16-17 on the open road.

The truck weighs in at 6400 in everyday drive trim, I have a wide ratio kit in the C-6, 3.73 rear gears in the Dana 70, and 215/85/16 tires.

 

79schaefer...Thanks for the responce. I assumed the shifting was not instant, looks like you have to shift in advance before hitting a hill. I was hopeing for "instant" like my trans shifts now to keep the momentum up. Anyway, planing to shift in advance would be no problem. I am suprised at your mileage, its quite better than what I get now and would be worth installing the overdrive even if I ended up with a little less than what your getting although it would take years to reach the break-even point since my truck is not a daily driver. Deen


Deen Hylton
Ford F250 460 C-6, K&N, Headers, Dual Exh.,Comp. Cams,Shift Kit
Pioneer CD w/Bose Speakers.
Other Passion: Blown 77 Corvette (Sorry Guys/Gals)
How I can afford to Drive the above: 93 GEO Metro

 

I attribute some of the mailage to the wide ratio kit and the gears. I usually do not use OD in town. I only use it on the road. On the road, in OD, I hold the pedal just above idle. It runs about 2000rpm in 4th. I am not sure what I did right when I put this combo together, but it takes little effort to get it moving and keeping it moving. The way my linkage is set up in the truck, the butterflies in the TB don't open past half way (my mistake in setting up the cable). I don't need it (except maybe on some of those hills, but then it may be to much air). I am running a slightly different computer system to control things tho. I am using a 1989 Mustang 5.0 computer with a Chris Johnson chip (to utilize the MAF). It is tuned to run right on the mark. My plugs are a light tan (almost too lean), but I have not seen any specks on the electrodes yet, so I will let it go.

I am still kicking around the idea of a small eaton blower or a single turbo. (To many thoughts, to little time).

Steve S.
54 F-100 (awaiting restoration)
76 F-350 Crew cab
77 F-250 Supercab (Camper Special 4x4)
79 Bronco (wife's)
79 Thunderbird (Pro street)
90 Thunderbird (drag car)
92 Thunderbird Sport (for sale)
97 Taurus LX (wife's, waiting for title to get back)
http://www.geocities.com/MotorCity/Shop/8663/