has anyone installed gearvendors overdrive with there sm465

[thaifighter]

Im thinking of bitting the bullet and going for the overdrive unit, I do allot of highway driving and mostly logging roads no crawling Ive got 373's and truck was stock with 16.5 inch rims so its a good highway rig with good towing capabilities but it would be nice to get some better gas mileage 3 gears with the granny gear is pretty limited, but theres little stronger or more reliable than the sm465 . As I understand it the gear vendors unit doesnt work in 4 wheel which is ok for me but I would really like to hear from someone that has it or knows someone that does ...........cheers

 

[skysurfer]

How many miles per year do you drive and what percentage of that mileage is out on the highway?

I looked into it and with the miles I drive the payback on the investment would have been around 70 years.

 

[thaifighter]

I guess I realy dont put on that many miles more of an rv , but are the fuel savings really not that benaficial? how did you calculate, obviously your using purchase price to miles per gallon but how did you calculate miles per gallon saved?? ........thanks allot for the help

 

[HotRodPC]

Yep, Gear Vendor is an expensive unit. Good strong unit nonetheless, but hard to recover the savings unless you using it quite often. But, some often forget Gear Vendors can also be underdrives. So if you have a good use for an underdrive, they can also pay off. If you have a reason to use an underdrive. Some RV's will use the underdrive to pull a heavy boat up a steep boat ramp for example when 4.10 gears and a tall first Gear in a Th400 isn't quite enough to get it started up the hill with the weight of the RV, the trailer the boat, and fighting the water too.

 

[skysurfer]

How did you calculate, obviously your using purchase price to miles per gallon but how did you calculate miles per gallon saved??

There's no accurate way to nail it down, too many variables, but let's say you drive 15,000 miles per year, get 10 mpg, and pay $3.75 per gallon. That's $5,625 for one year.

Ok, so now you install a GV overdrive and pick up another 3 mpg cruising at 65 mph. If highway driving was all you did your annual fuel cost would drop to $4327... a savings of $1298. But the problem is you're not driving at 65 all the time. Any miles on surface streets or in stop-and-go traffic eliminates the advantage of the overdrive. So that's where the question "what percentage of your driving is in high gear" comes from.

For me, I figure no more than 30% of my time is at freeway speeds, mostly rural two-lanes around here, so again, the od isn't going to pay for itself as quickly...30% of the estimated $1298 savings is $390. And to make matters worse, I don't drive anywhere near 15000 miles per year. Over the last two years I've averaged less than 2000 miles so I have to take that $390 and divide it by 7.5 to reflect the miles I drive for an annual savings of $52. A GV unit is something like $3300 plus tax, so figure $3500 out the door. $3500 divided by $52 annual fuel savings means the od will pay for itself in 67 years. Again, my miles driven is small so the numbers are skewed, but you get the idea.

There are benefits to a GV overdrive that can't be quantified though. If I understand it correctly, the supplied computer does all the shifting in-and-out, so a Th400 like mine effectively becomes a six-speed transmission with no input required from the driver. Drivability would be greatly improved...but is it worth the money?

 

[bucket]

There are benefits to a GV overdrive that can't be quantified though. If I understand it correctly, the supplied computer does all the shifting in-and-out, so a Th400 like mine effectively becomes a six-speed transmission with no input required from the driver. Drivability would be greatly improved...but is it worth the money?

OK, now I REALLY want one. Last I heard (an article at least 10 years ago) it was just operated by a switch and you had to do it all yourself.

 

[wildcatjason]

You really can't just base it on highway miles alone you should average your city and highway mileage because the gear vendors will keep your rpm range down through the whole acceleration process with its one over, two over, three over gearing.

 

[crazy4offroad]

The cost of the GV unit versus the cost of just grafting a 4L80e into your truck would be a great comparison, to figure out if it is worth it. I know the 80e is no 6-speed but if the overdrive is the main reason for wanting the GV unit, it is a comparable upgrade.

 

[HotRodPC]

The cost of the GV unit versus the cost of just grafting a 4L80e into your truck would be a great comparison, to figure out if it is worth it. I know the 80e is no 6-speed but if the overdrive is the main reason for wanting the GV unit, it is a comparable upgrade.

Yep, that's how I look at it too. I can come up with another solution for about 1/3 the cost in units alone. Then consider all the driveline work etc. If you're dead set on GV, just be paient and watch for a used one. They are almost bulletproof. I've seen used ones for as low as $700. Someone recently was selling a Square, I think the ad posted in the CL section, that had a GV and you could buy the whole truck ready to go with the GV for $2500 I beleive it was, might even have been $2000. I just knew the GV was worth more than the whole truck.

 

[bucket]

The cost of the GV unit versus the cost of just grafting a 4L80e into your truck would be a great comparison, to figure out if it is worth it. I know the 80e is no 6-speed but if the overdrive is the main reason for wanting the GV unit, it is a comparable upgrade.

If everything is new or rebuilt, I think the 4l80e swap would be cheaper... but also not quite as strong and a lot more work. With the GV, you get strength and ease of install with only one new shaft. With the 4l80e, you have to do both shafts, move the crossmember, adapt your current t-case or a new one, and then there's all the electronics to make it shift.

 

[thaifighter]

Thanks skysurfer, for the costs breakdown, and the point about keeping the revs down while gearing up is also valid, sometimes it feels like it takes forever to dump it into 4th with the 373s, even unloaded. lots of variables to weigh .........cheers

 

[wildcatjason]

Any opinions on option 3? The advance adapter ranger torque splitter.
http://www.advanceadapters.com/products/pn-760002m-27/

 

[HotRodPC]

Another pricey option. Seems like a cool idea also. But what happens when you decide to convert to auto trans? The overdrive/underdrive unit can be adapted to about any trans, that one there is only to 4 speeds.

 

[skysurfer]

Looks plenty stout, but I would like to see how the finished installation looks. It moves the shifter back seven inches and I wonder if that would create problems for short people that have the seat all the way forward.

 

[HotRodPC]

I say just get you another SM465 and install it backwards then you'll have 4 overdrives.
I've often also wondered why anyone hasn't thought to convert Dodges OD units to fit other applications. It can't be that hard if a company like AdvancedAdapters would make the adapters. Some aren't aware, Dodge didn't really make OD transmissions. Like GM went from Th350 to a 700r4. Dodge kept their same 904 or 727 Torqueflights and just put an OD unit on the back of them with an electronic activation not much different than the lock up TC system and gave it a new model #. So this is my understanding anyway. Haven't looked into it much myself.