gear vendors overdrive? what ya think?

[68gtx]

tossing aroundthe idea of a gear vendors overdrive for behind my 727 in a little project im building, anyone have any experience with them? are they holding up? worth buying used?? or stick with new?

 

[zyzzyx]

I was just looking at the same unit on their web-site. It seems to be built well, but I don't like the idea of the tailshaft being 7" longer than stock
and the fact that you have to "Bash in" your driveshaft tunnel for the speedo adapter to fit. The other thing is that they say you shouldn't use it with
a stall convertor any higher than stock. Other than that, you're actually turning that 727 into a Six speed! I Dunnow, I need more info too!

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Oh yeah, I forgot,
$2800.00! I can change my whole rearend for around $800.00!

 

[YY1]

Right now it's the only game in town, unless you want to do major metal cut and fab or switch to a 833 o/d.

"6 speed" IMO is unrealistic. Who's gonna push that button every time the trans shifts?

You're basically buying a button to change your final drive from what ever rear you have to one that is .8 higher.

How many times labor swapping out an 8 3/4 center is worth $2800?

 

[BIGSHCLUNK]

There's a very extensive post on C-C about the "6" speed part of the comments here. This being said GV may have worked that problem out by now. Out side of that a buddy of mine ran one and loved it. Then I found out another guy I know ran one also, he liked his too. I've thougt about it in my E-BODY. I'm currenty running 3.23's so I can hi-way cruise. With a GV I could run 3.91 and still have a 3.08 for the hi-way. That would ROCK!!!!! My HEMI would be allot more fun, thats for sure. Dont like the idea of hammering my tunnel tho..........

 

[2fuzy]

we put one behind the nv 5 spd in my dads cummins diesel it has been problematic but most of that has been in the tranny end of the equation it has had bad effects on the nut that retains 5th gear not a problem one would have with the 727
the idea that you get a six speed while technically correct you really will not because it is to slow in actuation to split gears so all you will get is a choice of high or low final drive
if that is what your seeking it is fine but dont get your hopes to high

 

[Supershafts]

I have 3, in 3 different vehicles

Best option for any in my opinion, others will argue some have better od ratios, but all you gain with them is a od ratio after 3rd and have no other use.

Have any specific questions please ask away be happy to answer, can even help with buying.
.

 

[YY1]

There's a very extensive post on C-C about the "6" speed part of the comments here. This being said GV may have worked that problem out by now. Out side of that a buddy of mine ran one and loved it. Then I found out another guy I know ran one also, he liked his too. I've thougt about it in my E-BODY. I'm currenty running 3.23's so I can hi-way cruise. With a GV I could run 3.91 and still have a 3.08 for the hi-way. That would ROCK!!!!! My HEMI would be allot more fun, thats for sure. Dont like the idea of hammering my tunnel tho..........

Yep that's the whole point. Adds a reduced ratio (less then 1:1) output to the trans to allow the rear end gear to stay low but the effective final drive ratio to be manageable.

I just don't see the "split shifting" thing as something people would actually do, not a problem, just not all that great a value.

 

[Kern Dog]

I wish I knew that suggestion about high stall converters!
I have a GV in the Charger. I also have a 9 3/4" 3000 stall converter. The car feels lazy at freeway speeds. While cruising along at 65, it runs under the stall rating and feels sluggish.

 

[747mopar]

I wish I knew that suggestion about high stall converters!
I have a GV in the Charger. I also have a 9 3/4" 3000 stall converter. The car feels lazy at freeway speeds. While cruising along at 65, it runs under the stall rating and feels sluggish.

If you have a cam that requires that kind of stall it will feel lazey at lower rpms. If you want to cruise at a lower rpm the motor has to be built with that in mind "theirs always a trade off". As for me I've heard nothing but good things about them and have thought about getting one but really think a 6 speed manual would be right up my alley.

 

[Supershafts]

I wish I knew that suggestion about high stall converters!
I have a GV in the Charger. I also have a 9 3/4" 3000 stall converter. The car feels lazy at freeway speeds. While cruising along at 65, it runs under the stall rating and feels sluggish.

You need to use TC's from people that custom build them for what you want, gotta stay away from the in stock sh!t at stores.

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I just don't see the "split shifting" thing as something people would actually do, not a problem, just not all that great a value.

Other than my truck i didn;t see the use of splitting in the cars, but it was free time since it was in the car for the OD gear

 

[Meep-Meep]

Gas mileage increase just from a $2800.00 OD unit will likely take forever to pay itself back but that's not the whole story for me. The lower cruise RPM will make for a much more enjoyable driving experience if you road trip your car. Pay back of the OD expense depends on your engine build, but unless you have access to fully computer controlled spark timing, EFI, etc.. to take full advantage of the lower cruising RPM your gains might not justify the expense of these OD trannys or bolt-ons.

My thoughts on providing comfortable cruising on the HWY (with a regular TF) would be first to build the engine to deal with the RPM range that you will spend most of your time in. Then put in a low gear set in the tranny with the appropriate converter (perhaps a custom with a higher than 2.1:1 break away ratio) and run 2.94's or similar. This will provide a true OEM look for those who have numbers matching drive trains. The only low first gear ratio I know of is the 2.77:1 but it might be nice if there are custom ratios available that provide an even wider spread. Since you probably have to build a tranny anyway it shouldn't be a huge extra expense and might as well put the expanded gearing inside and focus on a very efficient converter. Remember the Buicks with the Switch-Pitch?

 

[Supershafts]

That depends on the driving, for example the GV in my truck saved a full tank of gas on trip to LVR, that is a complete 30 gallons of gas on each trip upstate, the GV paid for itself in less than a year, and this was way way back in the late 80's when gas was NO WAY NEAR what it is today.
Back then we only put the GV in the truck for the 3 / 4 split that was to big, and then the additional use of od saved a tank per trip

It really depends on how many miles you'll use the car for and how you drive it.

Taking a motor that was built to run around 2400 to 2600 and get it out of the 3500 area is a huge difference in mpg, talking a motor that is built to be comfortable around 2800 to 3200 and running it at 1600 isn't going to get you a mpg difference like the other.
Most motors don't like or aren't all that efficient below a certain rpm, while many people believe the slower it turns the less it uses to be true, it is not true for all motors.

.

 

[Relax360]

I have one in my 67 barracuda. 4.10 gears outback. Best OD option for the money IMHO.

 

[george68hemirr]

tossing aroundthe idea of a gear vendors overdrive for behind my 727 in a little project im building, anyone have any experience with them? are they holding up? worth buying used?? or stick with new?

i have one in my roadrunner and its awesome.....customer service excellent.....has been around for years.....holds up to horsepower and if you just happen to have 2000 hp they can beef one up for you too......money well spent

 

[ArtH]

Gas mileage increase just from a $2800.00 OD unit will likely take forever to pay itself back but that's not the whole story for me. The lower cruise RPM will make for a much more enjoyable driving experience if you road trip your car. Pay back of the OD expense depends on your engine build, but unless you have access to fully computer controlled spark timing, EFI, etc.. to take full advantage of the lower cruising RPM your gains might not justify the expense of these OD trannys or bolt-ons.

I did the math on a conversion like this years ago and you are right. It's really not worthwhile unless you drive a lot of miles and/or the price of gas goes really high.

 

[Chickenman21]

My 69 RR is a 4 speed but I am looking into getting the GV OD. I plan on some long distance touring and even with 3.23 rear am still turning near 3000 RPM at 70 - 75 MPH and getting around 12 MPG. I'm not looking to lite up the tires and I do not like cruising at 3000 RPM for hours on end and better mileage wouldn't hurt a thing. The 3.23 ratio works well for my driving around town. I get my satisfaction in miles between fillups and don't worry about recovering the cost of the OD unit. I'll recover that cost in pleasurable cruising.

Yes............I am old.

 

[Grabinov911]

Yes............I am old.

Awesome

 

[Mr.SpeedFreak]

Personally the fact that it just works basically as a gear splitter and the trouble/price it'd cost, I'd rather convert to a Passon 833 5 speed OD. What I'm planning on doing anyway, still have a bit more research to do though

 

[Photon440]

It's still way cheaper than spending 8 bills on a TCI six-speed auto swap.

 

[69RRGTX]

I am adding one to my GTX before next spring. That behind my hemi box is far superior to any aftermarket OD trans IMHO, so that is what i am going to do.

Goodluck,
Mark