Anybody running a Gear Vendors OD?

Thinking about getting one for the TH350 in my 55. It's a built unit and I'd rather go this route than fuss with a 700R4 and everything that goes with them. I'd likely pick up a used unit, they seem to pop up for reasonable prices after the drag and drive events.
Anybody running one? What are your thoughts on it?

 

They work pretty well, although the control systems can give trouble...they have MSD making the control systems now, so if you ask them to fix an older system, they'll try to sell you the new one for about $500.

If the unit was used a lot, the cone clutches could be worn out. Cost to get it rebuilt is about half a new unit cost.

pay attention to the speedometer fitting, make sure it has the correct type (gear or electronic).

pay attention to the coupler, housing bushing, and shims, they're important. The bushing can wear out, etc.

Finding one with a 350 adapter and coupling is probably not as easy as finding one for a 400. And the price of the adapters from GV is pretty steep.

 

Squirrel is the expert with Gear Vendors experience.

For a street driven car I'd recommend the 700R4. It's an easy swap, done 100's of times. You already have a trans cooler. Drive shaft may need altering, which is a for sure with the GV.

What carburetor are you running? You will need a linkage adapter, unless it is a later quadrajet.

 

I’m running a Doug Nash OD unit
Operate it with a 2 speed rear end switch
Just remember to cut it off

 

Why not a 2004r? Less hassle to install than either gv or 700r4 and much cheaper than gv

 

I’ve got a gear vendors in one of my cars. I didn’t bother with the control system, just using a toggle switch. Going from 3.23s to 2.52s at the flick of a switch makes freeway cruising nice. The engagement/disengagement can be a little harsh unless you finesse the gas as you shift it.

 

you also have to be careful to never have it engaged in reverse, and you also need to wait for the car to get up to speed before engaging it, eh?

 

I’ve had Gear Vendors, 700R4’s and 2004r’s. I’ve even had a 400 s/p in front of a manual shift B&J (stuffed in a Vette of all things). The 200 was my favorite, smaller, lighter, better (for my use) 1st gear.

Buy the GV used, you’ve got the issues Jim stated. Pass on the controls, that’s your choice. They worked fine for me in street usage. But you just might be starting down a road for more money than a 2004r. Setting up the TV cable is not the big deal some say. Just read the instructions.

 

Yeah tv cable setting is actually quite easy. I actually had more issue with the kickdown cable on my th350 lol

 

This is how I set up700R4, TV cable on two different rods. Driven them way more than 100k miles with no problem. Others, no doubt have done it differently.

First, have your helper hold the throttle wide open, sitting in the driver seat.

Extend the TV cable to maximum length, adjust cable case length so cable attaches to the throttle linkage geometry corrector, while maintaing full throttle with TV cable fully extended.

What carb will you be using with your O/D setup?

 

Jim covered the GVOD, I'll touch on GM's two overdrives that would be simplest to install and run.

THM 700R4.
I've owned bookend 700's an '83 built '84 Sierra and a late '92 built '92 S10.
They were terrible transmissions.
Sierra's 700 was a special kind of garbage with it's early toothing issues.

1-2 ~50% gear drop.
Won't upshift to 4th under W.O.T.
Will pop out of 4th under cruise if you fart.

Dimensionally, it is unlike any other trans, it does not share mount location and requires the 400s slip yoke(HAH!).

THM 2004R

I've owned a 'CRF' unit pulled from an '85 Monte Carlo, and a 'KZF' pulled from an '85 4-4-2.

Only trouble I had was the CRF unit had a faulty TCC solenoid that would not unlock which caused stalling. Easy enough fix.

1-2 gear drop is much better.
Allows 4th gear upshift @ WOT.
Would stay in 4th gear with medium throttle under cruise.

Dimensionally 2004R shares the same case length as a 'short' tail shaft TH350, mount location is the same as a TH400, and the same slip yoke as a TH350. If you can slide your crossmember back for the 400 mount location install is easy.
Only on very tight tunnels the rear of the trans is a bit chunky and the pan reaches to the mount.

Wiring up the lockup function is easy, and most popular carbs have TV cable adapters readily available.

For the easy OD button for a TH350 replacement, the TH2004R is the best option.

 

700r4 is a over under trans. Real short first(3.06) and real long 4th. Most gripes people have with them is due to not being setup ideal. These days you can buy all kinds of cool stuff to make them do or handle anything you want within reason(600-700hp). You can make them stay in whatever gear you want whenever you want with tuning. I had one survive 15 years behind a blower and when it lost second gear the only thing I could find wrong was a stuck servo.
Old ones suck though,take all that out and update it.

 

If you purchase a used gear vendor and it's not for your application, There is a """Core ""charge on adapter for your needs if not ""Returning"" a adapter back to GV for core,
So you will be around 1,200 for adapter and core cost,
Also G-V will only Service &
sell replacement parts for a G-V with a Tag
(serial numbers)

 

The great advantage of the GV unit is that it can be used as a splitter, rather than only as a top-gear overdrive. Its overdrive ratio is close to the square root of the ratio interval of a typical three-speed automatic, so using it as a splitter gives six fairly evenly spaced ratios.

Because it operates at a far higher hydraulic pressure than the Laycock-de Normanville OD that it's based on, the low-speed engagement issue isn't as critical as it might have been. And it should be possible to introduce a pressure reservoir or even an external source, if that's considered worth the effort. Apparently the modifications required to convert an actual LdN unit to GV-level operating pressure aren't onerous.

The switching is ultimately hydraulic, so in theory the solenoid system could be eliminated and the hydraulic valving actuated mechanically.

One application I've thought of: 3-speed automatic with reverse-pattern full-manual VB + GV/LdN OD. A cable-operated short-throw shifter is mounted transversely to the transmission tunnel, with P to the left and 3 to the right. The entire shifter is hinge-mounted to rock forwards and back, with the rearwards position positively activating the OD and the forwards position de-activating it. That produces an effective 6-speed gate shifter, with reverse and park laterally to the left — and rigged so reverse and park can only be engaged with the lever in the forwards position. The result is a 6-speed transmission with a loosish torque converter below first gear, and clutchless but for a circle-track-style ball valve controlled by a "finesse pedal" in lieu of a clutch pedal.

 

Yes. I applaud the product but deplore GV's business model.

 

I'd just like to remind everyone that the GV has proven to have less than optimal reliability behind 3spd autos and 4spd manuals in 80s and 90s pickup trucks except at stock power levels and manufacturer recommended weights (lol).
So I would think twice before trying to use one as a splitter in a ~5000lb sedan with 500hp on tap. But for what OP has in mind it's probably fine.

 

The gear splitting thing is not very useful in a typical hot rod...

the main benefit of GV in high HP hot rods is that you can use a reliable highly modified 3 speed auto, plus drag race friendly rear end gearing, and then get an extra overdrive gear for highway cruising.

btdt

 

I built quite a few power glides with Gear Vendor OD unit for monster trucks some years ago. The trucks used the OD in longer course racing for higher speeds. I was amazed at the abuse the Gear Vendor unit would take in that application. As mentioned if you go the route of GV with a used unit, buying the necessary adapter parts could be expensive when dealing directly with Gear Vendor the company.

 

I have been looking for a 200r4, have not had any luck finding one.

 

they've been out of production for over 35 years?

 

Put a manual 5 or 6 speed Tremec in it and the only problem you have to deal with will be getting traction............You get good gear spacing and overdrive and not a bunch of electronics or toggle switches and probably better gas mileage. And a NEW trans costs about the same as a NEW Gear Vendors. They maintain their value as long as they still work. So years from now you will probably be able to get your money back.

 

But you'd also have to deal with a clutch, which can be a big issue if you're drag racing the car.

 

Cable clutch is simple to do and cheap. And then he gets the thrill from a perfectly thrown shift.......or not. No matter what he chooses, there will be some adaption, and the used gear vendors units often need some work ($$$) to get their control working right. Myself, I just always enjoyed shifting gears when the engine in front had a little umph available.

 

I like shifting gears when the engine has a little umph. But I like letting a torque converter handle the launch when it has a LOT of umph!

 

Thanks for all the input folks, it is greatly appreciated.

For those who asked, I run a modern Holley carb.

I'd love to have a manual in this car, but I'd need everything to do the swap, and likely new headers. Not really a problem to assemble the parts since everything is available for these cars. Despite the plans I had in the past, this car will never see a dragstrip again, it's 100% cruiser mode now. I just want to be able to make the 100 mile drive to the beach and not have the engine turning 3500rpm trying to keep up with the banzai traffic around here.

 

This looks like the linkage geometry corrector for aftermarket Holley carb with GM o/d trans.
https://monstertransmission.com/pro...0-200c-200-4r-ford-aod?variant=50481519165749

 

there is a 350 adapter on ebay right now for $400, pretty good price, if it's in good condition.

 

You have a point, but the problem then becomes the need for a higher stall speed to accommodate the usually higher idle speed often needed. For a daily street driver, someone has to strike a balance between a usable stall speed and one that gives best performance. Drag Racing doesn't have to deal with low rpm idle or low rpm driving needs. Even if a Gear Vendor unit is installed in a big engine high HP car, it still has to deal with getting a stall speed thats not too high. With a clutch, an engine can idle at whatever speed it needs, and drive at slightly above that rpm when cruising. My truck and the wifes SUV usually run about 1800-2200 rpms on the expressway and they are automatics. A high stall converter is probably going to need more than that even with a gear vendor unit. Then also driving around town where the Gear Vendor isn't helpful, the high stall can be harder to enjoy. I t's all about compromises no matter how someone decides to procede. I just like the fun of shifting gears and wide power bands.......... Pick your poison, so to speak.

 

I had a pretty neat setup in Plan II, a $300 switch pitch converter that would stall around 1800 in low, and around 3000 in high, with a manual shift 400, and GV with 3.89 gears. But you can buy a nice non-switch pitch converter these days what will handle a lot of hp (600-800) with well over 3000 stall when you get on it, but pretty tight at part throttle.

Clutches...yeah, they're fun to deal with. The guys who are going fast are into slippers, and they get to adjust them for street or drag strip, lots of work!

 

This is the usual conumdrum that rodders must deal with........they want decent performance but they want decent gas mileage and the lower rpms at highway speeds. The simple answer is "overdrive" whether it is an automatic or a manual trans. I think a 700R4/4L60 (not 4L60E) or a 200R4 would be your best solution even though you already said you don't want that. There are a lot of people using them these days as the old turbo 350 becomes obsolete due to its lack of overdrive. Good luck which ever way you go........