I was wondering if anyone has had any experience or has heard anything about one of those Gear Vendors overdrives?I was thinking of installing one behind my 79 k5 , but wouldn't it make my driveshaft angle in the back too steep?My combination will be a350/th400/d60 /14bolt ff 4.56 gears/np205 . I'm going with the usual 52 in front spring swap, 56in rear springs w/ shackle flip.I am fairly certain that these are durable units, cause the fastest cars at Hot Rod drag week run em.
CK5
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GEAR VENDORS OVERDRIVE
- Thread starter 4xfrankie
- Start date
black dawg
1/2 ton status
I have one in my suburban, and it does add quite a bit to the length. I can get a measurement if you need one. As far as being strong, there are some weaknesses that tend to get left out (on purpose??). It can be broken by backing up with a load with the unit disengaged. I have also seen one that was broken climbing a steep rough road in 2wd. I think they decided that the driveshaft angle (longbed pickup) along with some wheelhop broke it right off of the adapter. It was destroyed.
Man, Iwonder how those guys at Drag Weak run em with 3000 hp ?They must use em on the highway and take them out when they make a pass. I think it might just be better to go 4l8o ,then Iwon't have to worry about drive shaft angles being too short in the back on such a short wb vehicle. What would the fix be to correct the angles?pinion shims and a double cv custom shaft? I don't want to cut and turn the rear axle.
black dawg
1/2 ton status
I think they can take a serious amount of power, just certain conditions show the weaknesses.
My Dad had a GV overdrive unit in his truck, I'd spring for a good 700R4 before I spent the money on a GV unit.
The GV OD isn't as effective as a 700R4 OD (.75 vs. .70), can't use it in 4WD (not a real issue but if you make a mistake and do it...), and you probably don't want to run it when engine RPM's are below somewhere around 2000RPM. So again, limits it's usefulness if your gearing doesn't *require* it.
If you aren't towing, then go with the 700R4 and don't look back. If you need the option to split gears, the GV might be an option to pursue.
I just can't see the usefulness in the OP's case. Shorter driveline, need to cut the rear shaft, strength or gear splitting apparently isn't a necessity, relatively high cost, lower OD than a 700, other transmissions available that have OD, less components, etc.
I think the automatic units are a bit "better" than what I experienced...the manual ones you can't use under 25MPH, and have to manually engage/disengage.
I just don't see the benefit of a ~$3000 GV unit here...I assume a super stout 700 can be built for at most 2/3 the cost.
Never had an issue with the one in my Dads truck, towed a 10,000lb trailer over mountain passes behind both a 350 and 454....but he would have been happier with a 4L80E.
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Oh I agree, I just don't want him to be passing bad info that they are bad. I would go 4l80e, nv4500 or a even a 700. I found a place that was adding a ranger to a nv4500 the other day. I thought it may be silly but then I thought maybe it would be cool because you could have a lot more options. I don't like the fact that the GV doesn't allow 4x operation but I will more than likely be adding one to my th400 so it is more drive-able. If you had a truck you towed with a lot maybe a GV and a 4l80 or nv4500 would allow you to keep it in the power band.
No doubt the GV is a well-built unit.
They already have at least some electronic control/input, they should set an automatic one up so that it would gear split automatically (or at least normal 1-2, then split each gear afterwards based on MPH) and a 4WD interlock.
They already have at least some electronic control/input, they should set an automatic one up so that it would gear split automatically (or at least normal 1-2, then split each gear afterwards based on MPH) and a 4WD interlock.
