GearVendor..the good and bad so far...

[EagleEye]

Just broke down and bought a Gear Vendor and installed it. With the 4:10's, I've always wanted a higher gear for the Auto Trans.



Instead of changing the front and rear diff, and losing my great towing performance, double OD seemed like the answer.



Between GV and US Gear, I decided I may have a serious issue with (gas tank) clearance, and liked the fact that I wouldn't need to re-mount my transfer case and perform 'minor' body trimming. Besides, I am not going to use it in 4wd (even if the weather gets bad). I don't need to go 90mph during inclement weather.



Here's what is found so far...



The GV unit is NOT an 'Overdrive/Underdrive' unit as advertised. It is simply an Overdrive. It will NOT give you 'Double' the gears or change your 4 speed to a '8 speed' transmission as advertised either. It won't work in 1st gear UNLESS you are really haulin a**. Just won't shift unless above 18mph. OK.



Installed it and took it for the test drive...



This unit shifts HARD, going into OD and coming out of OD. Maybe I should finish hooking up the Torque Converter Lockup Clutch circuit to the GV electronic unit. I feel I could brake the dually rearend loose at 70mph and leave one LONG burnout.



After hooking up the TCC 'disable' circuit and testing, still hitting hard coming out of OD. Call Gear Vendors and find out the TCC lockup circuit is in for about 4 seconds on OD application and NO time delay on OD off. I was told to keep in the throttle during an OD off shift and that will help the teeth jerking that I am experiencing... I hope my transfer case and rearend can handle the shock loading coming out of OD.



I also checked with GV on raising the OD apply speed while in 'Auto' mode. $75 bucks and shipping and they will happily send me another chip to put in the control unit which raises the OD apply speed from 44mph to 55mph. That is on top of what I spent for the unit, the prop shaft, install time, oil, sealers, etc.



I cannot believe Gear Vendors would have their 'fix' to be "keep on the throttle". That is just wrong. Since GV doesn't seem interested in developing a 'fix', I guess I will build a timing circuit to disengage the TCC during upshift as well as downshift.



Also, you manual transmission guys beware. The instructions also say to do a 'half clutch' when engaging or disengaging OD. This goes DIRECTLY against their advertising again. GV says their OD can be shifted 'under power'. You can't unless you feel like grenading the transmission, transfer case or rearend. Their unit may handle it, but with 8 small bolts holding the OD on, and 4 bolts holding the adapter on, I don't see how stuff would survive.



The OD seems to need to be serviced every 10,000 miles, with the MOST expensive oil that can currently be had.



If I could have gotten away with it, I think I would rather have a US Gear (Nash) OD. You have to get outta the throttle with US Gear to shift, but you have to with Gear Vendors also. I just don't have the clearance (TransferFlow Tank) and didn't want to relocate everything and change 2 prop shafts. Maybe I should have. Caveat Emptor (buyer beware). Whats ADVERTISED is not EXACTLY what you end up with.



On the POSITIVE side, the unit shifts when it is supposed to, and does what it was designed to do (about 2000rpm @ 85mph... Nice), and fits in some pretty tight clearances. I only modified the front half of my 2 piece rear propshaft, the transfer case is in the same position, no body trimming, and works. I am seeing at least 2mpg improvement initially, but am still testing.



Feedback is appreciated, and I will update with more info later.

 

['strokeThis_'07]

What rpm were you running at 85 before the GV? Ive been thinkin of getting one both for cruising and also more top end (hopefully) at the track when I get to that point. What do you think top speed is (My truck cutsoff about 108-110, want/will need more at the track)

 

[MA2LA]

Its good to know what realy happens with stuff like this. I've been thinking about a GV unit but just don't have the funds to dump on one. I would love to see a nice drop in rpms at 80 plus since it spends alot of time at that speed.

 

[4xquadrod]

Just broke down and bought a Gear Vendor and installed it. With the 4:10's, I've always wanted a higher gear for the Auto Trans.

Instead of changing the front and rear diff, and losing my great towing performance, double OD seemed like the answer.

Between GV and US Gear, I decided I may have a serious issue with (gas tank) clearance, and liked the fact that I wouldn't need to re-mount my transfer case and perform 'minor' body trimming. Besides, I am not going to use it in 4wd (even if the weather gets bad). I don't need to go 90mph during inclement weather.

Here's what is found so far...

The GV unit is NOT an 'Overdrive/Underdrive' unit as advertised. It is simply an Overdrive. It will NOT give you 'Double' the gears or change your 4 speed to a '8 speed' transmission as advertised either. It won't work in 1st gear UNLESS you are really haulin a**. Just won't shift unless above 18mph. OK.

Installed it and took it for the test drive...

This unit shifts HARD, going into OD and coming out of OD. Maybe I should finish hooking up the Torque Converter Lockup Clutch circuit to the GV electronic unit. I feel I could brake the dually rearend loose at 70mph and leave one LONG burnout.

After hooking up the TCC 'disable' circuit and testing, still hitting hard coming out of OD. Call Gear Vendors and find out the TCC lockup circuit is in for about 4 seconds on OD application and NO time delay on OD off. I was told to keep in the throttle during an OD off shift and that will help the teeth jerking that I am experiencing... I hope my transfer case and rearend can handle the shock loading coming out of OD.

I also checked with GV on raising the OD apply speed while in 'Auto' mode. $75 bucks and shipping and they will happily send me another chip to put in the control unit which raises the OD apply speed from 44mph to 55mph. That is on top of what I spent for the unit, the prop shaft, install time, oil, sealers, etc.

I cannot believe Gear Vendors would have their 'fix' to be "keep on the throttle". That is just wrong. Since GV doesn't seem interested in developing a 'fix', I guess I will build a timing circuit to disengage the TCC during upshift as well as downshift.

Also, you manual transmission guys beware. The instructions also say to do a 'half clutch' when engaging or disengaging OD. This goes DIRECTLY against their advertising again. GV says their OD can be shifted 'under power'. You can't unless you feel like grenading the transmission, transfer case or rearend. Their unit may handle it, but with 8 small bolts holding the OD on, and 4 bolts holding the adapter on, I don't see how stuff would survive.

The OD seems to need to be serviced every 10,000 miles, with the MOST expensive oil that can currently be had.

If I could have gotten away with it, I think I would rather have a US Gear (Nash) OD. You have to get outta the throttle with US Gear to shift, but you have to with Gear Vendors also. I just don't have the clearance (TransferFlow Tank) and didn't want to relocate everything and change 2 prop shafts. Maybe I should have. Caveat Emptor (buyer beware). Whats ADVERTISED is not EXACTLY what you end up with.

On the POSITIVE side, the unit shifts when it is supposed to, and does what it was designed to do (about 2000rpm @ 85mph... Nice), and fits in some pretty tight clearances. I only modified the front half of my 2 piece rear propshaft, the transfer case is in the same position, no body trimming, and works. I am seeing at least 2mpg improvement initially, but am still testing.

Feedback is appreciated, and I will update with more info later.

1st-1 over-2nd-2nd over-3rd-3rd over-Overdrive-Overdrive over. This looks like eight gears to me.

I havent found a need for extra gears below 18 mph?

The amount of lube required to change at 10000 miles is minimal.

I have been shifting under power for 4 years now and haven't had an issue.

The only thing I don't like about the system is it is weak in reverse. You definitely don't want to jump on this thing in reverse. I have had issues with reverse. However they replaced the unit for me.

 

[TAbbott]

You're not supposed to use it in overdrive and reverse at the same time. It's a one way clutch and it should just slip in reverse.

 

[Pavemen]

The GV unit is NOT an 'Overdrive/Underdrive' unit as advertised. It is simply an Overdrive. It will NOT give you 'Double' the gears or change your 4 speed to a '8 speed' transmission as advertised either. It won't work in 1st gear UNLESS you are really haulin a**. Just won't shift unless above 18mph. OK.

In the automatic it is just an overdrive unless you manually shift the gears. In the manual its doubles your gears except for 1st (unless you like RPMs and the manual says that their oiling system requires 2nd gear or higher if OD is engaged)

Also, you manual transmission guys beware. The instructions also say to do a 'half clutch' when engaging or disengaging OD. This goes DIRECTLY against their advertising again. GV says their OD can be shifted 'under power'. You can't unless you feel like grenading the transmission, transfer case or rearend. Their unit may handle it, but with 8 small bolts holding the OD on, and 4 bolts holding the adapter on, I don't see how stuff would survive.

I beat on my US Gear Underdrive and its doing great. I can shift under power, just need to lightly tap the clutch and it will shift with no loss of momentum. Supposedly same with GV units. You can engage/disengage the unit between gears easily. You only need to wait 2 seconds from switching the unit and then tap the clutch.

 

[SRehberg]

I read the post about 1st over etc. Well the engine would surely be taching pretty high as the safety in the GV OD unit won't allow it to engage until the hydraulic pressure is up (approx. 20 mph). In my humble experience, I really dislike the thing. It jars the heck out of the drive train if ANYTHING isn't done EXACTLY perfect, not to mention forgetting to turn it off if you panic stop or just forget. It feels like you've been rear-ended. I can't see where that can be good for anything. The lag time engaging is pretty slow, you have to engage the GV before you come out of the gear you're in otherwise it will lag by the time you get to the next one. Try going DOWN. Better match rpm's or it's a big time bang. EagleEye is correct in the fact you don't want to shift under power, i. e. trying to go from say 3rd over to 4th direct. If you go from 3rd over to 4th over it's just like shifting the regular way, it's just when you engage or disengage the unit the issues come to play.



I carry a 5000 + lb cabover camper which I have an exhaust brake. Nope, you can't use the brake with the GV OD or else it will tear the clutch up according to GV. They say the planetary gears will actually try to pull the clutch out during braking, essentially destroying the unit. If you're doing 75-80 mph down a nice straight stretch of freeway, say 6 % grade, and you have 4. 10 gears, who wants to have a screaming engine? I think it's a poor design for anyone carrying a heavy load with an exhaust brake in mountains.



That being said, it is nice on the flat, it drops the rpm's on my truck to about 1700 @ 65mph. Good for long straight stretches but that's about all. If you can shift fast enough to do a OD in 3rd or 4th w/o losing speed and make it smooth, it would be good. It's not a fast shift, the lag is definitely there.



As far as the "special" oil, Mobil 1 75-90wt. works just fine and a quart will fill it.



I think it would be money better spent to have 3. 54's installed vs. the 4. 10's. Just my 2 cts.

 

[4xquadrod]

You're not supposed to use it in overdrive and reverse at the same time. It's a one way clutch and it should just slip in reverse.

You can't engage it in reverse and why would you want to. You also can't disengage it in reverse. The unit is stressed when you are in reverse and it is a weak link.

 

[EagleEye]

4xquadrod... How fast is your engine going when you get the unit to build enough pressure to shift into 1st over (above 18mph)? It may be possible, but I don't think I'll be using it. Also, the amount of lag going into OD and the jerk coming out of OD isn't very practical for splitting while going thru the gears. GV doesn't recommend 1st over in their manual. I count 7 gears per GV recommendation. Kinda funny... GV sent me a sticker that says 8 speed that I can put on my truck.



There is NO WAY to use it in reverse anyway (unless your going faster than 18mph to build shift pressure in the OD), so I feel the unit would hold up just fine under heavy load backing (1-1 ratio and not going thru any gearing on the OD).



Strokethis 07... I was seeing about 2625rpm @ 85mph. Quite a nice drop when crusing.



The exhaust brake thing... GV has a cutout in their control unit to shift out of OD when the exhaust brake comes in. I can't see how an exhaust brake unloaded would put more reverse torque on the OD unit than a fully loaded rig would just under normal deceleration... dunno. GV does NOT want an exhaust brake in while the unit is in OD. It will torque their gears in the wrong direction... OK. So what is a guy with a built auto or a manual supposed to do? This would take some serious switching/throttle feathering/etc to make it work well, and I'm kinda lazy when I'm on a long trip.



I am looking forward to trying this unit on the 1/4 mile to see what improvement the double OD makes for times. I just won't be splitting all the gears.



More to come...

 

[Coalsmoke]

4xquadrod... How fast is your engine going when you get the unit to build enough pressure to shift into 1st over (above 18mph)? It may be possible, but I don't think I'll be using it. Also, the amount of lag going into OD and the jerk coming out of OD isn't very practical for splitting while going thru the gears. GV doesn't recommend 1st over in their manual. I count 7 gears per GV recommendation. Kinda funny... GV sent me a sticker that says 8 speed that I can put on my truck.



There is NO WAY to use it in reverse anyway (unless your going faster than 18mph to build shift pressure in the OD), so I feel the unit would hold up just fine under heavy load backing (1-1 ratio and not going thru any gearing on the OD).



Strokethis 07... I was seeing about 2625rpm @ 85mph. Quite a nice drop when crusing.



The exhaust brake thing... GV has a cutout in their control unit to shift out of OD when the exhaust brake comes in. I can't see how an exhaust brake unloaded would put more reverse torque on the OD unit than a fully loaded rig would just under normal deceleration... dunno. GV does NOT want an exhaust brake in while the unit is in OD. It will torque their gears in the wrong direction... OK. So what is a guy with a built auto or a manual supposed to do? This would take some serious switching/throttle feathering/etc to make it work well, and I'm kinda lazy when I'm on a long trip.



I am looking forward to trying this unit on the 1/4 mile to see what improvement the double OD makes for times. I just won't be splitting all the gears.



More to come...

Eagle Eye, I want to thank you for taking the time to post this info and your earlier posts too. I was going to buy a GV unit this summer, but now that I read about how it shifts and how I can't have it engaged with the exhaust brake, there is absolutely NO WAY that I will own one. That is half of the reason for getting it. Up here where I live, its serious mountain grades almost any direction you go out of town, Rocky mountains, coast ountains, etc. If it beats the drive train going up the hills and will tear itself apart with an exhaust brake coming down them, then what the heck#@$%! especially considering that they call it an industrial type solution, but I bet it would create lots of problems on a truck like mine that is constantly loaded at max capacity. Anyways, thanks again, I really appreciate the heads up. I'm going to look into the US Gear set-up now to see what it offers.

 

[CContreras]

It seems there is huge misunderstanding on how the GV works. Just like when we learned to drive a manual transmission, it was hard shifts until you got the throttle/clutch manipulation down. It's the same with the GV. It's built to take the abuse until you get used to the throttle/clutch manipulation. As far as the inshift lag time, it isn't a factor if you anticipate for it.

 

[MA2LA]

If you think about it you shouldn't need the OD on when using the EB. if your trying to slow down the truck the last thing you need is to have it in 2 ods at the same time so it shouldn't bee a prolem.

 

[EagleEye]

To clear up a point with the GV unit... You CAN have an exhaust brake, just don't have the GV unit in OD when you use it. Their box has a lead to downshift the OD to direct drive when it sees an exhaust brake 'on' signal.



At least that is how I understand it. I figure the drivetrain and OD off (1-1 ratio) is about as strong as the original prop shaft.



Learning 'how to shift' the unit is difficult when I am missing the 3rd pedal in the cab. I have an Auto, and there ain't much us auto guys can do to ease up the jarring OD shifts.



Called US Gear yesterday, and wasn't impressed with their tech support. All I asked was 'what is the length my transfer case will be moved back in my specific application'. I couldn't get a straight answer. The best I got was "well... about 12" or about 12 3/4" if you need this certain adapter". Well, I'm calling to find out if I need the adapter. Hard numbers please! US Gear didn't seem too interested. That's OK... I don't have the room available with the Transfer Flow tank without some extensive modification. Oh well.



I am still happy with the top speed engine RPM, and still unhappy about other issues. Will work the bugs out, and I'll keep posting with anything new.

 

[Coalsmoke]

I hope this doesn't come across wrong, I'm not trying to add fuel to an arguement, but if I can't split my gears when coming down a hill then 50% of the Gear Vendors purpose is useless to me. I can understand how its not such a big deal on flatter areas, and everyone will have different applications / needs, but for me travelling here where you have up to 50 miles of 8-18% grades depending on the roads, the engine based brakes get a major work out. I guess I'm a bit miffed at myself for almost buying one of these units without first doing enough reasearch, I never would have thought that exhaust braking with it would be harmful to the unit.

 

[Coalsmoke]

Just wanted to add, I sent US Gear an email first thing this morning asking about some details about the unit and received an email back already with specific answers to my question. Same day reply is good enough service for this country boy.

 

[BPINE]

EagleEye, I have a transfer Flow with a US Gear. I cut about 6" off the tank or 3 gallons. I cut it back to the first step and welded the original end back on. My US gear on the 5 spd was 11 3/4 inches longer, different adapters for different tranys could affect this. The US Gear is a little clunky as well but it has worked perfect for over 100k now so I am very happy.



Blair

To clear up a point with the GV unit... You CAN have an exhaust brake, just don't have the GV unit in OD when you use it. Their box has a lead to downshift the OD to direct drive when it sees an exhaust brake 'on' signal.



At least that is how I understand it. I figure the drivetrain and OD off (1-1 ratio) is about as strong as the original prop shaft.



Learning 'how to shift' the unit is difficult when I am missing the 3rd pedal in the cab. I have an Auto, and there ain't much us auto guys can do to ease up the jarring OD shifts.



Called US Gear yesterday, and wasn't impressed with their tech support. All I asked was 'what is the length my transfer case will be moved back in my specific application'. I couldn't get a straight answer. The best I got was "well... about 12" or about 12 3/4" if you need this certain adapter". Well, I'm calling to find out if I need the adapter. Hard numbers please! US Gear didn't seem too interested. That's OK... I don't have the room available with the Transfer Flow tank without some extensive modification. Oh well.



I am still happy with the top speed engine RPM, and still unhappy about other issues. Will work the bugs out, and I'll keep posting with anything new.

 

[SRehberg]

I just wanted to comment about learning to use the GV OD which was likened to a manual transmission learning curve. With the transmission there is the ability to feather the load to the trans whereas with the GV unit, it's electrically/hydraulic actuated. I. e. it's either engaged or it's not, there's no middle ground. So you are constantly trying to guess lag time, rpm or even trying to remember the GV is engaged when coming to a normal stop. The "bang" is definitely unnerving.



The exhaust brake info seems to be conveniently left out of the advertisements and is something you discover AFTER the purchase. I for one think it's a poor design relying on a cone style clutch.

 

[EagleEye]

BPINE... thanks for the response... and the info. Does there happen to be anyone who has put a US Gear OD on an auto/transfer cased truck and know the dimensions it was moved back? I may consider modding my TransferFlow tank like BPINE did, but I would want a hard number so I can figure what I am up against as far as prep work. Also... How much did you have to lengthen/shorten the prop shafts? It is nice to have things ready before taking the jump.

 

[Pavemen]

I'm going to look into the US Gear set-up now to see what it offers.

I've got their underdrive version (though I'd rather than lower diff gears and an OD) but it been great so far. Its a 35,000 lb GCVW and is compatible with an exhaust brake in all cases (on/off, under/overdrive) according to the tech I talked to there.

the GV unit is compatible with the exhaust brake but only when its in direct drive. i confirmed this when i talked to them as well.

as for gear splitting the GV unit, its the same with the US Gear as well. If you are in an automatic, its more difficult to pick the right gear and you are reliant on manual shifting the auto and manually engaging/disengaging the OD unit.

On a manual trans (either GV or USG), the on/off switch mounts to the shift lever and it becomes second nature to shift and split gears.

 

[Coalsmoke]

Thanks Pavemen. Does anyone know do the stock fuel tanks on our trucks have to be modified to fit the US Gear OD or is it just these transferflow aftermarlet tanks that have to be modified. I'm a bit confused how a person is supposed to modify the stock plastic fuel tank. I have a reg cab 4x4 NV4500 if it matters.