Need more gears

[illflem]

when towing heavy. What do you guys think about switching over to a six speed? Anyone done it? How hard? Would a Gear Vendors or US Gear overdrive be a better choice? Is one better than the other? Truck is a '97 3500 pushing 400+hp. Has a 3k GSK.

 

[NVR FNSH]

Bill,

I'd say you're better off with a GV or USG than a 6spd. With 400hp I'm suprised you're running into trouble. The GV/USG will allow you to split 2/3 & 3/4 plus give you a taller overdrive for cruising down the hwy unloaded.



I am not totally satisfied with my 6spd - the gear splits are great but the shifting is so bad compared to my old 5spd I almost wish I had got a 5spd in this truck. If I had to drive my truck everyday in traffic I really wouldn't be happy with it. This is the second transmission and it's only marginally better than the original.



Brian

 

[willyslover]

Bill . . 100% agree with Brian



at first it was good but in retrospect the 5 sp. with a GV or USG would now be my choice. . I think GV would be it

 

[Got Smoke?]

Contact member Drees1 (Doug Resse) he actually bought his truck with a Gear Vendors and Pac Brake already installed!



Wish my truck had come with that:{

 

[M Barnett]

My vote would be for the US gear.

Michael

 

[NVR FNSH]

Bill,

I think there was an article in the mag about converting over to a 6spd - maybe 2Timer?



Brian

 

[RHARVEY]

Is it Gear Vendor that you can use with an exhaust brake?????



I'm glad that I found this post... I was seriously looking at changing to the 6 speed...



Rick

 

[RustyJC]

If you read the Gear Vendors literature and listen to users who have burned them up, you'll find that you cannot use an exhaust brake with the Gear Vendors unit engaged. This is because the Gear Vendors is basically the old Laycock OD unit found in Triumphs, MGs and Austin-Healeys. The clutch in this unit is designed to transmit torque only from the engine to the axle, not "backwards" from the axle to the engine as is the case when an exhaust brake is being used.



The US Gear design (it originated as the old Doug Nash modified Ford top-loader 4-speed) uses mechanical gearing to achieve overdrive/underdrive and does not have this limitation.



Rusty

 

[WDaniels]

Know a guy that has a US Gear and he says that, "that sucker gets hot" and overheats easily.

 

[LarryB]

Bill



I like my USGear 2sp, NV4500, 4:11 combination. Double over is great for economy. Have all the gears I need too. Makes it real nice when heavy. Only problem is the dang thing heats up easy. 70mph on the flats is about 200 degF with no headwind. Headwind will take it up to 250 easy. In the hills it's been almost useless in high range when heavy. I have been running LE607 in my NV4500 and USGear unit up until now. Before the last trip I changed the NV4500 to Castrol Syntorq and was rewarded with 50 deg cooler temps. Last week I changed the USGear to Syntorq too but have not driven it yet. I'm leaving for Baja mid Nov weighing 17,000+ so should have some feedback after that trip.



Larry

 

[illflem]

So now that the six speed idea has pretty much been eliminated don't the two speed guys offer both over and under drives? Would one run hotter than the other assuming it will mostly be used just on hills? Which would be better? Truck cruises 65 at 2000 rpm right now and is plenty fast when towing a 14k TT. Sure wish someone offered a two speed rear axle that would fit.

 

[LarryB]

You're right Bill. The UD is supposed to run cooler than the OD because of efficiency loss. Direct will run coolest of all though because the load is not going through all the gears.



I too dreampt of a good ole 2sp rearend, but to no avail.



I question if he really needs more gears though. Adding the 4K kit may help. The 4K kit makes it feel happier/easier at the higher RPMs than the 3K. Gives a really wide powerband. I noticed with the 3K gov I feel like I need more gears. With the 4K kit, 5 speeds seem to be enough. My biggest reason for adding the OD was 1600rpm at 65mph or so. Plus I wanted another toy real bad.



Food for thought.

 

[illflem]

Larry, he says he can run the rpms up good but has to do a very fast downshift to keep from losing much speed and that it will lurch, which doesn't sound like it could be too good for things with a heavy load.

 

[LarryB]

Bill

My thinking is that he just may be keeping the rpms up, but is it defueling up there? Say at 3200 with the 3k kit you won't make enough power to pull and hold a gear in some cases. With the 4k kit you will. This allows your RPM to be a few hundred higher when you shift and start pulling in the next gear, say 1600 instead of 1300. Big difference.



After running both the 4K and 3K and 5sp and OD, all at 17,000lbs plus, I think I would try the 4K kit before spending $3,000+ for the 2sp. It's only a couple hundred dollars and may be enough for him. Of course then again, maybe he secretly wants another gizmo to play with. Just like me.



Again, only my opinions.

Larry

 

[QRTRHRS]

Two Speed Axle

There must be someone on board here that is knowledgable with two speed rears. Only ones I ever saw even on mid 20k trucks were huge. Just wondering if anyone ever saw anything smaller. On the burner now but I keep Largecar's idea of the Brown-Lipe in mind. I would sooner add gears than a wider powerband.



Is there anyway to add an oil cooler to the USGear?

 

[LarryB]

There are lots of ways to add a cooler to the thing but a pump is also needed along with hoses/fittings, wires, fuses, switches, yada yada yada. All are parts that will cause problems. I had a Brown-lipe in my hands and proceded to cost out all the mods. Driveline mods alone would cost over $500 min. Then you must fab all the parts needed. Noise is a problem. Not to mention driveline snatch. (not that kind of snatch) No easy multigear answer that I can find. All seem to add complexity and expense. Again, after actually doing it myself, I think there is a lot to be said about the broader powerband.

 

[Bob Horrell]

Bill,

I have the GV unit and after about 56K miles of heavy towing I managed to strip the teeth out of the anulus - a very unusual problem. We think it was because I was using a McCleod clutch with solid centers and have over 400 hp. I tow my tractor on a daily basis for my business. I now have a 13 inch South Bend clutch and a new GV unit. GV now has an optional cooler for their unit and I installed a temp guage in it and I have not been able to get it over 175 degrees even when towing 12K lbs up hills. The temps have been cooler now than earlier in the summer. Max outside temp since installing the guage has only been 80 degrees. The cooler is an additional $350 but a worthy investment if you decide on the GV unit. A rebuilt GV unit cost me $650.

I use the GV unit so I don't have to tow under a load in 5th. I use 4th over instead which is almost the same gear. I think is works because I just checked my 5th gear and it was so tight that it didn't budge with 300 ft/lbs of torque. I staked it real good into the threads to make sure it doesn't come loose.

Hope this sheds some light.

 

[WDaniels]

Was told that the reason there isn't a 2 speed rearend for our trucks was the same reason that there isn't a Jake (compression Break) for our engines. To SMALL.

How bout the same system that the old tractors in the 50's used. A 5 and 2 gearbox? Some of you real heavy truck and equipment mechanics got any insights?

WD

 

[M Barnett]

How bout the same system that the old tractors in the 50's used. A 5 and 2 gearbox? Some of you real heavy truck and equipment mechanics got any insights?

I have one of those units for a Ford 8n tractor made in the 50's. It was made by Hupp. they were also made by Sherman and another I can't think of right now. These work great in a tractor as they were available in under drive, overdrive or both which mine is. They are mounted in front of the transmission in a case which is an extension from the bell housing to the transmission. It is a self contained unit with its own oil same as a U S Gear or Gearvenders. The problem, I think, would be they are straight toothed and would raise cain at highway speeds. In a tractor the gears turn slow. Has anybody considered the old brownings? I can't remember much about them. I remember having an early 50's Dodge flatbed, about a 2 ton with a six cylinder which didn't have much power. I found a Ford two speed axle and put it in. sure made a big difference and I loved it. I ran linkage all the way to the cab and shifted it with a gearshift lever. Would love to have something like that in my Ram. I've got a HD 13 speed in my Freightliner, lets see, it would make the Dodge ride a lot better and it might reach from the bellhousing to the differental



Michael

 

[Turbo Thom]

QH:

I thought of a cooler with mine but was told by Lee at US Gear the unit was to have 1 qt. of oil. No more and no less. The cooler as I see it would have to have more oil to cycle. The only time I use the OD is when starting a load to speed and never leave in OD while towing. I guess there is a way to allow for oil in the cooler and still have a qt. in in the box but I don't know how.



I don't have a temp gauge in the OD but I do in the transmission and have seen the temps there get to 200, so I have to assume the same is in the OD, if not more. I checked the oil in the transfer case yesterday and see it is time to change it now. That brite red Amsoil ain't "brite red" anymore. Everything gets hot under there. The Amsoil is made to take the heat but still should be changed every 30-40K. I installed the fastcoolers on the transmission and still get up there to 200. Its just the style of the monster.



I'm going to put mine on the dyno today and when I get home the thing gets new oil . I would like to keep the temps down but I just don't see how.



Any suggestions?



. . Preston... .