make my d350 into a 10 speed

R

roysd350

New member
Joined
Jul 13, 2010
Messages
76
I've herd of a unit you can put behind the transmission like a overdrive box or something . My truck only has a top speed of about 74. I need like three more gears but a 10speed would be sweet . Dose anyone know what I'm looking for ?
 
What gear ratio are your axles and have you done a 3200 or 4000 rpm gov spring?

US Gear and Gear Vendors have bolt on O/D units. I'm not sure how the US Gear units hold up, but most of my customers that run the Gear Vendors have had them fail. One customer went through 4 of them, after number 4 failed, he pulled it off and swapped axle ratios.
 
Thanks for the advice the piece I'm talking about used to come on big rigs back in the day to give them a high side and a low side on the trans . I have 4.10 I guess its a single rear wheel ton so I'm not sure .all that I know is I tow all the time and when not in tow I would like to drop the rpm to 1800 at 75mph. I need a couple extra gears not just one.
 
gear vendors is all you need

most all trans have the same overdrive ratio anywhere between .7: and 1:1......only way to lower your rpm is with a gear vendors or different rear end gears
 
OrangeNV said:
gear vendors is all you need

most all trans have the same overdrive ratio anywhere between .7: and 1:1......only way to lower your rpm is with a gear vendors or different rear end gears
Click to expand...
Yep, get an aftermarket OD unit.
 
alot of older 2ton dump trucks had 3 and 4spd auxilary boxes behind the tranny. You can also use one of them, but good luck getting one to fit. An after market OD unit would be alot easier to install. Basically makes your truck act like it has a 2spd rear axle.
 
They all got it covered with the gear vendors stuff, but just something else that is more important to diesel guys is the torque rating for the Gear Vendors. In direct (1:1 or low) they say it can handle as much torque as the transmission. In overdrive (0.7:1 or high) it can only take 700 ft/lbs. An engine making 400 ft/lb in first gear (5.61:1) puts up to 2244 ft/lb into the Gear Vendors. Just something to think about.
 
Thanks guys the gear vendor prob wouldent hold up for what I pull . And I like that the truck is low geared for off road but its killn me on the highways . I guess I'm between a rock and a hard place
 
The old spicers 3sp od is only .85 .That is only 15% and they leak like crazy I used to run 5831spicer and they are noisy.better off changey your gears.and you would be adding almost 250lb at least to the truck.If you have a standerd cab you won't have much to play with for your driveshafts.you might check with advanced adaptor they used to sell a unit that went inbetween the bellhouseing and the trany.


Dale
 
The easiest change would be to run taller tires. 235/85/16's are tall enough to help but still skinny enough to get good fuel mileage.

The next easiest change would be to regear the rearend.

You could also find a newer rearend with the gear ratio you want and disk brakes!!!
 
loganp said:
They all got it covered with the gear vendors stuff, but just something else that is more important to diesel guys is the torque rating for the Gear Vendors. In direct (1:1 or low) they say it can handle as much torque as the transmission. In overdrive (0.7:1 or high) it can only take 700 ft/lbs. An engine making 400 ft/lb in first gear (5.61:1) puts up to 2244 ft/lb into the Gear Vendors. Just something to think about.
Click to expand...

While its a valid point, I'd think that if you're in first gear, you'd keep the GV in the direct drive. Probably wouldn't use it until you get into third to split between fourth. That being said, it probably wouldn't be a real great option for much more than real mild upgrades. 6 spd and highway gears would make more sense, and in all likelihood, be cheaper to do as well.
 
Just swap in some 3.55's and call it done. With the torque of the cummins, you can haul as much weight as you can legally license it for with those gears anyway.
 
Aux transmissionon came with different OD gears. I have a 17% OD version in my 5500 that puts double over at .62 range. I cruise at 2000RPM at 70 MPH with 4.44 gears. Spicer made several of them with a .75 OD ratio also. They are big heavy units but they are not going to break either. I believe that most of the 3/4 OD units came from gas jobs with the .8 ratios coming from diesels. Pretty much anything over 2 tons had brownie boxes available and came from the factory up till the 80s. My Spicer 7041 auxiliary has bigger gears than the roadranger sitting in the bed of my truck!
 
Thanks burnin oil I think that's about the best and only option that will hold up to lots of tq and massive loads . Thanks again guys !
 
If I was doing it again, I'd use a Brownie unit. Some call them Brown-Lupe or Brown Lipe. They were auxilliary gear box units, and came in 2, 3 or 4 speed versions. Some versions were 6041, 7041 (mentioned above), 8031, etc.

I tried a Mitchell unit that was rated for 30,000 gvwr. I busted one of the gears and took it out. I paid over $2k for it and it had just been rebuilt. It's a beautiful little unit, but I just have bad luck. I'd make someone a deal on it if they're interested in getting a gear made.

--Eric
 
Watson=original company
Browne-lipe=bought out Watson
Spicer=was the big name in aux boxes for the last 50 years.
Brownie is the slang term people used for years.

I would go with a 3spd unit. No sense spinning that big low gear if you are not going to use it. If you want to really play you could run a 3.55 rear and in UD (20% under) it would be like a 4.10 axle. After you hit top gear then hit direct so its like having the 3.55 rear, then smack double over for a 2.91 rear equivelant.
 
You must log in or register to reply here.
Back
Top