AKA "brownie boxes".

I recently purchased a Eaton Fuller RT6609A transmission that was bolted to a 5.9 in a medium duty truck. I got all the hardware and everything needed to bolt it to my cummins. Only problem is the no OD part.

I've been looking at old spicer aux transmissions to remedy this. I found a Spicer 8345C that would probably work. It's a 4 speed with an aluminum case. Honestly, I'll probably just stick the thing in OD for most miles and maybe put it into direct for towing. I'm sure I won't be shifting the brownie at all when moving, since the RT6609 has plenty of gears.

Anyway, does anyone know what the OD ratio on the 8345C is? Also, I know this is a pretty heavy duty piece, but it is pretty old. Am I going to tear this thing up behind my puny 5.9 cummins? I know they were designed for big diesels and big loads, but I'm paranoid. The last thing I want to happen is for this thing to grenade on me hundreds of miles from home. I plan on running close to stock power levels... nothing over 250 horse at the most. I'm never going to tow more than 10k so I'm pretty sure the box can handle it.

Any input is appreciated!

 

mark the shaft's and count the turns to determine the ratio. it will handle the torque. you will really like the new low reverse gears. some of them had 4rh direct instead of over

 

Here you go.

http://rides.webshots.com/photo/2623...80251109VGJOGn

Some other information that may help.

http://www.4btswaps.com/forum/showth...946#post108946

 

From the plate on the 06, Grey Wolf, I'd say you were a Red Sovine fan. C U on the 14 sometime.

Gadget 35-06.

 

Yes it was one of my favorites in the sixtys when I was doing some driving myself. A day when a truck driver was known as a Knight of the Road.....

I'll keep a eye open for you too!

 

Quite a bit of Spicer auxilliary info on this page, also some Fuller RoadRanger info; scroll down to it :

http://www.6066gmcguy.org/SM420.htm

Also, there are a bunch of threads and guys that have already installed auxilliaries dispersed amongst the 6.9/7.3 IDI section here :

http://www.oilburners.net/forums/forumdisplay.php?f=34


Myself, I have a cast-iron Dana-Spicer 4-speed 6041 that is soon going behind my Cummins/Getrag.

 

I had an RTO910 (the O means OD, the 9 means 900 ft lbs tq and the 10 means 10 speed) in an old Binder and it could be switched to an RT by swapping some gears inside - taking the OD from the top and putting it on the bottom for a deeper granny but no more OD. I'd find a good truck gearbox man and see if that can be done to yours. Craig

 

Most of the older nines were 9th-gear=direct.

Adding the over-drive split yielded a 13-speed.

I love a 9-speed; I can live with a 13-speed; but, I highly dislike any 10-speed.

Later nines sometimes were "nine-over"; usually, these also had a "deep reduction" lockout that added five really really low gears, actually making them 14-speeds.

the nine-over with deep-reduction is my favorite of the bunch.

 

Install the second gear shift. It is real nice to be able to shift from direct to OD on the fly. The first to digits of the Spicer model is the Torque input for the main (not AUX) trans. I have a Spicer 7041 in my 5500 and it sure is sweet pulling loaded. I never realized there were so many holes in the gear splits of a G56 till trying to accelerate on a hill from a stop grossing 26k. The 3rd digit is the number of gears, and the 4th is the case material and the letter is the ratio.
You probably wouldnt need to split the gears much with a 9 speed unless they are all low gears. I didnt really need to on the G56 till around 35 MPH when the torque multiplication was less. Running empty I run in direct then hit OD on the aux, the truck likes it better than running in OD all the time. One word of caution is that AUX boxes arn't synchroed!