New tranny

[Exekiel69]

I have rebuild the getrag on My truck and I really like how easy it is to work on this tranny but I'm not so sure how well it will hold with Me pulling some heavy stuff in the long run so here I am looking for a possible replacement for it. I have little experience with medium duty trannys so I appreciate any experienced member that could share some light here.
I read about some 7spd then 9 and 10spd trannys, is there any of this that comes ready to fit behind a 5.9l cummins?

If not, what is the best option for a little city driving and heavy haul? I do not want a 5spd again if I'll get in the trouble of replacing the tranny.

 

[snicklas]

EZ, Take a look at Tonkadoc's RV Hauler Thread, he just bought a manual transmission, of has one in mind to replace the Allison in his RV Hauler. He has some names and model numbers over there.... and it is a 5.9L in a F650

 

[tonkadoctor]

Hey EZ, got your message, will help where I can.

Here's a link that could help.
http://www.sanco-bg.com/NV5600_Conversion_parts_list.htm


Medium duty truck trannies don't have to be originally from behind a cummins as they have SAE transmission belhousings. You just need the correct bell housing adaptor from behind a 5.9 Cummins, flywheel and clutch to hook them up. Easy to find in any truck salvage yard.

Most medium duty stuff is SAE#2 with 1-3/4" input shaft and a 14" clutch. Some medium duty trannies like the allison 545 have an SAE#3 bell which is smaller.

SAE#1 with 2" input is normally what you find on semi trucks.



5 speed, 6 speed and some 7 speed transmissions don't need air to shift them unlike the 8 - 18 speed trannies that need air to operate the splitters making them a better choice for your application.

If you want an overdrive gear in an eaton fuller 6 speed you need to look for the transmission model numbers that start with FSO like the FSO6406 or FSO8406 (Both are 6 speed .78 overdrive trannies rated for 660 and 860 ft lbs torqe respectively). If it just starts with FS like the FS5306A or FS6306A it is a direct drive trannie.

To the best of my knowledge, looking at the gear ratio charts I got from Eaton Fuller, They did not make any 5 speed overdrive transmissions. All are direct drive.

For the eaton 7 speed trannies look for a TX vs just a T......th TX-8607B is a .75 overdrive, the T-8607A and T-8607B are both direct drive.


Now there are some 9 - 13 speed trannies out there with 1-3/4" input shafts and SAE#2 bellhousings if that tickles your fancy.



Now I have not done my swap and may not as I am also considering just slapping the motor in mine and running the wheels off it while I look for a different ride............. BTW, just took a 2003 Freightliner Argosy mid roof cabover for a test ride today............. C12 430 hp CAT, fuller 10 speed autoshift, cruise, Jake, tilt wheel, air ride eveything and leather seats too .......

 

[Exekiel69]

That You so much Tonkadoctor . I'll start searching for a medium duty Jyard in My area (I don't know of any) and see if they have any of this 7spd with OD like You said. I guess I could grab the bellhousing to put it behind the cummins along with the flywheel and clutch and parts.

 

[Exekiel69]

Btw that is a nice site, I was wondering if they make hole kits to put this trannys on a regular pickup truck they show a parts list but I don't see any order forms. I'll give them a call.

 

[Exekiel69]

Alright, I called this man and unfortunately He does not make a kit. He did it "for His own personal pleasure to probe it can be done". Nice fellow and He was nice enough to put a part ;list for the conversion so I'll see if I can start gathering parts to make this a reality. He mentioned the fuller is a very easy transmission to work on, is this the 7 spd Tonkadoctor was talking about?

I'll start reading...

 

[tonkadoctor]

Just about any fuller tranny is easy to work on.

5 and 6 speed directs are easy to find. OD 6 and 7 speed trannies are harder to find and pricey.


Keep us posted. this is something the IDI and PSD gang could do too. They just need to find the correct IH SAE2 bellhousing adaptors.

There are some adaptors for Big block Ford gassers out there too for those so inclined (hiding in F600 - F800 gassers hint hint) Prolly some out there for the Gooberment Motors gang too.

 

[Exekiel69]

I see big old trucks for sale almost all the time in CL, I will ask them what tranny they have and find out about it. I was told You can turn a fs6406 into a fso6406 easily

 

[tonkadoctor]

You could contact the tech or engineering gurus at Eaton Fuller Roadranger transmissions and they could give you the specifics for a conversion.

I know some 9 speed directs can be converted to 9 over by flipping some gears and 9 speeds can be converted to 13 and 18 speeds

 

[spg]

If you come up with any information on the FS6406 to FSO6406 conversion please pass it along.

I see big old trucks for sale almost all the time in CL, I will ask them what tranny they have and find out about it. I was told You can turn a fs6406 into a fso6406 easily