Medium Duty fuller transmission questions

[gonecrazyi]

Im currently looking at a few fuller transmissions for a motor swap into my crewcab.

One is a fs5306 6 speed tranny with direct drive 6th gear. It is currently bolted behind a cummins and comes with all the sae adapters, clutch and flywheel.

The other tranny is a fso6406a from behind a cummins. Im waiting to here back if it has adapters and the clutch/flywheel. This is a 6 speed with overdrive

Both trannys are the same price, only difference is the first one is still in a truck.

I was reading that the fs series transmission could be converted to overdrive with off the shelf parts. If so I may go with the 5306.

What are your opinions on these transmissions?

 

[hesutton]

What's the price? I'd like to have found a FSO-6406 when I bought my FS-6306 for my DT466 project. Honestly, they are basically the same trans with some ratio differences. I really want an OD trans with my DT, but I couldn't find one. My FS-6306 was just $250, so I couldn't pass it up. I'm going to try and convert it to an FSO, but I've got to get my 6.9 rebuild done before I can think about the DT466 project again.

Heath

 

[paulb3]

FSO 6406 would be the one to get plus it has a higher torque rating than the 5306.

 

[gonecrazyi]

650 apiece. But I know for a fact im getting everything with the 5306. How hard are the fo models to convert to overdrive.

 

[gonecrazyi]

Would the cloth and flywheel/clutch sae adapter work on the 6306 that came from 5306?

 

[hesutton]

Would the cloth and flywheel/clutch sae adapter work on the 6306 that came from 5306?

The bellhousing is likely SAE #2, but could be a smaller SAE #3. The trans mounted adaptor simply bolts to the front of the trans like the bellhousing on a T-19. So sure, it should work.

Heath

 

[gonecrazyi]

What are the allison transmissions usually? I have the adapter from one or those still on the back pf it.

 

[hesutton]

650 apiece. But I know for a fact im getting everything with the 5306. How hard are the fo models to convert to overdrive.

Looking at the Eaton Fuller illustrated parts manuals for the FS-6306, the FS-3406, and the FSO-6406, it looks like you can change the input shaft, 5th and 6th on the counter shaft, and 6th on the mainshaft. It's been a bit since I looked at that info, but it's about 4 main parts.

Seems doable, but I've not tried it yet.

Heath

 

[hesutton]

What are the allison transmissions usually? I have the adapter from one or those still on the back pf it.

USE THIS CHART to find out if it is a SAE #2 or #3.

Heath

 

[gonecrazyi]

I took a better pic of my current sae adapter but my phone didnt save it.

 

[bike-maker]

Every Allison I have seen had a SAE2 bellhousing on it. I believe most all of the FS series stuff is SAE2 also. SAE2 clutches are also a standard piece; the engine specific stuff is the flywheel and block to bellhousing adapter.
From what I've seen, the standard size for medium duty stuff is SAE2; this includes 7.3 IDI internationals and Cummins. Many people out there claim they have a SAE3 bellhousing without actually measuring it.
Last I heard, the price for the parts to convert a Fuller into an overdrive trans was about the $650 price tag you listed (but I might be thinking of a RT trans), so I would go for the FSO.
Something else to check out is clutch linkage; there are both push and pull type clutches, and every one I have seen in a pickup had a pull type. The Fuller website also list a hydraulically actuated clutch.
Check the roadranger site for info.

 

[gonecrazyi]

I have a block to bellhousing adapter. Im assuming there standard and can be used with any sae2 tranny. What do flywheels usually run new for these types of setups?

Id really hate to have to piece a setup together and have it cost me a fortune.

 

[bike-maker]

A truck graveyard could be your friend.

Medium duty parts can get kind of spendy new, but they're pretty cheap used.

You have a starter for it?

 

[gonecrazyi]

I have the one that's on that adapter. I could go back for the allison but would rather not. Im trying to find a few good yards here that don't break the bank.

 

[Simp5782]

Allisons can have SAE 2 or 3. some 545s came with both, both md3060s and 643s came with 2s . I have a spicer 6352 5 speed direct 5th and 7.32:1 1st. it is SAE2 and will splint right into a clutch setup that had any spicer or clark behind it. And this you will never break.$400.