can a 4106 4 speed be installed in a 4104

[OLD -ED]

I picked up a 671TA for my 4104, Found a left hand rotation engine so my question is can I use a 4106 4 speed ? will the clutch and shift linkage work ? And can I use the 4106 differential ? and how much bulkhead cutting is involved . And can I use a 4106 radiator ?

[Hard Headed Ken]

Here's what I think I know. The V Drive angle on a 4104 is different than the V Drive angle on a 4106 and up. One is a 57 Degree and the other is a 63. I can't remember which is which and it may be 57.5 degrees, again I don't remember for sure. The 4106 Diff will fit in the 4104 housing if you open the area that provides clearance for the ring gear (The 4106 ring gear is larger) the axle spines are the same. The problem is the differential location in the axle housing, left to right is different on a 4106 compared to the 4104 because of the different angle. You might be able to use the complete 4106 rear axle assembly and make the swap. Maybe someone else can help with the rest of the questions.

Ken   

[HB of CJ]

FWIW, Pittsburg Fuel Injection had/has a gadget called a "duel power valve" that when turned on reduces the torque a hot Cummins Big Cam put out sosss a less-strong driveline would survive behind 750hp Cummins engines. When not engaged, the torque remains normal.

The torque setting was adjustable and could be set up several ways.  I'm wondering now if such a gadget exists for a Detroit to reduce the torque in the first 2 gears, then give full power for 3rd and 4th with a hot 671TI running a stock driveline?   Hope this helps.  HB of CJ (old coot)

[Len Silva]

We already have such a device. It is under your right foot.

[Barn Owl]

Yes, several have repowered a 4104 with other setups.

For example, see some photos in this old post:

Topic: better fuel economy with an automatic

[gus]

I don't think you have to change anything, a 671TA is the same size and shape as a 671?

Did you mean a 6V71TA?

[RJ]

Old Ed -

The 4104 and 4106 transmissions themselves are virtually identical.

The difference is in the location of the bevel gears - the '04 has them AFTER the transmission, the '06 has them in FRONT.

The differentials are also different, with the '04 having the pumpkin offset to the curb side, the '06 offset to the street side of the coach centerline.   (Or maybe it's the other way around, memory's a little foggy right now. . .)

If you've picked up an inline 6-71T, with mechanical, not electronic injectors, I wouldn't go to the time or expense to swap in '06 stuff, your '04 will handle it fine. 

OTOH, if you pump up the HP over 300, there is a possibility that you'll blow out the bevel gears, not the gearbox itself.

Be aware that the inline six mated to an '06 transmission assembly is too long to get all the angles lined up right downstream.

An '06 radiator will work, but you'll have to customize the installation to provide adequate air flow.  The radiator cut-out is considerably larger on an '06 compared to an '04.

The "ideal" repower of a 4104 for RV use is a 6V92TA / V-730 coupled with a 4106 or later rear axle. 

FWIW & HTH. . .

[OLD -ED]

Thanks for the help, It is a in line engine and setup @ 290 HP so I will stay with the 04 running gear and work on the cooling .

[gg04]

I've done the 6v92,8v71, and the 6L71taddec swap into 04's and the 6L71taddec is the easiest and works best...I have had no overheating problems running the original radiator...Just added a better shroud and a flexalite fan...My bus is set at 325hp and gets a little better than 11mpg average for the last 86000+ miles....easiest swap to improve your 04..rdw

[Kevin]

gg04, sent you a PM.

Thanks,
Kevin