overdrive for 440?
 

Is there any version of the 518 or any other overdrive transmission that will bolt up to a 440? What I have is a 1978 Dodge M500 motorhome chassis, so there's all kinds of room for a transmission. The present transmission is a 727 loadflight.

I keep reading that the 518 is just a 727 with an overdrive unit bolted on the back. I suppose it would be too much to hope for if that were literally true, so I could just add the overdrive unit to what I have.

I wouldn't mind a manual transmission (Eaton 13 speed anyone?) but the clutch and shift linkages are likely to be a problem, so I'd beter stick to automatics unless someone has a really good idea.

My situation is actually even weirder than it sounds. The 440 has already been replaced by a Perkins 354. It has an adaptor plate on it with the 440 bolt pattern to bolt up to the loadflight, so I assume anything that will bolt up to a 440 will bolt up to the adaptor. I'm not sure what pattern the Perkins itself has (SAE, maybe). It may be possible to bolt something up to it directly, but I don't feel like taking everything apart to see until I have a line on the parts I'll need.

The Perkins turns so much slower than the 440 that it really needs an overdrive. The previous owner solved the problem by installing a Gear Vendors free-standing unit in place of the hanger bearing, but it just exploded, so now I'm looking for alternatives.

I can't help you directly other than this:

I would not be looking at the "automotive" world, but rather the "truck" world, and by that I mean "heavy trucks." There are all sorts of combinations of transmissions in "that world" and I'd think Perkins would be right in the midst of it.

I would be tempted to ignore the 440 end of things and concentrate on the base engine.

Allison comes to mind.

I would then go back to a 440.

Gear Vendors add on Overdrive that replaces the tail shaft of your 727. Too many internal differences to just add the overdrive to your 727

the 518 has a bell housing for small blocks so if you can find a adapter small to big for a 727 your in business the over drive unit is good for 400 hp and with the right programming kit you can have a sweet running 518

Have you given any thought to changing the rear end gear ratio. May consider a two speed rear end from a medium duty truck.

I would look for a 47R out of a diesel truck to adapt

Welcome!

While there may be a kit or two that will allow you to adapt a 518a to a 440, I feel that you have better options out there.

• 618 - This is basically a 727 with stronger internals and overdrive. It can be found in dodge trucks with diesel and V10 motors from 90-93. This tranny has an input HP rating of ~450hp.
• 47RH - This is a 618 but has hydraulic controlled governor pressure and can be found in Dodge trucks with diesels and V10 motors from 94/95.

These are the only two that I would consider installing assuming you still have the 440 and want to swap it back in. Another option is to change out the rear axle ring and pinion. If it is an 8 lug then there is a chance it may be a Dana 80 axle. I could be wrong though.

No, I don't have the 440. The conversion was done a couple of owners back. Besides, I kind of like the diesel, slow as it is.

I don't know what the rear axle is, or what its ratio is. I don't have the right shop manual and I've never gotten around to counting turns. All I know for sure is its a 5-bolt dual-wheel with 19.5 inch wheels. In any case, I'd rather keep low gear and add another gear to the top, rather than raise the ratio in every gear.

It would certainly be neater to eliminate the 440 adapter and look for something that will bolt up to the Perkins. The problem is, I can't get a good look at it until I remove the transmission, and I'm a little reluctant to pull things apart until I know there's something available I can use. Maybe this winter if I run out of other projects.

The idea of using a 618 sounds interesting. I even have a '93 Dodge diesel parts truck, and I know I won't need the transmission out of it because my truck has a stickshift. However, I'd always heard that the Cummins had a unique bolt pattern and nobody makes adapters. If there's an easy way to use that transmission, that seems to be the way to go.

I've even considered using the Cummins and 518 as a unit. At least that way, I'd know the engine and transmission are compatible. But, looking at how much trouble somebody went to, to make the Perkins fit, I'm afraid of what unforseen problems I'll run into. Also, the Cummins has a lot more miles on it than the Perkins, and I really don't know much about its condition.

I AGREE THE HP AND TK OF THAT 440
THE 518'S I'VE USED WERE ALL ON SMALL BLOCKS

I Googled around and got nothing for absolute definite, but it SOUNDS like

The cummins in Dodges is NOT SAE but rather built (specifically?) for Dodge, AND the Dodge TRUCK (not auto) V-10s seem to use the same pattern

The car V-10s are based on a Mopar gas engine small block bolt pattern, but what I found indicates the truck V10s are different.

they dont bolt to the 440