I am looking to buy a 1986 ford cutaway (RV) E-350 6.9 diesel. The transmission is a 3 speed automatic. Can I install a transmission from a 1990 E-350 (van) 7.3 diesel with overdrive?

Is it worth it?

Thank for your answer

 

You can, it will bolt up to the 6.9. You'll have to be good at wiring as the E4OD is computer controlled. You'll have to get the TPS from the van, easy enough, but the tougher one it the speed sensor on the rear axle, the '86 won't have this so you'll need a newer rear end.

Worth it? That's your call, the 3 speed that is in there is the C6 and is as bullet proof as an automatic can get, but you'll have to make the call as to how important OD is to you.

 

A gear vendors overdrive is another possibility, but you still dont get the lock up converter like the e4od.

 

That'd probably be the easiest. To do the E4OD swap he'd also have to wire in a newer cluster if he wants a working speedometer.

 

Some would argue the existing C6 is the way to be. Personally I like the E4OD, its a strong transmission, nice with O/D and lockup converter, but its wiring and related issues are its downfall.

The easiest way I can think of to deal with the computer issue is to not try and wire the stock Ford system to control the E4OD, but get a controller like the Baumann unit (now called US Shift Quick 1 - $425 from the site); it doesn't require the computer. All you would need to do is fit the MLPS (manual lever position sensor - same as a TPS - throttle position sensor on a gasser) from a later model IDI to your IP, and all the other sensors are on the E4OD. The wiring harness is point-to-point, so adding it to the truck would be easier than working with the stock harness.

I'm going with this controller for my E4OD shortly, so I can have full control on the wiring and know it is solid and correct, and can troubleshoot without getting deep into the stock wiring.

 

That does sound better/easier then messing with the stock wiring. I take it the controller is designed without needing any input from a speed sensor?

 

thats what david85 did.swapped his c6 out for the e40d and used the aftermarket controller.

Search: Keyword(s): e40d, swap ; Posts Made By: David85

C6 to E4OD swap........Complete!

 

The diagrams show two options, one using the Transmission Speed Sensor (I think in the tailshaft, never seen it) or for 92-96 you tap the line into the PSOM. That might be something to call them about...

 

5spd ftw...

 

Thank you everyboby for your input, I am going to see the RV tomorrow and hopefully it in good enough shape to buy it.

Thank's again

 

Since this is an RV, how many times a year are you going to be using it....?


Add that in the factor of "is this swap really worth?". Say you only put 5-10k a summer on it. Adding OD will give you an extra 1-3mpg? And you'll spend how much on the swap? A good 2k $ just having a E4OD rebuilt, cause personally I wouldn't put a used E4OD in a motorhome... That's alot of fuel to save before the swap becomes profitable. If this was on a daily driver, ok then yes it be worth it, but on a camper? I don't think so unless you live it in it and travel year round.


My '87 6.9L Diesel 26ft class C motorhome, with the 3 speed C6 and 3.54 gears gets 11-14mpg, and 15mpg on the coast lines keeping it around 55-60mph on the highway.

Having traveled all over north America with mine, you'll see traveling with a non turbo diesel, elevation will have a great impact on power and mpg. The worst mpg I ever got with it, was in the rocky mountains of Alberta, and Colorado at over 9000+ feet, around 7mpg, climbing up hills in 1st gear, screaming on the governor doing 25mph! Ah that sound

If you do go ahead with the swap, you'll love this part of working on a van. After you disconnect all the linkages, and the TC bolts, the bell housing bolts can all be done from the top, very very easy dropping a tranny from a van!


Get pics of that thing, we wanna see!!

 

89-91 E4OD VSS would be tied to your speedometer cable in the tranny tail shaft.