Hey yall. i need a little help. iv got an 1980 fullsize that had a blown motor so i decided to upgrade.. i threw a 351 5.8 out of a 93 fullsize eddie bauer, with the E40D transmission. the engine is running fine and what not but now i want to make everything work including the speedometer. i know that the speedometer on the E40D is digital where the truck came with mechanical. i have the dash from the donor truck still. but i want to keep my oroiginal dashboard. is there anyway i can make this work? i know that i could convert it to mechanical but that would effect the computer if im not mistaken. iv gotton the rest of the gauges to work properly with some tweaks here and there and the pcm reads all them all with the assist of a scan tool. thanks

 

Unless you cam buy a converter that someone already made, there's no easy way to do that. One "hard" way is by designing and building your own converter using a digital to analog chip (DAC) and the necessary support circuitry.

 

My Bronco has an E4OD and has an analog speedometer, my odometer is digital.

 

Could he swap in a differnt t-case with the speedo hook up? Or would it still mess with his pcm?

 

i dont think swapping transfer cases will work. if im not mistaken this E4OD transmission is computer controlled so theres nothing i can do to convert it to mechanical. just wondering if theres some way i can make the digital one work in my old style cluster or if theres an adaptor thing to convert it. has anyone ever tried this before?

 

Folks, the problem here has nothing to do with the what is IN the truck. What is NOT in the truck is more critical. The fact that a 1980 model Bronco does NOT have the necessary VSS (Vehicle Speed Sensor) in the rear differential housing is going to cause no end of headaches. The VSS "tells" the PCM how fast the truck is moving. The PCM uses this information to control shift points for the E4OD via the PCM. The VSS information is also used by the cruise control system and the PSOM (Programmable Speedometer/Odometer Module) to drive the speedometer and calculate the distance the truck has traveled... if the truck actually has a PSOM. Unfortunately, a 1980 model doesn't.

I don't know if you have attempted to drive this truck but I highly doubt it will shift properly without input from the VSS.

Now I may be jumping the gun here and you have dealt with this issue. There is an aftermarket kit to relocate the VSS in vehicles that do not have a provision for it in the differential housing (before you can ask, no, I don't know who makes it but Kemicalburns might).

In any case, the E4OD has no provision for driving a mechanical speedometer like the one in your 1980. If you can install a VSS so it works properly into this truck, you will be able to drive it without issue however, you will still need some method of driving the mechanical speedometer in the dashboard if you intend to keep the original speedometer in this truck.

 

If the VSS is in the differental then what is the sensor at the output of the transmission for? there was a sensor on the differental but that was a simple antilock brake speed sensor, at least i thought it was .. Also i have yet to drive the truck. i am still waiting for new drive shafts to be made for the added length and flange change. i took the whole harness of the donor 93 and cut out the abs and all the unnessary componets. still have the dash connections and the important stuff. but the door chimes and ect are gone. this is the first time iv done somthing like this so im still learning on what needs to be done. so far all thats done is the motor and trans are droped and mounted. hooked up fuel lines with an inline pump from a 90 bronco that puts out 40 psi and it seems to idle and run good. tho its without exhaust and drivelines.

 

The E4OD uses the MLPS (Manual Lever Position Sensor) to tell the PCM what gear is selected; drive, neutral, reverse, etc. However, the VSS serves several purposes including providing both the anti-lock brake computer and the PCM with vehicle speed information.