Is there such a thing as a mechanical speedometer output/input with the E4OD?
I am retrofitting my 79 Bronco with the drive train from a 94 Bronco with the: 5.8, E4OD, and BW transfer. Unless the Borg Warner transfer turns the front drive line constantly then I will opt for my NP205.
Has anyone done this conversion and how did you address the speed sensor input?
I'm thinking maybe I should have looked for an older FI Bronco that may have had the mechanical speed output. I am curious what signal the transducer on the speedometer cable of my 79 produces? Maybe it would interface?
Thanks in advance.

 

You are going to have to look at the 87 to 91 F-series and FSbronco for the the VSS used in that body style. It essentially connected inline with the speedometer cable, e.g. speedo cable connected to one side, the other end held the gear that was then attached to the output shaft end of the B/W transfer case. It isnt going to be easy getting it to work with the NP205 as I think the cable attached differently, I think it screwed into the side of the case or something.

The NP205 is a different style of part time case as it was completely gear driven, where the B/W1356 used a chain to connect the front drive shaft to the rear drive shaft. Both are decent transfer cases with the NP205 being a stouter case, but the 1356 has a lower low range gear.

What do you mean by turning the front drive train constantly? The NP203 was a full time case, the NP205 had the ability to be switched from rear wheel to front wheel to 4wheels, and Lo/hi range in 4x4 and 4x2. Then you could take the range gear out of a 203 and attache it to the front of a 205 and get the doubler case.

 

dont bother looking at an 87-91. there is a company that makes a remote mounted VSS speed sensor that mounts behind the Tcase. this is an aftermarket piece. so do a google search for remote mounted vss/speed sensor.

a few guys over at FSB . com have used this and works well.

 

Thanks guys, both replies help.

 

What I mean is that the transfer case is always engaged to front and rear differentials. I don't know if it does or not. When I shut the Bronco down and started tearing it apart I had left the electronic shift in four wheel drive so now I don't have a way to test it. I know it turns the front driveline when I turn the rear driveline right now. I have seen some trucks and suv's from behind when following and their front drivelines are turning as they drive down the highway. Anyway I think I will at least start out with the BW because it seems like it may be an okay transfer case. At least it may be easier to retrofit it to an earlier VSS. What the heck was wrong with transmission VSS's anyway. Always a changin'

 

The VSS was put in the rear axle housing to facilitate the use of ABS on these trucks. The VSS also provides the ABS computer with traction information in trucks so equipped. Leaving it in the transmission wouldn't have allowed the VSS to perform double duty.

 

i wouldnt run an electric Tcase in your rig. they are notorius for failing. get a manual 1356 or like you said run the np205. either way you will need to get the vss relocation kit that mounts to the back of the tcase so the tranny gets the proper signals. other option which is more costly would be to install a D60 out back and have a tone ring installed onto the carrier and a hole drilled on top of the case for the sensor. or get a sterling 10.25 rear diff that already setup for this. either option will be 8 lug and require you to go 8 lug in front unless you plan on having 2 spares.

 

Using an NP205 with an E4OD requires you to notch the side of the tranny to get the driveshaft to clear. Not a big deal, just something to be aware of. Definitely go with a manual shift transfer case.

Since you need a different transfer case anyway, get one from an '87 to '91. This case will have a provision for the mechanical speedometer, and it will also have the VSS for the E4OD to use. A little-known fact is that the VSS in the rear axle is only used for the ABS and the electronic speedometer (if equipped). The other VSS on the output side of the transfer case is what the E4OD uses.

Other than the full-time transfer cases like the NP203, no part time case that I'm aware of is spinning the front driveshaft while in 2wd.

 

Actually the VSS on the rear axle is used for the transmission and fuel delivery too. It is a pretty important device. The one in the transfer case is only to prevent shifting from 4H to 4L on the go. Near as I can tell, that was just a quick look at the Helm's EVTM. I think I am going to go with the non-electronic transfer that way I get my VSS and speedometer too.

 

Sorry, but your information is all wrong.

If even part of what you're saying is true then why does my manual-shift transfer case Bronco have a VSS on the transfer case?

 

From what I understand the 87-91 has the Vss on the transfer case.
Otherwise it doesn't matter because I know what I need to do due to the first two replies.

 

Some people you just can't help. Good luck anyway.

 

andym, my 94 bronco doesnt have a VSS at all. it strictly runs off of the sensor from the rear diff. the VSS on the 87-91 was for a cable operated speedo. 92+ was electronic speedo.

 

The sensor on the rear axle is a VSS (vehicle speed sensor) - what did you think it was called?

Cable operated speedometers don't use a VSS.

Both my '89 F-150 and my '90 Bronco - both of which are 4wd, one has a T-18 and the other an E4OD - have two VSS's. One on the rear axle and another on the output tailshaft of the transfer case. This is in addition to the output for the cable-driven speedometer. I would assume that your Bronco has two as well, but I'm not sure on that. Obviously your transfer case doesn't have the provision for the cable speedo.

 

the sensor on the back is not a VSS. you can go to any autoparts store and ask for a VSS and they will hand you the incorrect part.

the sensor on the back diff is the abs sensor which talks to the abs computer and then sends signals to the PSOM (electronic speedo) in 92+ vehicles. the VSS in the tcase is no longer there. for the 87-91 models the VSS in the tcase turns the cable for the speedo and works with those years e4od (89-91). the sensor on the rear diff for those years controls rear abs unless it has the e4od which it also uses that pulse signal to work the shifting of that tranny electronicly but the vss in the tcase controls the speedo.

4wabs didnt arrive till 92+