I've got this 5 speed manual transmission, which came out of chevy pickup truck, 1995, I think. NV3500, which is a Getrag. I'm going to be putting it into a 39 Ford... I'm good with fabricating brackets and all that, and I've almost got the whole clutch thing figured out, BUT there's still a problem. Speedometer. The transmission is set up for an electronic one. I don't think I could use the factory one even if I wanted to - it seems it plugs into the computer, THEN into the transmission. Anyone have any knowledge on this? Will aftermarket speedometers work here? If so, the next question is why the hell are they so expensive? I've seen motorcycle electronic speedometers cheap, is there a way? Oh, and lastly, please don't tell me to use a different transmission - for every guy on some message board who says the nv3500 is junk, there are two other guys who say they beat the hell out of them all day long and they're fine... I just want to have a speedometer is all... Thanks to anyone who has a bit of advice!
What do the companies that make electronic speedometer say? I'd be asking them... btw in the old days the aftermarket cruise controls by companies like Perfect Circle used a magnet mounted on the driveshaft, and a pickup coil mounted on a bracket. Seems to me you could do this as a last resort if the sensor in the trans won't work properly with aftermarket speedos. You'll see something about PPM pulses per mile. Mechanical speedos work with 1000 revs/mile, driveshafts turn about 2000-3000 revs/mile. Typical electronic speed sensors that connect into a mechanical speedo cable (for newer cruise controls designed to fit older cars) produce 4000 or 8000 PPM.
yes, it is linked to the ECM and it will not work without it. there is no alternative - only older versions (i think until 1989) have a mechenic speedo. i can scan the wiring diagram if you are interested. but not this year...
I won't say they are junk. There is one version, however, that has a hell of a gap between first and second gear...4.0xxx for first and 2.3xx for second
Autometer electronic speedos, and probably others, will work with factory VSS. I've got a T5 with the factory sender and it works perfectly with the Autometer speedo. As for expensive, I guess that's relative. I bought mine for around $130 and considering how simply it solved a potentially complex problem, I don't consider that so expensive. Bob
Pretty much all the Chevy NV3500/Getrag 282's have that big jump from 1st to 2nd. I had one in an '89 1/2 ton with a 4.3 V-6 and 3.42 gears, I loved it. It shifted like silk but I didn't beat on it. When they break they can be EXPENSIVE to fix.
I have a Getrag in my Cummens Dodge. First is granny low and top gear is OD. The speedO drive is a common shaft that drives a sensor mounted on the outside of the trans housing. Thet sensor is wired into everything else. I don't see why a standard speedO cable couldn't be used. You might need to fab the clamp to hold it in place. It's to wet for me to go out and lay under the truck right now.
I have a NV3500 I plan to use and a Stewart Warner Electonic speedo (from the HAMB For sale ) which looks to be adaptable to just about any kind of pluse generation input. An electronic seedo output on the trans is just a pulse generator. The SW speedo is adjusted via DIP swithces to match the rate, gearing etc
There's also this option if you absolutely must have an older mech speedo. Pricey, but... http://abbott-tach.com/Welcome.html Click on Cable X
Thanks all. Definitely helpful... To bobscogin - where did you find an electronic speedometer for 130? That's not TOO bad; I've mostly been seeing $170 and up...
What you have behind your Cummins is an NV4500/Getrag.......bigger, heavier, more rugged tranny........
Check the Autometer speedos at Summit. The 3 1/8" versions are the least expensive. That's the one I have. Remember, you don't need to pay for a sender. You've got one. Bob
Thanks, I'll look... I think (hope) my nv3500 has a 3.something:1 first gear. The nv4500 has a 6.something:1! That would be pretty horrible...
I have an NV3500 behind a small chevy in a 48 ford sedan using a 3:73 rear gear and I am very happy with it. The car is old school so I welded a 39 ford lever to the threaded collar on the NV shifter stub, extended the lever another 8 inches, added an early Shure aluminum microphone for a knob and the setup works fine. One problem is the hydraulic slave cylinder which is built in to the bellhousing, located at the 5 0`clock position on the pass side which makes ground clearance tight. My research says that this trans came with a granny first gear and another version not so low first gear. The setup shifts great, you pick up overdrive and they are sronger nad more plentiful than a T5.
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