Nv4500

[Ozzy2013]

Hey guys and gals i have looked everywhere .Whats the best way to hook up a speedo on my2wd 68 GMC mechanical speedo. The nv4500 from a p 30 van that i'm putting in has a VSS electronic speedo out put.Has any one converted this trans to mechanical?Do i have to change the whole main shaft and housing?Has anyone converted the stock mechanical speedo to a electronic ?If so what parts did you use?I know i can get a converter from Abbott but they are over 300.00!I only paid 600 for my trans im trying to do this on a budget .Any help would be greatly appreciated.Oz

[69SCSS]

You will either have to swap in an electronic speedo or get one of those cable driver kits. Cheaper alternative is to swap the speedo, you can get it for less than $200, then you would have to modify your gauge cluster to fit. Any of the swaps for mechanical speedo on the trans will be expensive.

[Ozzy2013]

Have you done one?I'm wondering if i can remove just my stock speedo and replace it or if i will have to replace the whole cluster ?Thanks for any and all info.I am looking at replacement speedos and wonder if they will work with the NV4500 vss or if you need an additional adapter for the signal looking at GPS also .Thanks Oz

[hugger6933]

I almost sure that a speedo gear can be placed on the shaft where the reluctor is now on the mainshaft of almost any of the electric trans. also a speedo housing can be had the same size as the hole size in the case to hold the driven gear and to screw the cable on to. Jim

[LockDoc]

-
You could use a GPS speedometer, that way it wouldn't matter what transmission, rear end, tires & wheels or anything else you had....

Here are a couple of threads on them.

http://67-72chevytrucks.com/vboard/s...d.php?t=421745

http://67-72chevytrucks.com/vboard/s...d.php?t=453615

Most of the installed pictures in Andy4639's thread are down toward the bottom. He ended up using the full set of Speedhut gauges.

LockDoc

[69SCSS]

Originally Posted by hugger6933

I almost sure that a speedo gear can be placed on the shaft where the reluctor is now on the mainshaft of almost any of the electric trans. also a speedo housing can be had the same size as the hole size in the case to hold the driven gear and to screw the cable on to. Jim

From the writeups I've seen you have to change the entire tailshaft, since the gear on the trans is different. The swaps aren't cheap, and I don't know if I've seen one for an NV4500. I could be wrong, but i've never seen one.

Originally Posted by Ozzy2013

Have you done one?I'm wondering if i can remove just my stock speedo and replace it or if i will have to replace the whole cluster ?Thanks for any and all info.I am looking at replacement speedos and wonder if they will work with the NV4500 vss or if you need an additional adapter for the signal looking at GPS also .Thanks Oz

You wouldn't have to replace the cluster, you'd just have to trim the stock one to fit. You'll have to cut the back tin for the speedo to pass thru, and and front tin if it's a 5" speedo. A 3 3/8" speedo sits right inside the tin so you could sit the face of the gauge on it (so you don't have the cut the glass) and just mount it to the back tin. It might look a little funny with the stock numbers on the glass around it, but those will come off with some Goof-Off and a rag. It's a little bit of work and wiring but it'll work.

Also, if that NV4500 is from a later model (one with a PCM) it might not work with an aftermarket speedo. I think the year cutoff is '95? Not sure. Hope that all helps.

[Dieselwrencher]

Have you removed the sensor and looked inside to see if there is a gear on the out put shaft? I've removed the vss from several dodge 47rh's and replaced them with mechanical speedo drives from 727s. I know you can do it on the transfer case as I have done it too so I don't see why you can't do it on the nv4500. Usually the gear difference is the tooth count to change the ratio, and on these typically you replace the one on the vss or cable adapter, not the out put shaft on these.

[Ozzy2013]

Wow i will certainly look all the research i did said the vss had a reluctor wheel not a gear .Advanced adapters said i would have to change the shaft because the gear was a different size on the shaft than the reluctor wheel for the vss .Hope your right!Thanks for the info.Oz

[Ozzy2013]

Originally Posted by 69SCSS

From the writeups I've seen you have to change the entire tailshaft, since the gear on the trans is different. The swaps aren't cheap, and I don't know if I've seen one for an NV4500. I could be wrong, but i've never seen one.



You wouldn't have to replace the cluster, you'd just have to trim the stock one to fit. You'll have to cut the back tin for the speedo to pass thru, and and front tin if it's a 5" speedo. A 3 3/8" speedo sits right inside the tin so you could sit the face of the gauge on it (so you don't have the cut the glass) and just mount it to the back tin. It might look a little funny with the stock numbers on the glass around it, but those will come off with some Goof-Off and a rag. It's a little bit of work and wiring but it'll work.

Also, if that NV4500 is from a later model (one with a PCM) it might not work with an aftermarket speedo. I think the year cutoff is '95? Not sure. Hope that all helps.

Mine is a 95 from a p30 chevy UPS van

[Dieselwrencher]

All the NV4500's I mess with are from dodges. I don't know if that will make a difference or not. Good luck.

[azdeltawye]

Originally Posted by Ozzy2013

...I am looking at replacement speedos and wonder if they will work with the NV4500 vss or if you need an additional adapter for the signal…

The NV4500 I put in my ’65 had the digital VSS output. I ended up using a VDO digital speedo from Summit Racing along with a Dakota Digital SGI to reduce the pulse per mile count to something the VDO could use.
In the end you get the ability to dial in your speedo/odo accuracy to 0.5% by using a GPS to calibrate. This is nice because you’ll never have to worry about gear or tire diameter changes screwing up your speedo cal…

[Richard2112]

Originally Posted by hugger6933

I almost sure that a speedo gear can be placed on the shaft where the reluctor is now on the mainshaft of almost any of the electric trans. also a speedo housing can be had the same size as the hole size in the case to hold the driven gear and to screw the cable on to. Jim

I am looking closely at the possibility of doing this with a GM nv4500, 2WD. The reluctor wheel for the vss is fairly large and (in my opinion) rather over built for the sole purpose of a reluctor.

I am looking at using a speedo gear set from an SM465 and modifying the tail housing on the nv45 to accept the set. The geometry looks possible but I'm uncertain if the beefy reluctor wheel serves any purpose more than holding the reluctor teeth. For example, it looks like it might be built to reinforce the output shaft in which case I may not want to cut the reluctor wheel or turn it down to the necessary diameter.

I believe the dodge gas version had no reluctor wheel and it seems to be preferred so I'm assuming that the Dodge version shaft diameter is fine without the beefy, pressed on reluctor wheel that GM uses.

If those assumptions are correct then I can cut the reluctor wheel sleeve where the teeth are and insert a speedometer drive gear set.

That all assumes that the reluctor wheel is NOT designed with the intention of providing additional support to the output shaft. I really do know if it can be cut without sacrificing the strength of the output.

[LockDoc]

Originally Posted by Richard2112

I am looking closely at the possibility of doing this with a GM nv4500, 2WD. The reluctor wheel for the vss is fairly large and (in my opinion) rather over built for the sole purpose of a reluctor.

I am looking at using a speedo gear set from an SM465 and modifying the tail housing on the nv45 to accept the set. The geometry looks possible but I'm uncertain if the beefy reluctor wheel serves any purpose more than holding the reluctor teeth. For example, it looks like it might be built to reinforce the output shaft in which case I may not want to cut the reluctor wheel or turn it down to the necessary diameter.

I believe the dodge gas version had no reluctor wheel and it seems to be preferred so I'm assuming that the Dodge version shaft diameter is fine without the beefy, pressed on reluctor wheel that GM uses.

If those assumptions are correct then I can cut the reluctor wheel sleeve where the teeth are and insert a speedometer drive gear set.

That all assumes that the reluctor wheel is NOT designed with the intention of providing additional support to the output shaft. I really do know if it can be cut without sacrificing the strength of the output.

Please keep us updated on the progress....

Thanks,
LockDoc

[Richard2112]

Originally Posted by LockDoc

Please keep us updated on the progress....

Thanks,
LockDoc

I will, rain or shine. I'm hesitant because I do not have a dodge gas version to compare the output shafts. Finding design specs on the outputs, (specific lengths and diameters) is problematic.

I am wondering what the diameter of the dodge shaft is at the location where the speedo drive gear rides.

If the dodge shaft is reliable without the beefy reluctor wheel used on the GM versions, the reluctor wheel may not be structurally important. I know the sleeve is pressed against the fifth gear via the yoke nut, but that can still be achieved by a two piece spacer with a gear set between them.

These are just thoughts and I really don't know if it will work, but it looks like it might.