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Building NP241 in a NP208?

broncoman6524

broncoman6524

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chuluota Fl
My new engine/trans setup will require a VSS, yes I'm aware that a 90/91 np241 is what I need. However, I can't find one for less than 500$, nor closer than 150 miles each way.

Now, I've got 3 NP208 at the house, and I can find a drivers drop np241 cheap and easy.

But, does anybody know if I can swap the tail shaft into one of my 208 with the proper input. OR essentially swap all the internals from a 241 into a 208 case.

Essentialy the finished product needs to be a 32 spline input, vss output, pass drop case.
 
There are no parts, save possibly the speedometer gear, that interchange between those two cases. Totally different planetary gear set, totally different tailhousing design.
 
Well ****, and I can assume that the 208 case have minus the tail shaft housing, won't hold the 241 parts properly then?
 
Correct, no parts interchange at all, housings or otherwise. The mechanical speedo 241 is the tough one to find in these parts. Have you considered one of the in-line VSS generators that goes between the speedo bung and cable? Howell sells these as do some other EFI vendors
 
Actually I need the vss 241, sadly there are 2 mech 241 local.

I've looked into the inline adapters, however I need a 4k generator, all I can find are 8K. Plus I've heard they're not very accurate.
 
If you were closer I would swap you! See if you can find a later core from a salvage yard on the cheap for the drivers side drop 241 and scab all the parts off of it you need. It is a very easy unit to tear apart and put back together
 
I'm not afraid to build my own, but between buying 2 cases it'd be cheaper to just buy the correct 241.
 
How about a 30 dollar fix????
http://www.dakotadigital.com/index....tegory_id=311/home_id=59/mode=prod/prd109.htm

Screws into the existing speedo port send through to your speedometer and the 8k pulse for the vss.

I swapped out the gage cluster in my 89 Blazer. the 89 is a mechanical 241 . the VSS was generated inside the speedo with a hall effects counter inside the gage .When I installed the Dakotadigital gages I deleted the speedo cable and installed the generator.
 
Unless I'm mistaken, or reading something wrong, either or I'm willing to admit.

The LSX computers require a 4K signal, that only generates an 8K

And, that's an inline generator, and whilst yes it will suffice I had also read they're not as quality of a signal as a legit vss with a tone ring.
 
Let me come in with some wild ideas.

So why doesn't anybody make a steel tone ring that slides on a 208 output shaft in place of a speedo drive gear? What is that spline the gear sits on? Any chance there is a yoke that's the same? It could be cut off, turned down and then teeth ground into it or welded on it. Then use a 241 electric speed sensor or modify a 208 gear holder to hold a sensor. You could also weld long teeth right to the output shaft. But if you ever change gears or tire sizes....


Another double complicated solution is to get one of those screw-in pulse generators linked above and then get another box to convert the frequency. I don't know if "speedo adapters" can adjust that far. Since it's 2:1 you could also have a simple flip-flop box built to drop the frequency in half. That could be mounted elsewhere in the vehicle, too.

How about buying one of those pulse generators, opening it up and removing half of the teeth? If they are optical, you fill half of the holes.
 
oakknight said:
I swapped out the gage cluster in my 89 Blazer. the 89 is a mechanical 241 . the VSS was generated inside the speedo with a hall effects counter inside the gage .
Click to expand...
I was thinking of this same thing, but I don't know what kind of speedo is in the rig. I know that even early to mid '80s there was a sensor in the speedo in rigs with cruise control. But I thought all speedo cables turned 1000 rev/mile. The way the speedo is built, the steel will pass the sensor twice per rev, making it a 2k signal. :dunno:
 
Blue85 said:
Let me come in with some wild ideas.

So why doesn't anybody make a steel tone ring that slides on a 208 output shaft in place of a speedo drive gear? What is that spline the gear sits on? Any chance there is a yoke that's the same? It could be cut off, turned down and then teeth ground into it or welded on it. Then use a 241 electric speed sensor or modify a 208 gear holder to hold a sensor. You could also weld long teeth right to the output shaft. But if you ever change gears or tire sizes....


Another double complicated solution is to get one of those screw-in pulse generators linked above and then get another box to convert the frequency. I don't know if "speedo adapters" can adjust that far. Since it's 2:1 you could also have a simple flip-flop box built to drop the frequency in half. That could be mounted elsewhere in the vehicle, too.

How about buying one of those pulse generators, opening it up and removing half of the teeth? If they are optical, you fill half of the holes.
Click to expand...


Your idea about using NP241 vss stuff on my 208 is accurate, in fact on guy on pirate did it.

He filed grooves for the snap rings, then used the 241 output housing.
 
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