Brainstorming VSS

I'm working towards mixing and matching the parts from a NV242AMG with a NV242J (2340 lb-ft torque rating, 32 spline output, and 2WD mode) and one of the problems is that the Hummer shaft doesn't have the splines on it to drive the VSS.

[url="http://suzitech.org/albums/STWS_Transfer_Case_NV242_Hybrid/picture_38.jpg] [/url]
click to enlarge
Photo and idea credit to MJR on this board, top is Jeep; bottom is 1996 up AMG

This is going into a `01 XJ so the PCM is OBD-II.

Is there an aftermarket VSS sensor that can be used in situations like this? Something that doesn't plug into the transfer case hole?

Maybe a unit that takes the reading off the prop shaft or something along those lines?

Or, could something like this be used to read the tooth profile right on the transfer case shaft?

PDF (Diff mounted reluctor ring):

http://www.jagsthatrun.com/v8-s10-instructions/reluctor-ring-differential.pdf

For obvious reasons I'm not keen on running the reluctor right on the diff like that... but if there was a way to make it work within the t-case similar to stock...

Ideas?

Have you looking into the installs of a SS kit for a 231? IIRC my shaft was not cut for the VSS either , it included a plastic ring that went over the shaft. My kit was a Tera btw. The hole that the VSS goes into is huge, so i remember i had to reindex that.

I think with a little work that diff mounted VSS should be possible to mount on the rear ouput flange of the t-case.

Another option is a sytem called Racepak. it is basically an onboard data logging system for drag cars. But it has all kinds of sensors, including a driveshaft speed sensor. i guess it it used in addition to a Crank speed sensor to termine clutch slippage.

I do remember that the newer Dodge (up to about the new '02 bodystyle) has a VSS driven off a toothed plate on the rear differential, it mounts between the carrier and the ring gear. and the sensor mounts in from the top. I don't know what rearend your using but i know the use that setup on D60's and i think the 8.25 in the dakota.

The biggest problem i see you haveing to fight is the PPM (pulse per mile) of the new sensor. I'm not sure what the number is for a stock XJ. but you may be able to overdome that with one of the many speed sorrection boxes on the market, Superlift make one i know. it would give you a place to start.

Hope this helped, and keep us posted, i want to due this someday soon as well.

Dingo

Dingo509 said:

Have you looking into the installs of a SS kit for a 231? IIRC my shaft was not cut for the VSS either , it included a plastic ring that went over the shaft. My kit was a Tera btw. The hole that the VSS goes into is huge, so i remember i had to reindex that.

Click to expand...

Thanks, I'll definitely look into that.

I think with a little work that diff mounted VSS should be possible to mount on the rear ouput flange of the t-case.

Click to expand...

I was thinking about that. There is still the issue of mud obscuring the sensor though.

I do remember that the newer Dodge (up to about the new '02 bodystyle) has a VSS driven off a toothed plate on the rear differential, it mounts between the carrier and the ring gear. and the sensor mounts in from the top. I don't know what rearend your using but i know the use that setup on D60's and i think the 8.25 in the dakota.

Click to expand...

Good, another datapoint. I'm just not terribly keen on an "external" sensor. My understanding is that if the signal goes foobar the engine will still run but hard stops and such may cause the engine to stall. I dunno, just what i've read.

The biggest problem i see you haveing to fight is the PPM (pulse per mile) of the new sensor. I'm not sure what the number is for a stock XJ. but you may be able to overdome that with one of the many speed sorrection boxes on the market, Superlift make one i know. it would give you a place to start.

Hope this helped, and keep us posted, i want to due this someday soon as well.

Click to expand...

Cool, I'll check out the Superlift style box as well.

One of the machinists at my work said he'd make a reluctor ring to go on the shaft if I need one. If I can make a GM/Jeep hybrid sensor work with my reluctior ring and have it all internal to the t-case that would be ideal.

I'll let you know what I come up with.

Easy solution?

There's got to be a gotcha to this - probably the spline count on the 242AMG shaft not matching the 231J but...

Look at figures 17 an 18 on this page:

http://www.jbconversions.com/pages/products/np231/np231j_std_sye.html

Could it be that easy?

Anyone have a 231 apart and able to count splines for me?

that's exactly what i was talking about. I might have a 231HD apart right now, But it is a HD version (not a HD SYE) it is basically a 231 with the same 3 gear planetary set but with the wider chain, i don't know if the mainshaft is different or not.

but IIRC the 231 SYE uses a 241 shaft that is cut down, I think all the 231 shafts have the VSS helix cut right into the shaft. so you would have to have the spline count from a 231 SYE kit that includes the mainshaft. What they usually call a HD kit.

Now from my reading elsewhere the 241 and 242 shafts are the same near the rear output the difference is where the front output sprocket rides, but i can't remebr exactly what the difference is. if this is true then the plastci helix should fit both the 242AMG and the 241 (231HD SYE) shaft.

Dingo

My 231 hd kit (32 spline shaft) had a blue plastic peice that slid onto the splines for the vss. Call PORC and ask for the specs on the plastic piece.

It was covered in this topic here: http://www.naxja.org/forum/showthread.php?t=74313

Gojeep said:

It was covered in this topic here: http://www.naxja.org/forum/showthread.php?t=74313

Click to expand...

Just read the thread again and all I see is a lots of speculation - or did I miss it?

JB super short SYE for 241 is the idea but no one has actually done it?

I took the tail cone off my AMG case the other morning. The shaft has a plastic sleeve thingy there to drive the speedo. It appears to be a mechanical drive in this case, although the sensor was mildly mangled so maybe the wires were missing or something. This is the case from Jeepnuts311 in the other thread and neither one of us pulled the case from the source vehicle so the history of what was cut/removed is unknown.

I'm leaning towards an adapter for the JB Jeep sensor on those AMG worm/splines at the moment... I still need to source a 242J to compare against as I'm not willing to pull the one I have out of my DD and the other ones I have are 1989-1992 vintage so not certain if they are the same yet.

If you know how to solve the speedo issue I'd appreciate the pointer. I hope it doesn't entail using the housing of the the JB kit (or similar) as I don't want to lengthen my existing SYE/HD shaft if it can be avoided.

T!