Installing a crank position sensor set up on stock trans?

[eaglefreek]

My one major concern about using the CPS on the front damper, is that there is rubber involved and a chance of it slipping, causing your signals to be off. As I understand it, the CPS switches 5v or 8/9v ,depending on year, on and off in correlation with the notches on the flexplate. I wonder if you could use a toothed wheel attached to the center of the damper to keep the rubber out of the equation. I can't see the edge of the Hesco damper on their site, but I would assume they just drill holes in precise locations to mimic the notches in the flexplate. Here's an example of a toothed wheel attached to a crank pulley:

[eaglefreek]

I found a pic of a Hesco damper. Basically, you would just need to scale down the measurements from the flexplate and make sure you have the notches in the right spot on the damper in correlation with the flexplate. You could even make your mounting holes oblong to "play" with your timing. A little more work than drilling a hole in the bellhousing, but it is also an option.

[mach1mustang351]

So I was reading last night and I saw on Novak's website they said to call them for their 4.0 CKP sensor solution.  I called them today and they said for the cost of an hours labor (about $90) they would cnc machine a hole in the bell housing you mail them to accept the ckp sensor.  SO for $90 plus shipping in both directions you can have a nicely done stock setup and save some coin over the Hesco system.  Just thought I'd share.

[captspillane]

I wonder if Novak would still do that service if you sent them an empty TF727 front case instead of a bellhousing?

The potential problem with that service is that you then need to have CPS notches in the flywheel. On an automatic that is as simple as buying the proper flexplate. On a stickshift this means the 258 flywheel has to come off and a 4.0 flywheel put in its place. The 4.0 flywheel is a quarter inch thinner. The throw out lever should be able to adjust to account for that difference in flywheel width, but it will require adjustments not easily made on an Eagle. On a CJ7 or Spirit, the mechanical linkage has an adjustable spacer on the linkage. On our hydraulic system you don't have an adjustment, just a removable shaft. It might work just fine but have the "bite" point of the clutch at an awkard level in relation to the floor. The only way to know is to experiment with it.

Advanced Adaptors also sells a T5 bellhousing with both of the two different CPS sensor mounting holes already built into it. They currently ask $373 for it. That price is directly comparable to the Hesco CPS kit.

[eaglefreek]

Wouild an adjustable throwout bearing solve the issue of the thinner 4.0l flywheel? http://www.novak-adapt.com/catalog/clutches/adjustable_throwout_bearings.htm

[captspillane]

Oh dang that just earned you several eggs. I've never imagined such a beast. That really should account for the 1/4" difference without needing to adjust the linkage geometry. That is a big deal, since I'm pretty sure the linkage has a 2:1 mechanical advantage, meaning that a 1/4" difference in travel compounds to a 1/2" or more of linkage adjustment.

I really wish I had seen that a year ago. I beat my head against a wall trying to get the AMC Spirit mechanical linkage to work with a 10" clutch. A Spirit used a bizarre 9" clutch that isn't readily available anymore. The Spirit version of the mechanical clutch linkage looks alot like a CJ7 version, but it doesn't travel or adjust as far. This would likely add a necessary degree of adjustment.

[carnuck]

I wonder if Novak would still do that service if you sent them an empty TF727 front case instead of a bellhousing?

The potential problem with that service is that you then need to have CPS notches in the flywheel. On an automatic that is as simple as buying the proper flexplate. On a stickshift this means the 258 flywheel has to come off and a 4.0 flywheel put in its place. The 4.0 flywheel is a quarter inch thinner. The throw out lever should be able to adjust to account for that difference in flywheel width, but it will require adjustments not easily made on an Eagle. On a CJ7 or Spirit, the mechanical linkage has an adjustable spacer on the linkage. On our hydraulic system you don't have an adjustment, just a removable shaft. It might work just fine but have the "bite" point of the clutch at an awkard level in relation to the floor. The only way to know is to experiment with it.

Advanced Adaptors also sells a T5 bellhousing with both of the two different CPS sensor mounting holes already built into it. They currently ask $373 for it. That price is directly comparable to the Hesco CPS kit.

The HO and Renix tone rings (or notches on the std flywheel) are different. The flywheel itself is the same, but the tone ring was added and the starter ring was moved almost 1/2" closer to the motor so you have to use the 4.0L starter (not a deprivation there as it's a better design)
   For the auto you CANNOT use the AW4 flexplate. You need one from a Grand Cherokee with 4.0L for the HO system. It'll probably need to be custom made for the Renix setup.

As for the 727 bell CPS hole, it's pretty easy to mock up if you can borrow a 999 case from a TJ to make a template. I had planned to do that with the 727 I put in my Eagle but ran out of time before I could afford the flexplate and couldn't afford to pay storage anymore. I also moved my 999 case somewhere and haven't found it, the HEI I bought and a bunch of other AMC 6 performance parts including a header and cam.

[carguy87]

Here is a picture of the CPS on the bracket I made.  I had pictures of it installed in the trans, but they got wiped out when my memory card fried.  Oh well, hope this helps.

[mach1mustang351]

Oh dang that just earned you several eggs. I've never imagined such a beast. That really should account for the 1/4" difference without needing to adjust the linkage geometry. That is a big deal, since I'm pretty sure the linkage has a 2:1 mechanical advantage, meaning that a 1/4" difference in travel compounds to a 1/2" or more of linkage adjustment.

I really wish I had seen that a year ago. I beat my head against a wall trying to get the AMC Spirit mechanical linkage to work with a 10" clutch. A Spirit used a bizarre 9" clutch that isn't readily available anymore. The Spirit version of the mechanical clutch linkage looks alot like a CJ7 version, but it doesn't travel or adjust as far. This would likely add a necessary degree of adjustment.

This is good info.  I plan on running my 4 speed in my SX4 with my 4.0.  This will help solve a problem I didn't know I had yet.

[captspillane]

That picture does help. That's the round sensor I plan on using. The NSG370 6 Speed has a round sensor externally identical to that mounted on the side. The Flywheel looks identical to my 1992 AX15 flywheel, except that the tone ring is rotated to account for the sensor being on the side instead of the top like the square AX15 style. I've seen two threads in the Jeep forums where guys switched their 5 speed for a 6 speed or vice-versa and tried to use their old flywheels. The engine will not run.

The round CPS is available in both OBD1 5 volt or OBD2 8 volt. I plan on using the OBD1 sensor because its compatible with my 1992 era MPI system. For my TF727 I will drill a hole in the housing and mount it on top with a bracket similar to the one you just posted a picture of. On my 2006 NSG370, I hope the earlier round sensor will fit perfectly into the existing round hole in the bellhousing.