Crank Position Sensor Write Up

[Walton99]

I know that this will seem simple to most people but it would have helped me out a little bit when I started it for mine, so here's one for everyone else.

Tools needed

12mm socket
assortment of swivels and extensions
ratchet

Optional

di-electric grease
blue lok-tite

This is really a straight forward swap, the only thing that makes it a pain is the location of the CPS and trying to replace it if the engine isn't completely cool. I found that the new CPS is cheapest at Auto-zone at $85, dealer wanted $95, and Murray's, Advance Auto Parts and Napa all wanted somewhere around $125.

Here's the new part.


First thing you have to do is to find the old CPS, it's positioned on the top of the bell housing (auto) at the 11 o'clock position if your looking from the back of the tranny, it's held on by 2, 12mm bolts. Here's a picture of what it looks like from the top



and from the bottom


Like I said the only real difficulty in this procedure is getting the right swivels and extensions to allow you to get a grip on the bolts, I ended up using a 1/4" socket with a swivel, attached to 3 extensions before I could finally get a good bite on the bolt heads and have room to be able to turn the ratchet. A trick that helped me was to put the transmission into "1/2", this moved the lever on the tranny itself out of the way just enough to help a little, just remember to chock the wheels and set the parking brake.

Here are the bolts



Here's the old one dangling from the harness



Once you have it removed from the harness it's a simple matter or putting a little bit of di-electric grease into the fitting and trying to get the new sensor into position. At the top of the bell housing there is a small opening that the bottom portion of the sensor fits into, just put the sensor into there and then try and get the sensor to hold still while you start the bolts, I put a touch of blue loc-tite on these. The best way I found to get everything lined up was to reach around the front, through the exhaust, and hold the sensor flush against the bell housing while using my other hand to start the bolts from the back side. then it's just a matter of tightening the bolts up and making sure that she starts up. Hope that this helps someone, feel free to ask any questions.
Jeramy

[el_chupo_]

well done, thanks. I dont need it, but that may help a bunch sometime.

Matt

[Walton99]

thank you, I appreciate it

[JeepDrivr93]

This really helps, i may be doing this soon and this just eases the pain. Did you replace it becasue of the hesitation problem?

-Nick

[Walton99]

Did you replace it becasue of the hesitation problem?

yeah, she was having a pretty hard time starting, like 30 second cranks with a brand new starter, I threw this in and she fires right up

[Fozzy_Bear]

Nice Write-up.

Thanks for spending the time.

[H8CMENT]

Thanks! I need to do mine, this just gave me the motivation.

[milisakeracing]

<start rant here>You make this sound so easy as did the others in various searches I did (google Cherokee and CPS, it's a pretty common problem). Most said it is a 20min job tops and can even be done on the trail. Obviously they either don't have as much stuff in the way, have more room, or it is easier to do on atx trannies. The sensor is in the same place on a 5spd, I've got the same tools everyone else suggested, even two different types, not only wobbly extensions and u-joints but also a flex extension too. The bolts are 11mm, not 12mm as the you mention above but they could have been changed between an '89 Renix system and the newer OBDII systems with the HO engines.

I managed to get the bottom bolt out after about 30-60min of trying different combinations of the above tools and stopped trying to get the top bolt out after 3hrs of trying, even dropping the front driveshaft to get more room! I'm patient, but this is ridiculous. As you can tell, this is a sore spot. I enjoy working on my cars, this was not fun. When a buddy of mine gets here this weekend (hopefully before he gets here I'll have most of it done) we're going to disconnect the tranny mount and angle it down to get a better angle at the top bolt. Oh and you fail to mention that if you lose one of the bolts down that hole for the sensor, you have an even larger headache of trying to get it out via the observation plate on the bellhousing because you really don't want an 11mm bolt rolling around in there. </end rant>

I really do appreciate the great how-to you created, so don't take the above as being flamed. This is the most I've ever been frustrated working on a vehicle and that includes the times it took over a month to track down an elusive fuel problem on a Mazda and the time the Neon's water pump seized and ate 5 valves prompting me to redo the whole top end over a weekend.

[Greenmachine]

I have a 98 and went to AutoZone. They don't carry the 98 and later CPS. Had to buy a $113.00 Mopar CPS.
Tony

[JIMBOJAMES]

my CPS went out on me on the highway. I had no idea what was going on with it.

[dakotus]

Originally Posted by milisakeracing

<start rant here>You make this sound so easy as did the others in various searches I did (google Cherokee and CPS, it's a pretty common problem). Most said it is a 20min job tops and can even be done on the trail. Obviously they either don't have as much stuff in the way, have more room, or it is easier to do on atx trannies. The sensor is in the same place on a 5spd, I've got the same tools everyone else suggested, even two different types, not only wobbly extensions and u-joints but also a flex extension too. The bolts are 11mm, not 12mm as the you mention above but they could have been changed between an '89 Renix system and the newer OBDII systems with the HO engines.

I managed to get the bottom bolt out after about 30-60min of trying different combinations of the above tools and stopped trying to get the top bolt out after 3hrs of trying, even dropping the front driveshaft to get more room! I'm patient, but this is ridiculous. As you can tell, this is a sore spot. I enjoy working on my cars, this was not fun. When a buddy of mine gets here this weekend (hopefully before he gets here I'll have most of it done) we're going to disconnect the tranny mount and angle it down to get a better angle at the top bolt. Oh and you fail to mention that if you lose one of the bolts down that hole for the sensor, you have an even larger headache of trying to get it out via the observation plate on the bellhousing because you really don't want an 11mm bolt rolling around in there. </end rant>

I really do appreciate the great how-to you created, so don't take the above as being flamed. This is the most I've ever been frustrated working on a vehicle and that includes the times it took over a month to track down an elusive fuel problem on a Mazda and the time the Neon's water pump seized and ate 5 valves prompting me to redo the whole top end over a weekend.

I guess. But, you could take that to the nth degree.

"You neglected to mention that, if someone dropped an atomic bomb on my garage I wouldnt be able to find my 3/8 rachet in the debris. Points off"

[milisakeracing]

Almost forgot. The sensor was ~$52 at Autozone and ~$32 at Bumper-To-Bumper (seems to be a local chain).

[Walton99]

Hey milisakeracing, I can only post up what I know and did. I have a 2001 XJ, with the AW4 tranny and at that time 6.5" of lift, as in my sig. I had plenty of room to get my fat hands up there and not have that much of a problem with anything. For me the bolts were 12mm and things went pretty smooth, although I don't think that I'd like to try and tackle the job on the trail. Sorry that you had such a hard time with it and I hope that you finally got it replaced.

[workinprogress]

The problem I think is that he has the BA10 and I'm sure many things have changed from just that alone. Is the bellhousing removable on this trans so he can get just a little more room or any other suggestions from the pros over here? Thanks in advance guys, really appreciate it.

[cj7guy]

Anyone throw in an aftermarket CPS for a few degrees of timing advance?