which camshaft sync do i need?

[Xplorer82]

getting ready to buy one and on Rockauto.com there are two choices..

132mm shaft
or
123mm shaft

for a 1997 Explorer XLT 4wd, 4.0L SOHC

if anyone can tell me how i can find out which one i need or can just tell me exactly which one i need that would be sweet. thanks.






i might have a few more Q's here and there as i have a long list of parts i want/need to pick up from there. so bare w/me i will use the search b4 i post though so i dont bother everyone if not needed.

 

[rwenzing]

Are you asking about the Synchronizer for the Camshaft Position Sensor? If so, it doesn't exist on the 4.0 SOHC. The CMP sensor of the SOHC mounts directly on the driver side valve cover and reads a tooth wheel on the camshaft.

 

[Xplorer82]

Are you asking about the Synchronizer for the Camshaft Position Sensor? If so, it doesn't exist on the 4.0 SOHC. The CMP sensor of the SOHC mounts directly on the driver side valve cover and reads a tooth wheel on the camshaft.

that is what i thought it was called, but on rockauto.com they have it listed as a Camshaft sync so i was just going w/what was listed.

yeah i know it just mounts right up i read that while searching through threads. i just dont know how to tell if i need the 132mm or the 123mm shaft one.


and can you tell me what you ment by "reads a tooth wheel on the camshaft"?

thanks

 

[rwenzing]

As it passes through a magnetic field, a tooth on the cam induces a small voltage change in the coil of the Variable Reluctance CMP sensor. The PCM reads the voltage waveform of the CMP to differentiate whether the engine is on the compression or exhaust stroke. Then it can correctly time the sequential injection to the Crank Position Sensor (CKP).

I looked on the Rockauto site and they list the geared Synchronizer for both of the 4.0L Ex engines, SOHC and OHV, so they clearly don't have the listing right. The SOHC CMP is a small bolt on sensor that reads the overhead camshaft directly and they are showing only the complete CMP/synchronizer that is gear driven from the cam in the OHV block. Better look elsewhere. Personally, I would get the OE part from Ford.

OBTW, how do you know that you need a replacement?

 

[Xplorer82]

As it passes through a magnetic field, a tooth on the cam induces a small voltage change in the coil of the Variable Reluctance CMP sensor. The PCM reads the voltage waveform of the CMP to differentiate whether the engine is on the compression or exhaust stroke. Then it can correctly time the sequential injection to the Crank Position Sensor (CKP).

I looked on the Rockauto site and they list the geared Synchronizer for both of the 4.0L Ex engines, SOHC and OHV, so they clearly don't have the listing right. The SOHC CMP is a small bolt on sensor that reads the overhead camshaft directly and they are showing only the complete CMP/synchronizer that is gear driven from the cam in the OHV block. Better look elsewhere. Personally, I would get the OE part from Ford.

OBTW, how do you know that you need a replacement?

thanks for the explanation.

so i should just look elsewhere you think?
(screenshot, click to enlarge)



theres a few reasons. the main thing is i am rolling over to 200k and i am just replacing parts that can be replace easily and being cost friendly as well. the main thing is it fits in my budget right now and i would just like to replace it. and hopefully it will help w/my rough start up (as i have read that might be a cause of it)

 

[rwenzing]

Rock Auto's site is usually pretty good but it is wrong in that 97 Ex listing. The 4.0 SOHC CMP sensor looks similar to this:

 

[Xplorer82]

^yup thats the one ^

ok now one more question. do i have to find TDC when replacing this? if so i will try to find a how to somewhere. thanks.

 

[rwenzing]

do i have to find TDC when replacing this? if so i will try to find a how to somewhere. thanks.

Nope. Just swap it out. The cam is the sensor trigger and its timing won't be disturbed.

 

[Xplorer82]

awesome. thanks again man.