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How to replace a crank sensor

BillBoost37

BillBoost37

New member
Ok...here goes.

Air tools method:
Jack and support the passenger side of the car.
Remove the tension from the belt(s) and let them sit there.
Remove the passengerside wheel (stock is 19mm)
Remove the plastic splash shield that keeps you from seeing the harmonic balancer. (trim pop tool and sometimes phillips screwdriver)
With a 24mm socket, remove the harmonic balancer bolt.
Using an HB/steering wheel puller find the correct pieces to pull the balancer because the bolt hole area can be quite long. It requires the short rod and pulling piece in my kit. Along with three bolts M6 x 1.00 and 70-75mm in length. Check that you have these bolts before trying this procedure. 1/4 by 28 bolts will work in a pinch.
Pull the balancer off and set it aside
P1010698.jpg


Looking at the motor now, this is what you see. Plastic shield in way of the sensor.
P1010699.jpg


Disconnect the crank connector from the sensor.
Carefully pop all three holding positions of the plastic shield off to remove it.
P1010700.jpg


Now you are looking at the sensor. Using a 13mm, remove the two bolts holding it to the cover.
P1010703.jpg


Wiggle the sensor free. It sits on a post that aligns it on the timing cover. It can be quite a pain sometimes. Wiggling and gentle prying will get it off.
P1010704.jpg

P1010702.jpg


Put the new sensor in place and torque the bolts to 13ft lbs.
Install the shield back in place and using your 13mm socket and extension, give each of the three holding areas a slight tap to ensure they are fully seated.
Connect the crank sensor connector.
Put the harmonic balancer on the crank and rotate it by hand while pushing inward to the motor. At a point it will push in and engage the key into it's keyway. You will no longer be able to turn it.
Reinstall the harmonic balancer bolt. (I gun this on with an impact (this pulls the balancer on the rest of the way) and do not torque it properly. No loctite, no sealant, just reuse the stock bolt. Technically its a TTY bolt and per the FSM should be replaced. I never do and never have any issues with it.)
Put the belts back on and tension them
Start the car to ensure the new sensor works.
Put the splash shield back in place
Put your tire back on
Put the car back on it's feet and perform a case learn if you have the ability. (I also only typically do this when needed. If the car starts and runs well..a case learn will only optimize things.)


Hand tools method:
Loosen lug nuts
Jack and support the passenger side of the car.
Remove the tension from the belt(s) and let them sit there.
Remove the passengerside wheel (stock is 19mm)
Remove the plastic splash shield that keeps you from seeing the harmonic balancer. (trim pop tool and sometimes phillips screwdriver)
Remove the flexplate inspection cover.
Hold flex with a pair of vice grips
With a 24mm socket, remove the harmonic balancer bolt.
Using an HB/steering wheel puller find the correct pieces to pull the balancer because the bolt hole area can be quite long. It requires the short rod and pulling piece in my kit. Along with three bolts M6 x 1.00 and 70-75mm in length. Check that you have these bolts before trying this procedure. 1/4 by 20 bolts will work in a pinch.
Pull the balancer off and set it aside
P1010698.jpg


Looking at the motor now, this is what you see. Plastic shield in way of the sensor.
P1010699.jpg


Disconnect the crank connector from the sensor.
Carefully pop all three holding positions of the plastic shield off to remove it.
P1010700.jpg


Now you are looking at the sensor. Using a 13mm, remove the two bolts holding it to the cover.
P1010703.jpg


Wiggle the sensor free. It sits on a post that aligns it on the timing cover. It can be quite a pain sometimes. Wiggling and gentle prying will get it off.
P1010704.jpg

P1010702.jpg


Put the new sensor in place and torque the bolts to 13ft lbs.
Install the shield back in place and using your 13mm socket and extension, give each of the three holding areas a slight tap to ensure they are fully seated.
Connect the crank sensor connector.
Put the harmonic balancer on the crank and rotate it by hand while pushing inward to the motor. At a point it will push in and engage the key into it's keyway. You will no longer be able to turn it.
Move vice grips to other side to hold flexplate while tightening balancer bolt.
Reinstall the harmonic balancer bolt and torque to ensure it's tight.
Remove vice grips and reinstall flexplate inspection shield.
Put the belts back on and tension them
Start the car to ensure the new sensor works.
Put the splash shield back in place
Put your tire back on
Lower car and tighten lugs.
Put the car back on it's feet and perform a case learn if you have the ability. (I also only typically do this when needed. If the car starts and runs well..a case learn will only optimize things.)
 
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Bill

Had to get my junkyard block balancer off. I filled one of the cylinders with oil, put sparkplug back in, wedged a 6 ft pry bar between block and head and had my 12 year old standing on it to keep the engine from rolling while i broke loose the bolt with a breaker bar and cheater pipe.

How much does a good impact cost to break these bolts loose? I have a Campbell Hausfeld Impact and a 5hp single stage compressor(oil type) and it won't touch these or cv axle nuts.
 
You'll need a gun with several hundred pounds of breaking force. And atleast the required amount of psi for the gun, noramlly 100-150ish lbs.

I have an older IR and it'll snap lug nuts of bolts, if giving the chance.
 
Kinda funny, the gun I use all the time for this is a Stanley gun that I picked up for $82 new at Walmart in a pinch one day. It said 500 or 600ft lbs and it works like a champ for me. Actually I think I was doing my first crank sensor on my Bonneville. The compressor is about a 5hp and the pressure is 150psi. I used to do this with my previous compressor that was 120psi.

Logan...I've stopped taking pics for the most part a couple of years ago. What can I say, I try and help the next guy.
 


the damn crank pulley bolt won't come off!!! I've tried it with a breaker bar (18'' & 24'') and starting up the engine to loosen up the bolt and nothing!! Any other idea(s) to get it off... or an easier way to get to the cranck sensor!!!
 
Tired of seeing stuff that has nothing to do with the procedure or topic in the How to threads. If you had something posted, please post it in the correct section. I deleted it.
 
thanks Bill this information was awesome made it very easy for me take care of this issue with all your images in comments I appreciate it thank you. my pulley puller did not come with the right size bolts and with your post of what size bolt to use I was able to run up to the hardware store and grab exactly what I needed. I am pretty mechanically inclined but sometimes it's nice to just know what to do you have been very helpful and I believe the problem is fixed. thanks again bill
 
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Glad it helped. The hardest part for me was finding the bolts the first time. None of the kits at any of the parts stores or Sears had them.
 




Just noticed a typo. The 6mm bolts are hard to find. You can use 1/4-28x3. The op said 1/4 20. Great write up though, it walked me right through it.
 
Thanks for these directions - I'm pretty sure my sensor has been failing for a year or two and I now that I just bought a house, I finally have a garage I can do the things I've been putting off - like this repair!

Quick question - I have hand tools, jack and jackstands, but no air tools or torque wrench. Do I need the wrench for this or is it not a big deal to get these bolts tightened exactly?
 
I don't torque the crank bolt at all... I squeeze the trigger on the air gun and when it stops..that's torqued. The two bolts that hold the sensor on.. they expect ~13ft lbs..so it's a reasonable hand tight.

You don't need to be exact on any of these.
 
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