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944 reference sensor bracket.. desperate

 
Old 09-01-2018, 06:01 PM
  #1  
Rodneywright
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Default 944 reference sensor bracket.. desperate

My son and I are working on his 944. Our goal was to replace the crankshaft position sensor. After hours of wiggling it back and forth and trying to pull it out, it eventually broke off. I chiseled the plastic down, tried grabbing the "electrode magnet", to no avail. We tried tapping screws into the plastic but could not get enough purchase to hold enough to pull it out.


On to the bracket. We got the top allen screw out using a variety of custom made allen wrenches. We bent them with the torch to an acute angle. We could only turn the screw about 30 degrees. With allens screws you need 60 degrees to get to the next position. We custom bent another allen key to have a twist, so essentially half of the range of motion required. Using one, then the other, we were able to turn it out. Took several hours, but got it. Picture below. We put a foot long copper pipe on each to allow us to turn without having our hands down there.

Now the other screw is going to take three custom made allen keys, if not four. We are looking at over an 8 hour day for the other screw.

The rear speed sensor is very loose and we removed it's screw by accessing behind the ridged lines up against the firewall, that helped a lot. The sensor is very loose, rotates easily, but will not pull out despite all our best efforts of little custom made pry bars, etc. I can grab it and rotate it with my big hands but cannot pull it out. Luckily we are able to rotate it inline so it is out of the way.

We have tried our 3/8" flex head ratchet, with the 1/4inch adapter to allen bit, but cannot get enough turn to get the ratchet to click, just too much slack in the three pieces.

We have watched and read everything we can, no one elaborates on what they used to get them out. We have the lower screw loose. Only one turn, took an hour.

Please help, in all my years of work, I have never had this much trouble working on an engine. I have really big hands, so does my wife, and subsequently, so does my son.

Question: does anyone use another tool, perhaps a 1/4 ratchet with a swivel head?

does anyone ever reach in from below the car with long extensions, wobbles, and universals joints?

should we keep trying to get the rear sensor out the proper way, or just chisel it off. from that I mean, if we get it out, does it make the bracket easier to remove? From what I have read, removing the bracket even after the allen screws out is also very difficult.

does anyone ever drill through the radio, heating ducts and firewall to get in there?

as you can tell, we are tired.

We need whatever advice from whomever has done this job before, only.



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Old 09-01-2018, 06:38 PM
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wildcat077
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Could you use a long 1/4 inch wrench and insert the correct small Allen bit in the box end ?
Just put a piece of masking tape and insert the bit so it doesn't fall out every time , you could probably even use some sort of extension.
It doesn't look like you can use a 1/4 inch ratchet wrench?
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Old 09-01-2018, 06:41 PM
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Dave951
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If you remove the pivot and mounting bolts for the support bracket you can take the entire assembly out of the bell housing. Granted you will need to reset the alignment to the proper gap but since you are having such a hard time this will likely be easier.
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Old 09-01-2018, 08:22 PM
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Just pull the bracket, shouldn't take more than a few minutes to do so.
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Old 09-01-2018, 09:54 PM
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Rodneywright
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thanks Wildcat, good suggestion, will try it. I can also bend the wrench a little to clear everything. We tried bending a ratchet with the torch, bent well, but the guts of the ratchet had some soldering in it and all melted. The wrench may be the ticket.

dave 951, the bracket is what is giving us trouble, getting the bolts out is really tough.

Arominus, if it is so easy, please tell me which wrenches you used to do it. I would love to know how to do it in a few minutes. Please do a full write up on how you did it. I have found no where anywhere on the net where to do it so quickly. See where I am going.....

I will be trying the wrench taped to the bit in the morning. If anyone else has any suggestions from the way they did it, I would appreciate it. If you are just speculating, rather just hear from people who have done it themselves.

Thanks so much everyone, sorry for being blunt.

george and rodney
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Old 09-01-2018, 10:15 PM
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NRath
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My son and I fought those same sensors about 2 mos ago on his new to us 86. We spent a couple hours also but ended up in better shape getting them out. We finally got them out by wrapping tie wire around them and looping it up a bit and using a pry bar to pull the wire and sensor out. Worked like a champ.

Then you should be able to get the bracket out.

I hope it works as well for you as it did us.
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Old 09-01-2018, 10:20 PM
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Rodneywright
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nrath, hey I like that suggestion. We will try it on the back one. Good idea, still gotta get the bracket off now since we broke the front one. Wish we had seen it before. Thanks george

information from someone who has previously solved your same problem is so much more valuable than anyone else's.

thanks george and rodney
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Old 09-01-2018, 10:26 PM
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MAGK944
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Iĺve heard of folk simply breaking the bracket instead of going through hours of pain, apparently it breaks real easy being cast and good used ones are plentiful and cheap. Sometimes spending $20 is worth it instead of the alternative. Just a thought.
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Old 09-02-2018, 09:46 AM
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Dave951
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Just went out and used this exact combo to reach the bolts. 1/4" 6mm stubby hex drive attached to 1/4" swivel adapter (electrical taped to reduce movement) to 1/4" ratchet (regular or handle rotator); the upper easier one didn't require the swivel.
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Old 09-02-2018, 06:57 PM
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Is there enough stub of the core to grab with needle nose Vise Grips? If not, in the future, remove the adjuster from regular vise grips and replace with 24 inch length of all-thread. Run a nut up the all thread to serve as jam nut to lock Vise Grip adjustment. Cover all-thread with close fitting PVC pipe or cover with duct tape to smooth it up. Slide the biggest socket you have (nesting a couple with duct tape if necessary) over the all thread, then trap a washer between two nuts on the end. Use this home-made slide hammer to latch on the sensor and pull it out. Another thing, use lacquer thinner instead of PB-Blaster or WD40 on the sensors when removing. A varnish like coating forms on the sensor, lacquer thinner will soften or dissolve it making removal easier. That crud layer is why you can spin the sensor but not pull it out.

Last edited by jhowell371; 09-02-2018 at 08:11 PM.
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Old 09-02-2018, 07:27 PM
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A long time ago, I had a similar issue with my 944. Ultimately, I figured out that it was easier to break the bracket off and replace it than it was to try and get the bolt out. The bolt backed out easily by hand after I broke the bracket off, and I sourced a replacement bracket for $10 from a local salvage yard.
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Old 09-03-2018, 09:56 AM
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Dan Martinic
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Please see Post #22 in this discussion:

https://rennlist.com/forums/944-turb...cket-bolt.html

FYI my original sensors were siezed in the bracket; even on the bench in a vise using heat and blunt force, I could only get one out. I bought a used replacement bracket. Be sure to confirm which bracket you need (sleeved or not).

I assembled the new bracket with bellhousing off. (EDIT: this is wrong; in fact, I couldn’t install bellhousing with bracket in due to bracket’s aluminum sleeve. See next post). I’m not sure you can remove the bracket with bellhousing attached. Thread above deals with the allen bolts for gap adjustment.

Last edited by Dan Martinic; 09-03-2018 at 10:25 AM.
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Old 09-03-2018, 10:16 AM
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Dan Martinic
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Scratch that! I remember now: it was the bellhousing I couldn’t get on with the bracket installed, not the other way around
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Old 09-03-2018, 10:21 AM
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Pic of bracket bolts technique:



View from the bottom:


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Old 09-03-2018, 06:07 PM
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Rodneywright
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Success!

As per some of the suggestions, we made up a universal snake of three in a gang, all taped together. We had to turn 90 degrees. To keep it even this low, we loosened the A/C lines and sent the extensions down behind the lines right up agains the firewall. That worked ok, but just. The group tended to go "helix" too often.




We switched to the thumbscrew ratchet pictured for the rest, it worked well, once loose.

All this worked, but to crack the screws, loosen from tight, we used modified allen wrenches, as pictured above. Both torch bent, not quenched, to an acute angle. One of them we put a 30 degree twist and used one, then the other. Without these, I doubt the two methods above would have worked. Consider it, I feel it was well worth the few minutes to make.

Oh, the bracket. We were not able to get either sensor out, so prying off the bracket was fighting the sensors the whole time. That collar protrudes into the motor about a quarter inch, maybe 5/16. We just kept prying and prying with a big black slot screwdriver. Eventually, we got it off. Both sensors ended up quite bent but luckily stayed intact. The bracket was salvageable. You know when working, and you get frustrated to the point where you go beyond salvaging the part and say "frig it, if it breaks it breaks". We were well beyond that. The sensors just kept bending and bending till the collar came clear. What a relief. We were prying from the space next to the oil fill tube, and also from over by the other side of the engine and in under the heater control valve. Both helped. For us, what worked, was to just keep prying and prying. Seeing the end of the collar was sure a relief.
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