Dropped reference sensor bolt into ?

914efi · 10-29-2014, 04:53 AM

In a futile attempt to adjust the sensor positions, I dropped the ref sensor bolt. I think it went into the opening in the bell housing toward the bolt side of the sensor but I could not find it. I took off the starter, lower cover plate, rotated the engine by hand, looked around on the floor, etc. and no trace.

Car started and drove fine. Is there a logical place for this to end up either in a good or bad way?

It may still be on my floor, need to look more carefully.

mytrplseven · mytrplseven's Garage

I hope it's not in there somewhere. Are you sure it went into the hole and not down the side? It could get caught in the pressure plate (assuming you have a manual transmission) or behind the flywheel. A thorough search is definitely in order. You might consider turning the car over and shaking it.

914efi · 10-29-2014, 07:25 AM

I searched after I posted and read through all of the posts about this, plenty of episodes to see. I guess I'll just keep looking.

I still need to adjust the sensors, so maybe it will turn up then. One post says there is a place inside the bell where it can rest in peace...

944 Ecology · 10-29-2014, 09:14 AM

Quote:

Originally Posted by 914efi

I still need to adjust the sensors, so maybe it will turn up then. One post says there is a place inside the bell where it can rest in peace...

Not really, if it comes loose, it can jam itself between the flywheel and the block (can crack the block), or it can jam itself between the starter ring gear and the bell housing (can crack the bell housing).

I guess it depends on how lucky you feel. I never felt lucky enough to have loose bolts in those areas.

914efi · 10-29-2014, 09:27 AM

George, yes, you are right I need to find it.

DannoXYZ · 10-29-2014, 01:18 PM

Don't run the engine. Manually spin it back and forth to see if you can feel the bolt getting lodged into things.

You can try fishing around with a magnet on a stick. In some cases, it actually rolls down the bellhousing and sits on top of the torque-tube... very rare and lucky... Then again, what are the chances it'll fall into that hole?

argiopeweb · argiopeweb's Garage

Ooooh, that's a painful one... My sincerest of sympathy.

This previously happened to me with the nut for the block grounding line. I'd recommend pulling the starter and checking the starter well and bottom of the bellhousing. If it isn't there, a magnet from the top, light from the bottom, small mirror on an extension, or inspection camera with flexible lines are all good choices. Turn the engine over manually (I went so far as to push the car in gear) and see if it falls out.

The fact the car drove already is a good sign, but I wouldn't risk having it lying about the engine bay and falling in there. Definitely find a (temporary) way to cover the inspection hole from the top in case it's still sitting around the engine bay. I had an aluminum plate cut to size and mounted it with non-hardening adhesive (though I've since removed it permanently for TDC-checking purposes).

Worst case scenario, I'd recommend doing what I ended up doing: a full clutch job. Worth it for the peace of mind, if nothing else. Not a complete loss if your clutch is poorly aligned (as mine was) or your RMS needs replacing.

DannoXYZ · 10-29-2014, 04:24 PM

I find it's easier to pull out the engine to do a clutch job anyway. Faster and easier on your back & shoulders since you're not on a cold floor twisted up. On an NA, I can get the engine out the top in about 2-hours with hoist.

argiopeweb · argiopeweb's Garage

Damn, I'll have to remember that for next time. I thought the bloody bell housing bolts were my worst enemy (3' of extensions anyone?) till I had to put that torque tube back. Never again...

It would have been ever so much easier to pull/replace the pilot bearing with the engine out. Could have done some gaskets I've been putting off as well (oil pan...).

If you ever feel like putting up a video of a 2hr removal, throw me a link. I'd love to learn the secrets. It'd be worth my time to pull and replace the engine to do the aforementioned gaskets if I could pull it off that quickly.

Freaky · 10-30-2014, 12:03 AM

FIND IT! At some point, a bolt got dropped down the back of the engine and managed to find it's way into the ref sensor opening, don't really know when it happened. One day I started the car, and heard a loud noise the area of the bellhousing. Shut down, looked around and found nothing amiss. Took a light and looked down the back of the engine, and noticed the timing reference pointer was missing.

We pulled the trans and bellhousing and not only did the offending bolt break off the pointer, but I also destroyed the ring gear (tore up some teeth), and damaged the pinion gear on the starter , and the now adrift pointer lodged between the flywheel and the bellhousing, and tore off the 3 reference pins.

COST: One new flywheel, one used ring gear, one new starter and one used bellhousing, not to mention the time to remove and install the bellhousing and trans on a turbo....I learned then to cover that hole when ever I work at the back of the engine.

914efi · 10-30-2014, 05:24 AM

I'm already planning how to [a] find it and [b] remove it if needed.

I'll drop a scope in and look around first, fortunately I make scopes!

Borescopes | Custom Borescopes | RVI Instruments

argiopeweb · argiopeweb's Garage

Well, isn't that exceptionally convenient for you.

bell · bell's Garage

Been there done that......it can fall behind the flywheel......i have a bore scope camera and was able to see it after about 1/2 hour of positioning, was sitting behind the flywheel......cheap magnet on a stick with the wand bent funny is what it took to get it out.....
You can try a coat hangar to knock it about but you don't want to jam it somewhere where you can't fish it out.......

914efi · 11-03-2014, 05:44 AM

I got the bolt out, major pain! It was behind the flywheel actually sitting in a pretty safe place on top of the bearing/seal boss in the casting. I got a magnet down through the sensor hole and finally worked it out using a scope to see what was going on.

Still can't get the sensor bracket bolts loose to adjust it. I measure 1.5mm clearance on the front sensor to the set screw in the flywheel.

mytrplseven · mytrplseven's Garage

How did you go about measuring the clearance? I can barely see down the hole you dropped the bolt into.

914efi · 11-03-2014, 12:00 PM

I get the screw head [on flywheel] in the sensor port and then do a depth measurement with a caliper, pretty easy once you get lined up in the hole. You can put the car in 5th and roll while watching the port for the screw head.

John_AZ · 11-03-2014, 03:20 PM

Quote:

Originally Posted by 914efi

I got the bolt out, major pain! It was behind the flywheel actually sitting in a pretty safe place on top of the bearing/seal boss in the casting. I got a magnet down through the sensor hole and finally worked it out using a scope to see what was going on.

Still can't get the sensor bracket bolts loose to adjust it. I measure 1.5mm clearance on the front sensor to the set screw in the flywheel.

Fantastic!! ( about the bolt)

If you are able to get the passenger side bracket bolt "loose" ---very possible---you may be able to adjust the clearance without getting the drivers side bracket bolt loose. A gentle pry up and down on the bracket may work.

Removing the intake will give you more clearance for the drivers side bolt. Then you can do all the WYAIT for the top of the engine. AOS seals , hoses, clamps, new intake seals ++++++

GL
J_AZ

Paul Waterloo · 11-04-2014, 04:12 AM

The bracket screws are a bear to loosen/tighten. I used a long allen on a 3/8" rachet with a built in flex (Craftsman is what I have with the highly chromed handle that is slightly bent).

I would consider getting the allen head drives that are ball shaped at the end, or buy a long handle allen wrench and cut the short end to fit and bend the handle back towards the front of the engine so it's a custom fit.

Good luck!

thekidd · 06:13 AM

I did this a few years ago. Droped mine, and couldn't find it anywhere, took starter off, and the plate in front of the flywheel on the bottom, and had a magnet on a stick. Poked around for a few good days, rotating engine by hand. Nothing. Figured it was lodged somewhere in the engine bay, and it would fall drop down at some point while I drove. And I didnt find it untill about 2-3 years later when I was doing a clutch job. It was on a ledge, the size of the bolt head, on the inside front of the bell housing. I WAS VERY LUCKY

914efi · 11-04-2014, 10:52 AM

Paul, I tried your bent allen wrench already, I may try it again but the way the bolts are lined up I could not get it on. I also used a short hex in a 1/4" wrench, pushed hard until the hex deformed, no luck.

I'm going to go back to Home Depot and get the 6mm allen socket that I just bought replaced if I can and try again with that. It shattered the first time! I had a 12" pipe on the ratchet so not very fair to the socket but it illustrates how tight these are. I used a long cold chisel on the OD of the bolts also to try to move them. no luck but maybe I loosened them a bit for the next try. Maybe I'll try with the engine warm...