Bolt in Flywheel Inspection Area

[JBeau]

Now that I have cured my stalling issue, something else has come up.

There have recently been occasional "clanging" sounds from under my car, like dropping sheet metal. These were not reproducible, but sometimes sounded like something was dragging on the ground underneath. I initially thought they were due to loose dust shields on the rear axle, but everything was sound when I checked. I also went over all the rear suspension bushings and the exhaust, since those are all new. Obviously, nothing was dragging on the ground. I chalked it up to the fact that the flywheel inspection plate was loose, since a previous owner had broken one of the bolts holding it on (it was missing when I bought the car), and planned to fix it next time I had the car up on ramps.

At some point when driving today, there was a loud grinding noise from under the car. I stopped immediately and looked at where the inspection plate was loose. There was some smoke, and when I pulled the loose corner back, an 8mm bolt with what seemed to be a square head dropped out. The head was ground on at least one side, threads were worn, and the bolt had bent approximately 30 degrees from straight. It was not a bolt that I had put on, since it was stamped "FIAT 8.0" on the head. When I checked the size of the head with my sockets, the 16mm was the smallest that fit. It has been my experience (albeit limited) that an M8 bolt will have a 13mm hex head.

Pouring over the shop manual and forums, I can't really figure what this bolt is from. I am concerned that it is a pressure plate to flywheel bolt, but I am not sure how to check without pulling the trans to inspect the clutch. When the bolt came out, the noise stopped and the car drove back home (admittedly close) just fine, shifting as expected.

I suppose my questions are as follows:

Is my assumption correct? Are there any other bolts in that area that match this description, at least as far as anyone knows?

Is there a way to check the pressure plate bolts without pulling the trans? If not, at that point, I will just replace the clutch. I have no idea if or when it was done before, so it's likely time, but I have been avoiding it.

Thanks in advance for any help.

--Josh

[18Fiatsandcounting]

Josh, there is a square head bolt of that general description, in the bellhousing. The head of the bolt is inside the bellhousing, towards the bottom and passenger side, and it exits through a raised "bump" on the outside of the bellhousing and is secured with a standard 8x1.25 nut that takes a 13mm wrench. It's function is to secure the exhaust downpipe bracket in some models, but in some cases, this bracket wasn't used but the bolt was still there.

My guess is that the securing nut fell off, and the bolt eased its way out and got chewed up by the the ring gear on the flywheel, and there you are. My guess is that you'll be just fine without it, but you can keep it as a conversation piece when the parties get really wild and crazy.

To verify that it isn't a flywheel to pressure plate bolt: Unless these 6 bolt holes are blind, you should be able to remove the inspection cover and slowly rotate the engine by hand to verify through the rear of the bolt hole that each of the six flywheel to PP bolts are still there. You might even be able to get a small inspection mirror (or boroscope) through the clutch lever opening (remove the rubber boot), to spot the 6 bolt heads.

-Bryan

[spider2081]

I think Bryan is correct in his description of where the bolt came from.
My 1981 was missing this bolt and the exhaust bracket would make a strange vibrating noise at certain RPM. To replace the bolt I first I removed the clutch boot in the bell housing. I then inserted a thin malleable wire from outside the bell housing through the hole, forming it as I inserted it so it would head toward the boot opening. I was able to fish it out the opening . I then formed the end of the wire into the hollow of the threads in the replacement bolt. I believe I did this for about 4 threads. I then pulled the wire and bolt back toward the hole and into place. Once the bolt was through the hole I took off the wire and rotated the bolt until the head was seated in the bell housing. Then side loaded the bolt with a screwdriver and threaded the nut on and tightened it. Not the easiest task using jack stands but very doable.

[JBeau]

Bryan and Spider2081,

Thank you both for your information! I do not have an exhaust bracket installed, so it makes sense that the bolt would be there. I suspect that someone pulled the bracket and didn't replace the nut, perhaps thinking it was a stud and didn't need to be reomved.

I hadn't thought about the fact that the pressure plate to flywheel bolts would need to go into the flywheel and I should be able to see them from the front. I will inspect today and confirm.

Thanks again for your insights. This forum is an incredibly rich resource, largely due to folks like yourselves, willing and eager to share information and advice when you have it.

Thanks again.
--Josh

[JBeau]

My guess is that you'll be just fine without it, but you can keep it as a conversation piece when the parties get really wild and crazy.

You clearly know exactly what kinds of parties I attend.