after hearing a noise that resembled gravel being kicked up from the tires. Had a panic attack (not literally, but close), calmed down a bit. Crossed my fingers hoping it was the flex plate, pulled the inspection plate. Was disappointed when no chunks of flex plate fell out and even more disappointed when the flex plate felt very intact. Noticed that one of the bolts in there looked a bit damaged. Then noticed that there was a bolt laying on the bottom of the housing, almost ready to fall off the edge of the inspection hole. It is about 2" long, maybe at one time had a 5/8" head. Not too horribly trashed considering. The teeth that I could see on the flex plate looked undamaged.



What was the bolt doing when it was where it was supposed to be? And what do I need to do now? What kind of damage should I expect? The truck was driven max 5 miles after first sign of strange noise.

Augusta

 

Almost looks like one of the bolts that would hold the bell housing adapter to the engine block.

Rick

 

Boy Augusta, I've been looking all over for that bolt since I saw you last.
You can have it now, looks sort of messed up.

Seriously, it looks too small to belong in the place you found it.
If it was me I'd keep on driving.

 

Company I worked for bought me a truck to use back in the early 80's. I had a strange noise that would happen from time to time. Sounded like a loose connecting rod kind of. It would never do it for the dealer to find. Then one day it rattled really bad and I saw smoke coming out everywhere. I shut it off right away and called for a tow. The dealer found a bolt rolling around loose in the flywheel housing. The flywheel picked up the loose bolt and jammed it into the block busting a hole in a oil galley. That oil got on the exhaust and when it happened I was on the loop in Houston going about 60mph. I couldn't see and very easily might have wrecked. The bolt did not come loose from anywhere in the flywheel housing area. All the bolts were still in place. It was a extra that some assembly person left behind. Dealer wound up replacing shortblock, truck never was the same after.

 

The only bolts I can think of belonging in there are, as JYD mentioned, an adapter plate bolt, or possibly a transmission pump bolt. I don't think you can see around the torque converter to look at the pump bolts. It would be a big job to tear it all apart to inspect. Tough call.

 

I say take it for a few short spins to see if anything feels abnormal. If no smoke and / or weird feelings, just consider it overengineered and drive as needed.

 

As best as I can remeber you have 3 choises crank- flexplate , flexplate-T.Q. and front pump body- trans. , see if you can match to one of those.

 

Thanks everyone for your replies.

I should also mention that it was to a dealership about 10k miles ago and they put in a new shortblock. Maybe they left something behind or not properly torqued?

Augusta

 

Update. Stopped at the Cummins shop. 40mm 12x1.75. He looked on his computer and said from what he could tell - it was a flywheel housing bolt.



Now what?

Augusta

 

Sounds right- 12mm bolt is a big one and probably for the adapter (flywheel) housing. You might want to go have a talk with the dealer who installed the shortblock. My big fear, of course, is that the rest of the flywheel hsg. bolts are loose. That would cause a lot of damage. They might want the opportunity to fix it while it's a SMALL problem.

 

I would get a transmission jack and pull everything back, remove the torque converter, inspect the engine to housing adaptor, and the flexplate. There are 8 of those bolts that hold the adaptor to the block, and if one gets loose it will crash into the flexplate and the front of the converter as it works its way out. You are very fortunate that you have no more damage than you found!

If the adaptor is hanging one bolt short you will crack the adaptor or even can snap off part of the block, and then break the crankshaft just ahead of the rear main from the dynamic vibration stress.

It could be that the dealer did not use any LocTite, and the bolt backed out. OR, more likely you have a cracked flexplate, which is real common, and the vibration has caused one or more adaptor bolts to back out. Either way, it has to come apart.

While you are in there, be sure to pull the adaptor and check the rear main seal. They are easily damaged if the rear assembly gets out of balance, and if there is any leakage it is best to replace it now than to have to pay the labor to go back in again when it really starts pouring oil.

Go have a chat with the dealer or shop that did the work for you. I would expect that if it is related to their error they would make it right. But, based on the stuff you list in your signature I would be much more inclined to bet you will find a crack in the flexplate that caused the vibration that backed out that bolt. Those bolts are only torqued to 57 foot lbs, so should always be locked with blue LocTite on a truck that has any power boost at all.

If you do need a new flexplate, do not buy the OEM part, but go to the aftermarket and get a good one. Same for the converter.

Better yet, you have some DTT parts and are close enough to them to make a trip to their shop. So if you do not do your own work, take a short vacation and go see them. Figure on if you have a cracked flexplate that they will probably find a bent input shaft too, and you may as well get their billet replacement.

 

RCW - thanks, that is what I was looking for - detailed instructions/advice!

I spoke to the service department manager at the dealership that did the work 10k miles ago; he said it was most likely that the bolt wasn't torqued properly and backed out (and yes, he does know that my truck is NOT stock). He said the "consensus" was that if there isn't any noise or vibration that it would be safe to drive it to them so they can drop the tranny and check it out. 200 mile highway trip.

My DTT goodies include basically everything except the intermediate billet shaft and their billet flexplate (I have around 23k miles on the tranny). I had hoped that this would be a good opportunity to purchase their flexplate and have it there for the dealership to install, but I guess that the tight clearances when going to the billet plate make it a good idea for me to wait and make the 660 mile trip to have DTT do the install.

I will ask the dealership to check the rear main seal while they are in there as well as asking that they use the blue LocTite when putting it back together. I will also ask if I may take a look while they have it apart (just out of curiousity, not because I know anything).

Anything else? Anyone?

Thanks again - Augusta

 

It is good of the dealer to step up on this. Sounds like they still have common sense in Montana.

You may want to chat with them beforehand, because I suspect they will a cracked flex plate, or it will have dings from the bolt on the open spokes that will crack very soon. Any dents in the spring steel center section will stress crack in a few thousand miles, so you would be better off to take an aftermarket flex plate and TC with you.

 

I did mention to the Service Department manager that I was worried that the flex plate was damaged and likely weakened. We did not discuss specifically whether or not it would be replaced, but I trust that they will do what is best. I will know one way or the other tomorrow; I am headed that way first thing in the morning.

Augusta

 

Final update.

Truck never missed a beat on the 200 mile trip to the dealership. They dropped the tranny and found that the 2nd bolt from the top on the driver's side (adapter plate to the block) was the culprit. All others were tight. They did remove and re-install all bolts using loc-tite per my request. Rear main seal was dry and no damage to anything that I could see. Five hours and a short test drive later, they handed me my keys, apologized for any inconvenience and sent me on my way. I certainly wish that all service departments were as great to deal with...

Augusta