The other day I was driving home when I developed a wierd sound. It sort of sounded like a baseball card in a bicycle wheel. The first thing I suspected was the tranny. So I took out the tranny this weekend with a little bit of trouble ( My exhaust had been welded into place.) As I'm about to put my spare tranny in, I notice an odd piece behind the flywheel. When I figured out what it was, I was just in shock. Apparently one of the main bolts that holds the housings together had worked it's way loose ( How the hell does that happen?!). The flywheel managed to catch it just right and smash the crap out of it. The force of the repeated blows actually pulled the bolt out about 6 or 7 inches and turned it into a nice S shape with a good portion still heading into the rear plate. I'm pretty screwed right now. Do you guys think it might be possible to remove the flywheel and pull out that bolt? Can I just buy a new one and put it back in? Will it work if I re-torque all the bolts ? This is of course dependent on whether or not the bolt was sheared off or whether it just unscrewed. Has this ever happened to anybody else?

 

wow that is weird. i dont know how that would happen. i think thouse bolts are torqued to yeild. but i am not shure. i will look at my shop manual. but either which way you need to get the flywheel off.


ej

 

I'm going to post some pics when I get home, You guys wont believe this ****.

 

id be askin gmy self why did that do that? what else might be wrong? id love to see this.


ej

 

Yeah exactly, Why'd this happen? The motor only has about 75,000 miles on it. Are the other bolts loose? did this bolt loosen up or did it snap? I have a lot of questions that im going to have to answer with an impact gun and a 2 & 1/8 inch socket. The original position of the bolt was about 8 oclock when looking at the flywheel. The head of the bolt is now just a little past 6 0clock

 

hope you got a hell of an impact wrench, i had to take my motor to a john deere dealer and have them take the nut off.

 

just hit it with some bust rust, then a small hammer around the inner edge of the nut. then hit it with the impact. once you get the nut off the flywheel will most likely not wanna come off. so knock the ring gear on opposite sides of the flywheel to loosen it. good luck.


ej

 

Who knows why it came loose? I would highly dought that it accually snapped off though. It shouldnt be too big of a deal just to replace it with another. Just make sure to replace the seal on the bolt and to torque it to the correct ft/lbs. Good luck.

 

I have never heard of a tension bolt working loose, i have heard of
bolts snapping off, which bolt is it? is it the one under the exhaust manifold?
This is one of the reasons for coating the bolt or using shrink tube over
the body of the bolt to reduce harmonic vibrations which with time
cause the bolts to fail, cant say i have seen this in anything other than
motors which have been revved lots.

matt

 

hey 1fastt2, what seal is this your speaking of? I don't have much experience with these bolts other than taking them out while stripping an engine. Also, you don't feel that just replacing the bolt would have any adverse effects?

 

You should not have any prolbems with just replacing the bolt.

As for the seal, on all of the tensioning bolts there is a washer type seal that goes on right under the head of the bolt, its to keep everything all sealed up. Its most likely a dealer only part, should be quite cheap.

 

There is a washer with an o-ring on the back side of it that has to go on every tension bolt(except the lower passenger side one). The washer goes in with the o-ring side facing the engine, so it seals. If you go to mazda for another tension bolt you can pick one of seals easily.

 

now the only other wrinkle in this plan is that I want to do a turbo swap. I already have a donor TII. Am I being silly by just replacing this bolt? shoul I replace the bolt and strap on the turbo fltwheel and tranny for the time being? The Turbo's engine has 100k on it and im really not interested in using an engine with that much mileage. I'm technically already half way through the swap!

 

Yo,


TTT


Kevin
1989 GTUs "Deja Vu."

 

This is a known problem that Turrentine and others have identified especially in aviation applications, from sustained high rpm operation the bolts fail from a harmonic vibration. Their solution is to put a spiral coating of sealant on the non threaded part to cushion the vibration. Catastrophic when you are in a plane!

 

Yo,


Yep, sounds like my kind of driving!

*chuckle*

Thanks!

Kevin
1989 GTUs "Always sustained."

 

If you need a bigger impact gun and 2 1/8 socket and wrench,I have em.I used the wrench to pry out the flywheel.The impact gun and socket are 3/4 inch.This setup I have works wonders in removing the flywheel.If you want it I'll let it all go for $100 shipped.

Thanks
Danny

 

when I went on mazdatrix to look for the bolt, they offer short and long as well as ribbed bolts. which one am I looking for? i believe the bolt is the 18th bolt in the FSM's tightening schedule.

 

I believe you want the shorter tension bolt. The longer tension bot i believe is for the #2 bolt, in tightening sequence. I don't know about the ribbed part. I know that mazda made a modified tension bolt to deal with the harmonic vibrations. I think the best way to find out would be to call em up and ask them.

 

I'm a little bit worried from what I saw yesterday. It appears that the bolt may have done a little damage to the rear plate. The spot where the bolt goes in to the block has a somewhat raised bevel. It looks like that raised bevel may have been deformed a little. Will the new tension bolt seal mount correctly?

 

Take a file or dremel, and sand that beveled part flush.

Then use some silicon sealer. Barring any internal damage, you should have no problems at all.

 

That occurs due to vibration from the engine running constant, very high RPM's (7000rpm's and up). The centre of the tension bolt vibrates like a guitar string, breaks, then vibrates its way out. The trick around it when assembling the 13B is to use a layer of silicone RTV (any kind) for about 2" at the centre of the bolt. This creates a dampening cushion so the bolt won't vibrate and then eventually break.

Let me guess, it was one of the lower right corner bolts near the exhaust ports, right? You'll also have a water leak.

B

 

actually it was the bolt on the lower left hand side. it's position is #16 in the FSM. You say that it usually BREAKS and vibrates out, If it's broken, am I screwed? The engine is still in the car and I don't plan on rebuilding it. If th bolt is broken and stuck in there, can I still use the engine if I plug up the hole? How long would it last if I was able to do that?

 

also, could I just use a bunch of silicone instead of getting that seal? I really only need a couple more months out of this engine.

 

Well, how far did you get on it? I mean the only way to know what damage was done is to see if the bolt acually broke, or if it just backed out. If it just backed out it is worth trying to fix, all you need is a tension bolt and a washer. Find out what happened then get back to us.