philiptompkins

iTrader: (4)

So I'm driving from south Houston to North Dallas last month, about a 5 hour drive (aint no thang but a chicken ****).

When a vibration starts up...
I assumed to was a U joint at firsI've've have like a half a dozen of those go out on me so Ifamiliariar with the feeling), so I didn't worry about it tooo bad because those can usually vibrate for a while before total failure.
Then I stop for gas... about 3/4 of the way to Dallas because of course I was driving at my car's optimum BP stimulus speed. When I went to push the clutch in to get it out of warp drive the clutch pedal was totally flat, so I'm thinking "this POS is literally falling apart around me, first a U joint starts to go and now clutchluch has some kind of hydraulic problem". Also as I coasted in I could hear a HORRIBLE grinding sound that could be heard anytime it was running in neautral with the clutch out. But I can't see a clutch leak, refuel, and continue on.
After driving another hour or so the vibration gets REALLLLYYY bad, I'm talking like the plastic is jumping out of the dash aactuallytally slowed to the speed limit... very extreme measures.
Luckily one of my friends and fellow RX cluber offers to come get me when it flies apart.. so the next decideddecied to go for broke and head baHoustonouston.
On the way back to Houston what I noticed was that after accelerating and changing gears and pumping the clutch up, the vibration would be not so bad... but after a while the vibration would get horrible and the clutch would be flat. I basically kept stabbing the clutch when it got bad, or just always kept a little pressure on it.
So after driving 5.5 hours all the way to chuck's house, we were able to diagnose the problem as the flywheel was loose, sliding back and forth, and wobbling.

Here are 2 videos showing how far it would move at the clutch is pushed in...


And here is a video I made after the trans is off, It shows how much play it had.
I also found grease, not threadloc on the flywheel nut (oops)

And as far as I could tell the horrible grinding noise was the flywheel ring grear sliding back onto the starter gear. (orileys lifetime warrenty FTW)

misterstyx69

iTrader: (142)

You are lucky you still have your legs...

Molotovman

iTrader: (49)

I knew this thread was going to be awesome.
The ring gear broke off my flywheel once, I drove it for a month push starting the car.

NCross

iTrader: (18)

No kidding... I've seen videos of flywheels bursting through hoods and roofs of cars.

gerald m

I tend to agree about the thread lock , I bought a 86 for the engine only and when I took it out and began to work on it , the flywheel nut was not falling off but not even finger tight anymore . No damage apparent but I'm guessing that is why the dude only wanted 100 bucks for the car , It was no doubt making some horrible noise .
Me thinks there are a lot of e shaft nuts barely tight never mind the 300+ pounds torque required to keep it tight , probably because one time builders don't want to spend the 20 or 30 bucks for the big old socket and just tighten them up with what ever they have to use .
I'm sure there has been more than one flywheel come through the floor just like a wild buzz saw .

KompressorLOgic

iTrader: (6)

damn that's crazy! yeah ive seen cars with flywheel nuts with chizzle marks on and off, from shotty shops/owners

misterstyx69

iTrader: (142)

I actually got a Semi-Truck Tire Mobile Vehicle to stop by my house and zip the flywheel nut off,and then when I was done,I got him back to zip it back on.(engine was in the car or I would have used my "persuader bar" and socket)!
It was like 15 bucks a trip.Peanuts really when you consider that the alternative would be being called Stumpy!

Spirit-RE

iTrader: (25)

Holy ****!


This for sure.

gerald m

Or worse yet stumpy Mary !! Funny this thread popped up, Today I just did my flywheel nut so after reading this thread I gave him just a tad extra . I don't have a big torque wrench just 3/4 drive ratchet with a nice piece of pipe on the end , but he's Tight. He no come loose. I wanna keep the boys where they are .

diabolical1

iTrader: (3)

i bought a huge ratchet and socket (i guess for diesels or something) several years ago and i don't regret it at all because i've heard horror stories of when flywheels seek liberation at speed. needless to say, i torque all of mine down. i do not use Locktite though.

philiptompkins

iTrader: (4)

I had a helper and the correct socket when I put it on... I'm sure it was at least 100ft/lbs or so.. not exaclty loose.
And did I forget to add that it ran like that for OVER SEVEN THOUSAND MILES before trouble started.

gerald m

but its suppose to be 300

misterstyx69

iTrader: (142)

And..How did that work out for ya Philip?
I'd be checking the rear of that engine now.

RotaryResurrection

iTrader: (8)

I have never used any thread sealant or loctite on any flywheel nut I've ever installed out of the HUNDREDS of them that I've done over the past decade-plus. I have never had one come loose, either.

I just take the half inch impact gun and hold it on full for about 1 second (mentally say one-thousand-one) then stop.

Of course, if I were doing the job by hand with an actual breaker bar or torque wrench, I'd be more concerned with actual torque readings or loctite.

Just putting it out there that this is literally a 1 in 1000 issue, and everybody here shouldn't go having nightmares about this just because it happened to one dude.

JustJeff

iTrader: (13)

That's pretty crafty, I've transported my engines in my van to shops to have the flywheel nut loosened or tightened. I'll have to look into copying what you did.

peejay

150ft-lb plus 60 degrees. No massive torque wrench needed.

Black Knight RX7 FC3S

iTrader: (7)

just make sure your engine is ok Philip.

A massive vibration like that will wreck the housings and maybe some bearings along the way.

philiptompkins

iTrader: (4)

I have no idea if the engine is ok, it was still starting and running normally though.

And the bearnings also only have 7 thousand miles on them... hopefully they are ok.

eage8

iTrader: (9)

150 lb guy standing on the end of a 2 foot bar, no torque wrench needed

scathcart

A flywheel coming off likely wouldn't cause it to explode, or fly into the driver's compartment. In the case that the flywheel comes loose, as in this situation, the worst that can happen is rattling and the keyway falling out, which would cause the engine to be inable to transmit torque into the drivetrain, causing the car to be unable to move under its own power.
The clutch will prevent the flywheel from moving too far rearward, so the flywheel will merely spin on the eccentric shaft.

Explosions occur from low quality material/unbalanced flywheels being spun at RPM's in excess of what the material can handle. Heat from slipping clutches can also be a factor.

scathcart

I'd put close attention into inspecting the rear keyways on the eccentric shaft and the counterweight, and the key itself. With a loose flywheel, these would be the only parts transmitting torque to the drivetrain.
If either of the keyways are deformed, you might want to clean them up with a file to ensure the counterweight sits properly on its press-taper assembly. I'd likely just replace the key as well.

j9fd3s

iTrader: (3)

works for me too

lastphaseofthis

iTrader: (8)

I had this happen from under tightening once. impact tools only now. i was lucky it happened 200 miles into the build and a half a mile from my destination. it rotated the flywheel ~160 degrees out, and i thought the shaft had broke.... glad u got your legs still.

rx7_FREAKKK

iTrader: (1)

Now im scared. I should take mine out and redo it,. At least the car Got you there? Nice

KNONFS

iTrader: (14)

DUUUDE, seriously? Thats awesome