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914World.com _ 914World Garage _ 914 flywheel noise?
Posted by: Socal70 Aug 4 2014, 04:51 PM
So I just pulled my transmission out of my 70 (side shifter with a 1.8), I replaced my flywheel due to work teeth, got the car back together and the car sounded great for 5 minutes and then developed a light grinding noise. It's coming from the transmission area and most noticeable when it's idling. Anyone had similar issues?
Posted by: Socal70 Aug 4 2014, 09:36 PM
So I just pulled my transmission out of my 70 (side shifter with a 1.8), I replaced my flywheel due to work teeth, got the car back together and the car sounded great for 5 minutes and then developed a light grinding noise. It's coming from the transmission area and most noticeable when it's idling. Anyone had similar issues?
Eliminated pilot and throw out bearing
Posted by: 76-914 Aug 4 2014, 09:53 PM
Check the starter shaft/gears for scaring. Did you lose the big o-ring between the crank and flywheel when you changed it? Maybe one of the shims is rubbing on it. Pull the flywheel and check for rubbing/clearance issue against the case.
Posted by: rjames Aug 5 2014, 01:49 AM
May be the same issue that cause the flywheel you replaced to have worn teeth.
Posted by: ThePaintedMan Aug 5 2014, 07:27 AM
Starter motor gear not retracting fully? As said before, likely the reason why it wore out the first time.
Look for magnesium shavings at the access hole at the bottom of the transmission. If they are present, then it's a clearance issue with the tranny itself. If not, I'd suspect the starter.
Posted by: Mblizzard Aug 5 2014, 07:30 AM
Would it be necessary to reset then flywheel/crank end play when changing the flywheel?
Posted by: Dave_Darling Aug 5 2014, 08:22 AM
Yes, it is necessary.
--DD
Posted by: Cap'n Krusty Aug 5 2014, 08:51 AM
The o-ring has absolutely nothing to do with the shims.
The Cap'n
Posted by: Dave_Darling Aug 5 2014, 01:28 PM
But the flywheel itself does. (In case that was directed at my response.)
--DD
Posted by: colingreene Aug 5 2014, 09:21 PM
What O ring?
Posted by: Mblizzard Aug 6 2014, 03:14 AM
O-ring on the hub part of the Flywheel. Number 18 below. 
Posted by: 76-914 Aug 6 2014, 09:06 AM
The o-ring has absolutely nothing to do with the shims.
The Cap'n
It was a shot in the dark, Cap'n. I thought possibly if the o-ring was gone the shims might rub! I'm surprised you focus on mistakes rather than help a fellow teener who is still looking for the answer! I totally expect "useless negative comments" from someone that doesn't know shit from apple butter but not from someone with 40+ years experience. Why not use your keyboard to further conversations. Especially given your experience.
Posted by: flash914 Aug 6 2014, 10:13 AM
Yes Anytime you replace a part (case, crank, bearing, or flywheel) the end play needs to be rechecked. the pocket in the flywheel determines the amount of shim required. the face inside the pocket seats on the crank and the face on the outer edge sets the amount of shim required. The "o" ring stops oil from leaving the bearing or shim pack and going past the bolt threads onto the clutch. It set in the grove between the two faces. Back the clutch cable off and wedge the throw out bearing away from the clutch then start the engine. That will insure that the noise is not the bearing. next reset the cable, start the engine, push in the clutch, listen for a change in noise, with the clutch pushed down put the transmission in and out of gear, notice any change in noise- pilot bearing. Gordon
Posted by: Cap'n Krusty Aug 6 2014, 10:56 AM
I thought the conversation was moving in the right direction, so I simply made a quick mechanical point. Here we go with a more complete answer. No, you don't really need to set the end play after changing the flywheel, unless it's a knockoff. The crank and case are the primary determining factor, and the OE flywheels are pretty much right on the money. You should, however, ALWAYS check it. The noise described in the OP isn't likely to be a result of improper end play. Onward: While the release bearing can make noise, that noise is most common when the clutch pedal is depressed and the bearing is under load. If the ball cup in the release arm has become badly worn, or if the flywheel has been cut too far, the arm can touch the clutch cover and a grinding noise occurs. If the pilot bearing fails, significant noise will occur when the clutch pedal is depressed. It will rapidly deteriorate and shifting will become difficult as the mainshaft will be pretty much connected to the crankshaft. If the starter "hangs up", there could be more than one cause, and it'll both make noise and remove teeth from the ring gear. Starters get old, dry, and non functional in several ways. It works, so we know the bendix shoots out and turns the flywheel. However, it may not fully retract in a timely manner. Bad spring? Dry shaft? Can't tell, maybe even with the starter out of the car. Another cause may be a faulty ignition switch or feedback into the "50" circuit. Often the hangup will remain even when the engine is revved, but the noise of the engine drowns out the sound. This usually leads to a blown up starter. I've even seen the starter body shatter.
If the o-ring in the flywheel fails or is deleted, you're gonna have an oil leak, which will quickly coat the clutch disc, the flywheel, and the pressure plate with oil, but there'll be no noise connected with that problem.
There you are.
The Cap'n
Posted by: rjames Aug 6 2014, 10:59 PM
I thought the conversation was moving in the right direction, so I simply made a quick mechanical point. Here we go with a more complete answer. No, you don't really need to set the end play after changing the flywheel, unless it's a knockoff. The crank and case are the primary determining factor, and the OE flywheels are pretty much right on the money. You should, however, ALWAYS check it. The noise described in the OP isn't likely to be a result of improper end play. Onward: While the release bearing can make noise, that noise is most common when the clutch pedal is depressed and the bearing is under load. If the ball cup in the release arm has become badly worn, or if the flywheel has been cut too far, the arm can touch the clutch cover and a grinding noise occurs. If the pilot bearing fails, significant noise will occur when the clutch pedal is depressed. It will rapidly deteriorate and shifting will become difficult as the mainshaft will be pretty much connected to the crankshaft. If the starter "hangs up", there could be more than one cause, and it'll both make noise and remove teeth from the ring gear. Starters get old, dry, and non functional in several ways. It works, so we know the bendix shoots out and turns the flywheel. However, it may not fully retract in a timely manner. Bad spring? Dry shaft? Can't tell, maybe even with the starter out of the car. Another cause may be a faulty ignition switch or feedback into the "50" circuit. Often the hangup will remain even when the engine is revved, but the noise of the engine drowns out the sound. This usually leads to a blown up starter. I've even seen the starter body shatter.
If the o-ring in the flywheel fails or is deleted, you're gonna have an oil leak, which will quickly coat the clutch disc, the flywheel, and the pressure plate with oil, but there'll be no noise connected with that problem.
There you are.
The Cap'n
Meh. I much prefer the Good Captain when he's krusty.
Posted by: Socal70 Aug 8 2014, 01:43 AM
The noise has been found, turned out to be the fan and it was a coincidence being that I just pulled the flywheel. I did put a genuine flywheel back in the car but didn't think to recheck the end play.
Posted by: lsintampa Aug 8 2014, 07:39 AM
good find!
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