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Engine Vibration

Jdgephar

Bronco Guru
Joined
Sep 25, 2012
Messages
1,518
I'm starting to feel like Paul from Fab Rats about how it's nice because I have to do it twice...

Everyone here is probably thinking I got the wrong dampener / flywheel. It's not that. It's a later engine with 50oz imbalance.

After my recent trip, I started having issues with the syncho in 3rd gear on the manual transmission. Not 100% sure why, maybe the input bearing is getting some slop in it. I have a spare, so the plan was to swap out the transmission. I figure that while I'm in there, I'll replace the clutch and flywheel.

I had the engine rebuilt not long ago, and I know it's a 50oz imbalance assembly and dampener. I bought a new manual flywheel and a clutch kit. When I compared the existing flywheel to the new one, it has the same imbalance weight on it. I got it all assembled and the freshened up transmission put in. Now I have some vibration that gets worse with engine RPM. I can feel it while sitting still and clutch dis-engaged, or on the road with the clutch engaged. It's not severe, but I can feel it, and it rattles anything that's loose in the truck.

Now the question is whether the new flywheel or the new clutch is out of balance? I've read it can be the clutch. I've also read that the flywheel maybe isn't centered on the crank?

On top of that, the new throw-out bearing squeaks when I push on the clutch. Squeak goes away when I let go of the clutch, so I know it's this new throw-out bearing. Should I expect it to break in a little bit after some use? It was a sealed part, no grease zerk for it.

Worst case, I go back to the flywheel and clutch and bearing that was in it, and just put the new friction disk in it. The old clutch really wasn't all that old, and looks in really good shape. I just figured since I was in there, why not go with new? These new parts are killing me.
 

laserfish

Jr. Member
Joined
Feb 19, 2015
Messages
132
Check your driveshaft and u-joints as well. Had one start coming loose on me and it gives the same symptoms.
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,484
Loc.
Statesville, NC
Hi, remove the fan belt and make sure the vibration is not coming from the front of the engine. The squealing throw out bearing could be the problem. Good luck
 
OP
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Jdgephar

Jdgephar

Bronco Guru
Joined
Sep 25, 2012
Messages
1,518
Check your driveshaft and u-joints as well. Had one start coming loose on me and it gives the same symptoms.
No shake coasting down the road, definitely tied to engine rpm. It shakes sitting still and reving the engine.

Sent from my SM-S901U using Tapatalk
 
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Jdgephar

Jdgephar

Bronco Guru
Joined
Sep 25, 2012
Messages
1,518
Spent most of the day on Saturday pulling the transmission back out. I put in my previous flywheel and clutch (but used the new friction disk). Engine vibration is gone, as expected. I'm only bummed because of 3 things - 1) having to spend all day working on it again and wasting money on parts. 2) Bronco was down for 2 weeks until I had time to work on it again. Summers are too short here in Michigan. 3) clutch chatter was completely gone with the new (bad) flywheel and clutch. At least now it's back to what it has been for as long as I can remember. But it's really not that bad. It only really has it in reverse high. If I flip the twin stick to low when backing up, then it's no problem. At least the engine is smooth through 6k RPM again.

Back up and running again! Also noticed the front drive shaft u-joint was bad, so I fixed that. Hopefully also took care of a minor engine oil leak. I also have another oil leak at the passenger side valve cover, if and when I ever feel like messing with that.

It's dune ready for Aug. 2 if I decide to go to Silver Lake. Coast guard festival also going on in Grand Haven, and I may have some friends going up to that.
 
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Jdgephar

Jdgephar

Bronco Guru
Joined
Sep 25, 2012
Messages
1,518
did you have it resurfaced while it was out? Resurfacing cured my chatter issues.
No, but it was resurfaced when the engine was rebuilt several years ago...no difference.

It only does it in reverse, so not a big deal.
 
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