madkaw Posted July 9, 2012 Share Posted July 9, 2012 Flywheel is stock 230mm cut down to 16# by Top End Other mods were that I drilled around the perimeter of the ring gear in order to use a hall effect sensor someday. I was planning for a future megasquirt to control spark. In both cases, the flywheel was balanced afterwards. The balancing after drilling the ring gear was NOT done by Top End. My symptoms are vibration in the 2700- 3100 range- regardless of what gear I am in. At highway speeds it will blur my rear view mirror. Under hard driving it is most pronounced on deceleration. The vibration is rhythmic and simulates a tire out of balance. There is a time coincidence between noticing this vibration and the drilling of the flywheel. At first I only noticed it in final gear at high speeds and thought it was driveline. Now I have determined that it is RPM related only. My damper was rebuilt at the time of the engine rebuild- 10k miles. What else could be happening or what else should I look at? Recommendations as far as balancing the flywheel with the clutch? Could it be input side of my t-5 tranny? Quote Link to comment Share on other sites More sharing options...
akeboshi Posted July 9, 2012 Share Posted July 9, 2012 Try inspecting your clutch. When I fried mine on the turbo poopra it virbrated alot. It vibrated enough to loosen a few tranny bolts too but after I tightened them up it got significantly better. Its easy to check the bolts, not so much for the clutch though. good luck P.S. the stock flywheel is a 220mm unit. Quote Link to comment Share on other sites More sharing options...
Leon Posted July 9, 2012 Share Posted July 9, 2012 So this vibration happens when revving the car in the driveway, transmission in neutral? Clutch in or out? Quote Link to comment Share on other sites More sharing options...
duragg Posted July 9, 2012 Share Posted July 9, 2012 I posted in the Drivetrain section a little vibration analyzer that uses the accelerometer in your smart phone. If you can exactly isolate the vibration frequency you will be able to tell if it is crank speed, 2x crank speed, fan, alternator etc. Worth a try. Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 9, 2012 Author Share Posted July 9, 2012 Leon , That needs to verified- but I think it does. I will double check. Just had the assembly out for a rear main seal fix and everything was tight and went back tight- with Loctite . Also replaced pilot bushing and yes 220mm. Clutch was new ACT unit I believe . Talked to my machinist and I am going to closely inspect my damper before tearing things apart Quote Link to comment Share on other sites More sharing options...
rejracer Posted July 10, 2012 Share Posted July 10, 2012 I have the act clutch and it needed to be balanced new out of the box. I took my flywheel and PP to the machine shop and had them first balance the flywheel, and then mount the pressure plate and balance it mounted to the flywheel. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 12, 2012 Share Posted July 12, 2012 Flywheel and pressure plate need to be balanced and match-marked as a set... I ditto that advice. I would look at the clutch cover closely! Chances are it is your culprit. Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 15, 2012 Author Share Posted July 15, 2012 I'm listening to the advice here and I'm having a hard time visualizing the flywheel making my vibration. I took about a 100 mile trip the other day and did some more troubleshooting. My vibration is most noticable in 5th gear around 2700 to 3000rpm. When I shift down to 4th gear and try and duplicate around the same rpm, I can't even notice the vibration. Running thru the gears, I don't notice it either, probably because I am running thru the trouble rpm area to quickly. Revving the engine or holding the engine at rpm while in neutral I can't pick-up anything either. The other times I have noticed this same rythmic vibration is during decel under hard driving. The vibration will happen as the rpms come down thru the magic rpm zone. I have had this happen rarely( maybe I just don't drive that hard a lot), but I know for SURE, it was the same type of vibration. So why would this vibration be most prevelant in 5th-is this a clue? Quote Link to comment Share on other sites More sharing options...
Miles Posted July 15, 2012 Share Posted July 15, 2012 Could be hearing some harmonic from exhaust or some drivetrain part is touching the body. I had this problem which was caused by the shifter tower touching the side of the trans tunnel at random times. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 16, 2012 Share Posted July 16, 2012 5th spins the everything from the tailshaft back faster than the flywheel input speed. That points to driveline. I'd check mounts and make sure everything is straight like it should be. Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 16, 2012 Author Share Posted July 16, 2012 Wow, this is getting crazy. I wonder if I am chasing my tail here thinking I have several issues when one might be causing all. If anyone remembers I brought this up before and Tony said he thought it was the mount under the tailshaft of the tranny. There was definite play in the mount and I thought I compromised it(the rubber) when modifying(welding) my original tranny bracket. I made a steel cable strap to go over the tailshaft and moored the tranny against the mount. As I remember this just amplified the vibration and noise-but I passed that off as getting closer to having a solid mount. I loosened the cable thinking I made it to tight, which did lessen the severity of the vibration. Somewhere is all this I had changed diffs trying to chase a whine coming from there. Well the different ratio changed the rpm of the vibration. Confused yet I am. Well, let me review what I do know; Main driveshaft has been checked twice for balance and the angle of the dangle was checked by the same shop that specializes in driveshafts. I also had them check the halfshafts for balance. I have an RT mount that I made myself from instructions on this site.Now this might be an issue. I still get clunking when shifting at low rpm if I don't work the clutch just right. When I look under there I notice that my moustache bar is just about riding on my lower control arm down-brackets. It might actually be touching, it is hard to stick my head up in there to see. When I install my front diff RT mount, I have to shove the diff back to get my holes to line up in the chassis, but didn't think I was that close to the control arm brackets. When I remove the wheels and look at the alignment of my halfshafts to my diff, it is almost 90 degrees, but the diff is shoved back just a few degrees. The tires have also been checked, but ready to check again. Just replaced my moustache bushings with new stock rubber, and everythings tight. The rear bearing seems to be tight, and I went thru these when installing my Wildwoods. I followed Dave's instruction to the letter. . Soooooo,maybe my vibration is being carried thru the brackets because they are touching, because my RT mount is in the wrong place? The clunk is basically for the same reason, since the r-180 moustache bar is flexing under load it is hitting the brackets causing the clunk? Damn, I have a lot to figure out here. Also, haven't I read somewhere that the T-5's have issues with the output bearing? everything feels tight. Quote Link to comment Share on other sites More sharing options...
Leon Posted July 16, 2012 Share Posted July 16, 2012 Sounds exactly like the symptons I had with loose driveshaft bolts. Check and properly torque all driveline fasteners, starting with the driveshaft. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 19, 2012 Share Posted July 19, 2012 Check that the driveline is STRAIGHT between the tailshaft flange and the differential flange. If there isn't a STRAIGHT and PARALLEL to each other, you will get this type of vibration. Your hint was loosening the tailshaft mount cable. That altered the angle of the U-Joints in the driveline between tailshaft and differential. My case was the transmission was 'walking' sideways, causing the vibration. Yours may not be deflecting sideways, but you may have (view the driveline from the side to visualize this) a tailshaft that when put up against a square on a chassis plate 89 degrees on it, and the RT mount from what I've been told pushes the nose of the differential down a few degrees (so using the same scale it would be at 94 degrees)... If those aren't parallel (in other words, both flanges at 89 degrees and concentric centerline to centerline, you will have this type of vibration. ALIGNMENT more than BLANCE can make for terrible headaches here! Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 19, 2012 Author Share Posted July 19, 2012 I have read many posts of the importance of alignment, and this has been revisited several times. When I original set this up I actually put a laser pointer on the tailshaft and pointed it towards the diff to set everything up. I have also bought a protractor and measured and made an adjustment later by dropping the nose of the diff, it did not make a difference. Then I gave up and took it to ADM driveline that specializes in making and aligning driveshafts. Before I took it there I set up the diff on the RT mount to my original position. They said my alignment was great-near perfect. I would only assume they checked all parameters-angle and straightness. During all these processes, I have literally removed, replaced or reinstalled every component of the drive line. I've had 3 different diffs in this car, which meant two different moustache bars, which involved removing all driveshafts. At this point I think I am going back to ADM to help troubleshoot. They have a vibration monitor that involves hooking up sensors to the car to narrow down the vibration. I figure if they missed anything looking and balancing all of my driveshafts I can throw it back at them. These guys have been in the business for years with some very senior techs. As for today, the car goes up on jacks and gets some more scrutiny!! Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 19, 2012 Author Share Posted July 19, 2012 Okay, I dived under the car today and started checking things again. I ran a string line down my driveline to check straightness- looked pretty damn good. So good that I started looking elsewhere and found the culprit- I think. Halfshaft- shaft is worn . Universals are great, but there is audible and visual slop between the housing and shaft. So now I'm pretty happy to find this, but kind of pissed at ADM driveline ; who had a chance to inspect these when they balanced them , because I brought them in because I had a vibration. So I call them up and they recall having my car there. I told them what I found and the tech said that couldn't be my vibration because the shafts turn to slow. Then he proceeded to tell me that my car will always have vibrations because of the urethane bushings . Anyway, when I find a good halfshaft, we will see! Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 21, 2012 Share Posted July 21, 2012 Couldn't log on last evening via iphone to say "Your measurements are done static, not under load." The thing may be perfect, but under the loads imposed at speed an angularity is introduced that causes this phenomenon... Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 21, 2012 Share Posted July 21, 2012 A halfshaft will cause vibration. What was the APP mentioned for the smartphone that shows the frequencies? If it was named, I missed it, that would tell you right away where it's coming from. "In the Old Days", Ford Field Reps going out on an NVH Complaint had a reed box--you went for a drive, and looked at these little reeds vibrating. When they excited, you read the frequency... Then crossed it to a list of known frequencies at various speeds. Sounds lo-tech as hell, but MAN it was like a magic divining rod. I was out on one where it said to look at the alternator bearings... Guess what the source of the noise was? SAS: Bad alternator! Mercury and Lincoln owners were a PITA! Quote Link to comment Share on other sites More sharing options...
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