This is topic heavy vibration under load in forum Tech Talk at Northern California Ford Owners  .


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Posted by bentley mobs a stang (Member # 11119) on :
 
I recently replaced my motor mounts after getting new gears. After installing the vibration is way worse. I installed convertable mounts in the front and a urethane mount in the rear. In neutral and in gear with the clutch disengaged (pedal pushed in) there is no vibration, even while revving the motor. But when there is torque going to the tranny the vibration is heavy. It feels like its rubbing up against the body right under me and when I coast it goes away. I've tightened every part of the tranny mount nice and snug with lock washers, and I doubt its my driveshaft considering it goes away when I coast. Any ideas on what else it could be? The heavier I accelerate, the heavier the vibration.
 
Posted by 68stanger (Member # 7842) on :
 
since you did have gears replaced i would look into the driveshaft area first. could be as simple as re-clocking the driveshaft, see if that helps, also check if the U-joints are going bad.....or look into your engines balancer taking a shit (separating)

[ October 03, 2011, 03:23 PM: Message edited by: 68stanger ]
 
Posted by bentley mobs a stang (Member # 11119) on :
 
The vibration was low until I swapped the mounts. I feel like u joints and driveshaft would give me a vibration too. Am I right?
 
Posted by VendicatedSN95 (Member # 10671) on :
 
X2 on the u-joints but sounds like a driveline angle issue to me.
 
Posted by Duncan Motors (Member # 7045) on :
 
ive found that the trans rear input shaft sleeve behind the seal normally is shot.
 
Posted by blown95svt (Member # 8893) on :
 
I'm with Duncan, now you feel it more cause you have fresh mounts and that uerathane rear.
 
Posted by turbo50 (Member # 6700) on :
 
Reclock your driveshaft and if that doesnt help look into new u joints your driveshaft is now spinning noticeably faster with the gear swap.

Also if it was the harmonic balancer it would do it in neutral at a stop with the clutch in.

Dan
 
Posted by Duncan Motors (Member # 7045) on :
 
ive heard this a couple times but dont think it matters a bit. to reclock your drive shaft? it should be balanced at any position or clocking. ive never had a problem cause of a unclocked drive shaft. just my experience with over thousands of drive shafts installs.not tryin to step on any bodys toes with this comment, i just believe its a waste of time.
 
Posted by Duncan Motors (Member # 7045) on :
 
i can change that sleeve for a hundred bucks to, if u buy the sleeve and the seal. if that ends up bein ur problem.
 
Posted by turbo50 (Member # 6700) on :
 
Just something that has helped me in the past but I dont think Ive installed thousands of driveshafts it is free to try, however.


Anyway take it to Duncan let him replace your rear trans bushing and it sounds like this will be the end of your problem.

Learn something new everyday. I guess I just have to deal with the fact that T5s are pushing 30 years old now and I guess other than grenading third gear, other parts do wear out.

Report back after Duncan replaces this bushing so we can all know what the prognosis is and maybe save some frustration down the road.

Dan
 
Posted by turbo50 (Member # 6700) on :
 
And I still say it is the u joints. I always mark driveshafts after I remove them just as a precaution.

It has something to do with all the u joints being in the same plane when referenced to the splines in the transmission etc etc. It was something I read on spicers tech forum years ago.......

Here is some good reading as well with regards to pinion angles and such....to do with driveshaft harmonics.

Again, I am not saying the tailshaft bushing isnt causing your problem, I am just brain storming along with you and others.


http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php
 
Posted by Blind (Member # 3052) on :
 
sure the engine isn't just mis-firing under load?
 
Posted by Duncan Motors (Member # 7045) on :
 
my brain just farted lol. i understand about that clocking thinga ma jigy lol. the u joint needle bearings can wear into a groove on a particular side in there cup, thus making sloop in that area. maybe moving or clocking the drive shaft can put the under load needle bearings in the unworn spot thus clearing up the slop. that makes sense. and then u really just need new u joints like u already stated.good possibility. its all we can do from the other side of the computer screen is brain storm lol.
 
Posted by turbo50 (Member # 6700) on :
 
quote:
Originally posted by Duncan Motors:
my brain just farted lol. i understand about that clocking thinga ma jigy lol. the u joint needle bearings can wear into a groove on a particular side in there cup, thus making sloop in that area. maybe moving or clocking the drive shaft can put the under load needle bearings in the unworn spot thus clearing up the slop. that makes sense. and then u really just need new u joints like u already stated.good possibility. its all we can do from the other side of the computer screen is brain storm lol.
On the real he should just take it to you and have you replace that sloppy tail bushing and install new spicers and never look back if that is his issue.

I aint got time. Im only on here when Im at work sittin at my desk or Im takin a break after workin on a car or it is too late to run the air compressor.

Dan
 
Posted by bentley mobs a stang (Member # 11119) on :
 
Thanks for all the replies.

Blind- definately not misfiring. Id pick up on that in a ny minute. Understandable to suspect that, but not applicable to my mustangs symptom.

Dan and Duncan- when I pulled my driveshaft during the gear swap I noticed some wear on the yoke, but didn't make the connection. I pulled the upper boot off my shifted and its the front of the drive shaft hitting my floor board. Can't see it, but its obvious is u proportion the location to where my noise is coming from. I'm gunna reclock the shaft to see if I get better results. Never used to think it made a difference either even tho I mark it during removal anyways, but Dan makes a lot of sense. Regardless I'm gunna send my driveshaft to driveline specialties in san leandro to get balanced, new u joints and yoke. And I'm also gunna buy the new bushing to prevent damage to my new yoke. My friend apparently has the tool to pull it out and knock it back in. I'll let u guys know how it goes. I miss driving that. My silverado daily driver is fuckin boring
 
Posted by turbo50 (Member # 6700) on :
 
Great to hear. Let us know if this solves ur problems
 
Posted by Duncan Motors (Member # 7045) on :
 
ccooooool!
 




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