Weird Vibration - Lone Star Stangs

silverstang/306 · 10-16-2007, 08:40 PM

I have an 89 5.0 gt. I just recently had new motor mounts put on, and had my drivsaft re-worked and balanced. But im getting a weird vibration between 3000and3500. If you have any ideas please let me know....I think it might be the harmonic balancer so if you have had a problem like this then please let me know!

highspeed · 10-18-2007, 10:33 PM

It's possible the vibration could be the balancer... But if it started after your driveshaft was balanced, my bets would be on that. One other possibility is one of the wheels could be slightly out of balance. But again, unlikely if the vibration began right after the driveshaft was balanced.

Something to try, rev the motor around the 3000-3500 RPM range while the car is sitting still and see if the vibration appears. If the vibration does appear, you just eliminated the driveshaft and wheels. That may help narrow things down... Good Luck!!!

silverstang/306 · 10-19-2007, 05:08 PM

ok cool ill give that a try. thanks!

highspeed · 10-19-2007, 05:40 PM

Quote:

Originally Posted by silverstang/306

ok cool ill give that a try. thanks!

No Problem...

silverstang/306 · 10-22-2007, 12:35 PM

ok so i tried that and it didnt vibrate so what else could it be? Oh and its not the wheels there all good.

2k4mk1 · 10-22-2007, 12:40 PM

If you id as posted above and got no vibration Id say your D/S is not properly balanced.
You may try un bolting it at the rear end and turn it 1/4 turn and re attach it then drive it and see if it is better or worse you may have to move it a couple times. If it doesnt get better take it back and have um re balance it

silverstang/306 · 10-22-2007, 01:32 PM

Ok ill give that a try. Ok im not a master mechanic but if it was the drive shaft wouldnt you get a vibration at any rpm? Just wondering.

2k4mk1 · 10-22-2007, 02:08 PM

Not necessarily it may just have that spot that the harmonics are out of whack

silverstang/306 · 10-22-2007, 02:15 PM

Ok cool thanks!

Aerocoupe · 10-23-2007, 12:44 PM

When you experience the vibration at speed push the clutch in. If the vibration goes away then it is most likely between the balancer on the engine and the clutch assembly. If the vibration persists it is from the input of the tranny to the wheels. If this is the case do this again only put the tranny in neutral. This will only engage the output shaft of the tranny and futher isolate the problem to the output shaft to the wheels.

My biggest concern is you are saying is occurs at a specific rpm range. Is this in all gears?

Darren

silverstang/306 · 10-23-2007, 07:19 PM

Yes it occurs in first all the way through fifth. I will give that a try though.

Aerocoupe · 10-23-2007, 07:31 PM

If it is not a speed related thing and only based on RPM then is has to be something from the harmonic balancer to the output shaft of the transmission but not including the output shaft as it continues to increase in rpm as you change gears. Basically from the output shaft of the tranny to the wheels have now been eliminated.

Darren

silverstang/306 · 10-23-2007, 07:34 PM

Ok cool thanks. So basically what your saying is that no matter what im going to be dropping some big bucks to get this fixed?

Aerocoupe · 10-23-2007, 07:49 PM

Not saying that at all. Could be as simple as a bad harmonic balancer. You need to start with some known good parts from friends like a balancer. All that costs to change out is your time and it eliminates once source. Another freebie is to take the serpentine belt off or get a shorter one that will allow you to eliminate the accessories like the alt, A/C comp, power steering pump, and water pump. If you know someone with a good tranny then you could change those out...

On another note what kind of motor mounts did you just install?

Darren

2k4mk1 · 10-24-2007, 09:08 AM

You can try removing the belt and firing it up for a minute to see if it vibrates still if so it is the harmonic. However they usually will cause vibration as soon as you start it and at any rpm (usually increases as rpm's increase)

Id say that is probably were your problem is.

silverstang/306 · 10-24-2007, 12:33 PM

Quote:

Originally Posted by Aerocoupe

Not saying that at all. Could be as simple as a bad harmonic balancer. You need to start with some known good parts from friends like a balancer. All that costs to change out is your time and it eliminates once source. Another freebie is to take the serpentine belt off or get a shorter one that will allow you to eliminate the accessories like the alt, A/C comp, power steering pump, and water pump. If you know someone with a good tranny then you could change those out...

On another note what kind of motor mounts did you just install?

Darren

I just installed poly mounts. And if i have to replace the balancer whats a good one to go with? Also i have a borg warner 5 speed tranny and its fairly new.

Aerocoupe · 10-24-2007, 04:30 PM

I would recommend a Romac balancer any day of the week.

Another question, when excactly did you notice the vibrations? After the DS install and motor mount install? If so then I would definitely suspect the poly mounts have simply amplified the vibration as they will translate all kinds of vibrations and harmonics unlike the FoMoCo engine mounts. Continue to try and isolate the problem but it may as simple as the motor in your car is not balanced to a tolerance that will not get you a vibration with the poly mounts.

Darren

silverstang/306 · 10-24-2007, 06:48 PM

We started to notice the vibs about a week ago and we did the motor mounts and th ds about 2 months ago. Is there anything i can do to make it run smoother if it is just cause of the motor mounts?

Aerocoupe · 10-25-2007, 09:09 AM

All the poly motor mounts would do is amplify the problem not cause one. Being that you installed them 6 weeks prior to the problem occurring I would say they are not an issue at this point. You need to start diagnosing the problem like we have mentioned above. Start simple and cheap and work your way up. Keep asking questions as you go so you just don't throw money at it.

Darren

silverstang/306 · 10-26-2007, 02:06 PM

Ok cool thanks. If you are going to the dyno day tomorrow then you can look at my car maybe or drive it to see if you can figure it out cause at this point im at a blank.

10-16-2007, 08:40 PM	#1
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Weird Vibration I have an 89 5.0 gt. I just recently had new motor mounts put on, and had my drivsaft re-worked and balanced. But im getting a weird vibration between 3000and3500. If you have any ideas please let me know....I think it might be the harmonic balancer so if you have had a problem like this then please let me know! __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims! Last edited by silverstang/306; 10-18-2007 at 01:50 PM. Reason: no replies!

10-18-2007, 10:33 PM	#2
highspeed Registered User Join Date: Feb 2005 Location: San Antonio Posts: 556	It's possible the vibration could be the balancer... But if it started after your driveshaft was balanced, my bets would be on that. One other possibility is one of the wheels could be slightly out of balance. But again, unlikely if the vibration began right after the driveshaft was balanced. Something to try, rev the motor around the 3000-3500 RPM range while the car is sitting still and see if the vibration appears. If the vibration does appear, you just eliminated the driveshaft and wheels. That may help narrow things down... Good Luck!!! __________________ Modz Update!!! WTB: I need the following parts for my '94 Stang. PM me if you have any one of the listed components laying around or know someone that does. MAF support brace - '94 GT Maximum Motorsports Panhard Bar Canton radiator overflow reservoir Fidanza or Spec Billet Steel Flywheel - (50oz 302cid 10.5" 157 tooth) T56 Tranny with 5.0L Bellhousing & support brace Maximum Motorsports Tubular K Member Maximum Motorsports Tubular A Arms (std offset) Coil over struts

10-19-2007, 05:08 PM	#3
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	ok cool ill give that a try. thanks! __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-22-2007, 12:35 PM	#5
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	ok so i tried that and it didnt vibrate so what else could it be? Oh and its not the wheels there all good. __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-22-2007, 12:40 PM	#6
2k4mk1 DONT HATE ME CUZ YOU AINT ME!!!! Join Date: Dec 2003 Location: SanAntonio Posts: 6,528	If you id as posted above and got no vibration Id say your D/S is not properly balanced. You may try un bolting it at the rear end and turn it 1/4 turn and re attach it then drive it and see if it is better or worse you may have to move it a couple times. If it doesnt get better take it back and have um re balance it __________________ 04 Oxford White MACH1,5 SPD with IUP,K&NAircharger Borla Stingers,SLP Catted X pipe,Tri-ax,SCT Flashtune,Max Mtr Spt 4 bolt adj C/C plates, Drilled/Slotted rotors all 4 corners 281 rwhp on Mustang Dyno,306 rwhp on a Dynojet 94 Black Lightning Daily Driver&85GT FACH1 Project under construction

10-22-2007, 01:32 PM	#7
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Ok ill give that a try. Ok im not a master mechanic but if it was the drive shaft wouldnt you get a vibration at any rpm? Just wondering. __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-22-2007, 02:08 PM	#8
2k4mk1 DONT HATE ME CUZ YOU AINT ME!!!! Join Date: Dec 2003 Location: SanAntonio Posts: 6,528	Not necessarily it may just have that spot that the harmonics are out of whack __________________ 04 Oxford White MACH1,5 SPD with IUP,K&NAircharger Borla Stingers,SLP Catted X pipe,Tri-ax,SCT Flashtune,Max Mtr Spt 4 bolt adj C/C plates, Drilled/Slotted rotors all 4 corners 281 rwhp on Mustang Dyno,306 rwhp on a Dynojet 94 Black Lightning Daily Driver&85GT FACH1 Project under construction Last edited by 2k4mk1; 10-22-2007 at 02:43 PM.

10-22-2007, 02:15 PM	#9
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Ok cool thanks! __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-23-2007, 12:44 PM	#10
Aerocoupe UT Sucks Join Date: Aug 2006 Location: Longview, TX Posts: 194	When you experience the vibration at speed push the clutch in. If the vibration goes away then it is most likely between the balancer on the engine and the clutch assembly. If the vibration persists it is from the input of the tranny to the wheels. If this is the case do this again only put the tranny in neutral. This will only engage the output shaft of the tranny and futher isolate the problem to the output shaft to the wheels. My biggest concern is you are saying is occurs at a specific rpm range. Is this in all gears? Darren __________________ '83 5.8L TKO'd T-Bird on the bottle '93 5.0L Mustang coupe that beat your mom's LTD

10-23-2007, 07:19 PM	#11
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Yes it occurs in first all the way through fifth. I will give that a try though. __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-23-2007, 07:31 PM	#12
Aerocoupe UT Sucks Join Date: Aug 2006 Location: Longview, TX Posts: 194	If it is not a speed related thing and only based on RPM then is has to be something from the harmonic balancer to the output shaft of the transmission but not including the output shaft as it continues to increase in rpm as you change gears. Basically from the output shaft of the tranny to the wheels have now been eliminated. Darren __________________ '83 5.8L TKO'd T-Bird on the bottle '93 5.0L Mustang coupe that beat your mom's LTD

10-23-2007, 07:34 PM	#13
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Ok cool thanks. So basically what your saying is that no matter what im going to be dropping some big bucks to get this fixed? __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-23-2007, 07:49 PM	#14
Aerocoupe UT Sucks Join Date: Aug 2006 Location: Longview, TX Posts: 194	Not saying that at all. Could be as simple as a bad harmonic balancer. You need to start with some known good parts from friends like a balancer. All that costs to change out is your time and it eliminates once source. Another freebie is to take the serpentine belt off or get a shorter one that will allow you to eliminate the accessories like the alt, A/C comp, power steering pump, and water pump. If you know someone with a good tranny then you could change those out... On another note what kind of motor mounts did you just install? Darren __________________ '83 5.8L TKO'd T-Bird on the bottle '93 5.0L Mustang coupe that beat your mom's LTD

10-24-2007, 09:08 AM	#15
2k4mk1 DONT HATE ME CUZ YOU AINT ME!!!! Join Date: Dec 2003 Location: SanAntonio Posts: 6,528	You can try removing the belt and firing it up for a minute to see if it vibrates still if so it is the harmonic. However they usually will cause vibration as soon as you start it and at any rpm (usually increases as rpm's increase) Id say that is probably were your problem is. __________________ 04 Oxford White MACH1,5 SPD with IUP,K&NAircharger Borla Stingers,SLP Catted X pipe,Tri-ax,SCT Flashtune,Max Mtr Spt 4 bolt adj C/C plates, Drilled/Slotted rotors all 4 corners 281 rwhp on Mustang Dyno,306 rwhp on a Dynojet 94 Black Lightning Daily Driver&85GT FACH1 Project under construction

10-24-2007, 04:30 PM	#17
Aerocoupe UT Sucks Join Date: Aug 2006 Location: Longview, TX Posts: 194	I would recommend a Romac balancer any day of the week. Another question, when excactly did you notice the vibrations? After the DS install and motor mount install? If so then I would definitely suspect the poly mounts have simply amplified the vibration as they will translate all kinds of vibrations and harmonics unlike the FoMoCo engine mounts. Continue to try and isolate the problem but it may as simple as the motor in your car is not balanced to a tolerance that will not get you a vibration with the poly mounts. Darren __________________ '83 5.8L TKO'd T-Bird on the bottle '93 5.0L Mustang coupe that beat your mom's LTD

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10-24-2007, 06:48 PM	#18
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	We started to notice the vibs about a week ago and we did the motor mounts and th ds about 2 months ago. Is there anything i can do to make it run smoother if it is just cause of the motor mounts? __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!

10-25-2007, 09:09 AM	#19
Aerocoupe UT Sucks Join Date: Aug 2006 Location: Longview, TX Posts: 194	All the poly motor mounts would do is amplify the problem not cause one. Being that you installed them 6 weeks prior to the problem occurring I would say they are not an issue at this point. You need to start diagnosing the problem like we have mentioned above. Start simple and cheap and work your way up. Keep asking questions as you go so you just don't throw money at it. Darren __________________ '83 5.8L TKO'd T-Bird on the bottle '93 5.0L Mustang coupe that beat your mom's LTD

10-26-2007, 02:06 PM	#20
silverstang/306 Fred Join Date: Oct 2007 Location: bulverde Posts: 23	Ok cool thanks. If you are going to the dyno day tomorrow then you can look at my car maybe or drive it to see if you can figure it out cause at this point im at a blank. __________________ 1989Gt 5.0;302bored .030 over, gt40 heads ported and polished, typhoon upper and lower intake, 70mm throttlebody, mac coldair intake,bbk underdrive pullys, smog pump delete, mac equal length headers, mac o/r x-pipe, mac highflow mufflers,borg warner 5speed tranny,kingcobra clutch,ford racing flywheel, 4:10 gears, steeda tri-ax shifter, and last but not least 17by9 chrome cobra r rims!