93 mustang drive train vibration

[mustanggod93]

Hello would like to know if any one can help. I have a 93 limited edition lx convirtible.It started out as an auto matic i have now converted it to a 5 speed with a borg warner. Was fine for the first 1000 miles are so then it started to vibrate! I have replaced drive shaft u joints and tail shaft bushing all so had the drive shaft balanced still vibrates around 60 slight all most like tire out of balance but at 80 the car fells like it is going to shake apart vilent!!! some one please help!!!!!!

[85_SS_302_Coupe]

Do you have an aftermarket gear in the rear end? A lot of times stepping up to 3.73s will cause a harmonic vibration through the drivetrain. One fix (really the only one i've ever heard of) is to get an aluminum drive shaft. I had a bad harmonic vibration at 60mph and i got an FRPP aluminum shaft and it took care of it.

[mustanggod93]

I do have gears 3.73 but the gears were in the car when it was an auto matic

[85_SS_302_Coupe]

Hmm...i'm not sure then. Is there a difference in balance between a 5 speed shaft and an auto shaft?

[wildstang89]

I had the pinion nut back off some and cause a vibration. Hows your tranny mount? Check your motor mounts too. Going to a 5spd causes more stress on them. Keep us informed.

[mustanggod93]

yes i was told their were three different leghts i know two of them 45 3/4 is the longest i have found and 43 is the shortest i had one cut 44 1/2 which seams to be gust the right lenth. i do need to add the trany is out of a 4 cyl but i changed the 5th gear to 68 gear ratio out of a v8 that was trashed

[mustanggod93]

i have checked the pinion also the mount is not new but its does not seam to be cracked or oil soaked!

[plated]

sounds crazy but if your tires a shitty it will shake like hell ,if you have another set of wheels to swap out and see if it still does it?are your flywheels bolts backing out? also check harmonic balancer see if the ring is coimng off factory are 2 peice balancer, i've had a couple come apart over the yrs,check your fan clutch to see if it's shot grab ahold of it and see if it wobbles,but i'm guessing you got a broken belt in one of your tires and you think it's in the drivetrain;) let us know

[plated]

does it wine your tranny?if your using a 4cyl trans with the wrong pilot bearing it will hold up for a while but eventually the trans bearing on the front input shaft will peter out after a few months of driving like you expained

[mustanggod93]

thanks but i also had the same ideas about the tires hade them road forced to day the y all checked out. as for the hormonic balancer it is new also i can get the car up to where the vibration startes and shut off the engine and ingage the cluth and vibration is still their.

[mustanggod93]

their is no noise from the tranny its self but i have also had to replace the throw out bearing twice becouse it starts to squeak.

[ClevelandMstang]

check the pinion again, or use aluminum driveshaft, the gears should not matter if they are right, you may have had it with the auto but the trans will "soak" some of it up, you feel more with a 5 speed, usually this issue is a pinion., also check driveline angle, that can cause it but usually not..

[85 stang gt]

I too have this similar problem, 373 rear end, stock driveshaft,(been balanced) tire/wheels good, rear end good. Gears 1-4 are alright until I hit excess rpms of 4+ and 5th. is good until I slowly let go of pedal, just enough to maintain or cruise speed then chit happens. If I let go pedal all the way or even accerlaerate it will go away at least until I hit 75-80 then it vibrates constant no matter what. I checked balancer, it doesn't look bad but I did go ahead and ordered a new one just because I have tried everything else so why not. Do any of these symptoms sound familiar? If so please let me know before I go through the trouble of changing the balancer. And also, if I keep my hand on the shifter while it's in 5th. gear and it starts the vibration, well I kinda feel a heavier vibration about every 1 second, kinda like a rotation, there about every second, goes away for about a second then back again. If I disengage shifter, vibration still there??One last thought if I'm going up a hill on the hwy and the engine is on a "load" it does not happen. I guess if I drove uphill alll the time I'd be in good shape. Sorry for being so lengthy guys but if anyone could help I would appreciate it so much.
Rick

[ClevelandMstang]

Guys... it is not the balancer, if your balancer was making the engine vibrate that bad the engine will be toast, I have had balancers spin on me and wobble and still not had that type of vibration, also if it was the balancer, flywheel, water pump, fan or anything like that it would do it in every gear and sitting still.

that said.... do either of you have aluminum driveshafts? stock ones suck.. if you have a GOOD aluminum driveshaft the problem is most likely going to be the pinion, replace the pinion bearing, may not feel loose but think how hard it works at 80 mph... these issues are in the driveshaft, rear end or even the trans...usually not in the trans though..

[85 stang gt]

Mustanggod, I don't want to steal your thread, I am just having the same issue and maybe with me putting some more info out there these SBZ guys can help us before we drive ourselves nutts.

Clevelandmstang, I am still drivng with the stock DS, so your thoughts are to swap out driveshafts with a good aluminum one? What do you think I am feeling in the shifter? "The heavier vibration feel about every other second or so"

[Black Horse]

It sounds like driveshaft balance/harmonics to me. Try putting a tractor type hose clamp around the driveshaft near the transmission end. See if the vibration is better or worse. Rotate the clamp head position 90 degrees and check again. If you feel a difference keep rotating around until it is as good as you can make it. You may have to add one or two more clamps depending on imbalance. (Make sure the clamps don't hit anything when they spin with the driveshaft.)

The aluminum drive shafts have less rotational mass, therefore are less likely to have as much imbalance as a stock. If you prove it is out of balance using the hose clamp method, you might want to pull the shaft and take it somewhere to have it balanced.

[DeckerEnt]

I have a question. Does this vibration only happen in 5th gear? Or can you switch to 4th and it goes away? If that is the case, it is the trans. You said it was a 4cyl trans that you are now using behind a v8. Even in 5th, the v8 is putting so much more power and stress through it.
I would also check the rear end gear and pinion.
You also said that you can get the speedo up to 80, shut off motor and push in clutch and vibration is still there, Sounds like rear end bearings. Check it all. My .02
Keith

[kennebellcobra]

I too have this similar problem, 373 rear end, stock driveshaft,(been balanced) tire/wheels good, rear end good. Gears 1-4 are alright until I hit excess rpms of 4+ and 5th. is good until I slowly let go of pedal, just enough to maintain or cruise speed then chit happens. If I let go pedal all the way or even accerlaerate it will go away at least until I hit 75-80 then it vibrates constant no matter what. I checked balancer, it doesn't look bad but I did go ahead and ordered a new one just because I have tried everything else so why not. Do any of these symptoms sound familiar? If so please let me know before I go through the trouble of changing the balancer. And also, if I keep my hand on the shifter while it's in 5th. gear and it starts the vibration, well I kinda feel a heavier vibration about every 1 second, kinda like a rotation, there about every second, goes away for about a second then back again. If I disengage shifter, vibration still there??One last thought if I'm going up a hill on the hwy and the engine is on a "load" it does not happen. I guess if I drove uphill alll the time I'd be in good shape. Sorry for being so lengthy guys but if anyone could help I would appreciate it so much.
Rick

This sounds like a rearend problem or maybe some worn control arm bushing being that it does not do it under load or decel.

[mustanggod93]

I have found my problem i checked the input shafts that i had laying around 5.0 t0 4cyl the 4cyl shaft is smaller than the 5.0 i checked with the parts store to see if the bearing are the same and their not so does any one know if their is a bearing that i can use or should i go ahead and bit the bullet and buy a trans.

[facemelter71]

They should make an adapter bushing for the right input shaft for the trans.

[ClevelandMstang]

I have found my problem i checked the input shafts that i had laying around 5.0 t0 4cyl the 4cyl shaft is smaller than the 5.0 i checked with the parts store to see if the bearing are the same and their not so does any one know if their is a bearing that i can use or should i go ahead and bit the bullet and buy a trans.

That will for sure do it, I did not realize a 4 cyl trans was used, it late.. I was tired!

[Gearhead]

If you mean the pilot bearing, then one from a mid to late 1980's diesel ranger will work if you are using a 4 cyl T-5.

[mustanggod93]

hello again well i replaced the transmission with one out of 92 gt and installed a new pilot bearing because the other bearing was trashed. well the vibration i was complaining about has changed i know can get above 80 mph but their is a vibration under a load or deceleration i can get it up to speed and slightly let off the gas and it goes away until the engine starts to slow the car down. the only thing i have to add is the drive shaft is different and the front joint was a little tight!!!!!!!! ?????????????

[mustanggod93]

whatz up

[mustanggod93]

so does any one have any thoughts

[chad393na]

Swap in an aluminum driveshaft. I've had that fix that type of vibration countless times. I wouldn't trust the stock one anyways, unless it had just been rebuilt.

[facemelter71]

Did the same with mine.Swapped in an aluminum one.Only paid 100 bucks for mine though.HEHE.

[mustanggod93]

can any one tell me what the difference is between an auto and manual drive shaft is.

[mustang8998]

There isn't any difference.

I went from a 5 speed, to an auto and still run the same drive shaft.

[mustanggod93]

Well so far i replaced the polite bearing transmission new tail shaft bushing and replaced the drive shaft and u joints. but their still is a vibration at 75 and above so all i have left that has not been touched is the rear end. before i tear it apart does any one have any other ideas or advice thanks.

[mustangboy]

Have you tried the aluminum driveshaft like was suggested. I would do that before I tore into the rear.

[mustanggod93]

yes out of another friends car his is down with a spun main bearing so that is what im running for now

[mustanggod93]

the problem is fixed finally do not ask but i swapped out drive shafts once again so i could give my buddy back his. i had another friend give me one out of a 93 gt convertible installed new joints and went for a ride not thinking any thing would change but to my suprise no more vibration. but i want to thank all of you who gave me advise thanks!!!!!

[mustanggod93]

14862

[cmetalbend]

I too have this similar problem, 373 rear end, stock driveshaft,(been balanced) tire/wheels good, rear end good. Gears 1-4 are alright until I hit excess rpms of 4+ and 5th. is good until I slowly let go of pedal, just enough to maintain or cruise speed then chit happens. If I let go pedal all the way or even accerlaerate it will go away at least until I hit 75-80 then it vibrates constant no matter what. I checked balancer, it doesn't look bad but I did go ahead and ordered a new one just because I have tried everything else so why not. Do any of these symptoms sound familiar? If so please let me know before I go through the trouble of changing the balancer. And also, if I keep my hand on the shifter while it's in 5th. gear and it starts the vibration, well I kinda feel a heavier vibration about every 1 second, kinda like a rotation, there about every second, goes away for about a second then back again. If I disengage shifter, vibration still there??One last thought if I'm going up a hill on the hwy and the engine is on a "load" it does not happen. I guess if I drove uphill alll the time I'd be in good shape. Sorry for being so lengthy guys but if anyone could help I would appreciate it so much.
Rick

I swear this is the rear gears. It's fine until your on the "coast side" Easy to check pull the cover and check for proper lash. although I'd bet you can notice it from just turning the yoke at the rear end. Bad as it sounds. I also had a bent wheel that caused the "one sec" then off vibration

[85 stang gt]

All right guys, this is what I have been working on, replaced all u-joints, rotated DS 180, put hose clamp around DS, removed the dog bone and with all of this NOTHING. I really don't have the funds right now for a good aluminum DS so the only thing I have left to do is have the DS re-balanced, just had it done last year, but figured since I replaced the u-joints and taking it off and on I'll have it balanced. Took it to Cinci driveline yesterday and somehow it seemed to be bent, about a foot away from where it goes into the trans, they fixed the bend, balanced it. I put it on this morning, and YES, no more vibration. I asked how in the world did it bend from last year to this year, he said possibly heat from exhaust or from the torque. I have about 3" clearence from the exhaust so my wife decided to give her .02, stop driving it like you stole it, I said simply "but honey". I just want to thank everyone who chimed in on this problem. Thanks guys.