Vibration With Engine Rpm

[dirtboy33]

hey guys in new to this forum and also new to the mustang world. I bought a 91 hatch 5.0 with a t5 trans a few weeks ago and love it. but it has a vibration that changes with engine speed. doesn't matter if im sitting in my driveway to driving down the road. starts getting bad around 3000. its at its worst around 3500. then starts to smoothe out around 4000. but there is always a very slight vibration. at first I thought it was the dampner. I could see it wabbling a little. changed that with no help. then I removed the engine belt and ran it. didn't help any. so now I got it in my garage and I pulled the trans out hoping to find something wrong in the clutch/flywheel area. but don't see andthing wrong. the dow pins are there for the clutch and everthing looks good. so I removed the bell housing from the trans and put back on and installed the starter. started the engine with just the clutch and flywheel on the back and the vibration is completely gone. so my question is could a internal problem of the trans cause my vibration even with no vehicle speed or could it be something more simple like a trans mount or cross member bushings? I have been googling this issue for the last couple days and cant find anyone with my same issue. any help would be greatly appreciated.

 

[jrichker]

Check the harmonic balancer on the front of the crankshaft. The outer hub may be lose, wobbly or shifted from its normal position. The outer hub is bonded to the inner hub by a rubber ring. Sometimes the rubber ring tears up and allow the outer hub to move. This causes engine vibrations because the balance weights have shifted with the outer hub.

 

[dirtboy33]

I already changed the balancer with no effect. I thought that was the issue because I could see it wabbling some. But it made no differce

 

[mikestang63]

driveshaft?

 

[dirtboy33]

Does it sitting in the driveway.

 

[TOOLOW91]

Could be something in the TRANS. I had the same issue last summer . Pulled TRANS and it stopped . Installed new TRANS and it was still here . Turned out number 4 main bearing was spinning in the bore


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate

 

[A5literMan]

Could be something in the TRANS. I had the same issue last summer . Pulled TRANS and it stopped . Installed new TRANS and it was still here . Turned out number 4 main bearing was spinning in the bore


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate

That's my guess. Big clue is the fact you can see the balancer moving. I am assuming the crank is walking due to a bad bearing. Not that this is a sign necassarily but what's the oil pressure doing?

 

[dirtboy33]

I hope its not a engine issue haha. The balancer doesn't move anymore now that I have a new one installed. And I havnt hooked a Manuel oil pressure guage up to it yet. But the guage on the dash is above half way all the time even hot.

 

[Lscam580]

A long time ago I see a guy having the same exact problem with a ford ranger, only to find out that two bearings inside the trans was destroyed..

 

[TOOLOW91]

I hope its not a engine issue haha. The balancer doesn't move anymore now that I have a new one installed. And I havnt hooked a Manuel oil pressure guage up to it yet. But the guage on the dash is above half way all the time even hot.

Get a pressure gauge on it . My stock gauge looked great even with the spun bearing lol .


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate

 

[dirtboy33]

I'm gonna put a guage on it tomorrow morning before work. And I'm considering pulling the cover off the trans and taking a look around before I put it back in. Also gonna try a new trans mount and crossmember because my mount and bushings are looking pretty old