Vibration after new poly trans mount, need help

[jamnut87]

The vibration has nothing to do with speed of the car, cause it will do it while free revving). Comes in at about 1500 rpm then kinda goes away till 2000 rpm and it doesn't seem to be super consistent as to how much it vibrates. Its not a SUPER bad vibration but it does make the steering wheel vibrate a tiny bit... Had someone feel the top of the motor while i revved it to about 2000 rpm and they said it didn't really feel like it was vibrating.

Ive checked the timing and its right at 10 degrees like we set it after HCI. Balancer is only maybe 1 year old and looks fine (and the correct timing makes me think its not that)...

Motor mounts maybe? Flywheel bolts? (even though i KNOW we torqued them correctly, and it went on correctly). The vibration really seemed to be noticeable AFTER the trans mount.

Any suggestions on what this may be, as i don't know if its a problem or just a characteristic of the poly (i know its definitely stiffer).

Thanks for the help,
David

 

[fiveoho]

i had a pretty lengthy thread on the same problem you got. lots of guys said it was my mount ( energy suspension poly ). my vib started after a trans swap. during the swap i changed out the old rubber mount for a ES poly. mine also vibs under free reving.

ford dealerships can order a oem rubber trans mount for around $26 i believe. i am more than likely going to order one and swap out the poly. im not for certain this is my problem but like you, i have my suspisions.

 

[1TallMF]

There is a good chance the poly bushing is just transmitting a vibration that was already present when the stock mount was there.

 

[badstang123]

When I put my TKO in and used a poly mount I ran into the same problem. I couldn't stand it, so I went to Ford and got a stock mount and threw that in. I'm much happier now.
- Justin

 

[troyizmir]

The reason the poly trans mount works on a foxbody is because they have bushings between the crossmember and the body.

Ours are metal to metal and the vibration is right under your seat. Get rid of the poly mount and your problem will be solved. Poly motormounts are just fine but dont use the poly trans mount on SN95s.

Troyizmir

 

[demon40]

poly mount

If you running the poly trans mount and rubber motor mounts theres your problem. I did the same and a local mechanic told me you can not do that because of the differences in flex between the two, which causes vibration so i installed the motor mount to and problem fixed.

 

[speedytang]

Put the stock mount back on. Urethane is just to hard to absorb but instead transfers vibration.

 

[jamnut87]

Thanks all who replied

But now i got a few more questions

1) i remember a metal bar going between the rubber to each bolt hole on the part of the mount that goes to the trans... My other one was pretty old and instead of saving things like i normally do... i threw it away along with that bar and the two nuts (crossmember side of transmission mount). Do i need that bar?

2) Anyone know what size the two nuts are?

Thanks for any help, i know the description is a little confusing i can try and make a picture if you need it.

 

[go-stang5.0]

I have the same problem with my prothane mount. Got a rubber one from napa still gotta install it. Oh and jamnut btings up a good poit. I'm pretty suire I threw away my bar also...If I remember correctly its prolly important especially if the rubber on the mount fails....so where to get one?

 

[go-stang5.0]

I went to the dealer and they want $26 for that little tranny support bracket thingy. Anyone know where to get one cheap? Anyone with a poly mount wanna sell me theirs?

 

[go-stang5.0]

anyone?

 

[go-stang5.0]

bump

 

[Pokageek]

Cheaper than that? ....maybe 5.0 resto on line.

 

[go-stang5.0]

I'm almost done making my own..but I made mine out of 1/4" sheet metal. I dunno if its strong enough. It would help if I knew what it did, that way I could strengthen mine in the nescessary places.

 

[go-stang5.0]

Anyone know exactly what it does?