Transmission Mount

[skokie]

Has anyone every changed out a tranny mount? The reason I ask is becuase I have a vibration that I cant track down. I have had the following changed out.Torque converter, flexplate, harmonic balancer, & u joints.

Thanks in advance.

[rkarr]

need to be more specific with the vibration...... Where can you feel it? When can you feel it?, etc.

[Tx Firefighter]

I change them on all my stuff. Cost is under 10 bucks. Often, they collapse under the weight and allow the trans to settle onto the crossmember.

I have no idea if it's the source of your vibration though.

[Sweet72]

Drive shaft out of balance?

[70GMCer]

Just found out what my vibration was......a busted left side motor mount....

[truckdude239]

did you make sure your u-joint where settles in the driver shaft right? when i did mine i didn't get the going to the rear end right and had one of the wrost virabtions i felt

[shifty]

I just replaced mine and can't wait to see what it feels like

I got this one from Energy Suspension:
http://store.summitracing.com/partde...0&autoview=sku

It fits all GM models with AT (and some newer MT's) for most GM cars and trucks from 1960 to today.

[skokie]

Vibration can be felt in the steering wheel from 1100-1400 rpms. At 1500 it magically dissapears. Also this vibration can be felt with the truck sitting still and in park.

[Longhorn Man]

The your tranny mount isn't going to help at all. your problem is in the engine, and maybe in the tranny.
Jack up the truck, and unbolt the 3 bolts to the torque converter, and slide the converter towards the rear, away from the flex plate. Fire up the engine and rev it to those engine speeds, if the vibes are still there, it's in the engine, if it goes away, it's in the tranny.
Shifty, that is a killer tranny mount. I had one on my last truck and let it go with it when i sold it.

If you've ever seen adisplay of that cut in 1/2, you'll see it won't seperate in two if the rubber (poly) ever falls apart.
The one draw back on that mount is that it is a bit taller tha stock. Not an issue in most aplications, but I know I was unable to use it in my Caddy/TH350 aplication. My tranny is only about an 1/8 inch from the pinch weld on the tranny tunnle on the frame. A high hump would help, but I think cab mounts would probably do the trick in my situation.

[skokie]

I checked the tranny mount and its new. Must have been swapped out when I had the 400 turbo rebuilt. Well looks like its time to remove tranny from engine and fire it up. So how do I do that?

Thanks

[Longhorn Man]

Jack up the truck, and unbolt the 3 bolts to the torque converter, and slide the converter towards the rear, away from the flex plate. Fire up the engine and rev it to those engine speeds, if the vibes are still there, it's in the engine, if it goes away, it's in the tranny.

[Lippyp]

I found the energy suspension poly tranny mount transmitted so much driveline noise and vibration into the cab I went back to a stock (but new) rubber one and the noise went away.

[shifty]

Originally Posted by Longhorn Man

Not an issue in most aplications, but I know I was unable to use it in my Caddy/TH350 aplication. My tranny is only about an 1/8 inch from the pinch weld on the tranny tunnle on the frame. A high hump would help, but I think cab mounts would probably do the trick in my situation.

I had the same problem with my LS1/T56 swap. I cut out the low hump and upgraded to an automatic high hump. I have pictures and instructions on how to easily do this if you want them, I'll drop it in the FAQ or something. I haven't completely finished yet, but I'm almost there.

I gotta decide what to do about the old pinch weld and the body filler that popped out in the process.

Originally Posted by Lippyp

I found the energy suspension poly tranny mount transmitted so much driveline noise and vibration into the cab I went back to a stock (but new) rubber one and the noise went away.

I know this is a dumb question, but I gotta ask: Did you follow the directions? There are a few extra washers and bolts and stuff that come with the package and very vague instructions about applications using flanged bolts versus non-flanged bolts and how you instlal it in either. If you don't follow them properly, you'll see the response you mention.

[crazy longhorn]

Originally Posted by shifty

I had the same problem with my LS1/T56 swap. I cut out the low hump and upgraded to an automatic high hump. I have pictures and instructions on how to easily do this if you want them, I'll drop it in the FAQ or something. I haven't completely finished yet, but I'm almost there.

I gotta decide what to do about the old pinch weld and the body filler that popped out in the process.



I know this is a dumb question, but I gotta ask: Did you follow the directions? There are a few extra washers and bolts and stuff that come with the package and very vague instructions about applications using flanged bolts versus non-flanged bolts and how you instlal it in either. If you don't follow them properly, you'll see the response you mention.

That is a bad azz mount.....got 1 on my longhorn, & yes it does se the trans higher than stock (1/4" IIRC). As far as smooth, my longhorn is good to a buck & a quarter .......not sure she would be to a buckfifty tho(guess the old man is gettin old ) As far as the pinch weld on the floor pan.....MINE IS GONE I reccomend spot welding the seam on the topside of the floor to stiffen.....then take the pneumatic hack saw to the bottom side(DO WEAR GOGGLES) Dont ask why! You can then finish welding the topside of the floor(dont forget to shut the welder helmet......done that too ) my buds told to me that my "future was so brite that I needed shades" L

[72MARIO]

I also have the Poly tranny mount. They are awesome combined with the poly motor mounts the driveling is direct and has mabye 1/64" of twist under acceleration.

And no stupid vibirations.



What type of Fan do you have on you motor ? I have had a fan go out of balance on me and cause a vibiration.