Just googled up  "dynos"  There is a dyno machine at a place called Maximum Velocity Motors in the city of Leon TX.??? It might be time to put your car on a dyno and locate the vibration. Be nice to see what kind of HP she puts out at the same time.
 

There is a dyno day/car show this weekend, if I can spare the time to go. In Cuero, Tx I think

MS wrote:

HudginJ3 wrote:

A friend of mine bought a new T5  series for his vett. The installation instructions says how to measure center line at the input shaft and to measure and shim the bell housing to the engine and the transmission. I never to know that nore did I do it

Interesting since Corvette has fixed position differential

 
I would guess that on the vett the differential would be the place that you start from since it is bolted solid and then measure every thing from it forward instead of to the rear?n

MS wrote:

I don’t know why this never occurred to me before, but all the retrofit crossmembers for T5 and TKO transmissions utilize the early style ribber mount between the tranny and crossmember. The foxbody, where all those T5 trannys come from, uses a different style rubber mount.

I might build a new crossmember that utilizes the foxbody mount. Maybe they have some magic designed in from Ford to help eliminate the vibes.

Wouldn’t hurt if the crossmember was rubber-mounted to the frame rails like the foxbody, as well. It seems like Ford made a huge effort in those cars to eliminate vibes. All that, and weighted dampners, etc.

Sounds good I want one already.

 

Steve, I can't remember if it's ever been mentioned, but have you ever considered CV joints on the driveshaft?

Trying CV joints are a drop in the bucket of all the effort and money you've already spent on this. 
Good luck with the camera.

Last edited by 50vert (1/08/2023 5:47 PM)

50vert wrote:

Trying CV joints are a drop in the bucket of all the effort and money you've already spent on this. 
Good luck with the camera.

 
Amen brother.

Have you always had an exhaust crossover?

Was wondering if a flex exhaust connector as the H-pipe might have an effect on your vibration issue.
Basically it is one set of tubes hanging on an engine with a rotating assembly, with only motor mounts and the rear exhaust hangars.

Have any pictures of the BMW cross member?

Last edited by Nos681 (3/20/2023 9:27 PM)

I think you need a new approach to trouble shooting this because this logical, methodological, scientific approach isn't working. Just keep accelerating until whatever it is does finally come apart....then it will have revealed itself to you in broken parts that you can fix/replace and once the offending item(s) has been replaced you won't have to worry about it again!

Ron68 wrote:

Chaplin wrote:

I think you need a new approach to trouble shooting this because this logical, methodological, scientific approach isn't working. Just keep accelerating until whatever it is does finally come apart....then it will have revealed itself to you in broken parts that you can fix/replace and once the offending item(s) has been replaced you won't have to worry about it again!

Wow - that is some really hard core troubleshooting. Reminds me of an aircraft (A-3 Skywarrior) I worked on in the Navy. Had an intermittent condition where it would blow a fuse, but we couldn't figure out why or where the problem was. Got fed up one day and jammed my #2 Phillips screwdriver into the fuse socket. Looked for smoke. We found the short.....

 
🤣🤣🤣

Simple solution to a complex problem.

Ron68 wrote:

Chaplin wrote:

I think you need a new approach to trouble shooting this because this logical, methodological, scientific approach isn't working. Just keep accelerating until whatever it is does finally come apart....then it will have revealed itself to you in broken parts that you can fix/replace and once the offending item(s) has been replaced you won't have to worry about it again!

Wow - that is some really hard core troubleshooting. Reminds me of an aircraft (A-3 Skywarrior) I worked on in the Navy. Had an intermittent condition where it would blow a fuse, but we couldn't figure out why or where the problem was. Got fed up one day and jammed my #2 Phillips screwdriver into the fuse socket. Looked for smoke. We found the short.....

We used to call this “Neanderthal Troubleshooting”, when investigated intermittent issues, worked quite well.   

 

I keep my speed at 79 or below and the car is smooth as glass.
Might invest in a cruise control.

RTM wrote:

Every time I see a new post on this subject I rush to see if the problem was found.  Lol

Hopefully someday