Awful vibration (trying to make carlisle)

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Awful vibration (trying to make carlisle)

Post by xr89 » Wed May 18, 2016 9:04 pm

Hey guys,
I'm trying to make my first carlisle this year and i have a problem with my xr that I just cant get. Any advice would be greatly appreciated.
Car had been off the road for 5ish years, and before its transformation it was silky smooth on the highway, but now feels like Im driving over some gnarly rumble strips. This only occurs over 60 (by my inaccurate spedo) and during de-acceleration or coasting. When accelerating hard seems to clear up
Since smooth, its had a t5 conversion (along with complete overhaul)

My efforts to fix: 2 different trans, brand new driveshaft, 2 different diffs (one known good), driveline aligned with that tremec app for smartphone, new rear wheel bearings, new wheels, new tires, new rotors, and more i cant think of.

I realize this should be rudimentary mechanics, but i cant figure it.... and im at the end of my rope.
Sorry for the insanely long post.
My car is just like my girlfriend...
loud and temperamental.


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Re: Awful vibration (trying to make carlisle)

Post by mikek340403 » Wed May 18, 2016 10:11 pm

Does it feel to be a forward vibration or do you feel it more in your butt. I have seen alot of bad cv axles case that kind of vibration ( some get better with heavy load and some get worse) try grabbing the axle shafts and giving them a shake (with the suspension loaded). If any movement is felt that could very well be your issue. Food for thought

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Re: Awful vibration (trying to make carlisle)

Post by phild765 » Fri May 20, 2016 10:45 am

Motor mounts, I just had my replaced with the Supercoupe's it used to vibrate around 70, now much smoother.

Phil D
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Re: Awful vibration (trying to make carlisle)

Post by DPDISXR4Ti » Fri May 20, 2016 12:25 pm

Is the differential mount original? If so, it probably has a fair amount of play in it. I'd suggest a replacement from MC2Racing.

What about the transmission mount?

What Phil said too. You want to get the engine up the air a bit with clearance between the pan and X-member.

Regardless of the above, getting a Merkur to be vibration-free with a 1-piece driveshaft is VERY challenging. The thing I found after trying to get the angles "perfect" was that it was better to just do some trial-and-error experimenting a bit by raising and lowering the transmission, and then go take the car for a ride.

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