Driveshaft?

JerseyTrueBlue said:

Hey guys I'm looking for a way to tighten up my drivetrain, by this I mean every time I shift and let the clutch out quick, even if I'm not hard on the throttle, I get that "Cobra Clunk" in the rear end.

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The driveshaft is probably the tightest part of the drivetrain, unless yours is defective (i.e. blown U-joint.) If you think you've got abnormal slop, start with the bushings in the rear. I say "abnormal" because I suspect most Mustang owners simply live with a pretty sloppy drivetrain in terms of total lash. Add it all up and throw in some loose rear axle bushings (especially the LCA front bushings) and you're going to net a fairly loose car.

Also if I let off the throttle in 1st 2nd or 3rd gear quickly, instead of smoothly dropping in rpms it kinda jerks back and forth and the revs go up and down with the car shaking, like something just isn't tight enough.

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This goes in large part to the choices made for things like control arm bushings, transmission mount bushings and engine mount bushings. It's sometimes called "rubber banding" and isn't that uncommon. You can stiffen things like the aforementioned bushings to help quell some of it.

Also in a previous thread I said I had plans for a flywheel. This was because it feels like the motor revs down to slow, I'm shifting to quick for the car so I bog a lot of gears. Anyone else experience this or know how to improve it? Thanks for any help.

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Not sure how the engine revs hanging some in each gear can cause bogging. Indeed, if you went with a really light flywheel and the engine RPM dropped too fast between shifts I could see some driveability issues with that...

If the engine RPM is hanging too long between shifts, you may have an air leak around the idle control stuff (closed throttle plate, IAC etc.) Somewhere around is a how-to to modify the IAC valve gasket to restrict airflow a bit to reduce hanging. Not sure if it'll help during the short time between shifts though.

thats a pretty damn good response

i think it is a good responce also....just wanted to add that my car does the same thing with the clunk from the tranny or drive train. mostly hears in reverse.

do you still have non pi heads on your stock 01 gt?

JerseyTrueBlue said:

I'm really not sure whats on their now all I know is they are being replaced with new PI's.

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FWIW, your 01 GT already has PI heads from the factory unless someone replaced a damaged original engine with one from a 96-98 GT. PI heads were standard issue, factory parts on all 1999 to 2004 2V Mustang GTs, including your 01.

If you're having a shop replace the heads, please tell us which one it is. Any shop that agreed to do a PI swap on a 99-04 GT, a car that had PI hardware from the assembly line, is simply ripping you off to the tune of what, thousands of dollars?? People have to know which shop this is so they can steer clear of it.