mwood388

Kevin,

If I want to test it in RWD, it is as simple as disconnecting the drive shaft right? Do I need to worry at all about the front diff or codes from the computer trying to send power to the front? Just want to make sure I don't mess anything up.

32krazy!

yes no codes to worry about the car has no idea its 2 wd

"02996ttx50

you could be right. only time i've ever had "clunks" were bad t-mount.

op. yes, all you need to do is remove the cardan shaft and as kevin suggests and steve said, the car knows no difference. enjoy "one wheel" drive lol

mwood388

An update:

Double checked the trans mount while it was off the car. The part # is 99737503302, which is not the latest but at least its the 997 version. It has the bushing inserts too and the original rubber is in good shape. I put it back on for now and took out the cardan shaft. There were no major cracks in the guibo flex coupling and the u-joint that I thought had some play seems solid. I went for a drive and the noise is still there - might even be slightly louder now. I looked at all of the CV joints too. I'm not exactly sure what to look for with CV joints but rotationally they all seem fine. Moving the axles in and out produces some slight clunking at the front wheels. Moving the inner CV joints themselves (not the axles) axially produces clunks at the front diff and the trans, not sure if that's normal. Otherwise while driving it seems like the noise comes from the rear of the car and is probably the gearbox. I have reached out to Brian to see what his thoughts are.

s65e90

Axles will move about and make noise when pulled on as it's the CV moving in/out. When the CV are going it's more of a clicking. IMO maybe there's nothing wrong. Maybe worth changing the trans fluid and seeing how it sounds.

Carlo_Carrera

^ I agree, try trans fluid change.

"02996ttx50

eliminated the t-mount as a "possible" so.. what was the LAST thing done? talk to copans. with all due respect.

certainly checking all suspension components is critical. but judging from your posts, you'd have a sense whether or not this was an "internally" created sound or not, rather than moving suspension bits by hand to check. this is no gear oil issue. that's for sure.

mwood388

I took a short recording while I had a minute tonight (attached). Careful with the volume in the first 1/3rd of the video, I hit a reflector on accident which is the two loud noises. This is at 2k rpm in 2nd gear just gently applying throttle and backing off. I'll hopefully be contacting Brian tomorrow to see what he thinks. Also tomorrow I am going to try running the car while on jack stands and see if I can pinpoint where it's coming from.

s65e90

Yea that is pretty pronounced. My clunking I refer to is more gear lash backing on/off throttle and doubt it would be nearly that audible from a recording. I notice slight whine too, very minor, but again this is with a numeric shifter, cup cables, solid engine/trans mounts. Yours def sounds like something isnt right and almost like something is loose and banging around.

Lucidbassman

hi, I was wondering if you ever got to the bottom of the issue? I have the exact same sound from applying throttle then off. Im in the Uk took and it to my specialist today who couldn’t figure it out.

Lucidbassman

Hi, just listened to your audio clip. I have the exact same issue? It’s very annoying. Did you ever find out the solution?
cheers

mwood388

Unfortunately, no. It has been on the back burner for some time now. I still want to figure it out at some point.

Lucidbassman

2 years on and I'm still working on this. Just had the guibo changed and the gearbox mount bushes. Still there. Frustrating.

s65e90

Mine sounds something like this. Listen to the race car come on/off throttle, you hear a noticeable on/off metal clanging but also a little gear lash/whine noise.

2fcknfst

That car has a sequential box in it, probably with dog cut gears, thus the gear whine - cannot really make out the clunking - sounds like the 991 in sport + when it's shifting.