Rebuilt Transmission making a loud noise
 

So a few years ago I had my 915 rebuilt ($5k)by one of the big reputable shops and it sat because I had some life issues appear.
I just got the engine and trans back in the car and ran the car on my lift and I don't recall hearing anything.

Yesterday I took the car out of the garage for the first time in years to wash it and then let it idle for a little bit to make sure the engine was dry.

I went up to it and heard a slight knocking/ticking sound while it idled and thought it was maybe the valves but after sticking my head underneath I determined it was coming from the trans.

I put the car back on the lift, started it up and got underneath it and determined that the sound was coming from the front of the trans, near the cover on the lower passenger side.

While it idled the driver tire was spinning in neutral, this is not an LSD box and if I stopped the tire the noise was still there. I raised the idle and the noise increased as well. I can't road test the car as the seats are out to get new leather.

When I depress the clutch pedal the sound stops.

The car shifted great when I moved it in and out off the garage.

I put Swepco 201 in it and decided to drain it to look at the magnet and it was spotless, not a speck on the magnet.

I haven't called the shop as it's the weekend but wanted to see if any of you smart people would have an idea of the issue and if it has something to do with what's under that cover, I am not a trans guy at all.

I have a short video where it can be heard but don't think I can post it here.

Appreciate the help!

A 915 can rattle audibly if you let it idle long enough in neutral. Not super loud, but audible if you are listening for it.


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Thanks for the reply!

I started it cold this morning and heard the noise, it's fairly loud and can hear it over the exhaust.

Also, I drained the Swepco to check the magnet and filled it back up hours later and heard the noise again when it was stone cold just like in the morning.

If not adjusted properly, the 5th/rev shift sleeve teeth can contact the rev idler teeth and rattle nicely. Gotta check for clearance before installing the end cover.

Thanks, are you talking about removing the 'Shift Cover' (PET refers to it as that) and check for some tolerances there?

If so I could check with some manuals and see what to check but I was really thinking it had to do with something under that cover, I already placed a will call order from our host for a couple of gaskets so I'm covered.

I should add that I idled the car a few times for a length of time while on the lift and it wasn't until I reversed the car out of the garage that I heard the noise so it sounds like you're on the right track, I hope!

No, John is talking about the nose of the transmission. The shift rod sticks out of the end cover. You take it off to access fifth and reverse.

Mark

OK, so it sounds like I gotta take it all back out and go from there, was hoping that I wouldn't have to take the engine/trans back out of the car but oh well!

At least there wasn't any shrapnel when I drained it.

Appreciate the help!

What was the issue that required the transmission to be rebuilt in the first place?

Is it a knocking sound or rattling?

seafood..this is what is John W. talking abouthttps://www.porscherepair.us/porsche...shift-fork.jpg

And it only requires partial disassembly, not total disassembly.