Clutch shudder when car is warmed up

[hayday]

1984 3.2 Carrera. 13,000 miles on a rebuilt engine. 1,200 miles on a rebuilt transmission. No shudder when car is cold. After warm up, have the shudder in first and reverse. After tranny rebuild, told the clutch was fine and it was left in the car. Parts replaced were pressure plate bolt, Rel bearing guide, pilot bearing, clutch lever shaft seal, main shaft seal and crankshaft seal. There is no mention on the invoice about the clutch or transmission mounts. Asssuming the old ones were used. I've tried using higher rpm at start but that only works for a while. Shudder comes back even worse and rattles the doors. Only thing I've noticed is the alternator belt is vibrating quite a bit. Every once in a while, I'll back up, shift to first and I hear a clunk sound behind the seat over the rear wheels when car starts to move. But not very often. I also have a hard vibration in the floor at 2200 to 2600 rpm. This happens with clutch in or out and in neutral. Higher rpm smooths out the vibration. It seems to be RPM dependent as it happens in second, third and fourth as well.

[proporsche]

check your nuts which hold together the trans. and engine..15mm nut wrench, could be loose.Same time have a look on bolts on trans.mounts and engine..report after so we know

Ivan

[fallingat120mph]

Originally Posted by proporsche

..report after so we know

Ivan

Agree hope to hear the outcome.


Erik

[pmax]

Originally Posted by proporsche

check your nuts which hold together the trans. and engine..15mm nut wrench, could be loose.Same time have a look on bolts on trans.mounts and engine..report after so we know

Ivan

Uh ...

why would loose nuts care about whether they are cold or warm ?

Nuts on the drivetrain, that is

[hayday]

So this could help even though it only shudders when warm? When i took it in a couple of weeks ago, I had the tech check check the tightness of the transmission bolts. I don't think I asked them to do the engine bolts or the nuts between the tranny and engine. Should new tranny bolts be used after a rebuild? I'll be making an appointment with Porsche tech but it might be a while before I can get in there. I will definitely post any findings.

[proporsche]

ok i read it again...you put 1200 miles after the rebuild trans. and only now you get the vibration?
Something is loose for sure..
Ivan

[David Inc.]

I feel like that vibration at above 2000rpm is a telltale of something else. If you're vibrating with the clutch disengaged that sounds like engine or trans mounts are either loose or failing. I think I'd also check the smaller nuts that hold the transmission to the transmission support bracket.

[hayday]

Thank you for your replies. The vibration was intermittent but is now basically all the time, but is smoother at higher RPM's above 2,600. It is most prevalent from 2200 to 2600 and I feel it most under my feet and in the same area on the passenger side.

[hayday]

Thank you for your replies. I will be making an appointment today.

[eastbay]

Might want to check that your CV joint bolts are tight

[creaturecat]

ensure the bowden is oriented correctly - ie - not against the transmission case, and over the throttle "crossbar".
small cable adjustments can make a significant difference, as well.
checking the CV bolts is a good plan.