Transmission, Automatic

Flexplate Inspection

Flexplate Inspection

Hi fellow automatic drivers

this weekend I was underneath the car anyway, so I decided to take a look at the flexplate. Since I didn't want to drop the exhaust for taking off the bell housing cover plate, I found an easier and quicker solution: It is possible to use the small access hole covered with a plastic plug. After taking off the rear part of the belly pan and unplugging the hole. To be able to see anything in the otherwise perfectly dark bell housing, I soldered two wires to a 21 W indicator bulb (insulated it with tape) and connected the wires with clips to the 12 v terminal under the hood. The bulb fits right through the hole in the bell housing, so I was able to see and inspect everything in there and also fit the socket through the access hole to loosen and re-tighten the pinch bolt after I turning the engine manually until the pinch bolt was accessable. The whole work took less than 10 minutes and I'll plan to repeat it with every engine oil change while the oil drains out.


90 S4 Auto
928 OC, PCA Germany Region

I don't have an auto so I am probably out the window here but....

For a quick check how about this. Put a dial indicator on the front engine pulley. pry the crank to the rear and then to the front to check end clearance. If the crank pushes itself from one end to the other won't this indicate unwanted thrust on the crank?

Mark Grasser
1978 928 5-speed
Guards red/black/tan sheepskins

On mine we painted the shaft with the splines fully engaged [pinch bolt loose]. Next time I inspected it the hub had moved forward on the splines about 1 to 2mm. Released the pinch bolt the whole lot moved back to the initial position. Not happy about this. My shaft was new but we re-used the original flex plate. Beginning to wonder if that was a mistake.

Local agents contacted Porsche in Stuttgart. They recommended fitting a new pinch bolt and loading the torque by extra 10%. They also suggested replacing the flex plate [not cheap].

We will see what happens with the extra torque.


Fred R

Some very good photos of the thrust bearing can be seen at:

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