420SE (1990) starter motor

[jpm420]

The starter motor on my 420SE is 'sticking' , it takes 3-4 attempts with it clicking and clunking before it spins the engine. Take it out, strip it and clean it I thought - easy enough. But no, I cannot get the top allen bolt out.
Is there a visually hidden nut on the end of it or as it appears does it just screw into the motor body. In that case how do you get enough torque on the bolt to unscrew it , there is so little room between the exhaust down pipe, cross member and the bell housing.
Any ideas ?

 

[Francois]

I don't know what the setup looks like, but ussually when I encounter a stuck bolt, I spray something like WD40 on it very liberaly and leave it for a good few hours, even a day before trying again.

 

[jpm420]

Solved the problem - and here is the solution for anyone else who wants to get their started motor off.
A 10mm allen 'socket' is vital , use a sliding 'T' bar which will take an extension pipe. This allows you to manouvre around in the confined space and then slide the bar down behind the cross-member. A pipe can then be slipped over the bar to allow the necessary leverage. It was really tight even with extra leverage. There is no 'hidden' nut, the bolt screws directly into the motor housing.
Battery should be disconnected and the direct feed from the battery removed from the solenoid.
To extract the starter motor the steering needs to be fully over to one side to allow enough space for the motor to be withdrawn. Don't forget the solenoid activating feed which is only accessible when the motor is out of the bell housing but the wire has only a couple of inches slack so needs disconnecting as soon as there is enough movement to allow access to the cross-head screw on the inner side of the solenoid.
A real knuckle skinning job but you know its better than being stuck somewhere with an S class which won't start !