Can't Unscrew IP Idle Adjustment Plate!!!

[signalred280sl]

Screws with flat blade slots won't come loose after thirty or so years!
Second tip for the day - Get a heavy but short flat bladed screwdriver, preferably with a hexagonal shaped clear plastic handle (Craftsman has one about six inches long overall.) Drill one or more 1/4 inch holes radially through the handle just beyond the tang. Before drilling holes, put screwdriver blade in each of the two screws to determine where best to drill the holes. Insert Phillips screwdriver shaft into proper hole  to give you leverage to turn out the screw while firmly pressing in on the end of the flat bladed screwdriver handle. Not much space to work in but it did the trick for me!
Les 1970 280SL

[Joe]

That sounds like a good tip, Les. Another idea is to buy a set of impact drivers. These are available at Walmart or any auto parts store for less than 10 dollars. Put the tightest bit in the driver and smack it with a hammer. Hitting forces the bit downward in the screw slot while the spiral drive in the driver forces the bit to turn. This helps avoid the bit jumping out of the screw slot, because once it jumps out, you're screwed, but the screw is not.
An impact driver is indispensable for dismantling door innards.
Joe2

[ja17]

Les,
Tapping on the screw heads with a small hammer, before attempting removal, will often times lossen stuck bolts!

Joe Alexander
Blacklick, Ohio

[signalred280sl]

Thanks Joe and Joe - both good ideas for future reference! I shouldn't have the problem again on these two particular screws because I replaced them with stainless allen head cap screws! You know how it is; what should be a five minute job takes an hour because unforseen problems always have a way of showing up on these old cars! Fixing them up is a real love-hate thing!
Have a good weekend,
Les

[Ben]

Most of the Snap-On screwdrivers have a hex portion that allows you to use a spanner with them.

Joe's advice about the short sharp shock works great too !

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

[erickmarciano]

got a little oil seeping from that plate when I do an adjustment what should i do?
thanks

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[signalred280sl]

Erick:
Put a pan on the floor under it to catch about 1/8 quart of oil then remove the plate with the adjustment knob using the various methods mentioned here. When you remove the plate you will see an o-ring located under the plate on the IP side. Change the o-ring or, as I did, make yourself a 1/32 inch thick gasket from gasket material you can get from any auto parts store using the little plate as a template and using cuticle scissors to cut a bigger hole in the middle and a leather punch to make the screw holes. The other thing that may be leaking is a little round o-ring that seals the shaft of the adjusting knob. When you take off the plate you will see this small o-ring on its backside circling the adjustment knob shaft. To change it you may be able to stretch a new little o-ring over the blade part or otherwise you might have to disassemble the scalloped knob at the end of the spring from the shaft, put the new o-ring on and then swage the scalloped knob back on again. The little o-ring was OK when I went into mine. Good luck!
Les