I am planning on replacing the valve stem seals on the
240D and have the seals in hand. I need to find the
right size of stem seal installation tool (drift) to
buy. AutospecialtyTools have the SIR tools which is
identical as the tool shown in Mercedes shop manual.
Apparently they have 9mm and 11mm to choose from. But
according to the shop manual, the stem seals for
intake valve and exhaust are the same. The seals I
have look like the same size as well. Maybe there is
someone on the ShopForum knows the answer?

__________________
80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

rs899,

I replaced the valve seals without any special tools. The seal kit I used had a plastic sleeve that fit over the threaded portion of the valve stem to protect the seals when installing.

P E H

Threaded portion of the valve stem?

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sixto,

Yes, threaded where the acorn nut and lock nut screw on the valve stem.

All the MB OHC engines I've seen have threaded valves: 190D, 200D, 200D, 240D, 300D 300SD. Newer ones may be different.

P E H

I learned something new. I've only worked on 103, 116/7 and 603 heads and all there is at the small end of the valve stem is a groove or two which the retainer halves slot into to keep the spring in place. Those grooves are reason enought to use those protective sleeves that [should] come with a set of valve stem seals.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sixto,

The acorn nut is what you turn to adjust the valves on the older Diesel engines. The other nut is a jam nut to keep the acorn nut from loosening. I guess the engines with hydraulic valve lifters dont have the threads. I thought the hydraulic lifters started on the 603 engines.

P E H