Author Topic: Throttle Shaft Bearing Replacement  (Read 538 times)

ctaylor738

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Throttle Shaft Bearing Replacement
« on: August 15, 2024, 17:06:22 »
The bearing bracket sits on the left side of the engine and supports the cross-engine throttle shaft which is part of the connection between the throttle body and the injection pump.  I noticed that on 133, the bearing had worn and that there was play between the bearing and the shaft.  That meant that when the throttle was opened the throttle body lever would move before the injection pump lever.  Not good.

New bearings are available for $20 and change from a variety of sources.  I had the local dealer order two for me, part number A1270720185.  I ordered two, because the same part is used on the right side of the engine and it also was showing play.

To replace the bearing in the left side bracket, remove the cross-engine shaft, drive out the roll pin that holds the pump lever, slide the lever off and slide the bracket off.  Using a press or a vise, position a socket slightly smaller than the hole on the engine side of the bracket so that the socket will press on the bearing.  On the other side, position a socket slightly larger than the hole on the fender side.  Apply pressure, and the bearing will come out.  You will notice a snap ring in a groove in the bracket.  Leave this in place.  Apply a little lube to the new bearing and press it into place using the smaller socket from the removal process. Put the pump lever back on the shaft and re-install the shaft.

From memory, the socket sizes were 10mm and 17mm.

The bracket assembly is an amazing piece of design and manufacturing.  The snap ring, its groove in the bracket, and the bearing are sized so that the bearing will slide through, but once it does, the snap ring holds the bearing in place. A lot of work to make the bearing replaceable.

Pictures attached.

Cheers,

CT
Chuck Taylor
1963 230SL #00133
1970 280SL #13027 (restored and sold)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

TJMart

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Re: Throttle Shaft Bearing Replacement
« Reply #1 on: August 15, 2024, 17:50:20 »
CT,

Thanks for the very useful information. I’ll check mine out and now know how to replace if necessary.

Tony
Tony
1970 280SL, 4 Speed