Injection Timer, Front-Bearing 61x engines....
 

Definitely worth checking, if you have your engine in bits. This phosphor-bronze bush bearing sits behind the automatic injection timer, (the IP drive-sprocket behind the vac. pump)....

While re-building my 617, I assembled the short IP drive and skew-gear for oil-pump drive (N/A only) into the block, and checked the side-shake of this bearing.--Huge!

BUT the excess clearance was Not the bearing bush where it runs on the shaft, The bearing bush was loose in the block. Its held in place by a 10mm bolt with a large washer that sits in a groove in the bearing.

On removing the bearing, it can be seen that it has worn a nice groove, through preumably vibration to make it a loose fit in the block. A replacement bearing bush fixed the issue, and is a tight fit....:D

--Just thought I would let you guys know. This part is often overlooked in a re-build, as the bush bearing surface does not wear much in normal operation....

Stevo said bearing wear in on this bearing may have taken out his Vacuum Pump which intern caused other problems.

Considering the size of the haft and the bearing, there's lot of load I gues when using the type of vac. pump which runs on rollers with a cam-ring on the IP timer....

My vac. pump has a splined coupling to a rotating shaft, that operates the two diaphragms.....

There seem to be loads of different vac pumps for these engines!:eek:

Yep, when I pulled the timing device it had warn a circular grove in the block on the aft side. It had slammed back and forth due to that bronze bushing being warn. I dont know what the lateral movement should be but there was 2.5 mm in mine before I pulled it. This was on an 82 240D that had caught fire inside which I bought cheap but was running at the time. I pulled the VC (which I found too be trashed) as things just didn't sound right:eek:.