Convert Timing Chain to dual – 380SL

A Mercedes Benz “Star” mechanic, Mark, converted my 380SL to dual timing chain.  My 380SL had 40,940 miles on it when

I first heard what I suspected was “chain slap”.  I took it to Mark for advice.  I got two estimates – one to replace the timing chain with a single row along with tensioner and guides, and the other much more expensive quote was to do the recommended engine conversion to dual roller timing chain.

I had asked around and talked to other shops about doing the conversion for me and some quoted a lower price.  I decided on this shop because they seemed to have the most knowledge and equipment, and the shop seemed to be so neat and organized.  They also answered my questions with responses that I took that they had the confidence and knowledge to do this.

When the engine was disassembled, Mark commented on how clean and well cared for the car seemed.  He stated that the insides of the engine was extremely clean.  Another person stated that he had not seen so nice an SL as this in a long time.

After almost 2 weeks, I got my 380SL back.  It feels different – seems much tighter and more like a new car feel.  How do I feel – well for one, much lighter in the billfold, but much more confident in driving this car.  For the last 20 years when I first learned about the single timing chain debacle, this car has been a big worry for me.  Ever time I cranked it up, I listened intently for “chain slap” hoping it would not snap.  I did not like driving it for worrying about blowing the engine.  That is now changed.

Here is the Mercedes Benz Work Instructions for the conversion process.

Here are some photos Mark took for me as he worked on my 380SL:

	Remove hood and prepare to extract engine. Storing the hood on the convertible top is a good way to get it out of the way.
	Engine removed
	380SL and Engine on stand
	Dual Timing Chain parts neatly organized and ready to convert to dual roller chain.
	Removed parts are neatly organized.
	Underneath my 380SL with Engine installed. Subframe is perfect, clean, never damaged.
	Underneath my 380SL with Engine removed.
	Here is the Single row timing chain – the infamous “bicycle chain” Note the slack in “bicycle” timing chain.
Left Front view of engine on stand.
Right front view of engine on stand.
Engine upside down
	Here is the newly replaced Dual row timing chain. Note the color of the chain guides – milky white. The ones removed were dark red – I understand that when the guides turn red, its time to replace them. You can see the removed red colored guides in the “Parts Removed” photo.
	Even though the timing chain is now a dual roller, there is another chain, a single row, that drives the Oil Pump. Not as much stress on this chain as on the timing chain.
	Timing chain conversion completed and ready to put back in 380SL.
Parts removed – Chain, guides, sprockets.
Found a cracked Distributor, bad mono valve.