Broken camshaft bearing mounts on '82, 240D.
 

Two of the camshaft bearing mounts (towers) broke on my 240D at about 70 mph. Assuming that the camshaft is not bent, can I replace these towers with used ones, or do I need new ones that are center bored after being mounted on the head? I don't see anyone selling new ones. I know there are several different cams used on these engines. Do the same towers fit all these cams? The numbers on my cam, as near as I can read them, are (from front to back) ?15(E?), 8 (sideways), 616 (with the mercedes emblem in front of it), and 10. I have no idea what these numbers mean, but I saw a post on this site from someone who said that he also had a cam with the number 10 stamped on the back, and that he thought it meant he had an "uprated engine", whatever that is.

Anyway, any information on the cam and towers on these engines will be appreciated. I have a good mechanic, but he is not familiar with mercedes engines (though he does a lot of diesel machinery). He wants me to find out as much info. about replacing these parts and their availibility before he tears into the engine to find out what went wrong.

Thanks----Gene Williams

What do you suppose caused the cam bearings to break? The only time I have seen them break was when the valve hit the pistons after a chain failure. They could burn up without oil, but there is no reason for them to break in normal operation.

The number stamped into the rear of the cam determines the number. If "10" was the number then the part number would be 616 051 10 01. That is one of the various cam numbers for a 616 motor.

Steve is right - something caused them to break. Before you get too much "exploratory" money tied up in it you may be better off picking something like this up. Probably not a bad price.

Check it out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&item=2450838254

Do contact them before you bid to confirm the correct engine. The one pictured IS NOT a 1983 240D engine but that may just be an error in putting it on ebay.

Yea, that is not only not a 1980-1983, it is not a 1977-1979 240D. If has a pneumatic governed inj pump and the lower forward oil filter of the 1968-1976 220D/240D motors. If looking for a motor one must keep to whichever of those three eras one originally has. They really don't swap well.

Cam towers break for two reasons: busted chain and broken crank. Otherwise, oil failures usually cause the bearing to seize and the cam to snap.

Rotate engine and verify that the cam turns AND the rear of the engine turns. If only the front half does, you have a broken crank and need an new engine (there is almost no chance you didn't do the block in at the same time). This usually results in a chunk out the side, though, plus a terrible racket, so I'd not expect you to overlook that. Usually busts the pan, too.

A broken chain will just sit there are you turn the engine with the crank pulley, and in that case a new set of cam towers will fix you right up after you install a new chain and re-set the injection and cam timing.

Peter

240D Camshaft bearings
 

Steve, thanks for the part number--- the number 10 is on the rear of my camshaft. Are there specific bearing mounts for this shaft or are they all the same within a range of years (for example '77--'83) ? My Haynes book shows the rear journals for this cam to be slightly larger than for all the other cams used.

Thanks everyone for the help. Niether the chain nor the cranshaft seem to be broken--just the bearing mounts (towers). Of course we won't know why they broke till the head is off. I'll probably have more questions then.

---G.W.

The cam bearings are line bored as a set so they must be replaced as a set. It shows that there are two different part numbers for bearings for 123 cars by chassis number. I am not familiar with the differences. The only difference I know of is the later oil pressure chain tentioner gets it oil through a new channel in the forward bearing. I would have thought all 123 cars had this arrangement. I am looking at a euro EPC so its possible that this isn't true for US cars.

camshaft parts number 1982 240D
 

I have a number 10 camshaft on my '82 240D and two of the cam bearing mounts broke. My mechanic wants me to find out about the availibility of this cam and the mounts before he begins to look into why the mounts broke. Steve gave me a parts number for this cam as 616 051 10 01. If I order this part will it come with the towers? I asked the Mercedes dealer in my area and the guy at the parts counter didn't seem to know, nor did he have a parts number for the camshaft bearing mounts (towers). Also, if I order the cam from them, it will have to be shipped from Germany. Does anyone know of a number for these mounts? . Does anyone know of a source to get this cam and/or the bearing mounts new in the U.S.? I can get used ones but my mechanic doesn't wnat to use them. Any help with these parts and their numbers will be appreciated. Also, would it be unwise to use a different cam and mounts if they are easier to get? Which one(s) could be used?

The vin number of the car is WDBAB23A8CB343077

I know very little about this stuff (a little about old Fords but not much about Mercedes)

Thanks--- Gene Williams

I was surprised to find that the cam wasn't readily available in the aftermarket. I looked the numbers up again and the 10 goes to a 19: 616 051 19 01. The bearings are separate and have the number 616 586 13 05.

I was also amazed that these numbers are not stocked in the US by MB. I will say that orders out of Germany have taken as little as three days recently.

The cam lists for 228 and the bearings are 190 from a dealer that sells at list. I would verify all the problem before ordering and if there isn't too much other stuff needed I might suggest getting them used. I probably have a set or two lieing around.