OK Don wrote:
I replaced the badly worn belt tensioner lever (and pulley) on the '90
300D 2.5. last Wed. (beautiful day - 65F, sunny). The bolt that holds
the assembly to front of the timing case is supposed to be torqued to
100NM, about 74Lb/Ft. I don't know how far I got, but as I was
tightening it, it reached a point where it felt like the pressure was
constant, and the bolt was still turning. It was very similar to the
felling you get from a bolt that is about to strip out the treads.
Since this is screwing into the aluminum case, I stopped. The bolt
does have a copious quantitiy of blue locktite (after cleaning the
threads), so I'm going to watch it and see if it stays in place.
I vagely remember a similar experience when I replaced the same part on the SDL.
Anyone else have this experience? Were the bearings just getting
pressed into place, or are the threads really in danger of stripping?
The answer is YES! In early OM60x engines MANY timing covers were
stripped when tightened down. I can't tell you if it was carelessness
(not using a torque wrench) or that the cover (its been revised at least
once - maybe more) really was inadequate.
Dave M. has had the cover fail (really messy) and has pictures to prove
it. Replacement of the timing cover is a BIG job (8-10 hours flat rate
time as I recall). I have seen the threads strip. Later models should
not be as vulnerable (I have NOT heard of NEARLY as many tensioner arm
failures of any sort in '90s cars as with the assemblies in mid '80s cars)
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5