I talked to a dealer master tech yesterday about whether I had to take off the valve cover and pin the cam sprockets on the passenger side before changing my chain tensioner, as per the shop manual. He said that the clearance between the chain and the bottom of the valve cover is so tight that there is no way--with the engine off--that the chain could jump a tooth when the tension is relieved. Therefore, he believed I could do the job without even taking the valve cover off. Can anyone confirm or deny this?

Also, today, I read an old post on this forum that the new tensioners do not use oil pressure in addition to spring pressure. Can anyone confirm this?

Thanks.

__________________
1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

Ive replaced several chains and guides, etc, you will need to remove valve cover and pin it otherwise you wont be able to reinsert the tensioner and overcome the cams that are going to rotate without it being pinned.true the chain wont jump a tooth but the tensioner wont go in easily either, at least you dont have to pin the drivers side.

I knew there was a catch. That makes perfect sense. Thanks!

__________________
1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

Does anyone know the diameter of the pins used to pin the camshaft sprockets on the M119 (Part No. 111 589 03 15 00)? I read somewhere that a specific size of drill bit could be substituted for this $37 part. Thanks.

Attached Thumbnails

 

__________________
1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles

i've used ate brake pins to do the job. i think it's 4mm diameter. good luck, chuck.

I JUST MEASURE THE PIN TOOL AT 6MM OR .02360 IN OR 15/64 DRILL BIT IS CLOSE ENOUGH.