engine and drivetrain Timing Chain Tensioner

[Bwanadyk]

Hi,

 

I've been searching the forum for how to service my timing chain tensioner.

There's lots of stuff about fitting and bleeding, and measuring the correct length, but how does it come apart ?

Mine measures way shorter than spec, though the spring is fine.

After a good soaking, I can hear the ball rattling, but I can't budge the front end from the main body.

 

Any ideas ?

 

Thanks guys.

[Guest_anonymous]

Don't. If you hear the rattle, leave it. If you want, just go buy a new one

[c.d.iesel]

 

tensioner needs replacing every 34 years
how old is yours?

Edited June 24, 2013 by c.d.iesel

[Bwanadyk]

41 years.....

[Bwanadyk]

I've seen this pictures many times on here and it shows the tensioner dismantled, but doesn't mention how.... 

[Guest_anonymous]

Buy a new one first. By the time you're done fuching with it the piston will be unusable

[TobyB]

The tensioner is non- servicable.  You just remove and replace, making sure it's oriented the right way.  It's not like the later

M50/42/52/54 where it expands- it's just held against the tensioner by hydraulic force and that little spring.

 

Replace the spring, too, if you're in there.

 

t

[jgerock]

There are a bunch of threads on this subject but thought I would launch off this one...

 

I noticed the BMW factory "blue book" measurements for the length of the tensioner piston may be incorrect.   The specs. chart in the front of the engine section list one dimension and that same dimension is shown in the graphic with a pair of calipers.   BOTH my old piston and new one measure about 57-58mm from the end to the inside of central notched part.  The overall length is about 62mm

 

I also noticed the new BMW piston is slightly different in design than the old one

New one on the left (closest to my palm) compared to the old one removed from my 72tii engine

The bleed hole in the new one is in the center of the notched section.  The bleed hole in the old one is thru the side of the notched section.

I can see the little check ball inside the new piston.

Old one on left, new one on the right

Thought I would soak the new one in some oil before installation 

Notice the heavy wear on the old one

New one in place before bleeding.

I poured some oil into the cavity, rotated the engine (on the stand) so the plug position was a little lower than the piston the forced the tensioner back and forth to bleed the piston.  I did it until oil was pushed out the plug (wasn't tightened).