timing belt spring tensioner exploded

[nynor]

like a dumbarse, instead of removing the timing belt spring tensioner, i disassembled it in situ. thus, when i removed it, it exploded into its individual pieces. what a pain. seriously. it took me at least half an hour to reassemble it. that fkn spring is stout. luckily, the tension adjustment hadn't moved (it is really tight).

yeah, i thought i knew what i was doing. i failed to look it up, being that i only did this about 4 years ago.

anyway, i wanted to vent. i am done for the day. belts to be replaced and tensioned tomorrow.

[Guest765]

just double check that tension whatever way you feel most comfortable with.

[nynor]

i trust the spring tensioner (and the 'feel' of the belt). i've double checked the spring tensioner against the 9201 and it was spot on.

[v2rocket_aka944]

that spring tensioner is one of the "WTF were they thinking" parts of the 944 series.

[nynor]

huh. i like mine. i've tensioned belts on an '83, 85.5, and this turbo. YMMV

[John_AZ]

nynor,

Not to begin "Belt War XXI", I have no faith in the mechanical spring tensioner.

Cars with the mechanical spring tensioner (quote Porsche) must have the crank turned 2X CW and "STOP" at TDC. Then you release the spring tensioner after rocking the tension pully to remove the spring memory and gently place the roller on the cam belt and tighten nuts/bolts A & B.

The crank is not turned 15 degrees or 1 1/2 cam gear tooth CCW ---only for cars without the mechanical spring tensioner.

I have found many times the tension on the passenger side of the cam belt is overtightened.

Overtightened to a point of burning out the WP bearing or bearing seal.

I do not trust the spring tensioner.

John

[nynor]

~sigh~ you did see the part where i tested it against the 9201, etc. right. i have done this once or twice. anyway. over and out.

[HondaDustR]

My old spring tensioner tensioned a little too light compared to the P9201. It all depends on the car. Use other proven methods to verify an unfamiliar one.

[porsche4life]

Sucks man, I'm glad I don't have a tensioner to deal with....

[v2rocket_aka944]

it just gets in the way while trying to put the belt over the cam gear and adds half an hour of fighting, four-letter words and aggravation to a job that should be simple.

the early eccentric tensioner is simply a better design. its either right or its not. the spring tensioner can be off and youd never know it because you think its safe...

if i had a late car i would backdate the tensioner somehow. and also backdate the trans mount, another WTF were they thinking part...

moral of the story is, check your tension frequently

[TibetanT]

Nynor:

Sorry to hear of your "explosion" with the tensioner.

Not to pour salt on a wound, but the Factory Manuals are very clear on how to work with the tensioner.

As for me, I love the 1987 MY and the introduction of the mechanical belt tensioner for the timing belt. It makes belt replacement (IMHO) a "piece-of-cake."

Before I remove the auto-tensioner, I loosen both nuts (A and B) very little and then push the tensioner in to remove the tension on the belt. Once tension is removed from the belt, the nuts can be tightened again to hold the position. I then remove the mechanical tensioner as a unit using the Porsche Special Tool 9200; three separate bolts hold the tensioner to the engine block and those bolts are removed only after I use the PST9200 to move the tensioner to the position I want it and tightening the nuts again to ensure I can remove as a unit.

I must admit, it does take a little patience when installing the new timing belt and replacing the mechanical tensioner as a unit. Once again, the PST9200 is your friend with making the installation quick and easy.

Just a note to be happy about:
1)You did not loose a finger or hurt yourself, so that is a good thing.
2) You learned something in the process.
3) You will have a new timing belt on your engine soon.

Got to love those German engineers.

Cheers.

[v2rocket_aka944]

Originally Posted by TibetanT

Got to love those German engineers.

whoever designed a spring tensioner that has to be removed for a belt change rather than just swung out of the way needs to go swimming in a volcano.

cannot stress enough my dislike of that thing.

glad you guys find it as peace of mind but jesus it is annoying.

[FRporsche]

I gotta say, I've never had a car with the spring tensioner, only the old eccentric and the 968 hydrualic one, but from all the stories, I really don't want to have a car with the spring one. It's sounds ghey. Is it possible to back date? I thought there needs to be a special big stud in the oil pump for the old eccentric tensioner?

[nynor]

i like the tensioner. it makes it a much simpler and faster process, IMO. i would spend an hour or more fighting the concentric, rotating the engine, checking the tension, repeat, repeat, repeat, repeat. even if i have to add or release some tension, it is a matter of loosening the locking nut and bolt, and then tightening them, without the hassle of having to hold the concentric in place, praying that it doesn't move while turning the locking nut on the concentric.

yeah, i know the manual has the information about the spring tensioner. i screwed it up, plain and simple. i'd done it a couple of times before on this car and thought i knew what i was doing....

yes, the upside is that there were no injuries to me or the vehicle. it was a bit exciting there for a second!

my overall opinion on belt tension is that it is very much overrated by the 944 community. it is a belt. it isn't voodoo. like any other belt, there is a range of acceptable tension. YMMV.

[GHEN]

Yes I like the tensioner too. Comparing tensioning the timing belt (with tensioner), to the balance belt (eccentric rollers), give me a tensioner any day. Having said that it would be nice if:
A) The tensioner just swung out of the way instead of having to find the three hidden nuts

B) The tensioner was of a type that gave repeatable results. My spring tensioner sets the belt at the correct tension, but other reports indicate this is not always the case. A hydraulic solution, with a BUILT IN GAUGE would be wonderful.

There you go, swing out, hydraulic tensioner with a built in gauge and I am a happy camper.

GHEN

[nynor]

it is all back together and the car runs great!

cheers!

[bazar01]

Originally Posted by nynor

it is all back together and the car runs great!

cheers!

Yahoo !

Another vote for spring tensioner. Over 230k miles just relying on the spring tensioner every belt change.

[nynor]

the belt tension seemed perfect, by feel. they sounded great, as well; no whine, just 951 purring.

i'll adjust tension again in october.