Belt Tensioner Roller

[Rob001]

Got a bad belt tensioner roller (can wiggle) on my 98 C2 6speed.

Acoording to PET partnumber is 996 102 117 54 which is replaced by 996 102 117 56 but is for a model M 249 (tip)

Partnumber 996 102 117 00 is for M 480 model which is a 6 speed. Om my alternator I have no free wheel so which roller to order and what is the difference between the two?

Edited May 7, 2010 by Rob001

[Loren]

I think that is likely a mistake.

I think you want 997.102.117.00

[Rob001]

Thanks Loren, so far the German Pünktlichkeit in Pet 7

[Wayne R. Dempsey]

There are two idlers on the front of the engine, and although they look identical, they have different part numbers. I'm not sure what the actual difference is between the two, but you need to order the correct one. I have an article on replacing this (for the Boxster, but the pulleys are the same) here: http://www.pelicanpa...ler_Pullies.htm

Do you need the one with the yellow arrow or the green arrow?

-Wayne

Edited May 12, 2010 by Wayne at Pelican Parts

[Rob001]

I need the one with the white arrow which is the tensioner roller.

Note that my altenator does not have a freewheel pulley as far as I can see.

See below picture of alternator wihout cap so this is the confusing part in ordering the correct pulley.

Edited May 13, 2010 by Rob001

[Wayne R. Dempsey]

I don't know what you mean when you say your alternator has no "free wheel". The alternator has a pulley on it that is connected to the alternator guts - nothing else. The photo I posted is how your engine looks underneath all of the air cleaner stuff. That tensioner pulley is not attached to the alternator...

-Wayne

[Rob001]

Alternator for a 6 speed (M480) seems to have a pulley with a free wheel lock and a tip (M249) without according to PET.

Pending on which alternator pulley type there are two versions of the belt tensioner roller (not the idle rollers) as shown in my first post.

So what if you have a 6 speed without free wheel lock and what is the difference between the two tension roller partnumbers available in PET?

[slbates]

I need the one with the white arrow which is the tensioner roller.

Note that my altenator does not have a freewheel pulley as far as I can see.

See below picture of alternator wihout cap so this is the confusing part in ordering the correct pulley.

It does not matter. The freewheel pulley was an attempt to end some early belt shredding issues. Replacement 3.4 engines, whether manual or tip now come with the freewheel pulley. A separate replacement engine for tips was halted years ago...same engine with a wiring harness compatible for both.l

[RFM]

The thing is, alternators with a free wheel pulley use plastic rollers and are mounted on cars with a manual gearbox. Alternators with a fixed pulley use metal rollers and are mounted on cars with a Tiptronic gearbox. Over the years, have been done by mods and repairs/replacements, create a mix of different rollers and pulleys. The only thing what you should never do is an alternator with fixed pulley mount together with plastic rollers, a free wheel pulley with metal rollers can not hurt at all. Caution: the recommended replacement period for a free wheel pulley is 90.000 Km (info from pulley manufacturer)