Schocki

I'm getting my covers and manifold powdercoated and wanted to write about my experience about changing the nylon pads on the chain tensioners.
Porsche has a nylon pad set for the 928 S4 and younger. The pad that sits on the piston assembly is wearing out first (critical part in the 944).
Make your own tensioner tool (picture). Bent a small wire into a U shape and use it to keep the pad down. Pushing the piston down requires some force, but eventually comes down just fine. Remove the oil line and take the tensioner assembly out and replace the nylon pad (self explanatory).
The fixed pad showed nearly no wear at all and the pad that sits on the piston about 0.6mm. Which is still OK but both tensioner pads (for both sides) cost about $14.

The passenger side is easy. The driver side is harder because the tensioner is installed upside down. I removed the driver side tensioner without releasing the tension (worked just fine). I only used the "tool:"for installation.

Imo000

That old pad is still in a really good condition. I've seen some so worn that the middle of the chain was actually toching the plastic.

Schocki

True they are in pretty good shape. My 944 tensioners looked like sh$% after about 60k Miles.
This replacement was done as preventive maintenance. If the new nylon pad lasts as long as these (110 k Miles). It is cheap insurance...
WYAIT...

Chris

Its not just the wear you need to worry about, it is the brittleness of the plastic.

Chris

Imo000

Schocki: Yup, I agree it's agood preventative maitnance item.

Chris: The chain only slides on it with a film of oil beween the chain and the pad.There isn't any hard impact on the pads. I don't think brittleness is really a factor.

Chris

Here is my old one, battle scars and all. The 944 forum have more info.



Chris

FlyingDog

What's so different about the 944 that they wear more?

Schocki

Why does the 944 wear faster? Nobody knows for sure. Just like the Flexplate issues on the 928 and thrust bearing failure...

The pads do get brittle over the years. However, the non-moving pad lasts a lifetime. There is nearly no stress on the pad (look at the picture). The pad just dampens vibrations that's it. The one attached to the piston has to deal with both pressure and vibration.

Flormat

Sorry to bring an old post back but I think the reason the 944S & S2 pads wear so much more is because there is a lot more vibration. Those fours don't run as smoothly as the eights and as Schocki said, the pads dampen vibration.

Jfrahm

I thought it was the stiffer valvesprings on the 944's, mostly. Also the 944 head might see more heat as they make more power per cylinder.

-Joel.

Flormat

You are probably right, makes sense to me. That could also explain why the 944 tensioners themselves fail more frequently than the 928.

merchauser

BUMP

can you replace the pad without removing cams? can someone expand on the procedure?

Schocki

Absolutely yes. Just unbolt the oil pressure line (make sure you don't drop any of the four washers). Unbolt the tensioner and take it out
Installation is assembly in reverse order. Make sure you get new washers before. Do this procedure only with a very good, small torque wrench!

siscogts

One more question from me :crank at 45 degrees btdc ? Do I need to lock cams? Thank you.

Schocki

No, TDC is enough (actually any position will do). The cams are not moving at all during the procedure.