horst

I'd like to know how much trouble it is to replace the power steering belt in my car, with the engine in? -90 C-4- just as PM, really not experiencing problems, but the car IS 11 years old and has almost 50K miles.

Adrian

Dear Horst,
A word beginning with "B" springs to mind. The maintenance manual is very slack in this area.
Ciao,
Adrian
911C4

Roland Kunz

Hello

No trouble just work.

General:

remove muffler, remove carrier brace for the muffler, remove belt case cover and check the belt.

If bad then loosen the servo pump and the black plastic shield.

Now fiddeling out the old belt is pull it out on the camdrive and then push it upwards then get in the enginebay and pull the belt higher so the pump gear is in the middle from the beltlenght then twist the belt by 90° flat to slide it over the pump gear and then return so the belt is complete beside the gear. Then push it downwards and roll it together to remove it out from the lower case. You also can pull it out upwards.

Check the gears and clean the rubberdust away also look if the cam gear seal isnīt leaking then return the new belt and stretch it with the pump.

You also can go following way: remove the lower cam gear by loosing the screw and then only remove the black plastic cover to remove and reinsert the belt. Then just put the gear back in ( I think the screw gets 65 NM ) and the belt is normaly correct in tension as no other mechanic before ever touched the pump to retight the belt.

The secound way is faster but you have the risk that the screw will not come loose and using a impact wrench isnīt good.

If you have to do it while a regular service you need some 30 minutes.

Grüsse

horst

Three follow-on questions: Is the cam gear held by a schraube oder bolzen? ( 65NM=50 foot lbs. Kinda tight!) Is it recommended that this be replaced at any specific milage/time, or should I leave well enough alone. I can imagine that it could cause some excitement if it broke at the wrong time. Or will it give some warning? When you mention "30 minutes during regular service, you DO mean with engine in, right? I think I know which B***h word Adrian has in mind!

horst

How rude of me. I forgot my manners. Thank you! Horst

Kevin

Horst;

Lately you have been looking for every excuse to take that engine out.........

Roland Kunz

Hello

Schraube = Screw
Bolzen = stud

Its a screw. I was a once usage screw with microcapsuled loctite on it. High brake loose moment. No warning just "feeling".

The power stering belt is normaly replaced at the 100 000 km service. They will last much longer especially on highwaycruisers.
Had seen more leaking pumps then failing belts. However the problem is you canīt leave that desicion to a average Joe mechanic or the costumer so the 100000 km replacment is on the very sure side and driving a powered 911 without servopump is very iky ( OK if you are used to drive old Ferrari V12 or Masereati V8 you will feel home ). A failed belt mostly looses his theeth and then it will smoke up after a while. You then normaly have to replace the gears and sit a while to clean the rubber out of the case ( if normal mechanic do that )

It got replaced by the same screw siting on the other end from the cam holding the gearsets. Its a M12 x 1,5 grade 10.9 witch refers to something like typical 65 Nm preload. But Iīm not sure about the actuall numbers and I donīt have a repairmanuall on hand. I only have my old brain witch isnīt interesstet to keep phonebookdatas. Itīds always good to have rechecked datas at the job and if you work on rod bolts the best is to ask Porsche if they superseeded the routine again.

Now that bad word comes up. Iīm not to firm with all those bad words I should know.
I donīt see that the belt is in any way complicatet to manage. Its in fact a bit fiddeling and maybe not a beginners job but compared to a timing belt service on a 944 / 928 its a small practice to keep the fingers maintained. You will need that when you do the valves on Cly 6 intake.

If you are there then check the servopump for losse nuts and if the hoses are in good order.

Grüsse

horst

Thank you again Roland. Don't worry about the bad word. I accidentlly taught my graddaughter some of these words, as she watched me do several projects this summer, when she visited for 3 weeks. Her mother still is not speaking to me..