Thaddeus

Hi,

Doing the timing belt on my 86.

There's an orange ring on my crankshaft that has hash marks. They are: 2|0 1|0 0|1 1|0 etc. When I have it positioned at 0|1 the marks on the camshaft gears line up. I know I'm supposed to continue turning the crank until it is at the 45 degree mark. Which mark on the orange wheel crrespnds to the 45 degree mark?

many thanks in haste

Thaddeus

GlenL

Those are degrees. I believe the middle one is actually "OT" which is an acronym in German for TDC. (Made that up!)

So it's 10, OT, 10, 20. You've got to estimate 45 which will be past the 20.

Garth S

As Glen said, TDC is 'OT': When you arrive at the true TDC, where the cam wheel marks line up in sync with OT - then to get to 45 deg before TDC, continue turning the crankshaft an additional ~1.75 turns. This will put the engine at a 'true 45' deg BTDC. If the 45 mark is not there, then place a mark at a distance of twice the 20 + half of the 10 mark from TDC.

Tony

Isnt there a 45' mark on it? This should help in teh meantime.
http://members.rennlist.com/pirtle/svc.html

Thaddeus

So it's supposed to be 45 degrees BEFORE TDC? Or After? Pirtle's writeup doesn't say... can't fiind it in the manual...

Scott M.

I believe that only the 87+ had the 45 d mark.

Scott

Thaddeus

OK, I found it. 2 different sections of the different year 928...

Shane

My '86 has the 45* mark! I don't think it is an '87 and up thing but maybe a 32v item.

shaaark89

if you really get stuck, 45 degrees before tdc is 3.5 teeth (22.5 degrees)on the cam gear before the marks for tdc. (cams turn one revolution per two crank revolutions.)

Scott M.

My 85 doesn't have 'em though. And none of my early cars do either (79,80,80)

Another one of Porsches logic schemes I guess.

Thaddeus

The 86 has the 45 degree mark. It was just too grimy to see...

GlenL

The 16v cars don't need this step. The T-belt is done at TDC. Head removal as well.