oil pump repair question

jim ross · jim ross's Garage

Hey there! I am going to replace all o-rings and seals on my 928 oil pump tommorrow. My question is...must i drain ALL oil first? or just a quart or 2?--I JUST changed the oil..so i dont want to remove any more than needed. THNX! -J

Mrmerlin · 06:50 PM

you dont have to drain anything removal of the oil pump will have a loss of less than 1/5 of a QT all of the oil is below the pump except for the oil cooler.
Warning when refitting the oil pump pay close attention to the outer gear bevel, ( there should be a dot on each gear that faces the engine)
the beveled edge faces to the front of the car when the pump is installed .
Use STP to coat the pump shaft and the gears prior to fitting the pump to the engine, remove the 1 MM spacer washer from behind the oil pump gear if your fitting a new steel gear, the aluminum gear gets the 1 MM washer.
use silicone grease on the big O ring or STP prior to fitting the pump to the block, you can hand spin the pump this should prime the oilways since the STP will assist with the sucking action of the pump then install the belt and start it

jim ross · jim ross's Garage

SUPER! sounds easy...i think the hardest part was finding the tool to hold the gear in place while loosening the nut. and im using a 2 claw gear puller to remove the gear. any suggestions for use of these tools on aluminum gears?--I was hoping to be able to do this without disturbing the rest of the timing belt..is that possible?-J

morriss · 03-03-2010, 05:41 PM

+1 to everything Merlin said. I used STP on everything just like he said.
Since the front end will be jacked up (engine tilted rearward), there will be little, if any, oil seepage. I had MAYBE a tablespoon's worth. I used an old tb, routed it around the oil pump gear, and then wrapped the tb around some of the suspension parts real tight. This secured the gear enough for me to break the bolts free. I did the same when tightening the bolts after the new gear was on. Pretty white trash, I know, but I was not about to buy the special tool the WSM calls for.

morriss · 03-03-2010, 05:43 PM

Oh yeah, I had to use a gear puller to get the old one off too. The old aluminum gear cracked in the process, but no worries, because I was putting a new on anyways.

jim ross · jim ross's Garage

Quote:

Originally Posted by morriss

Oh yeah, I had to use a gear puller to get the old one off too. The old aluminum gear cracked in the process, but no worries, because I was putting a new on anyways.

whoa..i dont want to crack my gear....perhaps i should let the shaft soak with penetrating oil for a while first? good improvisation on using TB to hold gear!..i DIDNT buy the $100+ porsche gear holding tool, but found a similar tool at harbour frieght for $9.99!

jim ross · jim ross's Garage

oh..when you speak of STP do you mean reg oil or extra thick additive?? thnx! -J

Mrmerlin · 03-03-2010, 06:52 PM

the thick stuff STP that is, its also great for refilling the belt tensioner

jim ross · jim ross's Garage

I CANT BELIEVE IT!!! i soaked the oil pump gear w/ PB brand penetrating oil..the bolt just turned easy as pie..without even using a tool to hold gear..then the gear pulled off by hand!! SO EASY..im now soaking pump in de greaser, MUCH sludge found in crevases! BIG o-ring was shrunk and brittle as glass! SO glad i did this....ill report later if car starts..LOL!-J

jim ross · jim ross's Garage

G.D. it! LOL no start....timing off, im too tired to work tonite..tomorrow i will adjust timing, i have workshop manual. I get the jist of it....line up cam gears with marks on block...turn harmonic balancer to TDC cylinder 1?? does this mean line up pointer w/ #1 mark on h.b...? thanks for all your help so far guys, please help me thru this final procedure. 1984 S model.-J

Mrmerlin · 03-04-2010, 03:17 PM

DOH you take the belt off the gears after you have set the Engine at TDC. what part of this didnt you do???
OlT make sure the damper is put back on the correct way so you can read it while looking at the engine

jim ross · jim ross's Garage

Quote:

Originally Posted by Mrmerlin

DOH you take the belt off the gears after you have set the Engine at TDC. what part of this didnt you do???
OlT make sure the damper is put back on the correct way so you can read it while looking at the engine

I never removed damper..just the oil pump, i was hoping not to disturb timing belt..but after removing oil pump gear the belt slackened and belt came off. and i guess the cam gears moved. I have never set the belt timing before, so its new territory for me. kinda scary, but looks simple in manual!..its just the manual is in black and white and pix is grainy. i need to know what position exactly the pionter needs to be pointing to for true TDC.if i line that up..as well as the cam gears with thier marks and replace the belt she should fire right??

morriss · 03-04-2010, 04:10 PM

My gear was old and brittle, and like everything else on my 928, it seemed to be welded on and did not want to come off. You'd think the car was kept near the coast with the way every part seems to be seized in place.

Quote:

Originally Posted by jim ross

whoa..i dont want to crack my gear....perhaps i should let the shaft soak with penetrating oil for a while first? good improvisation on using TB to hold gear!..i DIDNT buy the $100+ porsche gear holding tool, but found a similar tool at harbour frieght for $9.99!

jim ross · jim ross's Garage

yah, i got lucky...i soaked the shaft and nut with PB buster penetrating oil and everything just literally slid right off! no puller needed or gear holder needed! and the gear was steel too!..i just ignorantly thought i could do this without messing up timing belt..yah right!..so now im trying to figure where exactly to set cam gears and harmonic balancer marks (TDC?) and reset belt and start her up!!

morriss · 03-05-2010, 04:38 AM

Quote:

Originally Posted by jim ross

yah, i got lucky...i soaked the shaft and nut with PB buster penetrating oil and everything just literally slid right off! no puller needed or gear holder needed! and the gear was steel too!..i just ignorantly thought i could do this without messing up timing belt..yah right!..so now im trying to figure where exactly to set cam gears and harmonic balancer marks (TDC?) and reset belt and start her up!!

Not hard. Use the 21mm deep socket to turn the big bolt clockwise until the pointer lines up with TDC (0 degrees) on the hb (16 valve). Then the cam gears have notches on the back of them that line up with the pointers on the covers behind the gears. When routing the belt you'll probably have to rotate the cam gears one tooth clockwise, put the belt over the gear, then tighten by bringing the gear back to position. This takes up the slack in the belt, which then allows you to slide it over tensioner roller.

jim ross · jim ross's Garage

Thnx! sounds easy enough....ill give it a go!-J

jim ross · jim ross's Garage

THNX for all your help guys!..i followed suggestions and...she fired right up! SO EASY! i had just never done the timing before..and sometimes the unknown scares me when it comes to working on my 928! NOW im cool with it, and will always feel more self sufficient. thnx ya'll!-J