Porsche 944 Camshaft Gasket Replacement Procedure

THE WHY

The trouble with fluid leaks is that it often takes some work deducing what fluid is leaking (water, engine oil, brake fluid, power steering fluid - to name a few) and where it is coming from. Having previously cured and therefore eliminated two fluid leaks on my 944 (power steering reservoir bottle and one from the OPRV Oil Pressure Relief Valve area) I was determined to get to the bottom of the next one. In this particular case unlike the previous fluid leaks (somewhere above the removable engine floor pan) this one was clearly coming from the rear of the engine and making its way down the back of the grilled engine sump. Being the middle of the week I thought I'd make a post on the Pelican Parts forums to see if anyone had some ideas as to where I should be looking. The response was fantastic.

THE TASK

10mm Socket
Small/Medium Socket Ratchet
Small/Medium Torque Wrench
Multi-purpose engine grease
800 Grit Emery Paper
Degreaser
Camshaft Gasket ( Part No. 9281058902 )

THE HOW TO

(Amateur mechanic job time approx: 1-2 hours)

Here's the picture I posted to the Pelican Parts forums, you can see the dark oily trail down the back of the grilled sump.

As I said earlier the response by the board members was fantastic and if you read the post it seemed pretty clear the oil was coming from one or more of four possible places.

The possibilities were:

A.) The cam gasket housing
B.) The lower balance shaft plug o-ring
C.) Balance shaft housing to block sealant
D.) Oil pan gasket

Judging by the discussion, possibility 'A' was the first thing to check after having taken photos of all the surrounding areas. Apparently the gasket is made of cork and doesn't have particularly long lifespan. Here's a picture to show the culprit area.

The cam gasket sits between the cover and the main head block at the back of the engine bay (circles below).

The easiest way to check if it is leaking is to get you fingers under the lowest edge of the cap and check for oily matter running down the back of the block. If like me you find some then wipe it dry and then give the car a good drive before you check again. If the oil has returned you know the gasket needs replacing.

As per a suggestion on the forum I followed the description on Clarks Garage (right at the bottom of the article titled "Rear Cam Housing Gasket Replacement)

Removal of the cam gasket and cap is fairly straight forward and involves undoing 3 x 10mm bolts, the lowest one is a bit difficult to get to so you will probably need a small 10mm socket and ratchet. With the three bolts undone and a little wiggle the cam cap and attached engine hoist loop will come off in your hands.

As you can see from the following two pictures there is a clear amount of oil present on the lower edge of both the engine hoist loop and cam cap cover.

(Engine Hoist Loop)

(Cam cap cover)

Now turning the cap over shows the charcoal-like remains of the cork gasket itself

Without scratching the metal surface of the cap try to remove the old pieces of gasket with a blunt object like a plastic scraper or bicycle tyre lever.

Next I cleaned up the cap with some degreaser and then laid down some fine 800 grit emery paper on a flat surface and lightly rubbed the flat mating surface of the cap to remove any fine pieces of gasket and dirt.

Here's a picture of the new OEM gasket from Porsche.

And here it is alongside the cleaned-up cap

Now take a small amount of engine grease and lightly coat one side of the gasket before aligning it on top of the cap. This helps create a good seal as well as aiding the re-installation procedure.

Next I cleaned up the surface of the engine block with some blue tissue paper making sure there was no old bits of gasket, oil or dirt.

Before installing the cap make sure you apply some more grease to side that will pressing against the block as well as remembering to attach the engine hoist loop. Do all three 10mm bolts up to finger tightness and then STOP.

This bit is very very important. The bolts must be correctly tightened using a torque wrench to 8 Nm (6 ft-lb). This is very important to make sure the cap seals evenly all round. Again I would suggest you get yourself a small/medium sized torque wrench as the bottom 10mm bolt is very awkward to get to.

And finally a picture to show the finished result.

How To Remove And Replace Porsche 944 Transmission Drive Axle Seals

THE WHY

If you're experiencing an oil leak coming from the rear of your Porsche 944 then it is probably coming from the transmission/gearbox's oil filling plugs (there are two) or more likely one/both of the drive axle seals (one either side where the drive axle meets the transmission). Other symptoms include harder than usual shifting or transmission whine due to lack of transmission oil. Having replaced the filling plugs for new ones at the last gearbox oil change it was pretty easy to trace the black greasy patch on the underside of the transmission to both the drive axle oil seals - they simply needed replacing.

THE TASK

I used the following:

8mm Spline Bit
8mm Hex Socket
17mm Hex Socket
Socket Ratchet Spanner
Torque Wrench
Socket Extension Bar
Small/Medium Heel Pry Bar or Seal Puller Tool
Seal Press or 38-40mm socket
Rubber Mallet
2 x Radial Shaft Seals (Porsche OEM Part number 016 409 399 B)
1 x Large Zip Tie or Length Of String/Rope
Spray Degreaser
Oil Drain Pan.
Stiff Scrubbing Brush
Axle Stands
Trolley Jack
Swepco 201 Gear Oil
Anti-seize thread lubricant
White Spirit
Karcher Powerwasher (optional)


THE HOW TO


(Amateur mechanic job time approx: 2-3 hours).

Start by raising the rear of the car and support on axle stands (the higher you can get the rear off the floor the easier the job becomes). As you can see from the photos below the seals on mine were leaking quite badly from both sides.

Depending how badly the seals have been leaking now might be the time to give the transmission underside a blast with the powerwasher and degreaser. The purpose of this is it makes the job a lot less messy and enables you to check for leaks once the job is complete.

Now follow my tutorial on how to remove the transmission oil, you will also need to refer to this when it comes to refilling the transmission once you've replaced the seals.

With the oil drained it's now time to remove drive axles where they meet the transmission. Start with the one that isn't under the exhaust (shown below) as it is the easier of the two and is a good way of getting a clear idea of what needs to be done when you start the slightly obstructed exhaust side.

To release the drive axle you need to undo 8 x 8mm spline screws. Make sure the spline bit goes in straight and not at an angle otherwise you risk rounding off the spline bit and probably the screw too. If you find it difficult to get a good angle on some of them then simply release the handbrake and rotate the wheel to improve the access.

With the spline screws removed you should now be able to move one end of the axle. Find a suitable place to hang the drive axle out of the way and cover the end with a plastic bag (this stops any grit getting stuck to grease in the universal joint).

The next step involves removing the flanged shaft. Start by poking an old screwdriver all the way through one of the empty spline screw holes, this stops the flange from moving when you release the 8mm hex screw from it's centre. Use a socket wrench with extension bar and 8mm hex bit to undo the centre screw as shown below.

Once the screw is removed the flanged axle should simply slide out. Give it a good clean and check there's no wear or rough areas on the axle near the flanged end.

Now we can see the large black coloured seal we are going to remove. I used a small heeled pry bar (or you can use a seal puller or other hooked instrument) to gently work around the seal and ease it out. Be careful when doing so as the blind side of the seal that you can't see contains and elasticated spring and it's easy to leave this behind in the transmission. Keep at it and the seal will eventually come out.

(Seal before removal)

(Blind-side of seal and elasticated spring)

(Seal removed)

Once removed it's a good idea to thoroughly clean the area so that no grit or muck enters the transmission when you come to install the new seal.

Here you can see the new seal (left) alongside the old seal (right)

You are now ready to install the new seal. Before you do so, take note of the small raised lip (see arrow below) that the new seal must press up against inside the seal hole. Now take a small amount of white spirit and lightly rub some of it around the outer edge of the black seal (this aids fitting and will shortly evaporate). Now press the seal squarely into the hole making sure the spring is facing in towards the transmissions internals. Now take a 38-40mm socket and a rubber mallet and gently tap the seal into place making sure it doesn't skew as you knock it in. Use your fingers every now and again to feel around the inside of the seal to see when it is fully pressed up against the lip on the inside.

Photo below shows a 38mm socket compared to the size of the seal.

And photo below shows the seal correctly fitted.

Now you can re-install the flanged axle and re-attach the drive axle shaft. You may also want to take this opportunity to refresh the grease in the CV joint at the end of the drive axle before reattachment.

Now all that remains is to repeat the procedure for the other side before refilling the transmission gear oil.