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Can you replace a cam seal without pulling all the timing covers?
Posted 05 February 2005 - 07:46 PM
I just got done with a relative nightmare of changing a cam seal. It started out simple enough, within 15 minutes I had the timing cover and cam gear off.
At that point, I could see that the cam seal was in bad, bad shape. it came out in my hand, and basically consisted of a metal ring with little bits of rubber stuck on it.
However, I found the housing refused to seperate. Hmmm. After two hours, in desperation I turned to increasingly large prybars, and ended up SHATTERING the housing, with it still refusing to come out.
At that point, I went about removing the entire passenger side camshaft housing. I had suspected that oil starvation had ground the housing and cam up so bad that they were now welded.
After a trip to the u-pull-it, I got a replacement camshaft and housing, along with a cam seal housing. Since I had procured a replacement, I took a hand sledge and started beating on the back of the cam to force the stuck housing out the front. It took several minutes of beating the piss out of it before it gave.
What I saw was absolute carnage of the bearing surfaces. Everything was scored beyond belief. It is obvious that the oil being kicked out of the fron seal was starving that head, and the bearing surfaces had been eating themselves as a result. This is a GOOD reason to not delay in fixing the seals!
After getting the new cam and housing in place, getting the timing belt back on was a piece of cake. I hadn't even taken off the alt of power steering belts!
I had already mooved the motor to TDC with the passenger cam gear dot up.
With that done, all I had to do was pull the cover off the access holes for the tensioner bolts, loosen and retighten them with the tensioner out of the way, stick the belt on, then retension. This was simple. I rotated it 720* to make sure I had it right, and sure enough, it was spot on.
The drivers side should be the same way, but I didn't have to go there.
Keep in mind that I am not advocating changing seals without changing belts. I had just done timing belts on this car the month before (and the friggin seals were dry at that point, damnit) and so had no reason to change the belts, but had this happened a year (or perhaps as little as 6 months) from now, I would have probably changed the belts.
However, you can do it pretty easily by just pulling the cover off, if you really don't need to change belts.
At the same time, This goes to show why most people don't mess around, and change water pump, mickey mouse gasket, cam and crank seals EVERY time they do a timing belt. Makes sense. The other stuff costs about 70-100 bucks all told, and that is MUCH less than my time wasted in "not doing it right the first time" today!
Learn from my goof! And don't run a motor with a bad cam seal unless you hate your valvetrain!
Posted 06 February 2005 - 12:24 AM
guess I know what I'll be doing next time I'm under the hood :-\
thanks for the info!
Posted 06 February 2005 - 02:15 PM
When I first noticed the leak, I was planning on doing what I do with most oil leaks- checking the oil every few days and adding as needed until spring comes around.
What I didn't realize is that the oil behind the cam seal is not leaking from the return side, its leaking from a supply side.
Plus, once it starts to leak, it is going to make itself worse and worse, as the seal will continue to shred itself. At first, its going to aereate the oil in that head, and as it gets worse the head will get less and less in the way of oil.
As a result of the leak, I found...
1. Cam seal housing completely stuck with the cam on the bearing surface. It would not break free of the cam even with a prybar applying enough force to break the housing in 3 pieces. The bearing area of the seal is still stuck fast to that cam.
2. Destroyed camshaft housing. The journals looked like somebody took 40 grit at 30,000 rpm to them for 8 or 9 hours. Heavily, DEEPLY scarred/melted. I don't know why the camshaft hadn't siezed.
3. Camshaft with trashed bearing surfaces, looking like the counterparts to the above.
4. Chewed up rocker arms. Not so bad as the camshaft, but they all showed heavy wear and had rough areas you could feel with your finger. I replaced them with ones I snatched from the junkyard.
5. Lifter tick- Before changing the seals, the lifters on that side would tick on startup for 15-20 seconds. I would also hear a faint tick once the car had got up to operating temp. That is now gone, even though the lifters have not been touched.
Posted 06 February 2005 - 05:05 PM
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