1998 V70 Removed cam gear to R&R seal w/o marking position

caldwj · Post by **caldwj** » 15 Nov 2014, 13:51

Ok, I just did a bone head move. My son and I pulled the head on his '98 V70 and had the valves and seals redone. The head's back on the car w/o any problems. We put the cams back in, replaced the valve cover and replaced both rear cam seals. So far so good right? Our next task was to replace the front cam seals. Keep in mind the cams have not been positioned to the marks yet. Without thinking I pulled the front cam gear and replaced the seal. Simple task with the homebrew PVC insertion tool outlined elsewhere on this site. In one of those infamous "oh crap" moments I now realize the cam gear has NO MARKS to give me some clue as to the position it should be set in. I get (3) possible guesses, only one of which is right... nope wrong approach, time to make a post to the forum, admit blunder, welcome laughter and hopefully recover w/o killing the valves. I've got the intake manifold off still. Can I put the cam gear back on, index the cam till I can see the #1 intake valves are closed, then remove the cam gear and reposition it w/ the timing mark at the correct position then bolt it in place? Any assistance appreciated.

Post by **cn90** » 15 Nov 2014, 14:24

- From the REAR of engine, line the camshafts by the book.

- From the FRONT, line up the cam sprockets so that the marks on the cam sprockets line up with the plastic cam cover.

- The issue of "advanced" or "retard" was also mentioned in that thread I wrote a while back. You will have to figure out where to place the slots before tightening the cam 3 bolts.

caldwj · Post by **caldwj** » 15 Nov 2014, 14:43

OK, not sure I understand your reply. The exhaust camshaft and gear are as they were when I broke the head down (so was the intake cam before I removed the gear w/o marking it's position on the shaft). If I rotate the exhaust cam and align the mark on the gear with mark on the cover, the exhaust cam will be in the TDC position. I removed the intake cam gear w/o positioning the cam to TDC when putting in the new front cam seal so I have no idea where the intake cam is in rotation.. I can turn the cam w/ the gear bolted on until I have continuity w/ the #1 plug wire on the distributor. This should get me within a degree or so of the TDC position. From there, I would need to remove the cam gear and reposition it so the mark on the gear is aligned w/ the mark on the cover, then bolt it back on. Is this OK or is there another preferred way to do this so as to identify TDC for the intake cam?

Post by **cn90** » 15 Nov 2014, 15:18

You need to remove the CPS and cap/rotor. Then align the rear of the engine as shown:
Volvo 5-cylinder: How to Replace the Head Gasket
http://volvospeed.com/vs_forum/topic/14 ... nd-timing/

The bottom line is:
- INTAKE slot is above the groove.
- EXHAUST slot is below the groove.

Now go back to the front and there is only one way the cam sprockets can fit (w.r.t. the 3 holes on the cam shafts).

Post by **erikv11** » 15 Nov 2014, 16:00

Presumably, the crank still on the mark, from the head work? If so, then ...

- Align the cam slots parallel as described by cn90. For rotating the cam(s) you can put the sprocket on temporarily in any orientation, just get those slots perfectly aligned.
- Now, go back to the front of the cams. The sprocket can fit on three ways, but only one of them will align the timing mark in the notch in the plastic cover. Choose that one. Get the mark as close as possible, then tighten them down. Make sure the cams didn't move during the process, they tend to.
- Proceed with assembly: install timing belt, etc.

caldwj · Post by **caldwj** » 15 Nov 2014, 16:46

Ahhh, light blinking on now....I didn't know about the cam slots aligning with the parting line between the cover and head. Everything's lined up now and the cam gear (intake side is back on) correctly positioned. Thanks all for the input and assistance. BTW, story here is this is my daily driver passed down to my 16 year old son. It's got 336K miles on the original engine. We decided to do a rebuild as a father / son project. The cars not worth anything, but for a few bucks and lots of weekend labor we've gone thru everything and someday I'm sure we'll both look back at how valuable the car really was. As the original post suggests we're closing in on completion. Todays lesson to my son was "if you're not sure, ask. It's cheaper than really screwing something up". Thanks again!