Login Register Sign up for the GRM e-newsletter

Login to post Forums » Grassroots Motorsports » Changing cam seals
  • Klayfish

    May 10, 2011 11:29 a.m. Klayfish Reader

    I'm getting ready to try to change the front cam seals on my '76 Fiat Spider. The car also has an auxilliary drive that has a seal, and I plan to change that out. In reading through the Spider forums, people mentioned that changing the cam seals in these cars is very similar to doing it in other cars. My challenge is that I've never changed any seal in any car. Everything is new to me. When I bought the car, my experience consisted of oil changes.

    If changing the seals in the Spider is a lot like other cars, I figured I'd ask the GRM collective. Does anyone know of a good write up and/or video of how to do this step by step? Kind of like a "Changing cam seals for Dummies" edition? Any tips/pointers you care to share for a total novice would be awesome too.

  • Dr. Hess

    May 10, 2011 12:02 p.m. Dr. Hess SuperDork

    Some pics would be helpful. I recently changed the cam seals in my Esprit. I drilled a small hole in the seal, screwed in a slide hammer dent puller, pulled the seal out. The new one went in with a large socket to drive it. Be careful not to damage the new seal on anything sharp.

  • Jerry From LA

    May 10, 2011 12:12 p.m. Jerry From LA HalfDork

    +1 on the above. It's easy to do on a FIAT twincam. Just be careful you don't nick the cam / auxiliary shaft. In this case, a sheet metal screw and a claw hammer will work just as well. Thread the screw into the hole a couple of turns, then yank the whole deal out with the hammer claw.

  • Klayfish

    May 10, 2011 1:21 p.m. Klayfish Reader

    Cool, thanks for the pointers.

    I was also hoping to get pointers on the steps before I actually remove the seals and put the new ones in. Any tips/pointers on accessing the seals? I know I'll be removing the cam wheels, but is it as easy as just taking the timing belt off and unbolting them?

    This is the best picture I could find of the car showing the engine bay. The timing belt is now on. Obviously, the engine isn't in "running" condition at this point. Once I change the seals, I plan to reassemble and try to get it running. Also adding a picture from a different angle. It's from my other Spider, which is also a '76 so it's exactly the same.

  • Jerry From LA

    May 10, 2011 2:16 p.m. Jerry From LA HalfDork

    To loosen the cam nuts, I put a bar through the holes in the cam pulleys and jammed the bar against the head. The cam pulleys are not held on with a whole lot of torque so you should be able to break them free relatively easily.

    Don't let the cams stray too far from their timed positions. Otherwise you'll strike a piston with a valve and bend the valve.

  • Dr. Hess

    May 10, 2011 2:33 p.m. Dr. Hess SuperDork

    Per the Lotus shop manual: Bring the motor to TDC on #1, remove the belt, back the crank off 90 degrees. This drops all the pistons to half way down the hole. You can then do anything you want to the cams/timing and not run the valves into the pistons. I see your belt is off already, so be careful and don't force anything when turning the motor or the cams.

    A small 2 or 3 jaw gear puller will work wonders getting those pulleys off. Put the grabber arms through the holes in the puley, not grabbing on the outside.

  • Klayfish

    May 11, 2011 6:48 a.m. Klayfish Reader

    Dr. Hess wrote:

    Per the Lotus shop manual: Bring the motor to TDC on #1, remove the belt, back the crank off 90 degrees. This drops all the pistons to half way down the hole. You can then do anything you want to the cams/timing and not run the valves into the pistons. I see your belt is off already, so be careful and don't force anything when turning the motor or the cams.

    A small 2 or 3 jaw gear puller will work wonders getting those pulleys off. Put the grabber arms through the holes in the puley, not grabbing on the outside.

    Thanks for the shop manual info. That picture was actually taken when I first got the car. I actually put the belt back on as one of the first projects, to see if I could turn the motor by hand. So the belt is currently on.

    When you say back the crank off, you mean turn the motor 90 degrees backwards (by hand), correct? Also, if I do everything correctly, the cams shouldn't move much. So theoretically when I'm done I should be able to turn the crank forward 90 degrees back to #1 TDC (not forcing anything obviously) and put the cam wheels back. At that point, I should be fairly close to having everything lined up right and only need some minor adjusting. Correct?

  • Dr. Hess

    May 11, 2011 8:40 a.m. Dr. Hess SuperDork

    Yeah, turn it to TDC, then remove the belt, then turn the crank back 90 degrees and the pistons will all be at the same level half way down the hole and anything you do to the cams/valves won't hit this pistons. You may not have to do that, but it's a neat trick to keep in mind. Then, when you're all done with whatever you're doing to the top (re-shimming the valves in the Lotus case), you put the cams back to the TDC timing position, turn the crank back to TDC and put the belt back on.

  • Jerry From LA

    May 11, 2011 11:17 a.m. Jerry From LA HalfDork

    The pulleys should come off easy without a puller. If not, a little penetrant should get 'em off. IIRC, the timing for this motor is actually when number 4 is at TDC of its compression stroke, not number 1.

 
Tire Rack- Revolutionizing Tire Buying

You'll need to log in to post.