I'm going to pull the cam housing on my OHC and I've been reading up on the whole process. Couple of questions for anyone who has done this before. The entire process seems like it requires a near sterile environment.
1. Since I have to remove cam sprocket, how do I go about getting the tension right on the timing belt? The service manual references a special tool, but gives no specs for the tension... Any recommendations on tools/specs would be appreciated.
2. Anything special to do about the lash adjusters? From the service manual, they seem to be pretty delicate so I'm hesitant to fool with them.
3. cleaning the cam housing? It is worth cleaning the cam housing while I have it off? Any tips there since cam rides in the housing.
You don't have to be any more sterile than opening up the top end on a pushrod V8. You don't want crap getting into either system. I have to ask, why are you pulling the Cam Housing?
WRT the belt, you want it snug, but not overtightened. Someone said you should barely be able to twist (by hand) the belt 90 degrees. You will easily be able to push down on the accessory drive to get it there. No prying is required. I have also heard to use a belt drive Harley as a guide. i.e., make it about that tight. Good luck.
One word of caution (well, maybe several) when you start messin' with all the stuff under the cam housing. Put everything back where it came from position-wise: Lash adjusters, rockers, you name it.
Hokie is right about the belt tension. Of course you'll have to loosen the bolts holding the accessory housing to get enough tension off the belt to get it off the cog. This means you will most likely have to replace the two housing gaskets.
If you're going to have it all apart you may as well give the lash adjusters a good cleaning. Follow the proceedure in the Service Manual. They aren't complicated, you just want to keep everything clean. When you have them all reassembled do not fill them with oil. Put them in dry and let the oil galley pressure do that.
When you put the new cam cover gasket on, be careful as they are fairly thin. Be sure to follow the spec's on torqueing the bolts in an alternating pattern.
All this is just skimming the surface of things to do and not do when pulling the cam cover as it is not a task to be considered lightly. The only reason I can think of to justify removing it is to correct a known or strongly suspected problem, such as unusual noises, leaks, or poor performance.
I'll retest again this weekend, but I've got water in my oil and enough positive pressure to push it out the filler tube. Pressure tested and it looks like cam cover gasket. Read through the service manual several times already about pulling cam cover.
Thanks for tips about belt tension and cleaning of the lash adjusters.
Was a bit worried about the belt tension because cam is riding in the housing. Bit worried about sterile environment because the lash adjusters seem pretty sensitive.
Its actually one of the easiest cam belt replacements there are. How have you been able to determine that the head gasket isn't blown? That is what would come to mind if I found coolant in my oil. Obviously if the head gasket is blown, the Cam Cover is the first to go. BTW, check with NAPA when it comes to the gasket set. It is listed under "valve cover" or something similar. They (Napa) are the only ones I have found to have said set.
As Mike and Marc stated mixing and matching cam followers and/or lash adjusters will get you in trouble real quick. E.g., don't fix it if it isn't broke.
If it was mine, I would go for the easy fix first(i.e., cam cover gasket with new timing belt). If that doesn't do it, time to rebuild the top end. Bottom line, I wouldn't be playing around with a hybrid of those two.
I would love to help you but we are on opposite coasts. Trust me it isn't that hard of a job. BTW, the NAPA kit includes the accessory drive gaskets and the cam cover. As stated earlier, you will need those as well.
I actually found a tension adjusting tool at Carlisle PA swap meet a few years ago. The guy didn't know what is was and said take it for 5. bucks.... It looked liked the one in the book and was the exact same number... I have it hanging on my OHC art wall. Just make it tight so it feels good... I am running the original belt on my OHC 6 with 88,000 miles....Enjoy the car I have Two...
69 RA III T/A Auto 69 Sprint vert 3speed 69 350 coupe 69 350 HO 4spd
I saw one of those tensioning tools on ebay. I wish the service manual just had PSI range, then I could have just built a jig and used my pressure sensor...
I'm ready to operate when the belt arrives. Will do more testing though on leak and might a well pull the radiator while I'm at it.
The engine is pretty much original with a few missing parts here and there like screwed up manifold heat control valve and some missing and incorrectly replaced bolts. I guess this is an opportunity to correct all those issues!