I finished my timing cover replacement as well. Pretty much a bolt-together operation. As MJ says, the gasket is sensitive - I overtightened and when the job was all over had a small ooze of oil on one corner of the cover. I also think I may have slightly warped the new cover when first fitting it, it hung up on an alternator
support bracket. I'd recommend removing the bracket before trying to refit
the cover. Adjusting bolt tensions didn't help in my case (that's why I think it's warped), a dab of Permatex cleared it up.
I bought a 1 1/2" socket to remove the front pulley, only to discover that the nut was hardly tightened at all. Torqued as recommended when replaced. FYI if anyone has trouble finding a properly sized socket locally (I did at first), most of the auto parts
stores have then or can get them. Discount stores also carry a low-cost wrench/spanner in 1 1/2" size in their trailer section, used to tighten nuts on trailer hitch balls.
The front crankcase seal must be carefully pressed into place, I did it with the timing cover off. Once everything was reassembled I ran the engine briefly without the crankcase pulley attached to check for leaks, only to learn that the front seal doesn't seat properly unless the pulley is in place - one I put it in place, no seal leak.
On the raw water pump alignment, I rented the special alignment tool (since I was replacing the timing cover I knew I'd have to remove the pump mounts) but found I couldn't use it. Turns out the 4.108 used two raw water pumps, Jabsco
and Sherwood. MJ's photos show his engine uses the Jabsco
, and it has the adaptor plate between the base of the pump and the timing cover. This is the plate that needs alignment, the central hole in the plate is just big enough for the pump key to pass thru and so must be perfectly aligned with the timing gear
My engine uses the Sherwood pump, which has a wider base flange than does the Jabsco pump. This flange takes the place of the adaptor plate, and so there's no central hole to align. I did do the alternate alignment procedure described in the owners' manual (turn the engine over a few times before tightening down the bolts holding the pump).
I installed a new raw water pump, the old one will be rebuilt and maintained as a spare.
So far in about 2 hours of test runs under load at the dock
everything is running well with no leaks. I'll continue to monitor
as I begin to run the boat under cruising conditions out on the water.
Biggest engine job I've every tackled. Appreciate the tips I got here.