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Old 04-15-2013, 02:15 PM
FYVMMF FYVMMF is offline
Join Date: Mar 2013
Location: Onset MA
Posts: 36
Originally Posted by svengruber View Post
"IP indicator blade is visible and centered, install the locking tool" - Is this done by looking through where the plug was removed in step #9? If so, is it doable with the IP still in the car (having a hard time imagine getting my head down there...)?

"Once out of the engine you can disassemble the timing device itself and swap your good rotating cam into place for the damaged one. Then you can reassemble everything in the reverse order lining up the paint markings on the timing device sprocket and the timing device thereby avoiding any timing alteration issue." Looking at the timing device, it doesn't appear it is easily dissembled. The entire timing device to include the cam/lobe appears to be pressed fit (no bolted connections, etc.). How would I go about swapping the whole timing device?
Yes, the IP bolt removed looking into the hole, most people use a mirror to get the best look.

I don't have a later model timing device at hand but the 86/87 vintage devices had two bolts from the rear of the device that held everything together.

If you need to swap the entire device the process is more involved in that the FSM describes removing the IP from the engine, then installing the timing device onto it and then installing both into place together. Of course that requires more work and parts removed to get the IP out.

The problem with just swapping timing devices from the front is there is a fixed relationship between the timing device's chain sprocket and the splined hub where the IP mates to it. When the IP/Timing device is installed as a unit the IP/Hub interface is fixed and locked by the IP locking tool, the chain is placed into position with no slack on the bottom between the timing device and the crank sprocket and once the timing device is in place the cam sprocket is returned to its fixed position the tensioner is used to remove/tighten up any slack in the chain run and the critical relationships between pistons, valves, and start of delivery is maintained.

When and if someone tried to swap timing devices it would be more difficult to while maintaining the correct timing device sprocket/timing chain position, to get the timing device hub/IP camshaft nose position correct, because of where it is and the lack of any reference marks at that interface. The spined hub/nose interface is numerous small splines so it is easy to get it off a spline or two in either direction. That is usually not much of a problem because the IP can be adjusted a bit in either direction. If you or the mechanic doing the job is comfortable potentially retiming the IP then that may be the way to go.

The rotating cam swap avoids the timing issue by using the same sp;ine/sprocket and establishing the reference marks prior to disassembling things, but if you can't swap the rotating cam it won't do you any good.

If you do end up removing the IP for any reason, get a new large O-ring that seals it to the block, often times once the original is disturbed it will leak quite a bit of oil and you'll eventually want to replace it necessitating complete removal of the IP again to accomplish that. With a new O-ring oil it and both the contact surfaces so that the rubber doesn't bind in place against the metal faces on either side of it when the pump is positioned and a leak develops as a result. If you have any of the gaskets on the IP itself leaking there will be no better time to renew those than when the IP is on the bench.
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