6.2 Timing chain replacement procedure

[TrenchFoot]

First off, I'd like to apologize for asking something that's probably been asked 100s of times before. I dug around the boards but came up more confused than before I started.

I am working to prep my 6.2 for my Jeep Wagoneer conversion and would appreciate some help with the correct procedure for replacing the timing chain. The engine came out of a 1993 P30 Step Van and is a 599 block (V belt) with 100k miles on it when it was pulled.

I am about to pull the injector pump, water pump, harmonic balancer, and timing chain/gears. From reading the Haynes manual, pulling the IP doesn't require worrying about specific timing, other than not rotating the engine after pulling it. I plan to static time by the marks on the IP housing then have my local dealer dial it in after the swap.

For replacing the chains and gears, the manual specifies a complex procedure for finding TDC. It seems to me that if I line up the gear markings and ensure that #1 is not on the exhaust stroke, I should be OK without breaking out a dial caliper.

The questions that come to mind:

Can this be done without taking off the valve covers?
Do the timing chain gears need to be swapped on a 100k engine?
Do I really have to worry about rotating the engine after pulling the IP (is this only relevant if I roll it a full turn or more)?
Can someone add some clarity to this procedure or point to a writeup somewhere?


Thanks in advance for any help.

[DmaxMaverick]

Welcome to the Forums!

No worries here. You really can't do it wrong, with the marks lined up. The pump has a dowel pin, and the gear has a hole for it (it won't fit wrong). Start at TDC before balancer removal, then return it to TDC when it's back on. Set the sprocket timing like with any V8. If the dowel/hole are 180° off, rotate the crank to TCD again. You will have to rock the crank a little to line up the pin, most of the time in any case. Take notes (and pictures) during disassembly, and reassembly should be a walk in the park.

[TrenchFoot]

Is the best way to find TDC is to use the timing marks on the gears and watch the exhaust rocker on #1 to ensure I'm not on the wrong stroke?

[DmaxMaverick]

The stroke doesn't really matter, and you don't have to remove the valve cover. Put it back like you found it, and it'll all line up. Once the water pump and timing cover is removed, line up the timing marks on the sprockets and gear before removal. That will be your true TDC, and you don't have to know what the rockers are doing. Keep it simple.

Also (forgot to add earlier), you don't normally need to replace the sprockets at 100K. Unless they look like they need replacement (chipped/missing teeth, crack, etc.), reuse them.