Has anyone ever removed driver side upper timing cover?

[Drake57]

Said cover holds the tensioner for the driver side timing chain, driver side upper timing cover removal procedure directs removal of tensioner before DSUTC is removed.

1994 FSM states that the chain will not slip timing unless (lower) timing cover is removed. See page EM-14, #16. This statement refers to the stopper. It seems the stopper is a device to prevent timing slippage when tensioners are loose for whatever reason, although the statement about stopper need not be used is puzzling.

My concern is avoiding timing slip when the driver side tensioner is removed. I'd like to believe the FSM, but also welcome the benefit of real experience and knowledge. Any cautions are welcome. I suppose I could mark the sprocket, chain, etc before removing the tensioner for peace of mind.

PS is crankshaft sprocket more likely to slip? It would seem so since circumference is a linear function of diameter.

Thanks, Drake.

[Q45tech]

Always tie wrap the chain as INSURANCE!

[Drake57]

Thank you for the warning. I see the tie wrap in the TC guide replacement pictorial, and I will do so if possible, but I had not planned on removing lower timing cover, and I'm not sure it's possible to place a tie wrap with the LTC installed.

[Q451990]

I don't think it's possible to replace the guides without removing the lower cover. Not to mention, you will want to change the oil pump chain and guides as well... and it's absolutely impossible to do do without pulling the lower cover.

Heath

[Drake57]

Well thanks, but my engine has already had guide replacement. My problem is an oil leak, I think where the driver side upper timing cover meets the lower timing cover. The long version is I f'd up my head gasket extensions when reinstalling lower tc, resorted to rtv only, now I have an oil leak.

Right now I'm using a dye to try to pinpoint the source of the leak. It's not easy to find the source.

If necessary, I think I'm going to have to remove ds valve cover and DSUTC to reseal the joint between upper and lower timing cover.

I think it is safe to remove the tensioner, but I plan on marking chain and sprocket to be sure slippage does not occur.

Thanks aagain, Drake

[cientortas]

I wonder if removing the driver side valve cover and securing the chain around the cam sprokets with zip ties will be enough. At that point it may be secure enough to remove the driver side tensioner and then the driver side upper front timing cover. Thoughts?

[Drake57]

It's necessary to remove DS tensioner before DSUTC is removed - tensioner is installed in DSUTC. I think the stopper cast into the lower TC will keep the chain from slipping on crankshaft sprocket. I'm not sure there is any space or place for zip tie before DSUTC is removed - I somewhat doubt so.

What I'd like to do is to remove and reseal upper TC *without* removing lower TC. I'd like to know if there is real risk of timing loss when tensioner is removed.

Thaks, Drake.

[maxnix]

Yes, hence the zip ties and rechecking your marks.