I started working on my 1989 GMC Safari to repair a coolant leak from the water pump interface to the block. Saw that the original crankshaft oil seal was leaking a good bit so I removed the timing cover. On the tension side the chain is pretty tight, but on the nontension side, I can wiggle about 3/8" of slack. The teeth of the sprockets look pretty good but the van has 165K miles. Is there a tolerance on chain slack? My Haynes/Chilton doesn't call one out.
Thanks!
Barry