My truck is a GMC 2003 Sierra 1500 4.8L. it has 115k on it I replaced the water pump, thermostat, clutch fan, rack and pinion, and did a coolent flush. As well as oil, filter. Looking at having transmission fluid and rear def(?) Changed soon.

Question is when should I worry about the timing chain? And are there any other things I need to look into.

she has been a great truck so far.
Thanks

 

Im at 204000 miles and the timing chain is the last thing on mult mind.

 

My old sierra had 258k on the stock chain and everything else, never once crossed my mind for replacing.

They rarely if ever need replacement. Seen several work vehicles and vans with 300k+ on the stock engines.

 

How much shipped for the 115k mile water pump? Please tell me you didnt throw that low mileage oem jewel away lol.

I would leave the trans fluid alone IMO. At 15 years old, im still using the original coolant too. Just changed rear diff fluid at 200k

 

Water pump was weeping, that's why I replaced it. And yes I throw it out.

 

on a stock hp vehicle I wouldn't really be worried about it. if you were going to do a cam swap then i would say you should. no reason to break the timing cover off especially if you aren't ready to pull that harmonic balancer!!

 

I got a WP with 205K miles on it you can have for cheap. 2004 Yukon LQ4. What is your def of low miles?

 

I don’t know exactly what year GM started validating the timing chains for 200,000 miles, as they have since the introduction of the LS2 style timing chains & tensioners, but never-the-less, the days of stretch prone link-belt chains and disintegrating nylon teeth falling off the timing gears are a thing of the past and for normal daily use, would be one of my least concerns.

 

Thanks folks