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Some fellow Forum members have recommended replacing the timing chain and associated gearing on L98 engines after approximately 100,000 miles. They claim that, over time, the chain stretches throwing off the cam timing. Moreover, with age there is the possiblity of chain failure which can have a catastrophic effect on various engine components.
My question being is this a legitimate concern and should I plan on completing this as routine maintenance? Also, I have read that the 96 GS engines have a special forged chain, as opposed to cast, and high strength forged gears with needle bearings. Will this set up work on an L98 engine? Should I just use OEM timing gear as a replacement or is there a better replacement option? ANY IDEAS?
At 100k, I say it's a good time. Here's my 100k chain. Slopping chain and the nylon on gear is cracked and missing pieces.
I replaced it with a cloyes street roller timing set. Reasonable price for a true roller chain.
I have 138,000 miles on my chain. I am a little apprehensive about continuing much longer with that plastic gear. I had a pickup with 154,000 miles with the plastic gear, and it was ok when I sold it, but the guy I sold it to I told to change the chain and gears soon.
I am guessing 140,000 is the max safe life that I would expect using sythetic oil as part of your normal oil change regime.
I have 205,000 miles on my 1987 L98, pressing the "Loud-button" frequently over the past 13 years. Recently I've started to experience symptoms of a stretch timing chain. So it is finally time to change it and the sprockets.
when you remove the timing chain cover and see the slop in that oem chain, you will see that your concerns were well justified. A double "true roller" timing chain with its associated sprockets is money well spent
when you remove the timing chain cover and see the slop in that oem chain, you will see that your concerns were well justified. A double "true roller" timing chain with its associated sprockets is money well spent
replaced my 85's with a cloyes double roller around the 110K mark. as I recall, around $60 at summit racing. while you're at it, replace the harmonic balancer (w/ GM service replacement), and the pan gasket with a one-piece felpro. triple up on the money well spent -
replaced my 85's with a cloyes double roller around the 110K mark. as I recall, around $60 at summit racing. while you're at it, replace the harmonic balancer (w/ GM service replacement), and the pan gasket with a one-piece felpro. triple up on the money well spent -
You mean the gasket for the oil pan, or the one for the crankshaft right behind the balancer? I've replaced my balancer but getting close to 100k and thinking of doing these other things.
Why cloyes?
What's wrong with the summit oe replacement?
I'm looking for opinions to buy the best timing set and ham balancer
nothing wrong with summit OE replacement. I selected cloyes based on past experience. for my harmonic balancer, just went with (GM) AC Delco thru my local dealer. (Bfenty) i'm referring to the oil pan gasket. I've never replaced the timing chain without re-doing the pan gasket. most will agree, the one piece felpro is top shelf.
Why cloyes?
What's wrong with the summit oe replacement?
I'm looking for opinions to buy the best timing set and ham balancer
whatever brand you decide on, get a "true roller" style timing chain; each round part of the link actually rolls on its own little axle as it engages the timing sprocket...if its not a "true roller" it may look the same, but lacks this feature.
dumb question but is the chain on the front or back of the engine? How hard is it to replace? Seems like it could be a tricky one...
Wow I didn't notice when it was started...talk about a necro thread. geez.
front of the engine behind the water pump. not so much tricky, as a fair amount of work - need to remove pretty much the front of the engine. with the harmonic balancer, as I said, might as well replace it while you're there. same goes with the oil pan gasket, and give consideration to the water pump if you're running an original. when I originally did mine, I replaced valve stem seals, injectors, plug wires, belt and hoses, and a host of other stuff. it's all considered project creep - you know, while you're at it, might as well take care of this, that, and the other....
front of the engine behind the water pump. not so much tricky, as a fair amount of work - need to remove pretty much the front of the engine. with the harmonic balancer, as I said, might as well replace it while you're there. same goes with the oil pan gasket, and give consideration to the water pump if you're running an original. when I originally did mine, I replaced valve stem seals, injectors, plug wires, belt and hoses, and a host of other stuff. it's all considered project creep - you know, while you're at it, might as well take care of this, that, and the other....
already did the balancer, it went bad on me. I need to do valve stem seals I think too, and yeah the oil pan gasket as well...why not just rebuild the whole dang thing (which I'm seriously considering, posted in another thread)
already did the balancer, it went bad on me. I need to do valve stem seals I think too, and yeah the oil pan gasket as well...why not just rebuild the whole dang thing (which I'm seriously considering, posted in another thread)
- now you're starting to understand project creep. owning a C4 is not for the faint of heart. you only need three things - a FSM, a decent tool set, and no fear. remember, it's just nuts and bolts, and pieces-parts. -
Timing Chain Replacement?
replaced my 85's with a cloyes double roller around the 110K mark. as I recall, around $60 at summit racing. while you're at it, replace the harmonic balancer (w/ GM service replacement), and the pan gasket with a one-piece felpro. triple up on the money well spent - 
- now you're starting to understand project creep. owning a C4 is not for the faint of heart. you only need three things - a FSM, a decent tool set, and no fear. remember, it's just nuts and bolts, and pieces-parts. - 