How do you know when the timming chain assy. needs replaced? Which should I use?
Vette is running fine but doing an 87k update.
Should I replace.
'84 vette.
What do my fellow members think?
tony

:chevy :chevy :chevy :chevy

 

:cheers: I wanna say .."when it breaks!"

But that's not what anyone wants to hear :D

I have never had to replace a timing chain on most of my cars with all pushing well over 200,000 miles on average(4 c.ars) But I did on my 82 Z28Camaro at around 120,000 miles.

I went with a Cloyes double chain and have put another 230,000 on it with no problem. My 85 has over 200,000 and has the original timing chain

It's not an expensive fix, so if it gives you piece of mind, do it

:seeya

:steering:

 

I'm going to replace my Harmonic Balancer with a StreetDamper, and a FlowKooler water pump. all at the same time. On my stock '84 vette.
Sound OK?
TONY
:smash:


[Modified by oldace84, 5:26 PM 8/15/2003]

 

If you are thinking about it- just do it. A new chain set is only $20. BUT to do it right you will need to remove the water pump and you might as well change that too while your at it. Then you have to take off the harmonic balancer while requires a puller. What most people dont know is that a hramonic balancer INSTALLER is needed to put it back on. I own one - a Snap-On, and its worth its weight in gold. Do not hit it on with a hammer no matter who tells you its OK. Not only can this damage the balancer, but it can also damage the rear main bearing. You will also need a gear puller to remove the old crank gear. Sometimes you will need to loosen the oil pan to remove the timing cover- sometimes not.

Im sure this sounds discouraging but timing chains do wear out. Will it break? who knows but a slacked chain will retard cam timing and your low end torque will diminish. Some stock GM timing sets have nylon coated cam gears- the nylon chips and cracks off and can clog the pump pickup as well as other orifices.

I have two rules when working on an engine; never llok at an oil pump without changing it, and never look at a timing chain without changing it. They are both too cheap yet too important to not replace.

 

i dont nessesarily agree you need a harmonic balancer installer... however, I do agree that hitting a balancer with a hammer is ALWAYS WRONG!!

to install a balancer just slide it on as far as it goes by hand then use the crank bolt to draw it on the rest of the way...


back on topic..

at 87k miles unkess you are taking the oil pan off for something i would highly recommend that you NOT replace the timing chain and gear set.. and this is why..

its a huge pain in the butt.. I have ran many cars well over 200k with factory timing chains.. also, when you change i, you will have to loosen the oil pan and drop it slightly to get the timing cover off.. when reinstalling this creates a huge potential oil leak.. and NOBOBY wants an oil leak..

besides an '84 L83 motor is not an interferance engine.. your timing chain can break and I belive it wont mess up your valves.. it will jsut run like poopie... actually it wont run at all.. and THATS when you put a new one it!

happy trails tony

 

Two points: 1. you do NOT have to drop the pan to put on timing chain. I have done it. It's a bit of a chore, but less so than dropping the pan. 2. The 84 engine will self destruct if the timing chain goes. Pistons and valves get together, they bend push rods. This would be less of an issue with all metal sprockets, but on the 84, 85 and 86 (I think) they have a nylon coating that wears out and the chain spins.

Bottom line is even if someone did get 200k on a timing chain, it doesn't mean that you will. So just do the math: $20 chain set or $1500 engine, which do YOU want to replace?

BTW, I had to learn this lesson the hard way. But one time was enough.

 

Make sure to get the whole set. Your vette probably has nylon cam gear teeth like my 85. The double roller chains are pretty cheap too from summit.

You'll need a new front main seal, get the sleeve n' seal kit just in case.

I pulled the oilpan to do mine, and used a one piece felpro oilpan gasket, it works like a charm. It also gave me the chance to check out the bottom end.

Never "had" to replace one? WTF does that mean? Never "had" to rebuild your entire motor you mean? There's no way to predict timing chain failure, so you might as well replace it every 100K or so, if not sooner like 60K.

There's a reason we sell all our old jetplanes to foreign countries. These sorta things are ENGINEERED TO FAIL. If the engine was designed to never fail from fatigue (which it can be), it'd weigh 6000 pounds, and have Rolls Royce stamped on it.

 

I just checked the timing on my car (85K miles) and it was 2 deg. out. I put that down to chain stretch, so I will replace the chain and gears this winter.

Keeps me out of mischief!

 

Why not put in a gear drive. They'll never wear and there super easy to install. :yesnod:

 

If it aint broke, don't fix it.

 

:nonod: :nono:

 

and they sound pretty badbutt! :yesnod: