Hello!

I recently purchased a 1978 280z with 112,000 miles. I've been going through the car, fixing this and that as well as assessing what types of maintenance issues might need attention. My question is, what is the typical mileage after which the timing chain, sprockets, and tensioners should be changed?

Thanks!

John

Typically, about 2 or 3 hundred thousand miles.

You won't hear of too many people changing them out unless they are upgrading the motor.

Dave.

I know for timing chains, you don't need to worry about those. Now, if it was a belt, that is a different story.

Chains are longer lasting than the toothed rubber belt technology however...

I would advise you to have a close look at the rubbing block on the tensioner, as well as wear from the chain on the chain guides.

If these surfaces are deeply grooved by contact with the timing chain then that may mean that the chain has stretched somewhat and would be better renewed.

It is wise to renew not only the worn guides, chain and tensioner but to do the upper and lower sprockets as well.

Then it will all be fresh and mechanically A1.

I believe Nissan as well as other Manufacturers have gone back to timing chains in lieu of rubber belts.

Interesting how the "wheel" turns:rolleyes:

I believe Nissan as well as other Manufacturers have gone back to timing chains in lieu of rubber belts.

Interesting how the "wheel" turns:rolleyes:

I've heard that the industry movement back to chains has to do with a change in US emissions requirements. Something about lack of required maintenance, or some such.

When you look at the mechanism of driving over head cams, initially a toothed rubber belt would seem easier to service, simply because it is external to the engine.

However, I recently did the timing belt on my R33 Skyline [2.5L turbo] and it was far from straight forward:rolleyes:

Nothing hard, just a lot of time demounting everything to get to the rubber band.

And that time would cost big $$$ if you had a shop do the job.

That is probably why a lot of drivers don't have it replaced at the recommended interval.

And that would be why a lot of engines get munched when the rubber band breaks:dead:

The oil bath chain drive also needs a lot of dissembly but it doesn't have the short service life that a belt does.

The result is that, barring a catastrophe, they usually last until a major re-build is necessary, as mentioned above.

Keep the sprockets (unless there is obvious excessive wear) and get a new chain and tentioner (from Nissan). You will sleep better at night.

Look for cracks in the camshaft sprocket especially. Uh.. eh.

Your alternative is a very expensive engine overhaul.

Nope. When I go in there it's sprockets, tensioner, chain, and front seal. Doesn't cost that much more so why not do it all while you're in there. (JMO)

It's not so much the miles as it is the adjustment. The original setup only allows for a couple of adjustments to timing stretch. if you go past #3 it's time to replace it all. But check it first before replacing it. The notches on the cam and sprocket should be in proper alignment and if the adjustments do that, your good to go. Do this at the same time as you adjust the valves. Two birds with one stone.

Like others have said, chains last much much longer than the crappy belts. If the car was well cared for, the chain should last 200,000 without any issues, but it's cheap insurance to inspected them on a high mileage engine because they can wear out and "Stretch". You can adjust the tension if the the slack is minimal, but if it's to the point where it's excessivly worn & "stretched" and adjusting it won't help, then it needs to be replaced obviously.

I won't buy a car if the engine uses a timing BELT :sick:

"I believe Nissan as well as other Manufacturers have gone back to timing chains in lieu of rubber belts." I sure hope so.