Need to change the 22r head gasket and have 260,000mi , might rebuild the motor in another 100,000-150,000 but wondering if the timing chain will last till then? '82 has the double row chain and someone said the tensioner is metal, not plastic? I hate to get in there but should I? I asked this a before but dont remember anyone saying how long those chains should last. My thought was to let it ride and if it goes can change it later as I was told the head wont have to be removed. Just looking for an established estimated life on the chain and tensoner. I've heard locally these motors are known to go 700,000mi with untouched inners...

 

If your pulling the head just do the timing chain and be done!!

There is no hard and fast rule on how long they will last so many factors involved.

It is much easier to change the chain with the head off.

Then it is you doing the job so if you don`t want to do the chain.

My luck things would move enough I would need to pull the timing cover to adjust the timing or the cam would need replaced.

 

700K? maybe kilometers.
it is all relative to how well a motor/truck has been taken care of.
the way i see some people drive they are lucky to get 30k out of a motor.
You have to pull the timing chain to get the head off anyway.
might has well replace it like Wyoming9 said

 

Well, really to do the head all you're doing is slipping the chain off the cam gear. You'd still need to take off the water pump, oil pump and timing cover to do the chain. Definitely a good amount more work.

But like these guys are saying, at this mileage, you just can't say without getting in there and looking. Anyone who tries to tell you, at 260,000 miles, a definite "yes" or "no" answer, without actually looking at the chain, is full of it.

For me, a lot of other things would factor into it. Is the timing cover leaking? When is the last time the oil and water pumps were replaced? If some of those things could use work anyways, I'd lean towards doing it.

Yes it has metal backed guides. Tensioners I think are the same as a single row chain, but the guides are a plastic coating over a metal backing. That just means there's much less chance of it wearing through the timing cover as it gets looser. What kills the tensioners is a lack of routine oil changes, and sludge or loose rtv if someone's been in there being sloppy with it, clogging the passages. Then they stop putting good pressure on the chain and don't keep it tight. I would at least get a flashlight, once you've got it opened up, and inspect the chain the best you can.

 

All good answers. I had the front cover off when I bought the truck with 154,000mi and installed new seal to stop a bad leak plus since replaced the water pump twice, last about 2 years ago with fan clutch. I dont know if theres a way to inspect the tensioner without removing cover? Guess I should do as Wyoming said and change it while open. Dont understand why the haynes book says to remove the oil pan?

 

You remove the oil pan so you can slide the cover on straight and not jack up your new front seal on the crank. Same reason why you technically should remove head when doing timing chain.

 

Yes, there are definitely people who swear by not needing to remove the head or oil pan to do the chain, but you've got to be really careful if you do it that way, and you'll definitely feel, as you're doing it that way, that it's not the "right" way to do it.

I feel like I got a decent look at the guides when I had the head off my 20R, but I don't think I could see the tensioners.

 

So its a bit of a toss up? I did have the front cover off once so I remember now loosening the oil pan also but didn't remove it, was too hard to get out cause of axle or something in the way, and think the crank kept it from sliding out, it was over 10 years ago? Guess ya need to use a hyd bottle jack to get some room? I checked RockAuto and the chain and tensoners aren't all that pricey. Either way I go I know its going to be a pain working in the driveway. With little room in garage will need to keep parts in truck bed covered. Good thing is I have use of another car but need the truck to haul some stuff plus hate driving newer cars...

ADDED: Im now thinking my springs could be weak and thats why oil pan just wouldn't squeeze out... seemed like I only needed an inch more of space? I'll figure it out this time

 

The pan will definitely come out from above the front axle without much issue. On IFS trucks it's a whole different deal...but I pulled the pan on my 83 without removing or jacking anything.

I'd personally go engnbldr or Toyota for the chain, but as long as you get something quality I guess you should be fine.

 

The tensioner on my '81 was letting things get a little noisy at 145,000 miles, so I replaced the whole timing set. The original chain was definitely elongated over the replacement, but not much. With those miles on yours, I'd be inclined to replace the timing set if I was going to have the head off. I've done three without pulling the head or oil pan. On an '84, I ended up dropping the pan anyway because the plastic guides had broken and fallen in there.

 

"noisy at 145,000 miles"? got to wonder if thats the real mileage on motor. Why have you had to replace so many. I try not to rev very high and if oil gets a bit dark I change it

Think theres no choice but to replace. Anyone have thoughts of "Cloyes" Brand timing parts. RockAuto has them and are the priceyest on there list, there claim is only making timing components for over 80 years?.

 

I would talk to engnbldr. When I was buying a rebuild kit, Ted explained to me how to tell quality components from inferior components. There is a way, just by looking at the links of a timing chain, to tell whether it's a high quality one or not, but I can't remember exactly what it was right now. Someone around here would probably know.

 

We bought the truck new. Tensioners going bad around that mileage are common.

 

I am thinking it will last till The San Andres Fault lets go and California gets new Coast line!!

 

Which is to say..."it's anyone's guess"... Could be 20 minutes, could be years...