开云体育

Pre 1983 4cyl engines had double row timing
chains and are bullet proof. V-6s use belts.

83 up had single row chains. The 22re has
a single row chain with plastic chain guides.

At around 60k the chain begins to stretch and
rattle against the guides. This is what you
hear on start up. It is the begining of guide
failure. The more miles with chain rattle, the
more wear on the guides. Eventually, guide wears,
the chain sharpens and cuts away the timing cover,
dumping coolant into the oil pan.

As the guide fails, pieces will break off and drop
into the oil pan (good luck). (On rare occasions
it will get into the gears and cause catastrophic
engine failure (bad luck). The 20 thru 22re are
"interference" engines. A chain failure will cause
major engine damage. But It's the plastic guides
that go first.

Back to the rattle: It sounds kind of like a deisel
running , then disappears almost instantly on
start up as the oil flows and the chain tension is
taken up. The longer the rattle period, the worse
shape the chain is in (stretched). A good one (new)
will make no noise at all.

It can be hard to tell what you're hearing here, but
as the engine is an OHC type, there is no lifter
or push rod noise to be heard. That said, the engines
are old and clunkie OHC designs, and do make some noise.

The owners manual says replace at 60k? Drivers
of the 22-22re on other lists say 100k? A survey
of failures on the 4x4 list showed guide failure
at 100-150k.

The fix is extensive. The pan is loosened, the
head and timing cover, (and all their attached
goodies) must be removed to get at the chain and
guides. Some shops have changed them without
removing the head by "fishing" the new chain on,
however, oil leaks can occur using this method.

The parts that are usually replaced are: sprockets,
guides and chains. The guides are usually replaced
with all steel, after market parts such as those
sold by DOA.

This job can be done by a "do It your self" type
if they are good. Toyota quoted one list member
$1,300, and that's for plastic guides. I have not
checked shop prices.

You can check the guides and chain slack by
removing the valve cover and looking down the chain
cover with a flashlight. This would also make a good
pre-purchase check for your mechanic if you are doubt
when buying a used machine.

Jack A2



To unsubscribe from this group, send an email to:
toyota-campers-unsubscribe@...



Your use of Yahoo! Groups is subject to