vibration dampener is wearing it's way through the timing cover! (92XJ 4.0)

Hi folks; started noticing an oil leak this week and went in to take a
look. I've discovered a condition that's puzzling and I can't find
anyone else on this list or the web describing something similar, so
here goes:

the vibration dampener appears to have moved rearward and is cutting a
groove into the timing cover. the oil is leaking down around the
dampener at a reasonable rate while the engine is running. I've never
had the timing cover off before so I'm not super familiar with the
layout in there - but I do have the shop manual.

So, the only puller I had laying around was a 3 jaw type - got it on
to the dampener and managed to pull the outer pulley donut off without
the middle piece of the dampener budging. Oops - didn't realize they
were constructed that way - so I'm off to get a proper balancer puller
today (and, I guess, a new dampener at the junkyard).

But what I realized was that, actually, it was that outer donut of
metal that I managed to pull off that had actually worked it's way
rearward and was cutting the groove into the timing cover. What
caused this? I looked at the TSBs this morning and noticed one about
the power steering pulley being misaligned - I'm in town and not near
the vehicle but is this the sort of effect that condition would have?

Oddly - I replaced my water pump last year that had a failed bearing
and a similar issue - the pulled had worn a groove into the housing.
Is there something else here I'm not considering that could be causing
the belt to "push" these pulleys rearward?

Is this oil seal what I should be looking at replacing? is it
possible to do without the "special tools" mentioned in the manual?

Finally - in the last year I notice an intermittent, loud clank-clank-
clank at idle, especially when the idle drops too low for a period
(it's an older truck and I live in the jungle). It goes right away at
1000+ rpms and there's no noticeable effect on performance so I wrote
it off as a loose heat shield sorta thing but now I'm wondering if it
might be related (loose pulley key or something?) or if I should be
otherwise worried about it.... .


thanks in advance!

elijah

 

Seems to be a common way for the virbration damper to fail.


the oil is leaking down around the

Did the seal fail or did the damper rub a hole through the cover ?

Most likely cause, poor construction.


I looked at the TSBs this morning and noticed one about

No. The power steering pulley would probably cause the belt to jump off or
wear funny.

The damper failed, get a new one.

Is it leaking ? If it were mine I would replace the seal now, while it is
all apart.


is it

Don't know, don't have a manual to look at. Usually all you need is
something to pry the old seal out with and I always ued a large socket, same
size as the seal, to drive the new one in with.

That's usually the noise that the damper makes when it fails like it did. I
think when you replace the damper the noise will be gone.


It goes right away at

You can start with the belts off, but with the damper still on, and see if
it makes any noise.

 

Awesome, thanks Mike!

 

I'm with Mike on this one - a new damper, not a junkyard one. They fail
with age.

Hope this is helpful.

PoD