Timing Chain Guide Replacement...
Finally, the project has begun. With the car laid up
for over a year I'm finally able to fix the car at a
reduced cost due to a spare engine with new replacement
parts that I need.
<< Before & After
pictures below >>
Disassembly:
 |
As with any job there are setbacks. Having an
automatic in this case didn't hep any. Since you
have a freely spinning torque converter to make
power there's no way to lock it into position
and to prevent the flywheel, crankshaft and crankshaft
pulley from spinning as well.
|
|
Before starting this project, after reading other
horror stories of Nissanforum.com members breaking
their pulley to pieces, I called up my local Nissan
dealer to find out the best way to do this. I
wasn't impressed with their answer "You need to
keep the engine from turning over some how" yet
when I asked how exactly he said "by braking the
engine". The only good bit of advice was his tip
about the exhaust camshaft, which I thought about
prior, but was hesitant to try.
From the picture above you can see the gruesome
setup we used to take it off. If you click the
enlarged picture you can see three large chips
of the pulley missing as we used Vice-Grips only,
in our first few attempts, to keep it from tuning
over while we tried to smack the bolt loose. The
bolt finally moved after holding the exhaust camshaft
with a 25mm wrench, wedging a solid piece of 2x3
between the pulley and alternator bracket with
Vice-Grips applied and using a long piece of 2x3
as a battering ram against our ratchet handle.
To make a long story short, the pulley is off,
without the aid of a pulley puller(didn't really
need one) and an Unorthodox
Racing pulley will be installed in it's place.
** An easier method that may have worked would
be wedging a chisel in one of the flywheel holes,
turning the crankshaft by the pulley bolt until
the chisel is held into place, resting against
the housing cover of the transaxel. Preventing
the flywheel from tuning by the teeth seemed risky
yet impossible anyway so I never tried. A similar
procedure can be found on Courtesyparts.com
for the Ultra S pulley. With the GA16DE engine,
you only need to remove the dust cover, which
is next to the base pan, held in by two bolts
instead of the starter motor to access the flywheel.
This procedure only applies to automatic transaxel
equipped engines.
|
With all the front cover bolts removed and cracking
the eight year old liquid seal, to my amazement, the
chain guide just fell out on the ground. Nissan quality?
I think not! There obviously could have been a better
way to construct this without need of the chain manoeuvring
around countless obstacles with the aid of guides and
tensioners.
What we found... Well, as you can see from the picture
below the lower chain guide was chewed up quite a bit,
broken into pieces actually. The engine was also covered
in heavy oil deposits and varnish due to infrequent
oil changes and overheating by the previous owner, my
father. Sorry dad...
When I finally removed the oil base pan the bottom
was covered in a liquid metal residue. This was before
I had the front cover off to realize the extent of the
damage. I should note, the car may have only been driven
one to two weeks after I first heard the noise. Eventually
it became more prominent and annoying as the guide slipped
out of place entirely.
Below: A few more pictures of the damage the
timing chain was doing to the front cover housing. If
left unchecked it will wear a hole through the outer
cover and into the coolant passage creating an unwanted
mess. This is what causes the ticking/rattle sound you
may hear in the GA16DE equipped Sentra' or at least
one of the known sounds.
 |
Left: Lower timing chain tensioner.
While it wasn't badly devastated we certainly wanted
to replace it to prevent cracking open the side
of the engine, again, in the near future. |
| Right: Upper tensioner that showed significant
signs of wear. It was difficult to know how bad
it was until we removed it. While the hydraulic
piston was functioning normal, we had an extra tensioner
and |
 |
| guide off the other engine we acquired
so we used that instead. Otherwise, if the tensioner
is functioning normal you probably only need to
replace the guide portion. |
Installation:
The new guide practically snaps in the guide rail where
there are virtually no stress points on the guide itself
but the potential for the chain to wear through it is
still there but not for another 200,000 Km's at least.
 |
The metal guide rail
is bolted into place where the existing guide bolts
where. You may have to loosen the idler sprocket
to get access to the bolt from behind it. We used
a pair of vice grips to loosen it. Thankfully the
redesigned kit came with actual bolts so you can
use a wrench rather than star driver bits. In order
to access the bolt this way, the idler sprocket
would have to come off, something we didn't want
to deal with. |
|
- During the dry fit the overhanging head gasket(since
we never removed the cylinder head) made it impossible
to reinstall the front cover properly or at all
so I had to remove it. After doing so I was left
with a 1.5mm gap that was too large for Ultra
Copper liquid gasket sealer. A trip to my local
AAA Canadian Tire and $20 later I had a sheet
of metal gasket which I cut the correct size and
shape that I needed, drilling the required holes.
After cleaning the old Ultra Grey liquid gasket
from the block and front cover with a blade, nail
and/or knife for the gasket grove and a paint
can opener in those hard to reach places then
wiping everything down with Varsol I was ready
to install the cover again. I also applied a bit
of multi-purpose grease on the two lower guide
pins.
- Make sure you install two new o-rings, in the
engine oil ports.
- Install and torque down the front cover bolts.
- Next, clean out the oil pan of old oil and
stuck on oil deposits. The best degreaser for
this job is again Varsol, scrubbing with a part
cleaning or other stiff bristled brush. Rags and
scrubber sponges work good as well. Remove all
traces of liquid gasket from the pan lip and from
the base of the engine block. Apply a 3.0-4.0mm
bead of Ultra Grey liquid gasket to the oil pan
in the grove and on the inner side of the bolt
holes. Make sure you have all your bolts and 10mm
socket, ratchet with extensions near by. Manoeuver
and hold the pan into place, install the bolts
and torque from the middle of the oil pan to the
edges. For my install I had two longer bolts with
a tighten down nut. These bolts go at the low
end of the pan near the flywheel.
- Finally, what I've been waiting for, installing
the UR Pulley. Apply a bit of engine oil to the
front main seal; I used a Q-tip to swap the inner
shaft of the crank as well. Apply multi-purpose
grease to the outer shaft and inner bore of the
pulley. Align the pulley with the crank spline
and gently push the pulley into place. You can
wiggle it slightly if need be. I also applied
grease to the pulley bolt as well if there is
any reason I need to remove it, so that it won't
be so difficult or corroded into place.
Installing the pulley bolt is opposite to the
removal.
With our 1-1/16" socket, 1/2" drive ratchet and
10" pipe extension I torqued the bolt to a point
where my leg, braced against the lower radiator
brace started to spasm. Torque range is between
98-112 ft-lbs. but I never had a 1/2" micro-adjustable
torque wrench on hand.
 |
Left: Final
result! While it is second hand, two years
old, I'm more than pleased how it looks. |
Since the project began, over two weeks ago,
the engine started to list, only being held in
place by one mount and supported by a jack. With
the worst contraption ever designed, especially
in road side emergencies, the trusty ol' scissor
jack came into play. Using a seven inch thick
piece of slate and 4x4 post I placed the jack
on top of that resting it against the rear side
of the on the engine block with the power steering
engine bracket as our jacking point. Now that
the engine is near it's original position I was
able to install the sprocket cover, cleaning both
it and the matting surface of the head to apply
new liquid gasket. Torque all bolts to 2.6-3.6
ft-lbs.
Before & After
pictures:
|
Startup cost:
Two Mack 2 Ton jack stands: $12
22 Drawer organizing metal cabnet: $11.99(reg. 19.99)
|
