Monroe Sensatrac strut leaking after 30K, seek warantee advice, do I need to replace in pairs

I have a 97 Accord with about 200K miles. I replaced my struts 30K
miles ago with another set of Monroe Sensatracs (which worked well in
the past for me). For the past 2 months I have experienced handling
problems. My mechanic found that the rear driver-side strutt is leaking
badly.
I plan on returning to Sears and ask them to replace it under
warrantee. A new strutt shouldn't leak after 30K miles. Any ammunition
on how to fight with Sears on this if necessary, would be helpfull.
I feel I shouldn't have to pay parts or labor. Also, should I replace
the strutts in a pair or is OK to just replace the defective one.

 

Unfortunately that seems to be a frequent experience with Monroes.
Struts get noticibly bad around 60k miles. Your struts are half way there. The
"good" one is already half bad. If it were me and I intended to keep the car for
another year, I would replace both. Next time don't get Monroes.

 

Yeah, the Monroes use fiber glass type pistons and are cheaply made.
But they should have lifetime warranty like all aftermarkets, but
you'll be stuck with the labor. 30K miles is usually past the 12K mile
12 month warranty. But your local Sears may offer better warranty that
includes labor? Labor is usually $50 each side plus alignment if
needed.

Good thing I decided to go with Gabriel Ultras (their top of the line)
and install them myself. Excellent struts with inertia sensitive
9-stage valving and iron pistons. More comfortable on streets and
better control on highways than stock. Buy these when AutoZone offers
buy-3-get-1-free.

Check out the G-Force video: www.gabriel.com/gforce1/eng/default.htm

You can also get Bilsteins at AutoZone but the HD and Sports are stiff.
Touring class may suit some better.

The stock Showa or the common KYB (Keep Your Bilsteins) GR2 have only
primitive valves which I don't like. For normal driving, these types of
struts (without auto adjusting multi-stage inertia sensing technology)
belong in the museum.

It's better to change out at least by the pair so the condition on both
sides are similar.

 

wrote in article

You've opened one up and seen this piston?

ALL shocks are "inertia sensitive".You can open and close a shock by hand,
but hit the end with a hammer and it will offer more resistance.

Even the $9.95 shock you buy at the corner tire store is "inertia
sensitive."

The more stages of valving, the softer the shock actually is. This was
pointed out to me by a shock engineer, and I probed it on my own shock
dynamometer.

No performance shock would use iron pistons.The industry has used aluminum
for years, why would they want to go to iron and add the inertia to the
moving shaft?

Again, have you ever taken one apart?

First half of that statement is true for shocks with more than two or three
valving stages.....second half is argueable.

You REALLY can't have it both ways. You either have good control or a soft,
boulevard ride.

Could be because they are performance shocks?

What sort of "primitive valves" do they contain?

I suppose you would also class Penskes and Ohlins racing shocks as
"primitive" due to their valving?

Where the rules allow adjustable shocks, some of our oval-track customers
are having success with the KYB.

Boy, the guys who write advertising copy for the shock absorber
manufacturers must REALLY love the way you have swallowed that whole "auto
adjusting, multi-stage, inertia sensing technology" thing.

That sort of language has been used for decades, because it can actually be
said to be true - even of the old, non gas-charged Monroes and Gabriels of
the '60s, where such advertising claims began.

They were, actually, "self-adjusting" to conditions - offering more
resistance to potholes and large bumps as the piston tried to move through
the hydraulic fluid, forcing it through orifices - based on shaft velocity.

They were, actually, "multi-stage" - using piston bleeds at the low end
shaft velocities and coil-spring-controlled valves at the higher end.

And they were, actually, "inertia sensitive" - See suggested hammer
demonstration above......

......amazingly, just like today's shock absorbers that operate on the same
principles and technology!!

Could not agree more....the older unit - having seated the internal seals -
might actually offer better damping than a new, out-of-the-box unit, which
would create an imbalance.

Actually, you should probably change all four to avoid a front-rear
imbalance.

By tracking stock shocks - which many of our customers are mandated to use
in certain oval-track racing classes - we've discovered, through weekly
dyno-testing, that shock pressures change over the course of a shock's
life under racing conditions.

We have found - to our surprise - that shocks actually *improve* after the
first week of racing - probably due to the o-rings seating to the inner
tube crosshatch - then they deteriorate approximately five percent each
week they are raced.

That's not to say they deteriorate that fast in normal use - unless, of
course, your shock gets so hot after a trip to the corner Kwik-Mart for a
Slurpee, that you can actually blister skin by touching it.


The best thing any of you "shock experts" could do - *before* offering
advice gleaned from shock absorber advertising - would be to cut open a
shock or two to actually *see* what is inside.

I have a basic $12.95 Monroe and a basic $12.95 Gabriel shock - same
application - that I have cut apart to show customers.

Were it not for the color - blue for Monroe and red for the Gabriel - you
could NOT tell them apart. Inner tubes, pistons (including valving) and
rods are all interchangeable.

Many of today's "real racing", twin-tube shocks - Pro, Carrera, Afco, etc.-
that cost up to $100, simply have truck shock internals.

I have a take-apart Carrera into which I have swapped NAPA treuck shock
piston and valves, and it tests out to match one of the valving options
that are available in this shock.

If you do decide to scrounge a couple of shocks out of the local tire store
iron pile, DO be careful and drill them first to relieve any residual gas
pressure.

You will be surprised at the similarities between shocks and the dearth of
innovation among different shock manufacturers.......

......that's why they need to present obfuscation such as, "....auto
adjusting, multi-stage, inertia sensing technology".

 

Then how much would you say shocks actually deteriorate in normal road use?

Assuming no stickiness or leakage, why exactly do shocks "wear out"?

I still have the original shocks on my '91 Integra after 277,000 miles.
They feel OK with the bounce test, but I'm wondering how much of a
difference new OEMs would make. They are neither sticky nor leaking fluid.

 

I would venture a guess that after 277K, you have grown accustomed to
the deteriorating ride. Put a new set of OEM's and you might hafta be
hospitalized for shock due to the greatly improved ride quality...

<G>

JT

 

hee hee hee. I am not talking about the likes of performance struts
used in street rods or other hard-driven vehicles, which feel like
steel rods to most of us in typical driving, and I said so in the
message. And no, I ain't buying Bilstein HD or Sports or other
performance struts that you use.

For me the Gabriel Ultras do perform better than the stock Showa or the
common KYBs in clover-ramp turns without transmitting every crack in
the pavement. So IMO the multistage inertia sensing technology work as
advertised.

Even the Monroe Reflex (to phase in and replace SensaTracs) can improve
roll and pitch stability by 12-18% while removing impact bumps. An
otherwise unimperssive Nissan Altimas is an example in reviews.

And I agree that low end struts may all come from the same production
line and maybe even from overseas, most likely "re-badged". That's why
I pointed out Gabriel's high end "Ultra."

 

wrote in article

......as it does in every other shock!

As I pointed out, the more stages, the softer the shock.......which,
apparently, gives you the ride you are seeking.

How did you come up with those exact numbers?

Do you have the equipment and testing procedures to come up with these
numbers?

Or is it simply more Monroe advertising?

And, BTW, the Monroe Reflex has been around for a decade or so.

All Gabriels are built in Canada - where Gabriel also builds a number of
re-badged "racing shocks" (aka truck shocks) for AFCO, Carrera, and
Pro-Shocks

Monroes are built in the USA.

Separate companies.....separate production lines.

 

Mostly wear in the seals......the O-rings that seal the piston to the inner
tube, and the seals around the shaft that allow the fluid to leak out.

On occasion, a valving component such as a spring will break - allowing the
valve to stay open and offer no hydraulic resistance.

 

Have you had any experience with Edlebrock shocks? I've used them and
Monroe's and like the Monroe's better. When I called Monroe tech with
a question about shock application showing they were not going to have
the Sensatraks anymore for what I was looking for, only the Reflex, he
said it would actually still be the Sensatraks but they were calling
them all Reflex from now one, some would really be the reflex valveing
apparently and some would still use the sensatrak valving.

 

The Edelbrock uses a shuttle valve to open/close a bleed orifice - which
controls the low-speed damping.

When the shuttle valve closes the bleed orifice as the shock shaft velocity
increases, this makes for a sharper, more aggressive transition between
stages - something that I do not like in a racing application, because it
can create an unexpected change in stiffness - upsetting the car as the car
rolls into the turn.

It might, however, be just the thing somebody wants for their street-driven
vehicle.

While there might be some differences, it isn't the valving that
distinguishes the Sensatrac shock from the others.

In the middle area of the shock's travel, there are four grooves machined
into the inner tube. These act as bleeds that soften the low speed damping
(Remember the "boulevard ride" I spoke about?)

At the ends of the tubes, these grooves disappear, so if the wheel
encounters a sharp change in velocity - such as a pothole - the shock
stiffens considerably as the piston moves from the grooved area - where
fluid bleeds past the piston - to the non-grooved area near the ends of its
travel - where ALL the fluid must pass through the piston's valving.

I have racing customers come in with "the best" shocks that they have just
bought, and I dyno them for the customer.

But, before the customer leaves, I show them a dyno sheet from a Monroe or
Gabriel shock - just to show them the difference.

Nine times out of ten, they are back in a week or so with a set of "cheapo"
shocks to have them dynoed.

Again, I am talking oval-track applications.

As was pointed out by one poster, the "boulevard ride" was actually what he
was seeking, so the Sensatrac made a lot more sense for him.

I guess my point is that "more shock control" can be interpreted in many
different ways.

Several stages of damping that allow for a smooth, "boulevard ride" can be
interpreted by some as "more shock control" while I look at the actual
stiffness curve of a shock, and the cheaper shocks have a much steeper
curve than the gold-plated ones - giving me "more shock control" for the
applications I deal with.