Time for new shocks or wait

[wormwood1978]

2008 Trailblazer, 56000 miles or so. Suspension feels fine but shock sleeves are rusting out. Should I change them now or give them another winter?

I plan on fluid filming the undercarriage this fall, road salt is obviously taking its toll.

 

[coolasice]

Mine did the same thing.. I just touched them and they fell apart... I doubt they will let me pass inspection this fall so I'll be replacing mine in a couple months. If they aren't leaking and you don't need inspection they should be OK, but it wouldn't hurt any to replace them now.

 

[Playsinsnow]

Is that a hole in the resonator? Cut that off when you replace the rear shocks. As soon as wallet allows.
Are those shocks stock? Over time one becomes used to how worn something is and it becomes "normal".

 

[Mounce]

Is that a hole in the resonator?

Looks kinda like a water vent hole. I know our 03 Silverado had one in the muffler.


As for the OP, if you've got the money, might as well start researching shocks and buy a set. Might not be long before the actual chamber rusts through and leaks all of its oil out rendering it useless. Also inspect the trailing arms, they're known to snap when they catch the rust cancer.

 

[wormwood1978]

Yes the shocks are stock. As for the resonator, that did catch my attention a few months ago last time I was under the vehicle, I do believe it is to allow for water to escape.

 

[Tiggerr]

Of your staying at stock height, I'd say it's time for a set of bilsteins HD's, that's what most run in these trucks. 50K miles is the average lifespan for shocks. That's what they say anyway.
With that much cancer on them I'd get them out of there myself. You could pull the lower mount and see if there's any pressure left in them. If you can push them easily in and out. That'll tell you how the valving and charge are. If they push in easy, they're done.

 

[wormwood1978]

How do the Bilstein's compare with the Monroe Reflex shocks, are they worth the extra $20 each? Also, should I be looking at the spring or air shocks?

 

[littleblazer]

Most prefer the bilsteins as do I. The monroes are going to be factory cushy ride. The bilsteins are a little stiffer, but not that much.

 

[linneje]

I put the Reflex on and I am happy with the ride. I don't off-road, though. It was not a difficult nor expensive job, I should have replaced my rear shocks way sooner.

 

[Daniel644]

WOW, didn't even realize that upper shroud was made of something that could rust, I replaced my stockers because I felt like it with some Bilstein HD's, didn't notice much if any change to the ride in the rear, but I stupidly did that before I researched and priced things, when I realized you need a shorter rear shock when you do a drop I ended up getting the belltech kit which comes with new shocks all around and now I have a set of rear Bilsteins HD's with maybe 2k miles on them that are only a few months old sitting in the garage. Real easy to do, I didn't even jack the truck up to do it, just backed it up on ramps for clearance, probably wouldn't hurt to jack it up, but you don't even need to take the wheels off.

 

[wormwood1978]

So I have to decide between air and spring shock absorbers. Is that based on my personal preference or whether my TB currently has air or spring (I don't know what it has)?

 

[Mounce]

You have springs so it'll be the spring option.

 

[Camdo]

[SIZE=medium]I just put 4 Bilstein HD in my 05 Envoy with 184K miles. The shocks replaced were the originals, so my vehicle rode like a boat. For comparison, things that I noticed after replacing the shocks were:[/SIZE]
[SIZE=medium]Coming to a stop at a stop sign, no overshoot and pullback. The vehicle just stops on the spot. [/SIZE]
[SIZE=medium]No more wheel hop over roadway hoop dee doos. The vehicle used to do a sideways skittle over closely spaced periodic bumps.[/SIZE]
[SIZE=medium]Firm sure footed feel making a steep downhill decent into a left turn junction. This used to feel like an out of control body bounce. [/SIZE]
[SIZE=medium]My side abdomen muscles felt noticeably tired after short in town trips. That is gone. [/SIZE]
[SIZE=medium]Driving over challenging road heaves like in construction areas, is a noticeable improvement in performance. [/SIZE]

[SIZE=medium]My first impression driving with the Bilstein HD was that it feels like a pickup truck. The road definitely telegraphed into the cab. That was not the feeling I wanted. I really wanted the stock GM feel. GM's best choice to sell its cars. The Envoy I have is loaded with options and plush inside. It is more like a Cadillac. Unfortunately I have never driven a new Envoy, so I have no direct comparison. Now that I have tried the Bilstein HD and know how they feel, if I had to buy another set of shocks, I will try another brand like GM Direct Replacement Parts. I know now that I do not want heavy duty. I don't want to be aware of the shock action. I don't want yellow, I want black shocks. [/SIZE]

 

[Mooseman]

[SIZE=medium] I don't want yellow, I want black shocks. [/SIZE]

Could always paint them

I have the Bilstein HD's on my 02 TB EXT, improved the ride substantially. I didn't find that it made the ride harsh at all. In fact, I find it a bit soft but not overly, definitely better than the originals. I wear my yellow as a badge of honour.

 

[Tiggerr]

WOW! After 184K on OE shocks!?!? ANYTHING would probably feel stiff and a bit harsh! Lol

 

[Camdo]

WOW! After 184K on OE shocks!?!? ANYTHING would probably feel stiff and a bit harsh! Lol

Your right Tiggerr. In comparison to what I had (no shock) anything would feel stiff. I did not mean to be detrimental about Bilstein HD. They are definitely good shocks. What I was trying to say, is be clear about your objectives. I really wanted the OEM ride. I am into restoration. So GM shocks captures my imagination. Other objectives such as road performance, off road performance, track performance, cost, put something in and sell it, you name it. There are lots of possible objectives. The shock manufactures cater to objectives. If you see it on the track, it is a track shock.

Much is said of shocks, primarily about brands, but specifics are never mentioned. The shock and vehicle manufactures never give a specification of shock action. The shock used on the TB are a combination of dampener and gas spring. The manufactures don't state the gas spring rate, the dampening coefficient or the initial constant. The user is left with vague wordy comparisons of no specific value. It all becomes subjective. Try it and see if you like it.

 

[Camdo]

2008 Trailblazer, 56000 miles or so. Suspension feels fine but shock sleeves are rusting out. Should I change them now or give them another winter?

I plan on fluid filming the undercarriage this fall, road salt is obviously taking its toll.

Wormwood1978, I noticed how large and detailed your pictures are in post 1 of this thread. Could you please state the procedure you used get this effect. What is the original picture pixel size, are they hosted and linked or uploaded?

 

[Mooseman]

He used photobucket, which has less restrictive size limits, and linked them back here.

Although the original shocks are Bilsteins, they were the lower quality non-HD ones that start self destructing as soon as you drive off the lot. Have no idea if the valving is the same. Even my originals with 230K km weren't that rusty. I remember having to be careful on a particular bouncy on-ramp as my rear would swing out while bouncing.

 

[littleblazer]

What I don't understand is why the cover is metal. My oem in the rear had rubber or plastic covers like the hds do.

 

[Tiggerr]

Holy crap! I can't believe y'all go that long in a set of shocks lol! My OCD would be beating me with a hammer by 75K LMAO.

Don't mind me..... I'm not well lol

 

[Daniel644]

Holy crap! I can't believe y'all go that long in a set of shocks lol! My OCD would be beating me with a hammer by 75K LMAO.

Don't mind me..... I'm not well lol

Mine where stock at about 208k and surprisingly not all that bad, some oil seepage from the front shocks (see pic) and I didn't feel much of a change in the rears when I switched them with the HD's.

 

[Tiggerr]

Mine where stock at about 208k and surprisingly not all that bad, some oil seepage from the front shocks (see pic) and I didn't feel much of a change in the rears when I switched them with the HD's.

I believe you. I'm just way to OCD for that to ever happen. Plus... My father's been a mechanic since before I was born. I grew up getting maintenance rammed into my consciousness as
well. lol

 

[Daniel644]

I believe you. I'm just way to OCD for that to ever happen. Plus... My father's been a mechanic since before I was born. I grew up getting maintenance rammed into my consciousness as
well. lol

My OCD was the whole reason I replaced the rears with the HD's to start with, they didn't really feel like they needed it but with that mileage I wanted to do it just because. I almost bought a set of fronts but I got into reading the threads on lowering and it said those weren't good for lowering so I went with the Belltech kit instead.

 

[Mooseman]

Chrisfix, member Dogfish246, did a neat video of rear shocks before and after replacing them. Really cool how you can see the difference with new shocks.

https://www.youtube.com/watch?v=MEZSB1JglDM


He has a few videos specific to our platform.

 

[Camdo]

Holy crap! I can't believe y'all go that long in a set of shocks lol! My OCD would be beating me with a hammer by 75K LMAO.

Don't mind me..... I'm not well lol

Please define OCD.

 

[Tiggerr]

Please define OCD.

Lol! OCD=obsessive compulsive disorder. In other words I have uncontrollable compulsions to do maintenece and repairs, whether they need it or not. Like replacing shocks/struts every 50k miles or so, or changing oil every 5k even with full synthetic oil and top of the line filters, washing my ride even if it's gonna rain....lol...things like that. Just can't help myself

I'm the type of person that replaces both headlights when one goes out, both wheel bearings when one goes out, always does brakes all the way around never just front or rear and always either turns or replaces rotors, usually change calipers too and brake hoses flush the fluid every time. ( I'm horribly OCD about brakes) changes wiper blades with the seasons

Basically a parts store's wet dream lol

 

[DocBrown]

IIRC, I put a set of Monroes on my TB, that were supposed to be OEM ride quality. And they were. More important they were twice the shock that came stock.

Shocks on the GMT 360/370 are a 20 minute job, and that's stopping to take a drink of beer. What are you waiting for!

 

[Tiggerr]

IIRC, I put a set of Monroes on my TB, that were supposed to be OEM ride quality. And they were. More important they were twice the shock that came stock.

Shocks on the GMT 360/370 are a 20 minute job, and that's stopping to take a drink of beer. What are you waiting for!

The Monroe sensa-tracs are good stuff. Used them on many vehicles. The cheaper Monroes think they are called Reflex, or maybe econo-matic not so much.

 

[wormwood1978]

The Monroe sensa-tracs are good stuff. Used them on many vehicles. The cheaper Monroes think they are called Reflex, or maybe econo-matic not so much.

Are you sure its not the other way around? I think the Reflex is $10-20 more than the sensa-tracs.

 

[Tiggerr]

Are you sure its not the other way around? I think the Reflex is $10-20 more than the sensa-tracs.

Looking at Monroe's site I guess it's the econo-matics that are the cheapos. Reflex seems to be for trucks/SUVs. The Oespectrums look like they replaced the sensa-tracs maybe....idk

Either way as long as your stay off the econo-matics, Monroe had always been good stuff. Been using them for many yrs. cars/trucks/semi

 

[Camdo]

Lol! OCD=obsessive compulsive disorder. In other words I have uncontrollable compulsions to do maintenece and repairs, whether they need it or not. Like replacing shocks/struts every 50k miles or so, or changing oil every 5k even with full synthetic oil and top of the line filters, washing my ride even if it's gonna rain....lol...things like that. Just can't help myself

I'm the type of person that replaces both headlights when one goes out, both wheel bearings when one goes out, always does brakes all the way around never just front or rear and always either turns or replaces rotors, usually change calipers too and brake hoses flush the fluid every time. ( I'm horribly OCD about brakes) changes wiper blades with the seasons

Basically a parts store's wet dream lol

Now that's the way to maintain a machine.
Have you found it to be cost effective to be proactive with maintenance? I would presume that in the long run, your vehicle breaks down less, rides and looks better than other cars of similar age. You have full confidence in your vehicle as a dependable daily driver. How do you see the payoff for OCD maintenance? Will your vehicle last longer? Will you keep it longer? At what point do you get a new one?

 

[Tiggerr]

Now that's the way to maintain a machine.
Have you found it to be cost effective to be proactive with maintenance? I would presume that in the long run, your vehicle breaks down less, rides and looks better than other cars of similar age. You have full confidence in your vehicle as a dependable daily driver. How do you see the payoff for OCD maintenance? Will your vehicle last longer? Will you keep it longer? At what point do you get a new one?

I definitely have full confidence in my vehicles. Anything can break down, but you do what u can. My vehicles last as long as I want them to really. If the motor goes, I replace it etc. till I get tired of a vehicle or rust gets bad I'll keep them quite awhile. I never worry about my vehicle though. I'd drive it cross country tomorrow if I had a need to.

 

[kjkim93]

The GM shocks that were used on some models of our platform were repurposed and the cheaper end bilstiens. GM did not want to spend a lot of money.

 

[wormwood1978]

Made the switch over to the Monroe Reflexes. $86 for the pair after a coupon at Advance Auto.

 

[Tiggerr]

Made the switch over to the Monroe Reflexes. $86 for the pair after a coupon at Advance Auto.

Should be one hell of an improvement, over those stockers! lol

 

[Pittdawg]

I installed Sensatracs in the front and Reflexes in the rear. The front rode horribly and made a weird popping noise over bumps/rough roads. I switched out the Sensatracs in front for Bilstein HDs which provide a much better ride. Still have the Reflexes in the rear and am happy with them.

 

[vipergg]

The Monroe sensa-tracs are good stuff. Used them on many vehicles. The cheaper Monroes think they are called Reflex, or maybe econo-matic not so much.

The cheap ones are the Economatic line , stay away from those . OEM ride is the OE Spectrum line from Monroe. Just had these put on and the ride is almost exactly the same as the originals. So far so good with these , really like them . got them at rock auto , think they were $26 a piece for the rears and $112 a piece for the complete OE Spectrum quickstrut with springs . If you buy from rock auto be careful they don't seem to know the difference between the Economatic line and the OE Spectrum line, twice they shipped me the Economatic (blue shocks) instead of the OE Spectrum shocks which are black .