Aftermarket tensioner shock bad already - PeachParts Mercedes-Benz Forum

cmac2012 · #1 09-13-2019, 06:32 PM

Looked through my thread of a year ago, about a month or so less than a year actually, didn’t find it, didn’t want to read it all again, but I seem to recall someone saying the aftermarkets weren’t worth it on this job. Unless I did something wrong that caused it to go bad, I will affirm that sentiment.

I just got a new one from the dealer for about $105, I forget exactly. I think Pelican no longer carries it or is unavailable or something.

At least I know how to do it now. If I remember that is, I can’t remember what the minimum is you have to remove. I think maybe the belt needs to come off, not sure.

They say memory’s the second thing to go and I forget what the first one is.

Does anybody know what the danger is of not doing this job right away? It’s been about 10 days since the noise started again, crap I am busy lately.

Squiggle Dog · #2 09-13-2019, 06:45 PM

I hope it's not Stabilus brand that's the bad one.

83w126 · #3 09-13-2019, 07:57 PM

You would have to unhook the spring and take the fan and fan shroud out I think, not too hard a job though.

Squiggle Dog · #4 09-13-2019, 10:28 PM

I don't think the fan and shroud need to come off. At least, I'm picturing it in my mind and it seems like all you have to do is loosen the spring and undo the two bolts on each end of the damper.

83w126 · #5 09-14-2019, 01:26 AM

Quote:

Originally Posted by Squiggle Dog

I don't think the fan and shroud need to come off. At least, I'm picturing it in my mind and it seems like all you have to do is loosen the spring and undo the two bolts on each end of the damper.

Just looked and you are right, you only have to unhook the spring and that's all that has to come apart to do it.

cmac2012 · #6 09-14-2019, 04:21 AM

Dang, I'm worried. Diseasel300 would normally be all over this. Here is my earlier thread, a lot of the stuff was covered there:

http://www.peachparts.com/shopforum/diesel-discussion/395523-another-weird-noise-my-300sdl.html

Sorry I dumped all the photos from my hosting service.

Diseasel300 · #7 09-14-2019, 10:18 AM

Have I developed a reputation for thread-pouncing on 603 issues already? *sigh*

To change the shock you don't need to remove the fan or shroud. Release tension on the spring, move the belt out of the way. Remove the top bolt holding the tensioner shock, then pull the tensioner lever up as high as possible on the shock side. You can then thread the lower bolt out. It's tight, but it's far less BS than pulling that STUPID FAN! I'd love to meet the man who approved that design and kick him square in the nuts!

Consider installing a clutched alternator pulley. It *REALLY* helps the belt flutter issues, even with the stock alternator.

cmac2012 · #8 09-14-2019, 11:37 AM

Quote:

Originally Posted by Diseasel300

Have I developed a reputation for thread-pouncing on 603 issues already? *sigh*

To change the shock you don't need to remove the fan or shroud. Release tension on the spring, move the belt out of the way. Remove the top bolt holding the tensioner shock, then pull the tensioner lever up as high as possible on the shock side. You can then thread the lower bolt out. It's tight, but it's far less BS than pulling that STUPID FAN! I'd love to meet the man who approved that design and kick him square in the nuts!

Consider installing a clutched alternator pulley. It *REALLY* helps the belt flutter issues, even with the stock alternator.

Oh absolutely not. I'm lucky you've responded as quickly as you have many times. I don't check in as often, I'm not an awful mechanic but my experience on these things is still developing. On the BMW E30 I'm a badass but those things are fading from the scene. *sigh*

Ashes to ashes, dust to dust ganji! (Indian holy man accent)

Good feedback. I'll look into one of those pulleys. So the alternator adds the hard bumps so to speak? I gather too long with a bad shock can lead to belt failure. Might ought to spring for new one after this.

cmac2012 · #9 09-15-2019, 11:53 PM

Quote:

Originally Posted by Squiggle Dog

I hope it's not Stabilus brand that's the bad one.

Yup, it was. I couldn't remember, swapped it today. But who knows, maybe the spring is bad. It's the same old one I've had all along. I'm thinking I should get a new one ASAP. I'm guessing aftermarket wouldn't be a big issue with those.

Squiggle Dog · #10 09-16-2019, 12:31 AM

Quote:

Originally Posted by cmac2012

Yup, it was. I couldn't remember, swapped it today. But who knows, maybe the spring is bad. It's the same old one I've had all along. I'm thinking I should get a new one ASAP. I'm guessing aftermarket wouldn't be a big issue with those.

As far as I know, genuine Mercedes is the only spring that's available.

cmac2012 · #11 09-16-2019, 12:50 AM

Quote:

Originally Posted by Squiggle Dog

As far as I know, genuine Mercedes is the only spring that's available.

I find only two at Pelican, both from URO parts, one is $36, the other $29.75:

https://www.pelicanparts.com/cgi-bin/ksearch/PEL_search_2016.cgi?command=DWsearch&description=tensioner+spring

I'm curious, why were you hoping it wasn't Stabilus brand that had gone bad? Best guess is you have one on your car now.

Squiggle Dog · #12 09-16-2019, 01:04 AM

Quote:

Originally Posted by cmac2012

I find only two at Pelican, both from URO parts, one is $36, the other $29.75:

https://www.pelicanparts.com/cgi-bin/ksearch/PEL_search_2016.cgi?command=DWsearch&description=tensioner+spring

I'm curious, why were you hoping it wasn't Stabilus brand that had gone bad? Best guess is you have one on your car now.

Well, I'll be... it even has the brand name printed right on it in large letters.

The new tensioner damper that I installed in my roommate's car is a Stabilus. But Stabilus also makes them for Mercedes. The original had the star logo on it and the Stabilus brand name.

cmac2012 · #13 09-16-2019, 10:39 AM

I read somewhere that the spring and shock should be renewed together. Will do that soon. OTOH, you would think if the spring was bad I'd have some belt squeal. Who knows.

Diseasel300 · #14 09-16-2019, 11:49 AM

The spring doesn't get weak, it becomes metal fatigued or fractured from the rapid vibration and fluttering. It's more likely to break and fail catastrophically after being run with a bad shock. Cheap insurance to just replace it with the shock, you already have it off anyway.

cmac2012 · #15 09-17-2019, 12:05 AM

Quote:

Originally Posted by Diseasel300

The spring doesn't get weak, it becomes metal fatigued or fractured from the rapid vibration and fluttering. It's more likely to break and fail catastrophically after being run with a bad shock. Cheap insurance to just replace it with the shock, you already have it off anyway.

Good point. This spring assembly looks pretty danged old. I'm a bit sheepish to admit how easy a job this is, compared to what I thought when I first did it. OTOH, I also replaced the rocker and idler that time which made it more complicated. Will be an easy matter to put in a new spring.