Mercedes R129 500SL M119 engine serpentine belt tensioner removal and replacement

How to remove and replace the serpentine belt tensioner on a Mercedes m119 V* engine 500sl shown follow me on twitter / fupabox

[@Scanadian123]

Thanks for taking the time to make these videos. I have a 93 500SL. The exact same belt squealing issue started with me last night. Used your video to help with disassembly. Same issue, new tensioner required. Very helpful information 👍

[@brandonfowler6013]

Another SUPER helpful video!!! Thank you

[@rioraton]

One other thing..is it possible that the mechanic that did the last job did not reset that dial? I tightened up on the rod and it still is squealing only when you give it gas and it does not go away.... wonder if it is the belt? any way to ck the belt mine it seems good tightness is the way you showed in the vid?

[@callelindstrom4789]

Thanks! It helped me ! 👍🏻😊

[@zxtenn]

HAD TO WATCH TO SEE IF YOU MENTIONED THE PEICE WHICH YOU DID, good you ere able to replace yourself

[@derick3482]

any experience with R230 power steering pump removal ? i am trying to remove the pump no idea how to approach it

[@saamanneriman1294]

Hi there again. I have just had my tensioner and pulls replaced. Are these supposed to oscillate left and right when the engine is running? I notice it moving on it axis when the belt goes round. Thanks in advance

[@fupabox]

they should move a little bit to keep the belt tight as rpms change ,and as the belt goes round it can move since belts aren't 100% constant in thickness

[@Dynamics831]

my tensioner is the original 92 500sl belt is not loose have a belt squeal in the mornings on cold starts belt is not cracked or damaged was replaced 3 years ago

[@thaddeauscaldwell7101]

Thank you for another great video. The 1995 320SL has a tension damper shock and isn't adjustable. Do you know how i can release the belt tension , so I can change the idler pulley ? Any information is great appreciated.

[@fupabox]

there should be a bolt attached to the tensioner just underneath the tensioner pulley . you can also use a socket on the pulley itself to lever it down. it may loosen the pulley nut by levering it , but you can just retighten it

[@thaddeauscaldwell7101]

@@fupabox , thank you very much for the information. As always, I enjoy your videos.

[@SuperBranFlakez]

Hey I seem to be missing that bushing that goes in between, where can I find that?? I’ve been looking everywhere. Belt was loose but I tested the tensioner and I can’t even move it a millimeter so I assume it’s because I don’t have the bushing so when I tighten 13mm it goes on an angle and doesn’t tighten right

[@SuperBranFlakez]

Seems the 13mm tightens to a point and then becomes loose again. Threads are ok on it

[@mags3186]

Hey fupabox, I have gotten a lot of great help from your videos. I have recently thought of replacing the driving belt on my 1993 500sl, but I realized the adjuster stick isn't even there... Will I be able to do the job properly without it?

[@fupabox]

I believe your 1993 has the spring loaded type with no adjuster rod.

[@mags3186]

@@fupabox Found no rods for models older than 92, so I figured that must be the case as well. :)

[@rioraton]

Hello AGAIN, remember me... brake light/switch issue on my 92 500sl you helped me figure out it was also the 3 High tail light issue. Now Have the same squeal however when I pull up on the belt the tensioner moves up and down and the belt feels tight? BUT the needle is like yours all the way to the right. I just had this tensioner replaced about 3-5K ago how could it be bad again? Any way if I were to tighten up on the tensioner rod bolt is that what is used to change the belt and also used to tighten up the belt?

[@fupabox]

The tensioner rod bolt sets the initial tension and the spring inside allows the belt to contract without breaking. You can try a little extra tension by tightening the rod bolt, but if the pointer is all the way right , the tensioner could just have been faulty.. also possible the pointer is loose ? see if you can move the pointer ..it should be locked firmly and not be able to wiggle, also possible as you said the mechanic didn't reset the pointer. When my tensioner went bad, the adjuster bolt flopped around and the belt was just hanging limp. If the belt has been slipping it can polish and harden the surface and make it no longer grippy. You can try a non slip belt dressing spray . They make the belt more sticky and soft

[@rioraton]

You know I was able to move the the dial.. it clicked when I started to move it back to the top? What does that mean? I have a few more questions is there any way i can private message you? You have been very help full and more then that inspirational..you videos are VERY instructional tell which way to turn something.. how to remove.. torque specs.. bolt sizes etc. I was just going to take my car to my INDY but said screw it I want to see if I can fix it! Any way in case you want to keep you personal info personal here are my questions. When You changed your belt how did you do it? Loosen the tensioner only? Next, did you do every thing from the top of the car when you replaced it or did you have to get underneath and drop the pan..from the video it looked like you did it from the top. I did tighten the bolt on the rod but when I started it up and give it gas it still squealed ..I only put a 1/2..3/4 turn on it I did not want to over tighten? Let me know when you can REALLY appreciate it

[@fupabox]

All done from on top ..tensioner is the only thing you would need to loosen to change the belt. If the pointer moved then it's likely the mechanic who changed it didn't have it locked onto the teeth properly. Once it clicked I'm betting it won't move any more. Check the tightness of the main center bolt.. if the needle could move it might have have been pinched between the bolt washer and the tensioner body .. If that main bolt is loose it could cause the squeel. 19mm tightened to a bit less than a wheel lug nut. Check that bolt..I have a feeling that is the issue

[@rioraton]

Thanks again, hope you are right... will ck and torque to 75lbs and report back

[@rioraton]

YOUR THE MAN! Spot on dude! So, I loosened the rod... loosened the main bolt... re calibrated the pointer to the 1st mark re tightened the rod and set the tension to about the second mark... snugged the main bolt and torqued to 75 lbs. No squeal on start up and air running. Drove it up to 55 mph NO SQUEAL. Soooo, your “BET” was spot on. You should come out here to Las Vegas where I live and you should cash in on your Bets :). I think what may have happened is that where I live..just outside Vegas.. it was 117 degrees on the 21st when the squeal started. What I found out was that the inside of these tensioners is not a spring but rubber. It may have contributed to the fact that the main bolt not being tight enough and the heat caused the problem. Who knows..All I know is that your advise has paid off TWICE Big Time. REALLY do appreciate your help. Do you still have your R129? I am a subscriber so I am sure I will speak with you again. THANK YOU!

[@johnnytocr]

Can u please helo me My car shacking a lot, rpm going up and down 😢😢😢😢😢

[@chocolatier9597]

Did you find out what the problem was?

[@TheStiver]

Haha, yeah, down and to the right... Plenty of chainsaw action up here in the mtns too, winter is right around the corner.

[@fupabox]

+The Stiver The chainsaw was going for 3 days ! ..walking the dogs I saw why. The guy is using a 14 inch trimming saw to carve up a n old maple with a 3ft diameter trunk. LOL. :)

[@TheStiver]

+fupabox dude holy crap no wonder hahaha. Gotta do whatcha gotta do I guess. I cut down like an 12" diameter tree in my yard with a sawzall so I'm not one to talk...

[@MMWA-DAVE]

that pulley on the tensioner is utterly screwed - that is not worth saving ;)

[@fupabox]

+MMWA Oh yeah it is, thought it may have a small replaceable bearing..nope, 1 piece

[@MMWA-DAVE]

+fupabox I' about to take this job on a m104, that tensioner looks freakishly similar. After all this time now I finally understand how that adjustment works and I've always been doing it wrong! it certainly is a different design used on US made engines.

[@Baerchenization]

I asked Jesus to make it break all the time now so you won't be able to sell it - that will show you the error of your ways :)

[@fupabox]

Lol... Pure evil. ;)