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Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4244
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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ML350: , I'm trying to replace the belt on a 2011 Mercedes

Customer Question

Hi, I'm trying to replace the belt on a 2011 Mercedes ML350. The belt is actually the same belt that was on the car before, it just slid off due to an oil leak. I know the belt is correct. I've got the tensioner loosened but I still don't have enough slack to put the belt over the pullies. Do you have a routing diagram for this model or any suggestions?
Submitted: 1 year ago.
Category: Mercedes
Expert:  Lou P. master tech replied 1 year ago.
Hello my name is ***** ***** i will do my best to help you , i strive for EXCELLENT service and nothing less.i am getting you the diagram now.
Customer: replied 1 year ago.
Ok thank you
Expert:  Lou P. master tech replied 1 year ago.
here you go, hope this helps, Lou.Please take a second and click the box and rate my service GOOD OR EXCELLENT SERVICE if you feel I have been helpful and please request me in the future. If you feel I havenot been helpful please DO NOT RATE BAD OR POOR AND WASTE YOUR MONEY , I will opt out to see if another expert can provide more or better assistance so you're not wasting yourmoney!!. Thanks for choosing just answer. Lou. also , if you feel i deserve one , BONUSES are GREATLY APPRECIATED ! 😉
Customer: replied 1 year ago.
That kind of helps, but that's exactly how I've got the belt routed and I don't have enough slack to get it on
Expert:  Lou P. master tech replied 1 year ago.
ok, make sure that none of the ribs are on the edges of the pulleys
Expert:  Lou P. master tech replied 1 year ago.
is this a new belt??
Customer: replied 1 year ago.
All cleanly aligned... no the belt slid off because of a slight oil leak out of the oil filter housing. The belt is in perfect condition. I'm not sure what I'm missing
Expert:  Lou P. master tech replied 1 year ago.
im not either cause these belts are pretty forgiving, the last pulley you should put the belt on should be the tensioner if i remember how i did them
Customer: replied 1 year ago.
Ugh jeez ok, I hoped you might have some magical solution. I'll just start from step one again.
Customer: replied 1 year ago.
Thanks Lou
Expert:  Lou P. master tech replied 1 year ago.
and you are using a 17mm socket or a t60 torx bit in the tensioner? they used both designs,
Expert:  Lou P. master tech replied 1 year ago.
well hold on lol, i may have the magical answer, i know this process is slow but im good at these things
Expert:  Lou P. master tech replied 1 year ago.
there is a hole in the back of the tensioner and a hook thingy on the part that adjusts, you can flex the tensionor enough to put a allen key or a dowl pin inside to lock the tensioner in place.
Customer: replied 1 year ago.
Ha ok... I'm using a 17mm socket. The tensioner turns easily and everything is lined up. I've actually changed a ton of belts, just never on a Mercedes
Expert:  Lou P. master tech replied 1 year ago.
ok, the ac and bottom of crank and bottom of alternator can be tricky, so make sure you are on those perfectly
Customer: replied 1 year ago.
ok. I double checked everything again. Belt is lined up everywhere, no twists in it.
Expert:  Lou P. master tech replied 1 year ago.
how close is it to the tensioner pulley? is it nowhere near the pulley or just a mm from the pulley?
Customer: replied 1 year ago.
Half an inch or so
Expert:  Lou P. master tech replied 1 year ago.
ok that is way off. try to put the belt on the tensioner and take it off the top pulley, and try to put it on the top pulley last.
Customer: replied 1 year ago.
ok.
Expert:  Lou P. master tech replied 1 year ago.
also the top of the power steering pump just under the reservoir is where the belt also catches on the edge of the pulley and takes up slack,
Customer: replied 1 year ago.
Ok. I just tried the top pulley, still not even ballpark
Customer: replied 1 year ago.
I guess I can take the belt to the car parts store and measure it against a new belt... I really don't know what else to do here. Replace the tensioner?
Expert:  Lou P. master tech replied 1 year ago.
is the tensioner bottoming out when you try to move it? if not try from a different angle, im really trying to visualize what could be happening over there\
Expert:  Lou P. master tech replied 1 year ago.
if that belt came off then it should go on, no issues, where was the oil leak?
Expert:  Lou P. master tech replied 1 year ago.
and aftermarket belts are never good, they are always smaller for some reason.
Customer: replied 1 year ago.
Yeah it bottoms out. I have a pin in it since i'm working alone, but it's basically bottomed out. There was a slight crack in the upper O-ring. Over time enough oil seeped onto the belt tensioner to cause the slippage needed for the belt to slide off.
Expert:  Lou P. master tech replied 1 year ago.
ok, so if the tensioner is locked then the belt for sure should just slide on .
Expert:  Lou P. master tech replied 1 year ago.
ok wait, if the tensioner is locked make sure the belt is not cathing on whatever it is you are using to lock the tensioner into place i used a metal dowel pin and would ofter loop the belt over the pin on accident and would get me everytime.
Customer: replied 1 year ago.
It's not catching
Expert:  Lou P. master tech replied 1 year ago.
ok, im sure your frustrated with the belt and me asking you these questions lol. please forgive me
Expert:  Lou P. master tech replied 1 year ago.
could you take a second to hold the belt as tight as you could and also take a video of the belt and pulleys so i can see what you got going on there? or we can facetime via iphone? or text videos? ill send a offer over if your interested in that, let me know. im trying to help lol
Expert:  Lou P. master tech replied 1 year ago.
Did you get it ?