OT need step by step on this alternator/pulley/belt replacement

[DerbyDad03]

Your domain reads as rule.com. Rule is a camera shop in Boston.

[Lab Lover]

Lol! I never would have guessed that! Thanks.

[RobertMacy]

thanks, needed a source for parts.

Never thought about this before, but on what basis does one select an internal or external star washer?

From the photo, the external have more pitch, and therefore more compression range, so why the expense of the internal?

Any Mechanical Engineers out there can answer that?

[Lab Lover]

Don't use a steel star washer behind the wire terminal. Steel has a very high resistance. The wire lug and the terminal itself are made out of a non ferrous material with a lower resistance.

Just snug up the nut well.

[Lab Lover]

When tightening the B+ or primary wire to the alternator, the proper torque would be approximately 25 in/lbs. (not foot pounds). Without a torque wrench, if you are using a 6" long wrench, I would say it should feel like you are exerting about 5 lbs of force (weight of a bag of flour) on the end of the wrench while tightening.

[H. H. Lovel]

Does the Mercedes also have belt tensioners? If so, you might want to consider replacing them, while you're there.

[RobertMacy]

Didn't see any.

[Lab Lover]

One last word of caution, when you do this, resist the temptation to over-tension the drive belt for the alternator. Too much tension and you will destroy the bearings in the alternator in very short order.

Do you know how to properly tension the belt?

[RobertMacy]

Thank you for your reply.

No, I asked around and was told 'no idea, mainly by the mechanics sense' which doesn't sound very repeatable. Knowing German design, there must be some way to do it properly. I just assumed about 1 inch deflection out in the middle somewhere would be ok. There are THREE belts between that alternator belt and the outside world! and the tension on one of them is so strong you could bounce a quarter into the next county off it.

[Lab Lover]

Belt tension is one of those universal things. 1 inch deflection in all the belts would be desirable.

If things start squealing, you can make them tighter. I would take the opportunity to inspect and possibly replace your belts. Buy the more expensive, higher quality Goodyear brand belts if you can. There is a big difference between brands.

Also, use a plastic scrubbing pad to clean your pulley surfaces if possible. Just be sure you get all the residue out of the pulley after cleaning.

When are you going to do this deed?

[RobertMacy]

Sunday I spent two hours just removing the pulley to replace with, you guessed it, one completely different! sigh.

Since alternator is shot, didn't even bother to replace the 'fan' section [have a stack of left over parts], just bolted back together capturing the belt which by now is very disdended [even small sections thinned by wear - shudder.]

After that experience, and having all my auto tools in storage with NO access, so won't buy more, don't feel real confident to take on the task. Tested the pulley and belt combination with short drive. This is te first time ever the belt stayed on for that long a time. AND didn't flip over! kept its V-notch toward the inside! So armed with confidence I can drive to the nearby garage that I've been talking with, will let the pro do it. ...I couldn't even find where/how to remove the other THREE belts to even get at that bottom belt!

I guess I've verified the adage relating the ability to drive nails or be an automechanic. I can drive a nail very well, three hits and its in, so I guess I'm a rotten mechanic. As verified by the two hours JUST to replace a pulley!

Are you at Rule in Boston? just to taunt you, it's 71 here.

Thanks again for the URL with pics. That gave me the confidence to go replace the pulley to make it to the garage. Oddly, downtown Phoenix has a myriad of 'mobile' mechanics, but rural has none. Seems backwards.

[Lab Lover]

Nope, I am about 2600 miles from Boston. And just to taunt you, it rarely ever goes above 85 here.

[RobertMacy]

We set our thermostat at 82 ! with this cold wave, we're freezing, the house got down below 80. And don't even run the cooler til the house gets above 92. think about delta temp, with outside usually less than 20-30 degrees different than inside, we're prety energy efficient. Now compare to your area, probably 10 versus 68? that's a difference of 50+ degrees !!! correlary here would be either 20F outside [very rare, if ever] or

140+ outside [hope that NEVER happens!]

But on the plus side, you won't get burnt by your car when you touch it. ...only the occasional tongue frozen to a flagpole.

[Lab Lover]

Ever been to San Diego?

[RobertMacy]

ARRRGGG!!! a bit jealous! beautiful area

We used to go to Europe about twice a year and to relax from those 'vacations' we used to go down to the Del Coronado and stay a week in 'our' room. - little known room in the old section on the fifth floor with NO rooms beside or over you, overlooking the ocean. With the sash windows open you can hear the ocean, smell the breeze. There's an old fashioned popcorn machine at the nearby liquor store the type that pours it out as it pops. We'd sit in the room in bathrobes with our feet on the window ledge, drink champagne, eat popcorn, look/listen to the view, and just relax. sigh.

yep, a bit jealous.

[Lab Lover]

I don't live in the hotel Del, but I have similar weather.