Author Topic: Fan belt replacement  (Read 928 times)

Brennie

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Fan belt replacement
« on: March 28, 2022, 13:46:23 »
Fan belt question.. I have a lot of slippage with my fan belt( it squeals a bit) I’ve adjusted it but it still happens.. it looks new but it is a v shape .. the one I’ve just ordered is ”knarly” for want of a better word..notched at the bottom..will this solve the problem do you think? 
Also.. the rubber bushes on my alternator mount are gone.. I’ve offered new ones.. are they easy to fit? And, is the fan belt east to fit myself? I’m a lie on the floor sort of mechanic…

naristodemou

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Re: Fan belt replacement
« Reply #1 on: March 29, 2022, 05:56:13 »
A new fan belt should cure your problems, make sure the belt tension is correct (you should not be able to push the belt down in the middle of its longest sector by more than 1/2 an inch).

Fairly easy job to do, including alternator mounts, for a person with average skills. Even simpler if you have no air-conditioning fitted since AC compressor complicates matters a little bit.

Read the technical manual, it helps.

Nicolas
Nicolas Aristodemou
Nicosia - CYPRUS
280SL Auto 1970 US spec (W113), 380SL 1982 R107, Citroen DS23 Pallas 1973, Triumph TR4 1963, Triumph Stag 1973, Mini Cooper S Mk1
1965, Jaguar 3.8 Mk2 1962, VW Beetle 1978 Karman Converible, 1987 Ferrari 328GTS

Brennie

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Re: Fan belt replacement
« Reply #2 on: March 29, 2022, 09:19:24 »
Thank you.. no Ac.. is all I have to do is slacken the tension on the existing belt and slip on the new one? Will it fit over the fan then onto the alternator pulley ? Is it that simple?
( he asks fingers crossed)…

Pawel66

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Re: Fan belt replacement
« Reply #3 on: March 29, 2022, 09:56:51 »
Do you have power steering? I do not remember, even though I did it a couple of months ago, which one you cannot remove without removing which one...
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

Lorsar

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Re: Fan belt replacement
« Reply #4 on: March 29, 2022, 13:28:09 »
I did this recently.  Yes the belts will fit over the fan.  The front smaller belt will have to be cut off. The alternator can be slacked enough to take off the old one and put on the new one.  For the front belt, I found a tip in forum to just get it on as close as possible, then pull the wire from the coil and bump the starter.  It went right on.
Lori
1968 280SL (US)

Brennie

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Re: Fan belt replacement
« Reply #5 on: March 29, 2022, 15:51:52 »
Hi
I don’t have AC so it is just one belt …alternator to the fan….so, slack off the alternator remove old belt….loop the new one over the fan..then the pulley…adjust and tighten? Is it that easy?
The old slippy belt is just V shaped..the new one is knobbly (for want of a better word)at the point of the V…I’m hopping for more grip…

Brennie

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Re: Fan belt replacement
« Reply #6 on: April 18, 2022, 05:08:30 »
Sorry.. I’m still confused.. to replace the alternator/fan belt I have to CUT off the smaller front belt? So, I have to sacrifice that belt in order to replace the alternator belt? Therefore needing two belts to replace just one?

Pawel66

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Re: Fan belt replacement
« Reply #7 on: April 18, 2022, 07:11:38 »
By small belt - do you mean the power steering belt? No, you do not have to cut it, you need to remove it to remove the alternator belt. Depending on its condition, it may also need to be replaces since you are there.

In order to remove the power steering belt, you have to loosen the screws holding the power steering pump (3 of them, 2x13mm, 1x14mm if I remember correctly),  then loosen the length adjuster, then do the trick as described - observe which way the engine is turning, remove partially the belt from the pulley, crank the engine with ignition wire out of the coil just for a fraction of a second so that it comes off. Put it back on the same way, apply tension via adjuster, tighten the three bolts.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

Brennie

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Re: Fan belt replacement
« Reply #8 on: April 18, 2022, 07:24:55 »
Thank you so much … very helpful..

Pawel66

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Re: Fan belt replacement
« Reply #9 on: April 18, 2022, 07:45:31 »
Well, I wrote before, that fan belt replacement is easy, but when you have other belts there, it gets complicated... To remove the power steering belt, you need to be able to get under the car a bit (safety!) and need to be able to pull off the belt partially from the pulley for brief engine crank to do the rest of the trick. If you have experience in this kind of work, it is ok. If not, then someone's help would be useful.

You have procedures for tensioning of both belts in the Technical Manual. Removal is similar, just takes it one step further.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

Brennie

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Re: Fan belt replacement
« Reply #10 on: April 18, 2022, 08:00:45 »
Thank you as always..

Lorsar

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Re: Fan belt replacement
« Reply #11 on: April 18, 2022, 13:47:06 »
Do you know how old your power steering belt is?  It would be in your best interest to replace them both at the same time. The belt costs around $6 us. 
Lori
1968 280SL (US)