alternator belt

basil · Unread post by **basil** » 21 Oct 2004, 22:59

How much tension should there be on a alternator/ac belt[?]
At tickover the tensioner is wobbling in and out but at increased revs it stops wobbling,the bottom run of the belt flaps up and down at low revs and is still at more revs [:I].Is this correct[?]
Xan 19td a/c
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Uggs

JohnD · Unread post by **JohnD** » 21 Oct 2004, 23:29

Sounds too loose. Under firm thumb pressure there should be around 5mm of movement on the longest stretch between pulleys.

TheWorker · Unread post by **TheWorker** » 21 Oct 2004, 23:56

if its R reg onwards have a look at the manual tensioner to see if the square hole is, if its at the bottomish shine a torch at the auto adjuster spring to see if the bush has worn out

Stuart McB · Unread post by **Stuart McB** » 22 Oct 2004, 01:13

I agree with JohnD. As a rule of thumb a quarter of an inch deflection under mild hand pressure on the longest run of the belt is about right.

basil · Unread post by **basil** » 22 Oct 2004, 02:50

Thanks for the advice it is a 95n xan.
Also the adjustable pulley is not as free running as the other two smaller pulleys.Would some wd40 be ok to free it up[?]
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Ferrari f2001 history

Unread post by **alan s** » 22 Oct 2004, 03:09

Be wary using WD40 on anything with a bearing involved.
It works good to penetrate into a rusty thread but it's also a pretty efficient degreaser and has the habit of washing grease out of bearings which then subsequently seize.
Alan S

espzetec · Unread post by **espzetec** » 22 Oct 2004, 11:58

my belt wobbles too. however its not loose. it doesnt squeel at idle but i get a bit of a minute squeek when i do about 70mph? in fact i think the belt is too tight as i could not get it on when i replace it. i had to take the alternator off and then put the belt on. the alternator was then levered back into position before re-fixing it.

JohnD · Unread post by **JohnD** » 22 Oct 2004, 12:14

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by espzetec

in fact i think the belt is too tight as i could not get it on when i replace it.
<hr height="1" noshade id="quote"></blockquote id="quote">
Did you release the manual tensioner? Is it the correct belt?

reblack68 · Unread post by **reblack68** » 22 Oct 2004, 19:58

I had the same problem on my Renault diesel. It transpired that I had followed the wrong route and the water pump was now running backwards.

Unread post by **alan s** » 23 Oct 2004, 02:18

Speaking of manual jockey wheel/tensioners, I have heard that this part is no longer available (for BXs) but it does have an SKF part number on it so may be used on something else.
If all else fails, I reckon a BX16V cambelt tensioner would almost fit although the diameter would be smaller and so a smaller circumference belt would be required.
Re-routing the belt (and using a shorter one) without using the tensioner doesn't work as it reduces the area around the circumference the belt contacts and then regardless of tension applied will slip and eventually destroy the harmonic balancer.
Just thought I'd drop that one in based on bitter experience.[V]
Alan S

basil · Unread post by **basil** » 23 Oct 2004, 02:52

What is the harmonic balancer?
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Triumph speed triple

Unread post by **alan s** » 23 Oct 2004, 02:59

The pulley mounted on the crankshaft that has a rubber centre vulcanised between the boss of the pulley and the V pulley section. It is there to reduce vibration and often, particularly in the cases of BXs, seperates due to age, oil contamination or ovetightening or slipping of belts which causes it to overheat due to friction. Often when people have problems getting belts to adjust correctly, it's due to this part of the pulley flexing.
Alan S

Stinkwheel · Unread post by **Stinkwheel** » 23 Oct 2004, 03:00

Isnt that similar to a flux capacator? But you only get them on CX turbos i think

basil · Unread post by **basil** » 25 Oct 2004, 02:03

Update-have rechecked the belt tension,I adjusted it with the engine running.As it was tightend a rattling noise started so I decreased the tension until it stopped.At this tension the sprung wheel still wobbles.
Any ideas?
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FOURTH-GENERATION CHEVROLET CAMARO HISTORY

Mads · Unread post by **Mads** » 26 Oct 2004, 02:08

Changed the tensioner on my Xantia due to a wobbling wheel. New wheel also wobbles [V], guess thats the price of experience [:I]. Good thing it's a lot cheaper than paying a pro to expand on his [8D]