Crank pulley loose??

[rockatansky]

Hello,

I am fresh to the MR2 scene having just bought a MK1. An '89 with about
80k on the clock, but it has been standing for several months.

The first job I have had to rectify is a snapped alternator belt. On
further inspection, the alternator pulley was found to be seized. Took it
off to find cracks in the casing! Fitted a new alternator and belt, fired
up the engine, then 'ping', the belt snaps.

Fitted another belt and felt all along for anywhere the belt could be
rubbing on. Then found that the inner crank pulley, (that the belt runs
on), was loose and rotates freely!

Isn't this the pulley that powers the alternator, off the crank? Does
anyone know how it is fitted? What would cause it to come loose/break? (Why are there two pulleys off the crank, for superchargers?) And how will it come apart? I know there is limited space, but is it possible with the engine in? I bl**dy hope so!

Any help very much appreciated.

Thank you.

Ross

[MartG]

The crank pulley is a two part design - a hub which bolts to the crank and an outer rim fixed to the hub by a rubber vibration damper. Its not really repairable if the rubber has given up - simplest solution is to get another pulley from a scrapper.

[rockatansky]

Woah, that was quick, thanks.

Is it only the inner pulley that is fitted with the rubber damper.

Do you know how the outer pulley is held on? Just bollted to the crank hub,
with a woodruff key maybe?

Thanks again.

[kevin..in]

the pulley is bolted to the crank with an either 17mm or 19mm head bolt (depending on year), you will also need a puller to get the pulley off. it seems to be quite common for this pulley to delaminate, in your case probably due to the alternator seizing and causing the belt to slip which caused a heat build up burning the rubber damping. I had one go last year when my water pump seized the bad news is £200.00 plus from MR T so you need to try all the breakers you can also a wanted add on this forum may get you one this should serve as a warning to all MK1 owners that if your belt is squeeling attend to it before it takes the pulley out with it the outer part of the pulley runs the aircon pump on cars equipped with it

[rockatansky]

Thanks for your reply. Scrappy time again then! Couldn't belive Mr T price for an alternator alone.

Is it possible to get the pulley off with the engine in situe? Thinking that there's not much space to use a puller?

[kevin..in]

yes it will come off in situ I use a Sykes Pickovant two legged puller from halfords it was I think £14.99 you will need to lock the flywheel to get the bolt undone, I take the bottom cover off and wedge a big pry bar between the flywheel and gearbox housing though, I also use an old socket over the end of the puller thread so as not to damage the threads in the end of the crank.I am sure there is a more mechanically sensative method than this ( hope you didn't pay MR T price for an alternator about £350.00 plus VAT )

[ldavies83]

As above really, I had this happen when I did a timing belt change, luckily I knew of a spare 4age engine that my brother had, so I transported that up 330 miles to swap the pulley over

There where suggestions of tapping bolts between the "sandwich" to stop it from rotating, however I see it as rubber was put between the 2 for a reason

If you dont have any luck at the scrappies, be sure to post in here, theres a few Mk1 guys with more spares than they care to admit

[kevin..in]

As above really, I had this happen when I did a timing belt change, luckily I knew of a spare 4age engine that my brother had, so I transported that up 330 miles to swap the pulley over

There where suggestions of tapping bolts between the "sandwich" to stop it from rotating, however I see it as rubber was put between the 2 for a reason

If you dont have any luck at the scrappies, be sure to post in here, theres a few Mk1 guys with more spares than they care to admit

a repair was not feasable because there have been cases of the pulleys flying to bits and at up to 7,000RPM its not a good thing if only for the mechanical damage caused let alone the personal injury potential

[ldavies83]

Enough Said!

[Icsunonove]

You can jam the flywheel by using a big screwdriver like this:



This puller from Machinemart will just fit:



Hope this helps. Best of luck!

Tom

[rockatansky]

Thanks for all the info guys! I'll be getting on with it as soon as I have the time!

"( hope you didn't pay MR T price for an alternator about £350.00 plus VAT ) "

HaHa no, buying an alternator from Mr T would cost more than I paid for the car!

[Kieran Williams]

HI
just a thought, my alt seized completely and snapped the belt. I thought no problem and got a new one. Whaen i fitted it i found the the sleave for the bottom bolt had seized and as a result was not squeezing up tight even though the bolt head was against the bracket. This meant that the alternator was slightly loose and would have wobled about causing the bearing to self distruct again!
A quick clean and some copper ease fixed this no problem.
Just thought i would mention it, its worth a check.