viscous fan pulley bearing

[Mikey D]

Hi , my 300TDI fan pulley bearing is noisy / rough when spun. Having had the timing cover off to change the timing belt i noticed there was a plastic cap where the bearing is situated in the cover . Has anyone changed the bearing sucessfully ?

I dont fancy buying a comlete new cover , needless to say the haynes manual is very quiet on the subject .

cheers Mike

[JimAttrill]

With good reason. The bearing is made of unobtainium and always was.

[Mikey D]

What is this unobtainium you speak of ? and where can i find some

So does anyone have a straight answer ?

Cheers Mike

[eddyoz]

All is explained in this link from Aulro My link

[Mikey D]

cheers Eddy Just the info i needed .

Mike

[JimAttrill]

Eddy, can you post this very interesting info in the technical forum? I had tried before with SKF, even in Brazil, but as your link rightly says:

"Interestingly SKF do not produce/ will not sell the part that is used in the OEM timing cover and they do not stock a generic pump bearing of the correct size"

Which is a pretty poor show for such a big company.

[splutter]

What is this unobtainium you speak of ? and where can i find some

So does anyone have a straight answer ?

Cheers Mike

Hi Mikey D, I know its a bit late in the day but her is the answer for the future

The bearing number that will fit all be it a fraction longer than the original is JD9448 and costs £19.38p.... It's a John Deere Tractor water pump bearing.The extra length ( It's only a few mm ) can be lost in the inside of the housing where there is a recess........... it will need to be trimmed with a 1mm cutting disc at both ends, but just hold the cutter steady and don't press hard let the disc cut slowly and you'll be fine, I've done loads with a 4" grinder and a 1mm cutting disc.

here's where to get if from .............http://www.nytractorparts.co.uk/.............. 01673 828883................ Ask for James, he'll order you one and post it out to you. The bearing Dia is 1.5" or 38.10mm the barrel length is about 50 to 52mm ( 3 to 5 mm longer than the original) the spindle dia that you need is 0.626" ( 15.91mm) and needs trimming to 27mm longer than the end of the barrel The other end also has a spindle but that just needs cutting off as close to the barrel as possible, I usually manage 2 to 3mm without any trouble.

Hope this helps. So there you guys have it, I've given you a trade secret away, how good is that!............Don't ever say that the bearing can't be replaced and you have to buy a new front timing cover.. You Don't

Kind Regards to anyone reading this.

[splutter]

Hi , my 300TDI fan pulley bearing is noisy / rough when spun. Having had the timing cover off to change the timing belt i noticed there was a plastic cap where the bearing is situated in the cover . Has anyone changed the bearing sucessfully ?

I dont fancy buying a comlete new cover , needless to say the haynes manual is very quiet on the subject .

cheers Mike

I know its a bit late in the day but her is the answer for the future The bearing number that will fit all be it a fraction longer than the original is JD9448 and costs £19.38p.... It's a John Deere Tractor water pump bearing.The extra length ( It's only a few mm ) can be lost in the inside of the housing where there is a recess........... it will need to be trimmed with a 1mm cutting disc at both ends, but just hold the cutter steady and don't press hard let the disc cut slowly and you'll be fine, I've done loads with a 4" grinder and a 1mm cutting disc.

here's where to get if from .............http://www.nytractorparts.co.uk/.............. 01673 828883................ Ask for James, he'll order you one and post it out to you. The bearing Dia is 1.5" or 38.10mm the barrel length is about 50 to 52mm ( 3 to 5 mm longer than the original) the spindle dia that you need is 0.626" ( 15.91mm) and needs trimming to 27mm longer than the end of the barrel The other end also has a spindle but that just needs cutting off as close to the barrel as possible, I usually manage 2 to 3mm without any trouble.

Hope this helps. So there you guys have it, I've given you a trade secret away, how good is that!............Don't ever say that the bearing can't be replaced and you have to buy a new front timing cover.. You Don't

Kind Regards to anyone reading this.

[Snagger]

I had a new shaft made up and the cover machined to suit standard bearings as the LR unit is unavailable separate from a new timing case front cover. £££!

[Boydie]

The problem comes in two parts, the first is the flange, its heat shrunk onto the shaft the second is the bearing - there are in fact two.

Okay, heat the flange up to below red/cherry hot and with a puller pull it off the shaft, mark or measure how far the shaft protruded before you remove it.

Next remove the plastic cover and discard it. the bearings have a removable cage, lift this out and the roller bearings and the shaft will draw out.

You can obtain a new seal, do so and fit it - I got mine from a company called Bearing Services, its a standard size. Check the bearings, in most cases its a simple case of poor lubrication due to thick dry grease. repack and replace the bearings, if any balls are badly brinnelled (cracked) replace them, I got a whole load of them from my local bicycle shop.

Lastly, go to my pictures, you will see the replacement cover I made out of 3mm alloy and tapped a grease nipple into it, fit this new cover give the assemble three or four good squirts of grease - not that much that it comes out of the seal.

Re-heat the flange, this time to cherry hot, fit it onto the shaft and quickly wrap it with a wet rag, keep wetting it down until its hand cool,

refit the cover, you should get many more miles out of it.

[Snagger]

That flange is nigh on impossible to remove - not only is it an interference fit, but it's made from crumboleum, the brittlest metal on Earth! The replacement shaft I had made up to take regular sized bearings (two sealed bearings instead of one pot) has an integrated flange, all one piece. The timing cover needed reaming out a little for the bearings as the pot type is a non-standard size. The whole job, which was a first for the engineering shop (so needed a bit of thinking time and development) still cost less than a new cover and bearing assembly, so is worth considering. This page will give you an idea of what was done: http://www.nickslandrover.co.uk/range-rover-april-2014-update/ The shaft is even along its length from the shoulder on the external part before the flange to its tip, save for the circlip groove. The cover was machined from each side to take the bigger diameter bearings, but leaving an uncut step in the middle that each bearing seats against. That distance is the same as the distance between the shaft's shoulder and clip groove, so even if the bearings did somehow come loose from their interference fit in the cover, the shaft will keep them and the fan in the correct place because of the uncut ridge in the cover plate between the bearings.

[Boydie]

Snagger,

I think you and I went through this some time ago when I rebuilt my spare cover and had a new shaft machined with standard taper roller bearings, seals and a new flange with a left hand thread so it easily screwed onto the shaft.

That said I have rebuilt two other covers and, if you treat the original flange with lots of TLC it will come off in one piece, As an added precaution I submerge the flange in an arsenic mixture to give it a good case hardening before re-fitting. On the ones I've rebuilt I've not seen one with shot bearing races, the balls fail first and show clear sings of brinelling (they must be male components )

It would seem to me that the weakest link is the lubrication grease that was used, despite the temperature the case reaches it goes solid and simply isn't up to the task of lubricating the rollers.

[Snagger]

That's right, Boydie. I did this about 18-24 months ago.