LadyInBed
Well-known member
All is not lost, you will know for the next time ?
Any tips, please, on using a cheap 3 legged puller?
- Thread starter NealB
- Start date
superheat6k
Well-known member
Best way to put the bearings on is to gently heat them to just above 110oC, they should then drop straight on. A hot air paint stripper will easily get them warm enough. Only use flame heat if you know what you are doing. We use an induction heater at my factory, which to allow for cooling once the piece is removed from the heater we set to 130oC. This means the bearing is still just above 110oC when it is placed onto the shaft.
NealB
Well-known member
Thanks for adding a bit of commercial inside information to posts 16 and 19.
Norman_E
Well-known member
If you are prepared to destroy the shaft just remember that the puller has aleady moved the bearings some distance along it, therefore they will move back again. With that in mind cut the shaft close behind the bearings and remove any burrs left by the cut. Get a piece of steel drilled through clearance diameter for the shaft, place it on a solid surface and use a steel punch and hammer to drive the shaft out of the bearings, driving them back the way they came.
WoodyP
Well-known member
Am I missing something here? You need a new shaft, two new bearings and are faffing about trying to retrieve the spacer?. Why not just get a new spacer as well?
Caraway
Well-known member
Faffing is an integral part of maintenance.
NealB
Well-known member
Yes, a new spacer would be simple, but:
1) The kits I've seen online don't seem to have new spacers (yes, that seems odd to me, too).
2) The rebuild kit I bought, certainly does not include a spacer
3) The several videos I've watched all emphasise the need to keep the spacer.
WoodyP
Well-known member
Just watched the video, and it appears that there are two spacers. One is plastic separating the o rings , and one metal separating the two bearings. It looks as though it could go wrong and the cost of new pumps looks horrendous. Good luck! Perhaps a trip to an engineering workshop may be cheaper in the long run.
NealB
Well-known member
The plastic one comes out very easily, and is safely stowed in the garage (phew!!).
Still struggling with the steel one, and that trip to a friendly local workshop is imminent.
The new VP pump is over £400, though there's a suspiciously similar (identical?) one available for just over £200.
Having said all that, it would be good for my self-esteem if I could do it all myself (it's the first 'engineering' I've done since my late teens, fiddling around with Minis, Heralds and Anglias!).
WoodyP
Well-known member
I have an infinite capacity to try and mend things until they are completely beggared. Confidence exceeds ability in my case?
NealB
Well-known member
Yes ..... that's something I'm VERY familiar with (particularly these last few days).
Actually, I'd say it's more 'hope' than 'confidence' (or, maybe, even 'wishful thinking') in my case!
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Norman_E
Well-known member
If you follow my method above, you will only have to drive the shaft to get one bearing off, as the spacer is likely to be a loose fit.
ean_p
Well-known member
Are you sure about these temp levels? Are they for ordinary bearings? I've always understood that 100°is about the limit for normal bearings and less if fitted with seals or shields! Just looked at the SKF web site and they reckon that 125° may change the fabric condition of the bearing!
38mess
Well-known member
If the shaft is kaput just knock it through with a big hammer
gordmac
Well-known member
I wouldn't try putting the new bearings on with the puller. If you pull on the outer bit you will likely damage the bearing.
Caraway
Well-known member
It seems to have become a very difficult issue. How can removing buggered bearings be so hard?
38mess
Well-known member
They usually just slide on
gordmac
Well-known member
Not if it is an interference fit which is likely on the rotating part. The non rotating part is usually a transition fit as, in theory, only the friction torque in the bearing is trying to rotate it. Mind you, it is quite a while since I did any design of stuff with bearings so I might be miss recalling!
RichardS
N/A
He probably means "slide on" after you've done the heating/freezing bit discussed earlier, when it almost certainly will.
Richard
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superheat6k
Well-known member
Been doing this with the induction heater for many many years - as an example of this practice the entire Virgin Pendolino train fleet AC compresors were overhauled by my firm in 2012 - nil failures. My understanding is no degradation occurs below 150oC and most of these bearings will tolerate 120oC continuous running temperature. Most of our bearings wil have an ID between 35 - 75mm. If we heat to 110oC by the time the bearing has been taken off the heater armature, then slid over the end of the shaft and perhaps touched the cold shaft on its way down to its intended position they can stick before fully home. Taking them to 130oC avoids this problem.
Those who heat bearings with a torch really have no idea what temperature they will be gettingn plus the temperature wil be very uneven.
An old electric chip frier is an excellent bearing heater, but might make the chips taste funny.
