Replacing 4 1/2" Grinder Gears

[Tomfromuk]

Hello,

I've got an old Bosch PWS 600 4 1/2" angle grinder with worn crown and pinion gears. I've stripped the gears out and it looks like I can get replacements ones for about £6. I suspect the gears have worn because there is something bent or a bearing is worn.

Has anyone any success replacing these gears?

Cheers,

 

[daedalusminos]

For the price of a new grinder and the time taken to repair your old one, perhaps it's time for a rethink.

 

[bourbon]

Agreed, What is the price of the same model grinder? If it's a cheap one, then bin it. If it's pricey then go for it. If you can get the gears, then what have you got to lose? apart from a few quid and an hour or two of your time

 

[stuvy]

My 1000w dewalt with super skinny body was £50

 

[ronan]

4 1/2" grinders are usually a bargain, i bought a hitachi for about 60 quid years ago, worked it hard and its still perfect. I have had my moneys worth, if it were to break, i'd bin it and buy another.

 

[RichardM]

I replaced the gears on my grinder years ago. Never had a problem since. Although if it goes now I may just take the buy a new one option.

 

[nickk]

If it’s the Bosch I remember from the ‘80-early ‘90’s,then they’re well worth repairing,on the basis of the 3 I’ve had ,they’ve outlived the newer models of Bosch,hitachi,Makita,several times over.

 

[RichardM]

^^^ good to know - it's still going strong

 

[Dcal]

I've changed gears in grinders, usually making one or two usable grinders out of a box of scrap.
For 6 quid why not give it a go, but I would check that the bearings are available (and cheap) before going too far.

What have you got to lose and if it works it should last for years.
I'm all for extending the life of gear instead of just dumping it (wheres the fun or learning in that)

 

[frank horton]

If the gears have gone the bearing won’t be far behind....
When on special at Screwfix i bought 10 box's of Hitachi grinders for £85
They contained a 9” and a 4,5” grinders in each box..it was a while ago tho....but specials r out there...
They are all out with different blades and wire wheels....never looked back....hahaha...

 

[Gareth J]

I replaced the bearings on a Bosch gws 4,1/4"

Not expensive and it's still going well but does take a while considering the cost of new. After doing it, I probably told myself that it was a waste of time and never again.... but, knowing me, I'd probably do it all over again anyway.

Since then, the brushes and a "noise suppression" gismo have gone. Trigger's broom.

 

[sardine]

Replacing bearings on the PWS is easy, basically drop in sealed bearing units like most small grinders.

 

[Tomfromuk]

Thanks for the input lads, I think I'm going to do both I'll cough up the 5.80 for a crown and pinion gear (inc delivery). I've had a play with it today, one of the small 608RS bearings wants replaced (£1.99 from the usual suspects).

I'm also going to keep an eye out for a sale at the likes of screwfix or toolstation. Wouldn't mind picking up one the £50 makita grinders, they seem to get good reviews.

Cheers,

 

[nickk]

Don’t get excited,Makita are not what they used to be,I’ve junked 2 x4.5” and 1x 5” recently that had an average life of 4 years,my old 1020w 5” the one with a long body,is still going,that’s from the early ‘90’s

 

[sardine]

Are they gen Bosch parts for £6 ?

Hard to believe .

 

[Kent]

Not worth an hour of my time and invariably something else will give up soon after.

 

[Wallace]

Use quality bearings such as SKF like for like, ie if they are metal shielded don’t be tempted to replace with fully sealed as the seals created extra drag and eventually burn out due to the speed.

 

[eLuSiVeMiTe]

Don’t get excited,Makita are not what they used to be,I’ve junked 2 x4.5” and 1x 5” recently that had an average life of 4 years,my old 1020w 5” the one with a long body,is still going,that’s from the early ‘90’s

Don't do brand loyalty and swap and change with 240/120v tools.
Grinders I prefer Bosch some of mine have been going for years and that's masonry and concrete more than metals so very dusty in comparison.

 

[Dcal]

Not worth an hour of my time and invariably something else will give up soon after.

@Kent not having a go and I totally agree that something else could go pop soon after.
Also I really appreciate input from the professionals on here but, (theirs always a but)
Personally, I like taking something apart to see if I can make them work again.
I don't work with hand tools in my day job and if they were the tools of my trade I might have a different opinion.

Some people do Morris Dancing or assemble jigsaw puzzles to relax.
I prefer 3d jigsaws that gets me off my **** and the trickier the better. Ok so a grinder might be a 10piece jigsaw but if you don't start you will never know.
I've had plenty of fixes that have beaten me but half the fun is in the journey (and knowing when to give up.)

Each to their own and remember this is a hobby for lots on here.
There are plenty of people ready to tell us we are mad with how we spend our spare time without people on the forum telling us to be sensible. (Even when they are probably right)

 

[Wallace]

Check the brushes and commutator whilst apart and the motor bearings. Pay particular attention to the motor end float and how it is taken up as that affects gear meshing. Power tools can be fiddly to repair and have some quirky design features for bearing and cable retention. They can be satisfying to repair especially if they are free and only need brushes.