Gear help needed please.

[j king]

Hi all. I have a problem trying to determine what I have and or need.
The water pump drive gears went dry on my car and they want a **** load of money for the 2 gears.Being a machinist I can't see paying the price if I can avoid it.
I can't figure what the pitch is.One gear is so bad it can't be measured and the other is pretty bad.I set the gears up on the mill and laid them together and read the center distance as close as I could.This is with them clamped together so it's probably tight.
The center distance is 1.670. Small gear has 24 teeth and larger has 43 teeth.I was looking for off the shelf gears that I can bush or bore the hub to my needs.
I don't care if the gear ratio is a tooth or so off.this is on a supercharger that runs from idle to 6800 rpm so I can't see a little ratio change to be a killer.
So can anyone figure what will work with the supplied infro.? My head was spinning reading up on gears.The more I read the more I realized that it's above me.lol. Thanks. Here is a pick of carnage.



I don't know if the pitch is imperial or metric..

[RichR]

Hi j king

I set the gears up on the mill and laid them together and read the center distance as close as I could.

Wouldn't it make more sense to get that measurement from the piece the gears mount on?

[rklopp]

I will be amazed if you can pull this off and make gears that survive in the home shop. I have little doubt the OEM has pushed the design to the limits to save cost and weight. Hence your material and workmanship has to be top notch.

BUUUT, all that said, why am I not seeing any signs of oil?

[TGTool]

From the photo it looks to me like the original design may have been compromised. It appears like the mating gear didn't mesh properly from the grooved track left on the one in the photo. With proper mesh, the gear teeth should reach close to the root.

[j king]

I will be amazed if you can pull this off and make gears that survive in the home shop. I have little doubt the OEM has pushed the design to the limits to save cost and weight. Hence your material and workmanship has to be top notch.

BUUUT, all that said, why am I not seeing any signs of oil?

I said I would modify factory made gears. No oil? I suppose that's why it crapped out. Holds 2 oz. that's it and you have to disassemble the whole car to service this. Pull nose off car remove supercharger ect... It's a joke. I will drill housing so I can put a piece of wire into cavity to check level and be able to add oil. Only 40000 miles!

[j king]

From the photo it looks to me like the original design may have been compromised. It appears like the mating gear didn't mesh properly from the grooved track left on the one in the photo. With proper mesh, the gear teeth should reach close to the root.

I don't know why the one gear was narrower than the little gear shown. I will make them the same thickness.

[j king]

Hi j king

Wouldn't it make more sense to get that measurement from the piece the gears mount on?

Sure would. I could set up super charger and sweep the rotor shaft and remove needle bearing and get that bore. Was hoping to get someone who knows gears to chime in

[RichR]

OK, I'm no gear expert by any stretch but here's what I would do. Take the gear with the groove worn into it and measure the height of the teeth at the
unworn section (peak to valley). Then take the mating gear and measure the diameter from valley to valley and add twice the measured tooth height
to determine the original diameter.

[JCHannum]

As the teeth of the gear in the photo appear intact in the undamaged area, they should provide the necessary information.

http://www.engineersedge.com/gear_formula.htm

Not knowing anything about the engine, ie manufacturer, country of origin, one can only guess at to whether they are metric or imperial. Also, automotive applications are not necessarily held to stock gears, they more than often use a modified tooth profile to suit the application so an off the shelf gear may not fit. Then you get to materials of construction, heat treat, etc.

[j king]

As the teeth of the gear in the photo appear intact in the undamaged area, they should provide the necessary information.

http://www.engineersedge.com/gear_formula.htm

Not knowing anything about the engine, ie manufacturer, country of origin, one can only guess at to whether they are metric or imperial. Also, automotive applications are not necessarily held to stock gears, they more than often use a modified tooth profile to suit the application so an off the shelf gear may not fit. Then you get to materials of construction, heat treat, etc.

Yes I know Jim.I calculated the small gear earlier. I took the 24 tooth gear and added 2 and then divided by od and got 19.847. So guessing this is a 20 pitch? Not sure . I'm thinking it's right.I can't find the 43 tooth gear stocked so was wanting to see if a gear wizened could change count or even modual gear to adapt.They want 275 for these two gears.

To add..the small gear od is 1.310. The larger one is approx 2.25 It is wore on the od a little so that's a close guesstimate .thanks

[j king]

These gears are butter soft too.I drilled the small gear between the teeth and hub to split it to get it off the rotor shaft.a file on teeth confirmed this. Cheap crap.it is an Eaton blower.

[Willy]

This is on a Mini right?
I've heard that this is a very common problem with the supercharger/water pump pto gears. There are a number of kits available in various trims to fix this issue. Spend an hour looking for Mini Eaton supercharger water pump pto gears and or kits and I'm sure you'll get some results.
Don't have a lot of time at the moment but have a look at post #32 in the link I quoted below.
Good luck!

http://www.northamericanmotoring.com/forums/stock-problems-issues/143264-supercharger-water-pump-gear-failure-what-s-the-fastest-it-s-happened-2.html

Supercharger Waterpump gears/drive solution!

---

We now replace the 43 tooth & 24 tooth
water pump drive gears in the supercharger. We also
a gear replacement kit. We see this problem with the gears
on the MINI supercharger quite often. There seems to be
a problem with oil leaking out of the gear case. The sealant
used seems to be the problem.

We also offer a water pump gear/PTO gear replacement kit for $325.00
Kit comes with rebuilt rear plate (bearing,seal,43 tooth gear),
24 tooth gear, shaft seal,needle bearing,sealant,oil,magnetic
oil fill plug,etc.

Supercharger Technologies
352-542-0147 Fax: 352-542-9468
[email protected]

[John Stevenson]

Jim,
Just standard stock 20 DP gears.





You need to find a supplier who has these in the right width and right tooth number.
Can't help with US suppliers but over here the common one is HPC Gears at Chesterfield who list both sizes as stock gears.

[j king]

Jim,
Just standard stock 20 DP gears.





You need to find a supplier who has these in the right width and right tooth number.
Can't help with US suppliers but over here the common one is HPC Gears at Chesterfield who list both sizes as stock gears.

Thanks John! Good to here from you too. Hope things are going well for you..

[j king]

Man I can find the 43 tooth in Europe but not in the USA !! What the hell