Removing gearbox screws/bolts? HELP!

[oldsckooler]

Whats the best way of removing the flat head screws/bolts on a gearbox and water pump housing?

Thanks, Emrys ; this forum is fantastic!!

[AusOB_Collector]

Hi Emrys

Equipment needed:

- good fitting screwdriver
- blowtorch/ heat source
- wd40/ penetrating oil
- adjustable spanner

All you need to do is heat up the general area of the gearbox where the screws are to remove the end-cap. When you deem it to be hot enough, try unscrewing the screw (if it is quite tough, try gently with the adjustable spanner on the shank of the screwdriver to help give you a bit more leverage). Once you wind it out a couple of turns, spray some wd40 on the visible threads; it should with any luck soak through and help you remove the screws with less effort. This all depends on the amount of corrosion on the screws.

For the screws on the pumphousing... you either have an original 40 or 100 series motor (or a non-original 102, they had hex-head bolts).
The best way to get those screws out is to remove the powerhead and the exhaust tube from the entire motor, so you are just left with the gearbox attached to the drive tube with the transom bracket still on.
Now just repeat the aforementioned process (with the exhaust tube removed, you should be able to get to the inside screw easier now).

Good luck!

Cheers
BP

[Oyster 49]

Heat is definitely your friend here, get the area of the case nicely warmed and put the screwdriver in and give the driver a firm tap downwards with a hammer, which can also give the threads a good jolt. take your time and be careful not to damage the screws. If you have to repaint the case then so be it. Make sure the screwdriver is the right size for the slots and not too small.

As a sensible modification use cap head bolts as a replacement (Allen screws) and apply copper grease to the threads upon re-assembly.

Best of luck

[headdownarseup]

Blowtorch and a good fitting IMPACT DRIVER with some longer than normal bits.
Perhaps a selection of suitable screwdrivers too, but they must fit the slot of the screwhead nice and snug.

Never (ever) had one i can't undo and dismantle using this method. Some that i've worked on have been completely covered in corrosion, but they've come apart without too much grief eventually.
Heat is your biggest friend here, then the shock of the impact driver is usually enough to get things moving.
And as per Oyster, always use some form of anti-seize compound on the bolts upon re-assembly.
That's all i ever use

Jon

[oldsckooler]

Well I managed to get three out. Two from gearbox and one from waterpump housing..The final water pump housing screw in the countersunk one. The slot has started to get messy looking now....oppps

What my options? Drill it out? Any other ideas?

[Twinkles031]

After weeks of soaking it in penetrene, and hitting it with an impact driver, i ended up resorting to drilling the head out on that one. Once the head was off and tension was released, the rest screwed out easily, but it was not going to budge as it was (didn't help that it had been sitting outside at the local rubbish tip for 10+ years).

[headdownarseup]

You need to be careful if you decide to drill out what remains of the screw. I bet it's the one in between the 2 tubes rather than on the front edge of the box!

I've only ever done 1 in this situation, all the rest have come out with an impact driver and LOTS of heat. Dont be shy with the heat either, these boxes will take a LOT of punishment before they throw in the towel.

What you need to do is drill enough of the screwhead out but be very careful NOT TO DRILL the aluminium casting. All i can say is GO STEADY with it.
I have plenty of spare pump housings for most gearboxes in my spares boxes if you need one, just in case.

Best of luck

Jon