agm mp40 trigger block/switch

Yep any front wired v3 block will do but you can only use one of the contact block securing screws depending on the model of mp40.
I used guarder high speed gear grease on mine and had no problems for about 4 years continuous use.

I tend to use black moyibdomen grease on the gear teeth and regular mineral grease on the axles ,while there I'd lube the piston with silicone oil not grease , airsoft world sell a 3 pack of lube by element thats very good and cheap as well .

Cheers for the replies.

Have a switch on its way and some grease.
I have some silicone oil from an r/c shop.....3 different viscosities from almost water like to not quite water like. Think they range from 2000 to 250.

Is it worth me doing anything else whilst gearbox is open ? Perfectly happy with performance before it stopped playing ball but anything that would be worth changing for reliability ? Everything is stock
Fire-Support sell Dirty Works Switch Life Extenders which apparently reduce sparking/arcing...thinking of adding one in if compatible with the mp40.
Reading up on shimming at the mo.....as have 4 that came out the gearbox but not too sure which cogs they came off as the innards were all over the shop as I opened up.....yep I'm on a learning curve....I've put it back together a few times over the last week testing and practising.

The silicone oil must aid the air seal but not be so viscous that it adds friction ,if your talking about rc shock oil then you should be fine but if its rc diff oil its probably too viscous .
With shimming generally out of the box you get one shim on either side of the gear ,probably the same thickness . when re-shimming your aiming at getting the maximum engagement or the gears without the sides of the gear rubbing each other and you will need to buy a pack of shims of different thicknesses in order to get it right ,look up a YouTube clip as there are many good guides out there ,it does not matter what airsoft gearbox the YouTube clip is for as the principal is the same .
On most guns there is also a screw that adjusts the motor pinion gear engagement by pushing the motor in or out of the gearbox ,the grub screw for adjusting it is not fitted on the mp40 but the screw hole is there as is the metal disk it pushes onto and I'd recommend fitting the adjuster screw if your changing the shimming otherwise you either end up with a screeching gearbox or an overheated motor ,again there are plenty of YouTube clips about motor height adjustment so just have a look .
If you get stuck just ask as there's plenty of good tech's on here and we're happy to help.

Cheers Dadio......have shims on the way and gave been watching a few vids.
Just been sat looking at the motor and housing looking for the screw hole and scratching head....quick search turned up your post from a couple years back and an 'aaaaaaah'.....m5 x 5mm.

Much appreciated info and pointers as always

Just send the cash to the usual place

Took the trigger assembly off the motor to check situation.......hole and plate present, though threading isn't. Do I get a thread cutting tool for 5 mm or should it be a size bigger ?

As I remember an m5 tapp (5mm) is what you need (the hole should be 4.2mm ish to tapp out to m5) ,I think mine was already threaded but its long time ago and I could be wrong .
It might also be worth checking that the little disk is fitted behind the motor's rear bearing ,as that is where the grub screw pushes on to to adjust it ,if they stopped cutting the thread they might have left that out as well and you don't want the grub screw pushing on the end of the rotating motor axle .
Oh you probably realized but you need to adjust the motor height before re fitting the trigger as you have no access once the trigger is fitted ,most YouTube clips will show it done on the completed gun as thats the way they are designed .

Checked , disc still there. Just waiting for Mr. Postie

I really need to increase my German sweaty vocab!
Will be on attempt #6 at putting the gearbox back together tonight.

How do you keep everything in place while closing the shells ? Anti reversal latch seems to be the usual suspect for popping at the last second.
Also tappet plate is vexing me somewhat.
I'll try assembly without the latch......just to see if I can close it up and then deep breath and try properly.

I hold the cylinder and spring down with my left hand and put in the spur gear last so the reversal latch doesn't fly out. If I ever meet the original designer of those gearboxes I would slap him.

Think I'd go for some sort of insertion.

Not out of the woods but have found one problem...new switch block was just a little too wide, so shell was never going to close snugly. Bit o jiggering got the contacts from new into old block. So if you need to replace your switch and want a straight swap avoid poisonapple....tho they do appear nice n sturdy.

I've done a few with poison apple switches. Some fit some don't. Think the gearboxes have different tolerances depending on batches. Still a bit of dremel work and it'll go in eventually

The hole for the anti reverse latch is so wobbly and poorly cast its a right mare to fit but don't be tempted to leave it out ,patience pays off in the end.
You mentioned the tappet plate , after closing the gearbox be sure the tappet plate is free from friction ,one of my first attempts at shimming gears I cocked up and put too many shims under the sector gear and it jammed the tappet plate.

Think it's sorted for final attempt tonight.
Hadn't occurred to me that the cylinder head could have moved in the cylinder - probably when cleaning the crud out.
So the cylinder was that bit too far back and fouling the sector gear.
Will have to reshim as had moved bushings around to see if that made any diff.

Thank you Raffles and Dadio for the pointers and explanations....think I will get there tonight

Just been through this with my mp40, contacts just weren't contacting on occasion, really annoying. Got an shs trigger switch but it didn't fit too wide..........it fits now! A light touch of a small file here and there and it went in eventually.
I've gone down the mosfet route, no more burnt contacts, should have had a slight increase in rof, but at the moment I've only got an11.1v lipo to fit in the space with the mosfet.......a little too much on the rof! It's running 780rpm according to my chrono, waiting for the postie to deliver a 7.4 lipo, that should then slow it down again, if not I will change the mosfet for a programmable one.