Kraton Arrma motor mount screw confusion

[Airwolf076]

Not that I'm considering using either of these, the stock motor mount screws are complete junk, but trying to get an idea what size and pitch I need to order, so thought I would pull up the arrma part number.......... and....... wtf Arrma? Which is it?

Edit: Since on the topic of motor mount screws, I used a pitch gauge to check the thread pitch on the M4 screws that came out of the diff housing, assuming that all of their M4s are probably the same pitch, The closest I could measure for pitch was 0.7mm, but man it's really hard to tell for sure when the threads are this small. Can anyone who's had to order their own motor mount screws confirm or deny that it's a 0.7mm pitch I need?

 

[GraniteFox]

18mm is correct for the two top screws on the motor mount. I replaced them with 18mm M4 caphead screws. Far better than these things that strip out after one adjustment. You may need to grind back the plastic a little to accomodate the cap head depending on the size pinion.
If using a cap head add a washer as well

 

[Airwolf076]

18mm is correct for the two top screws on the motor mount. I replaced them with 18mm M4 caphead screws. Far better than these things that strip out after one adjustment. You may need to grind back the plastic a little to accomodate the cap head depending on the size pinion.
If using a cap head add a washer as well

Cap head with washers is the way I'm going to go as well, atleast one of my motor mount screws needs to be slotted because it's on the verge of rounding....... what were they thinking using such a shallow head for such a critical screw?

 

[Camaroboy383]

Yes, .7 pitch is correct.. what are you using for drivers? Can't say I've ever had an issue with the factory mount screws..

 

[Airwolf076]

Yes, .7 pitch is correct.. what are you using for drivers? Can't say I've ever had an issue with the factory mount screws..

Thanks. Mine came from the factory with a ton slop in the heads, just sneezing on them will round them. I haven't rounded them yet, but I can feel they're about to go.

 

[AIan]

MIP drivers are worth there cost in my humble opinion

 

[Engineer]

The factory fasteners are horrible. I use flanged Grade 12.9 M4 SHCS from McMaster Carr:

 

[Airwolf076]

The factory fasteners are horrible. I use flanged Grade 12.9 M4 SHCS from McMaster Carr:

Now THOSE are nice.

 

[JKWoods]

The factory fasteners are horrible. I use flanged Grade 12.9 M4 SHCS from McMaster Carr:

View attachment 222120View attachment 222121

Do you have a link or part number for those?

 

[Engineer]

Do you have a link or part number for those?

Here you go: https://www.mcmaster.com/catalog/128/3417

 

[RcDad23]

M4 Socket Head Cap Screws, 12.9 Alloy Steel w/ Black Oxide DIN 912, Coarse 0.70
That's what I bought on ebay

 

[GraniteFox]

I used the 3mm cap head. Can really crank on them with no issues.

 

[dure16]

The factory fasteners are horrible. I use flanged Grade 12.9 M4 SHCS from McMaster Carr:

It looks like 18mm isn't an option (only 16mm or 20mm). Do you buy 20mm and dremel them down?

 

[Smilinbri]

It looks like 18mm isn't an option (only 16mm or 20mm). Do you buy 20mm and dremel them down?

The 16mm fit fine with no adjustments. I use these from McMaster-Carr.

 

[Engineer]

It looks like 18mm isn't an option (only 16mm or 20mm). Do you buy 20mm and dremel them down?

As mentioned above, 16mm works fine. I ordered them from McMaster-Carr

 

[aaronw]

Home Depot has the M4 socket head in 16mm, work perfectly

 

[mryan884]

The stock ones are indeed trash. stripped one out the first time I removed them. I ended up ordering some Scorched RC 3mm hex grade 5's. They've been great.

 

[aaronw]

Get this from Home Depot;