Help with Input shaft pin - RC-Monster Forums

luvsrc · **Help with Input shaft pin -** 04.13.2007, 03:49 PM

Hi guys I was practising today and the pin on my input shaft got broke any suggestions to make it stronger? thanks

ClodMaxx · 04.13.2007, 03:54 PM

i've heard of guys snugging a 2mm allen wrench (cut to fit) in it's place.

BrianG · 04.13.2007, 03:54 PM

There was another thread recently that mentioned that. IIRC, they mentioned something about using the shaft from an appropriately sized drill bit...

ssspconcepts · 04:21 PM

Quote:

Originally Posted by luvsrc

Hi guys I was practising today and the pin on my input shaft got broke any suggestions to make it stronger? thanks

Assuming you completely sheared the pin the secures the input gear to the input shaft follow these steps:

1 drill out the old retaining pin from all parts.

2 find the next size allen key/wrench that is just barely too big to fit in the holes you just cleaned out.

3 take a dremel with a cutting wheel and ever so slightly grind some of the edges off of the allen key/wrench...keep doing this until you can eventually force the allen key/wrench into the holes. It stands to reason that when grinding the key/wrench, make sure you grind more from the front (point of insertion) and less from the rear....kinda like a tent peg.

4 cut the key off at the gear collar and grind & file to perfection.

5 for added retention, carefully apply a dab of JB Weld on both sides where the new pin (allen ke/wrench) is visible. let it dry/cure per instructions.

6 clean and file to perfection using fine jewelers file.

Information on JB Weld:

http://jbweld.net/products/jbweld.php

ssspconcepts · 04.13.2007, 04:23 PM

Quote:

Originally Posted by luvsrc

Hi guys I was practising today and the pin on my input shaft got broke any suggestions to make it stronger? thanks

By the way...I have bullet proofed two input shafts to date and wanted to let you know that it is a pain in the butt:028: . But it is worth the effort once it is done.

zeropointbug · 04.13.2007, 06:31 PM

LuvsRC, once I get my parts for my truck early this week, I will do the pin mod right away and I'll post the results for you... if you can wait that long.

BTW, you don't need to drill out the pin.... just take the gear off, and get somethign smaller than the hole to hammer the pin out. I agree though, using an allen wrench is the best bet, I think that's what I'll use, because you can easily take away material from those edges.

ssspconcepts · 04.13.2007, 08:52 PM

Quote:

Originally Posted by zeropointbug

LuvsRC, once I get my parts for my truck early this week, I will do the pin mod right away and I'll post the results for you... if you can wait that long.

BTW, you don't need to drill out the pin.... just take the gear off, and get somethign smaller than the hole to hammer the pin out. I agree though, using an allen wrench is the best bet, I think that's what I'll use, because you can easily take away material from those edges.

I recommend drilling out the hole...this serves two purposes:

1 makes the hole just a tad bigger for a larger/stronger hex key.

2 cleans the metal so the JB Weld will stick better.

zeropointbug · 04.13.2007, 11:01 PM

That's true that it will make it stronger, but how strong does it have to be?

What size allen key did you use? And drill bit size?

zeropointbug · 04.13.2007, 11:02 PM

Actually I shouldn't say that.... :005:

Have you checked out my Quark heatsink thread? To big?! :005:

ssspconcepts · 04.14.2007, 12:50 AM

Quote:

Originally Posted by zeropointbug

That's true that it will make it stronger, but how strong does it have to be?

What size allen key did you use? And drill bit size?

I started out by using a small nail....actually drove it down inside the existing hollow pin. It eventually failed. Then I spent the next couple of days disassembling my maxx tranny and doing it the right way. You ask how big does it (the pin) need to be....well there is definitely a balance-afterall you don't want to weaken the shaft.

I ended up using a 2mm hex key...but bear in mind that it did take a little bit of gentle grinding to get it to fit in the hole. I think I used a 5/64 drill bit.

luvsrc · 04.14.2007, 08:22 AM

thank you guys:027:

zeropointbug · 04.14.2007, 12:38 PM

yah, thanks sssp.

2mm would be more than enough yes, what are the pins in the cvd shaft's? around there, and alot more torque(plus it's loose fit), so this should last for sure.

Finnster · 01:46 PM

Quote:

Originally Posted by BrianG

There was another thread recently that mentioned that. IIRC, they mentioned something about using the shaft from an appropriately sized drill bit...

I did the hex key trick a while back, but just sheared it clean off last week.
This time I drilled out the holes a bit bigger and put a drill bit shaft thru instead.

I was going to use green locktite (max str bearing retainer formula) on the gear and shaft as well, but I got impatient and just went with the drill bit.

If it breaks again I will use the locktite, and possibly drill bigger and tap w/ 3mm to use a driveshaft thru pin. Don't want to go too big and weaken the shaft, but I think it would take it.

zeropointbug · 04.14.2007, 03:25 PM

Finnster, was your hex that you used very tight in there? If it's not in there very tight, the strength of it will be severely compromised. I think it should only be able to be put in with a hammer, or a vice (tighten it up). How was yours?

ssspconcepts · 04.14.2007, 03:27 PM

Quote:

Originally Posted by Finnster

I did the hex key trick a while back, but just sheared it clean off last week.
This time I drilled out the holes a bit bigger and put a drill bit shaft thru instead.

I was going to use green locktite (max str bearing retainer formula) on the gear and shaft as well, but I got impatient and just went with the drill bit.

If it breaks again I will use the locktite, and possibly drill bigger and tap w/ 3mm to use a driveshaft thru pin. Don't want to go too big and weaken the shaft, but I think it would take it.

Wow...what are you running that you sheared the 2mm hex key?