Typhon Stripped Pinion Grub screw

OrangeDRAGON

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I ran into a problem with the pinion gear, whoever built this car really tightened the crap out of the grub screw and/or used too much thread lock. While I was not using ball-hex drivers, I was using a quality set of metric Allen keys (not the kit crap keys) and just when I thought it broke the grub screw loose, instead it rounded it out. Now I'm trying to decide whether I'll be fine sticking with the 14t for a while (on 4s) or if I should break out the Dremel tool and get this one off to put on the 16t (which was my original intent) :/

EDIT: Well it looks like that idea won't work either. I can't remove the motor from the aluminum mount with the pinion installed and the grub is on the 'inside' of the pinion so there is no way I can grind it out without damaging the motor mount.

The last thought I have is to put the pinion in a vice and use a tap and hammer to try to punch the shaft down out of the pinion, seems like the least 'dangerous' option. I'm afraid any attempt at just 'prying' the pinion will damage the aluminum mount.

Anyone else have any ideas?
 

OrangeDRAGON

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Heat it and use a torx head to get it out...
Hmm, I thought about that - the Torx driver I have is a tad big, so I assume you mean hammer the crap out of it to push it into the grub end? Heat the pinion/grub to break it loose? Or to swell the pinion so it's easier to get off the shaft?
 

Dustin Mustangs

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Post a picture of the pinion and grub. If you don't care about the pinion, there are definitely ways to get it off.
 

OrangeDRAGON

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IMG_0404.jpg

Well as you can see I notice a 'lip' on the end of the shaft, so pounding out the shaft (or using a pinion puller) is out...

I'm going to try hammering in a Torx driver and heating it.. if that doesn't work I'll have to break out the drill bits :/
 

Walter

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Ideas to try:
  1. Use a screw extractor
  2. Dremel a cut in the pinion screw and use a flat head screw driver
  3. Grind off the lip on the motor shaft and use a pinion puller
  4. Glue an allen key into the pinion screw, let the glue set and then try to break the screw free.
  5. Call Arrma and ask for a new motor, motor mount and pinion... you might get lucky.
 

OrangeDRAGON

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Well its done, but it easily one of my worst experiences. I've had pinions get stuck, but never as bad as this.

I tried the torx, and and then used a US Allen wrench (just a hair bigger than 2mm) along with heating the pinion. Both seemed close to working but just stripped the grub further, eventually I reached a point where there was nothing but a threaded in slug.

I broke out the dremel - but knew no matter how careful I was I would still get some marks on the shaft, so before I dremeled I used a punch to push the pinion off to the end of the shaft. Which is a good thing because as you can see there are a few marks on the shaft - but since the new pinion's grub won't sit there (you can see where it sits further back on the shaft) I don't expect any issues.

Thanks for the help everyone!

motor-shaft.jpg bad-pinion.jpg

You can also see just how damn tight that grub was, it left an indentation on the shaft :eek:
 

Jerry-rigged

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Wow, ugly. Glad you got it off...

The heat is supposed to break down any thread lock. The torx works on SAE sized allen heads, because the distance across the points is the same from allen to torx, so the torx can grab the corners of an other wise stripped allen screw. but sometimes nothing works, other than a grinder and a big hammer... :)
 

OrangeDRAGON

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I think the heat helped, but I just couldn't get it hot enough. My soldering iron is not hot enough and when I used even a tiny butane torch the motor mount started getting hot. The torx did exactly that - fit corner to corner perfectly, but that too eventually broke free and rounded out. I went up in size on the torx, hammered it in and thought for sure this was it, nope... :( It really wanted to fight me all the way LOL

Wanted to add, I spun the motor up on the bench to make sure no damage and spun true - and it was all good.

I installed a new 16T pinion, set the mesh, took it out for a test drive and it so far it seems perfect!
 

Typhon

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Well ^ sounded like hell. How in the heck am i going to change my pinion now considering im rocking a sling for my right arm.
 

Trillium

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I changed the 14t to 16t on my new Typhon yesterday and can confirm that although it was a bitch to get out (way way too much locktite on every screw thread) I did managed to get it out "slowly" with some serious hex key bending. However many muppets Arrma have putting these things together they seriously need to be told to only apply locktite to a few threads only! Honestly the screws holding the motor in place looked like they had been stored in the dam stuff.. ! massive overkill and costly for everyone. C'mon Arrma, update those dam manufacturing procedures man.

Anyway the pinion is now done.. wheels, springs and shock oil next!
 

Hypnotoad

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This happened with my SSenton. Eventually I just bought a new motor mount the same day I got the truck in the mail. i had a spare Castle motor laying around, so I just put that in there. Stock motor is still stuck to the original motor mount to this day.
 

Kauaiguy

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This happened with my SSenton. Eventually I just bought a new motor mount the same day I got the truck in the mail. i had a spare Castle motor laying around, so I just put that in there. Stock motor is still stuck to the original motor mount to this day.
Use heat before you ever put a hex key on it,or anything that doesn't move easily,before you strip the head.Its a lesson learned.
 

Brainsick67

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Same happend to me...way really mad..never had it happen before, luckly i took it to work, theu got it off..whew.
 

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