HH Trailmaster Sport 550 21t install help...

[high plains drifter]

Went to swap out the factory Titan and I notice some differences that are hampering the install.

The shaft on the HH is noticeably shorter so I'm having to slide the pinion almost all the way down on the shaft. That means that when it's mated to the factory motor mount and installed, that the pinion and spur are not making full contact across the gear faces. I have a pic here to show where I'm at. What am I doing wrong here or what's up? Is there another HH 550 that has a longer shaft and I simply ordered the wrong one?

[indybama]

Is it the same amount if u flip the pinion the other way? If u flip it the other way n it sticks the teeth out past the spur on the other side, wat bout puttin a shim between motor n mount to set the pinion on the spur where they meet evenly? I would think a thin washer (or 2) would shim it enuf to make the mesh even

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[soze]

So looking at the picture, it looks like it won't work no matter which way the pinion is facing.

What it looks like will work for you is to flip the pinion the other way, and use a motor heatsink/spacer

Yeah Racing Aluminum 540 Motor Spacer Heatsink - https://ebay.to/2ODY1j4

Oddly enough, the Yeah Racing Hackmoto 550 Brushed motor has a longer shaft than the Holmes Hobbies 550 motor. (I currently have one in my BOM and a HH 550 to compare with)

[Topher Builds]

Hmm I’ve had one of those (27t) in a trx4 before and don’t remember issues setting the mesh. I had the pinion flipped the other way though.

This is the one I ordered... https://www.amainhobbies.com/holmes-...t55027/p716284

[high plains drifter]

indybama- I dunno why I didn't think of flipping it. I believe that would solve the issue. I guess I just don't remember seeing it done like that so my mind was stuck on installing the pinion exactly as it was installed on the factory motor shaft.

soze- I'm not sure I understand about using the spacer. Looks like that would just make things worse.

From what I've seen, this is a very common upgrade and I thought it was just an easy drop in replacement/ plug-n-play with no mods or xtra parts required.

[33m]

Flip the pinion around.

[high plains drifter]

Originally Posted by Pant Danza

Hmm I’ve had one of those (27t) in a trx4 before and don’t remember issues setting the mesh. I had the pinion flipped the other way though.

This is the one I ordered... https://www.amainhobbies.com/holmes-...t55027/p716284

I'm assuming that you changed your spur size as well? It looks like flipping it will work but I didn't want to do something not advised by those that have done this or that know more about this than I do lol.

[Topher Builds]

I had the stock spur and pinion in there. Stuck with mounting holes C and it worked out for me

[high plains drifter]

Gotcha. Thanks. I'm guessing that the truck ran slower with the 27t & stock gears?

Really appreciate the info, guys. Gonna flip the pinion and see if it all lines up that way. Mainly just wanted to make sure I wasn't doing something wrong or had the wrong motor. Thanks much.

[soze]

Originally Posted by high plains drifter

soze- I'm not sure I understand about using the spacer. Looks like that would just make things worse.

From your picture, it looks like if you flipped the pinion, it would still overshoot the spur gear by the same amount that it's undershooting right now.

So what I was suggesting is to flip the pinion so that it overshoots.... then use the spacer between the motor mount and the mount to back off the motor until the pinion is in line with the spur gear.

[Topher Builds]

Originally Posted by high plains drifter

Gotcha. Thanks. I'm guessing that the truck ran slower with the 27t & stock gears?

Really appreciate the info, guys. Gonna flip the pinion and see if it all lines up that way. Mainly just wanted to make sure I wasn't doing something wrong or had the wrong motor. Thanks much.

A little bit, it didn’t seem too far off from the 21t with 9t pinion. Still fast enough to flip itself over on tarmac with the drag brake on at 100%

The only other thing I’d mention is that the HH motor spins forward, whereas the stock traxxas 21t spins reverse, so just flip the positive and negative on the esc and it will run the right direction.

[high plains drifter]

PD- Can't I just solder the neg lead to the pos tab on the motor and visa-versa with the pos lead to the neg tab?

I think things are looking good now!

[Topher Builds]

Originally Posted by high plains drifter

PD- Can't I just solder the neg lead to the pos tab on the motor and visa-versa with the pos lead to the neg tab?

Yup! That’s what I did.

Looking good HPD!

[soze]

Looks like you were able to get it lined up after flipping it. Looks good!

[high plains drifter]

Thanks again, folks. And I know some of the questions are dumb but you never know... Sometimes when it's something new, you tend to overlook things that are obvious to the more experienced guy. Okay... now to get this thing done so that I can run some trails this weekend!

[indybama]

The only dumb/stupid question is a question not asked. Granted there a million threads on the same subject, but they dont always have the answer to 'your' question. Glad we could help out!

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[high plains drifter]

Yea... I try to search as much as I can first but there have certainly been instances where due to specifics, it was simply more beneficial to start a thread. I appreciate the understanding.

She's up and running now. Flipped the pinion and reversed the leads as advised. Then got everything buttoned up and gave her a little test run around the house. 100% back in business... no issues. Thanks again, guys.

[OSRC]

Glad you got it worked out. Curious to hear how the Holmes motor compares to the stock 550. Considering one for my TRX as well.

[high plains drifter]

Originally Posted by OSRC

Glad you got it worked out. Curious to hear how the Holmes motor compares to the stock 550. Considering one for my TRX as well.

I could've sworn that it felt less "jerky" upon pulling the trigger in both fwd & rev while running it around the house last night but that could've just been a false observation since I was being extra careful not to run into any walls... not sure.

[o0wiz0o]

Great motor choice. I have 200 miles on my 27t HH motor!