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Jbo6543

Lunchbox Pinion Gear Problems

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...I recently bought a re-re and have done all the mods I found on here (Lexan runner shell, chassis stiffeners, oil dampers, 3rd shock addition, Sport tuned motor).

Since I've completed all the mods, everytime I run it, the pinion gear loosens and the trannie spins without engaging the wheels after about ten minutes of running the truck.

All I can figure, is that maybe I need to change out the pinion gear from the original to accomodate the sport tuned engine? There doesn't seem to be any kind of hole on the motor stem to line up when tightening the allen bolt on the pinion gear. Is there a "correct way" to attach the pinion gear that I'm not aware of?

Any suggestions welcome, thanks in advance!

Jim

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The motor pinion 'shaft' has a flat on it - make sure that you are tightening the grub screw onto that. I run a 17t motor in mine and have no problems.

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make sure the set screw hits the flat spot on the motor shaft

And use loctite or thread lock of some sort

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you need to really tighten up the grub screw hard, especially on a new build with a brand new pinion gear.

its got nothing to do with the motor (unless somehow you've got one with no flat on the shaft!) as the same system is used to hold pinions on near enough any electric rc car with a 540 sized motor.

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Thanks for the reply, guys.

Of course!, duhhhhhhh......

I'm sure that'll do it.

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The motor pinion 'shaft' has a flat on it - make sure that you are tightening the grub screw onto that. I run a 17t motor in mine and have no problems.

17 turn? That Lunchie must be next to impossible to keep upright! What ESC/Motor combo are you running? I think I'm going to attempt a Wheelie-Bar mod next. Any suggestions?

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17 turn? That Lunchie must be next to impossible to keep upright! What ESC/Motor combo are you running? I think I'm going to attempt a Wheelie-Bar mod next. Any suggestions?

Its actually not as bad as you might think! I run an Mtroniks RV11 ESC (11 turn motor limit) with a Venom Fireball 17t Double motor and its fast but not stupid - I actually think I could have gone for a faster motor - but I wanted to keep the torque for wheelying - which it does - lots! :rolleyes:

Here is MMIB's wheelie bar mod - he has made a nicer job of it than I did...

http://www.tamiyaclub.com/forum/index.php?...st&p=243153

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can it wheelie ok from a rolling start with the 17 turn motor?

badword yeah! :rolleyes::(

As you will see on the 27th!

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One thing I always make sure of when I get a loose pinion is to clean it with a solvent cleaner such as HPI Nitro Cleaner before refitting. Because the LB gearbox is sealed and greased, the problem is that as the grub screw loosens, grease gets onto the pinion gear and/or motor shaft, and then however much you tighten the grub screw, the grease is going to allow it to loosen off.

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sorry to steele this thread, but what extra pinions, or brand is rekomended for the LB?, i know it is a little odd vs the regular 48P (Lois,AE etc) can someone link me to a good store of pinions for the LB? i have a major order from Towerhobbies on tuseday, so that store would be great if someone can give me a link to Tamiya LB pinions

thanks

/Thomas P

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Hi well im running a 15x3 with a rv11 esc only problem i have is fits of laughter i have fitted tlt shocks all round and it handles very well ! :D

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sorry to steele this thread, but what extra pinions, or brand is rekomended for the LB?, i know it is a little odd vs the regular 48P (Lois,AE etc) can someone link me to a good store of pinions for the LB? i have a major order from Towerhobbies on tuseday, so that store would be great if someone can give me a link to Tamiya LB pinions

thanks

/Thomas P

32 pitch gears

are needed for the lunchbox-pumpkin-hornet-grasshopper

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billg4: thanks for this info, but how is it, are there a adjustble mount, or is it fixed(motor) if it is adj, what app range of pinions sholud you recomend Mr ?

/Thomas

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You can either run a stock 10 tooth pinion.

Thats a specific pinion made by tamiya, as its specially designed to work with the long motor mount plate.

Or, remove the motor mount plate, and use an 18 tooth pinion gear from a tamiya hornet.

These are the only 2 choices you have as far as i know. I've not seen an adjustable motor mount plate that works with that gearbox.

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You can either run a stock 10 tooth pinion.

Thats a specific pinion made by tamiya, as its specially designed to work with the long motor mount plate.

Or, remove the motor mount plate, and use an 18 tooth pinion gear from a tamiya hornet.

These are the only 2 choices you have as far as i know. I've not seen an adjustable motor mount plate that works with that gearbox.

The trouble is, 10t to 18t is a huge jump, it shouldn't be too difficult to fabricate an adjustable motor mount along the lines of the MRC? / CRP? mount for the Brat / Frog chassis I would have thought. Even if it was only a small adjustment range it would give you some better pinion choices.

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Thanks mates. I will be stuck with the 10th pinion for a while..il change motor insted =)

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to fit the CRP frog type mount you will need to do some sanding/grinding to make it fit. It can be done, just not a ''bolt on'' item on the pumpkin/lunchbox

Also, it may not allow a full range of gears because of how it has to set in there, but will allow a better variation than 10 & 18

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