Nice work! What motor/ESC you running? and what about tires?

I got adjustable motor mounts and Tamiya high speed gear kits on the way for everyone in my group, so we can all start playing with the gearing . We ran some test laps today and it looks like my group's first actual spec race will be tomorrow.

Hobbywing MAX10 EZRUN 4000kv and I'm running the BSR 32mm wide racing foams. Also a 3d printed big pinion gear cover, cause you can't fit this gearing without it lol

Question for the TT02 gurus.

I accidentally ordered a diff case for the TT02RR, not realizing this is the sealed diff and isn't 100% like the standard diff case.

For my purposes, speed running and bashing, would it be worth it to order the metal innards for the RR diff along with the seal, orings and pinned drive cups?

I do round off the diff gear that holds the axle cup in place every once in awhile, but I now know what caused that. Not the gear part but where the drive cup sits in the gear.

TIA

It may be cheaper/easier to buy the Tamiya 54875 TT-02 Oil Gear Differential Unit than to piece one together. I will try to compile the parts list you need.

Entire Unit
Tamiya 54875 - TT-02 Oil Gear Differential Unit - https://www.tamiyausa.com/shop/optio...erential-unit/ (1 complete diff)

Individual Parts
Tamiya 9805776 - RC 2X9.8MM SHAFT: 49175 - https://www.tamiyausa.com/shop/7-dig...m-shaft-49175/
**Tamiya 9803157 - RC GEARBOX JOINT: 47382 - https://www.tamiyausa.com/shop/7-dig...x-joint-47382/ (NOT AVAILABLE FOR PURCHASE)
**Tamiya ITEM# 51146 - RC GP TG10-MK.2 DIFF JOINT CUP - https://www.tamiyausa.com/shop/nitro...iff-joint-cup/ (Might work instead of above 47382)
Tamiya 9804129 - RC 5MM O-RING (THIN): 44042 - https://www.tamiyausa.com/shop/7-dig...ng-thin-44042/
Tamiya 51144 - RC GP TG10-MK.2 BEVEL GEAR SET - https://www.tamiyausa.com/shop/nitro...evel-gear-set/
Tamiya 51145 - RC GP TG10-MK.2 DIFF. CASE PK - https://www.tamiyausa.com/shop/nitro...-diff-case-pk/
Tamiya 9804477 - RC 2X8MM TAPPING SCREW: 58492 - https://www.tamiyausa.com/shop/7-dig...g-screw-58492/
Tamiya 0444412 - RC DIFF GEAR CASE: 47439 - https://www.tamiyausa.com/shop/7-dig...ar-case-47439/

Here are the manuals for the TT02 RR and TG10-M.2. Note that the oil filled diffs are assembled similarly, but the Nitro car has extra gears inside the diff. This may be for extra durability
Tamiya 47382 - TT02-RR - https://www.tamiya.com/english/rc/rcmanual/47382.pdf
Tamiya 84423 - TG10-MK.2 - https://www.tamiya.com/english/rc/rcmanual/84423.pdf

I hope this information helps

If you are damaging the interal diff gears, GPM makes metal gears for inside the stock? diff. Here is a link for this product on Amazon -

I haven't damaged the diff gears at least on the gear faces. The gears being nylon is the issue however. I was just curious if it'd be worth it to piece together.

The diff I got is the case, spur and pinion; However I run a modified metal WR02 driveshaft pinion on both ends of the driveshaft.
They appear to be the same screws as the WR02 standard diff? I have leftovers of those.
I feel the metal gears with the pin drive cups would be more robust here. I've got the metal lock block in the front diff so it's not an issue up front.
I'll see if it's worth it to build or buy complete. Either way would work.

It is always good to create a shopping list before buying. I sometimes use the online shopping cart on TamiyaUSA.com to help keep an eye on costs. Sometimes Amazon or online shipping can be cheaper but don't forget to factor in taxes & shipping costs/time.

In case anyone is having difficulty describe the different gears in a TT02, this info might help.

- Small Bevel Gear - the smaller gear that is inside the differential.
- Large Bevel Gear - the larger gear that is inside the differential. The gearbox joints are connected to the Large Bevel Gears

- Beveled Ring Gear - the large plastic gear that is on the outside & part of the differential assembly
- Beveled Pinion Gear - the smaller plastic or metal gear that attaches to the propeller joint

- Spur Gear - the typically plastic gear that attaches to the rear propeller joint
- Pinion Gear - the typically smaller gear (metal or plastic) that attaches to the motor shaft.

- Propeller Shaft - the long plastic or metal shaft that connects the front & rear propeller joint (to the differentials).

I am using terms that Taimiya uses in their manuals. Some of these gears have different names depending on the part of the world you may be in or the person you are talking to. For example some people refer to the small and large gears inside of a differental as planetary and sun gear. Other people might refer to a propeller shaft as a drive shaft where Tamiya uses the term drive shaft to describe something different

Hope this info helps

My TT-02 club racer is coming together nicely, but I am still waiting on just a few more parts to make it complete. Coming soon is a nice 25.5 brushless motor, the 3 degree rear hubs and the adjustable upper rear arms. Here is the chassis for now. My gearing is 75/51 that gives an FDR of 3.82 and as you can see I needed to modify the motor cover to allow for the large pinion gear. The motor installed is a Team Powers Actinium 21.5

Check in Thingiverse. There is a modified cover for 3D printing. I did one for my sons car.

Thanks Eotz, looks to be this part;

https://www.thingiverse.com/thing:4946454

I don't have a 3D printer but will ask around to see if I can get someone local to print this for me.

If anyone out there in TT-02 Land happens to have a stock white motor cover that they'd sell please contact me.

Yes it is. I don't have a 3D printer either. A work colleague printed it for me.

I found someone local who will print this for me using white PETG and I should have it in a few days. Will post my results.

I printed this out and fiddled with the settings and couldn't get it to fit right. I'd tighten it down and it would snap down by the mounting holes.
EDIT- I have printed countless other parts for my TT02s that fit without issue, but it is a cheaper printer.

So I printed another and cut only what I needed off of it. Cut the stock cover where it needed to be cut, and used super glue and baking soda to fill the gaps and mount. Added a little PS-5 Black to a paintbrush and added to the glue/baking soda.

Now it's not pretty, but it works 😂

Will post a few pics when the sun comes up. Also got the Rallye TT02 buttoned up as well!

Yea it can get pretty confusing. Having rebuilt full size transmissions and rear ends, sometimes it makes me scratch my head how loosely some of these terms can get tossed around in different countries/dialects.

Hence I always try my best to simplify but clearly explain geartrain parts.
I'll always refer to the smaller gear as the pinion, and the larger gear as the spur(even when the pinion is larger than the spur on the motor &#128514, but I usually call out location too, IE driveshaft, motor or diff.

With the things I've learned personally I refer to diff internals as spider gears, pinion and spur on the driveshaft (diff), and pinion and spur on the motor. I feel these descriptions to be hard to confuse.

​​​​​​I have yet to see a true planetary gear set at these scales, though I am absolutely sure they exist.

The motor cover part was printed and I picked it up today. It was pretty rough, but that might be due to the material and printer used, no clue. The 4 mounting holes did not match up with the chassis and I had to do some milling with my Dremel to get it to fit. Still not perfect and definitely not a 'drop fit' like the kit stock part. It was an experiment and I will run it to see what happens.