My first RC car build - Hotshot rere - bearing issues (Solved again)

[Aviator]

After dreaming about Tamiyas in my younger days I finally could start my first build many years later. I am currently building the Hotshot rere after an initial delay waiting for a replacement for the plastic bearings. 

I only got to section 2 before running into problems. First I could not find B7 to attach the drive gear to the rear gearbox. After scratching my head I found it together with the cage and the battery side guards. Moving on, I am now at the part where the Bevel Gear (MR11) mates with MR13/MR2/MR15/MD2/BD4. When inserting the Bearing (MR2) into the gearbox housing, it does not fit flush and the Drive gear scrapes on the edge of the bearing. I have tried all the MR2 bearings and even my extra 1150 bearings but none of them seems to sit flush in its hole. Could I please have some advice here?

[Saito2]

Starting with the obvious, is the bearing fully seated in the gearbox housing? Sometimes they can be tough to push in fully. If so, remove the bearing. Measure the thickness of the bearing and the depth of the hole. Calipers are useful in this case. If the bearing is thicker that the hole depth, then nothing you do will help. The bearings are the wrong size or more likely, not toleranced well. The Hot Shot comes standard with bushings. Where did the bearings come from? You could also compare the bearing thickness on a flat surface to that of the standard plastic bushing for any great discrepancies. These are just some "diagnosing" ideas I'm throwing out. I've never encountered any molding issues with the Hot Shot gearcases but there's a first time for everything. Good luck and let us know how it works out. 

[Aviator]

49 minutes ago, Saito2 said:

Starting with the obvious, is the bearing fully seated in the gearbox housing? Sometimes they can be tough to push in fully. If so, remove the bearing. Measure the thickness of the bearing and the depth of the hole. Calipers are useful in this case. If the bearing is thicker that the hole depth, then nothing you do will help. The bearings are the wrong size or more likely, not toleranced well. The Hot Shot comes standard with bushings. Where did the bearings come from? You could also compare the bearing thickness on a flat surface to that of the standard plastic bushing for any great discrepancies. These are just some "diagnosing" ideas I'm throwing out. I've never encountered any molding issues with the Hot Shot gearcases but there's a first time for everything. Good luck and let us know how it works out. 

Thank you for the reply. After about 100 attempts and some knife scraping in the hole the bearing finally seated. My main concern was not to break the plastic if excessive force was applied.

[Saito2]

Good deal. Glad it got worked out.

[WillyChang]

9 hours ago, Aviator said:

Thank you for the reply. After about 100 attempts and some knife scraping in the hole the bearing finally seated. My main concern was not to break the plastic if excessive force was applied.

That bearing seats flush all the way in afaik.

Other concern should be you mustn't be pushing laterally on the inner race of ballbearing - it's not designed to handle sideways forces, that'll dent the works & fail prematurely. Bearings should be pressed in by pressure on their outer race only.

 

[Aviator]

Additional question: When replacing plastic bearings with metal ones on the axles. Do you also replace the Ceramic Grease with Molybdenum?

[Aviator]

And now I’m stuck on the front uprights. I can’t get the 3 BC2 2x6mm screws to sit. The ball connector seems too big to fit between the ball plate and the suspension arm. I’m guessing there is supposed to be some play here as it is a ball connector, but this seems very tight. 

[Aviator]

Never mind. After fiddling with this for way too long I figured out that all my D6’s are mounted upside down on the uprights 🙄