261LikesTraxxas 4Tec2.0 Ford GT...this thing is awesome!
09-03-2018, 06:06 PM
#286
We never broke the C-Hubs, they were just so soft that they allowed the screws to come out of the hub, the dogbones to jam, of for the dogbones to fall out after contact. We all experienced this. See my video in this thread for just how soft they are.
I think that the stripped spur gears came from the fact that after a few weeks of racing, the spur will back off of the pin on the driveshaft and push up on the back of the frame. We fixed this by putting a bearing behind the spur. 75% of us experienced this failure but not all of us had our gears chewed up like in the picture that I posted.
I've been using dry lube on my gears. They are in perfect condition, even better than I thought they'd be at this point.
09-03-2018, 06:26 PM
#288
I think that the stripped spur gears came from the fact that after a few weeks of racing, the spur will back off of the pin on the driveshaft and push up on the back of the frame. We fixed this by putting a bearing behind the spur. 75% of us experienced this failure but not all of us had our gears chewed up like in the picture that I posted.
09-03-2018, 06:55 PM
#289
The barriers on our outdoor track are two 2x4's stacked up. They don't move and are like sandpaper from hell. When you brush up against them at speed they destroy things. Point is that this exposes weaknesses quickly.
We never broke the C-Hubs, they were just so soft that they allowed the screws to come out of the hub, the dogbones to jam, of for the dogbones to fall out after contact. We all experienced this. See my video in this thread for just how soft they are.
I think that the stripped spur gears came from the fact that after a few weeks of racing, the spur will back off of the pin on the driveshaft and push up on the back of the frame. We fixed this by putting a bearing behind the spur. 75% of us experienced this failure but not all of us had our gears chewed up like in the picture that I posted.
I've been using dry lube on my gears. They are in perfect condition, even better than I thought they'd be at this point.
We never broke the C-Hubs, they were just so soft that they allowed the screws to come out of the hub, the dogbones to jam, of for the dogbones to fall out after contact. We all experienced this. See my video in this thread for just how soft they are.
I think that the stripped spur gears came from the fact that after a few weeks of racing, the spur will back off of the pin on the driveshaft and push up on the back of the frame. We fixed this by putting a bearing behind the spur. 75% of us experienced this failure but not all of us had our gears chewed up like in the picture that I posted.
I've been using dry lube on my gears. They are in perfect condition, even better than I thought they'd be at this point.
09-03-2018, 07:13 PM
#290
One of the kids in the junior high school r/c club I work with had the dog bone pop out on his 4-Tec this past racing season season. He had the one with the Mustang body. He didn't find it. It's a common issue with a lot cars when something happens to the "C" hub. One of the classes at the race I was at this weekend was the TT Class. The TT Class, as some of you know, is a class for the Tamiya TT01E's and TT02's. I saw that some of the guys had brightly colored shrink tubing on their dog bones because they can be hard to find, That idea might work for the 4-Tec. I use a little Tamiya anti-wear grease on the spur and pinion. It's tacky. I guess I was lucky yesterday with the contact I made with the concrete retains wall.Your information is good to know.
Last edited by JC3; 09-03-2018 at 07:41 PM.
09-03-2018, 07:18 PM
#291
Yes, of the chewed up spur but not the bearing. Posts #114, 120, 122 and 191. Symptoms of the spur backing off are, a loss of power, loud noise, and on one occasion a completely locked up drivetrain. Probably easiest to remove the rear section of the car to work on this. I think it's one of the coolest aspects of the 4T's design that you can separate the car into thirds so easily.
Last edited by JC3; 09-04-2018 at 04:02 AM. Reason: added failure info
09-04-2018, 06:14 AM
#293
I think we are talking different parts.
this is what I'm talking about.
https://www.amainhobbies.com/traxxas...ra8379/p668439
I bought an extra ring gear set so I could just swap the two out if I wanted to.
https://www.amainhobbies.com/traxxas...ra6879/p158409
this is what I'm talking about.
https://www.amainhobbies.com/traxxas...ra8379/p668439
I bought an extra ring gear set so I could just swap the two out if I wanted to.
https://www.amainhobbies.com/traxxas...ra6879/p158409
09-04-2018, 09:59 AM
#294
The only mod so far is cutting open the year cover and I added a spool.
Last edited by Kregger; 10-08-2018 at 10:23 AM.
09-05-2018, 05:05 AM
#296
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Knew it was here in the thread. Back on page 4. Post #48
If my Math is correct, to get close to 3.6 you would need to be around a 47/60 in 48 pitch or 63/80 in 64p.If 21/70 results in a 9.49 FDR, then the internal ratio is around 2.85, meaning your pinion:spur ratio needs to be around 1.26.
09-05-2018, 08:03 AM
#297
2.85.
Knew it was here in the thread. Back on page 4. Post #48
If my Math is correct, to get close to 3.6 you would need to be around a 47/60 in 48 pitch or 63/80 in 64p.If 21/70 results in a 9.49 FDR, then the internal ratio is around 2.85, meaning your pinion:spur ratio needs to be around 1.26.