First Gen Tranny Problems

[Clovis Crawler]

I'll try to make this as short, but descriptive as possible.

I was finally ready to make my first attempt to put this truck on the rocks this weekend.

I did the bind thing and set up the esc. When I pulled the trigger slowly, with the crawler elevated, I got this horrifying sound come out the tranny and the wheels weren't turning. It sounded like gears were stripping. I then disconnected the drive shafts and checked the axles for binding. Fortunately they were good. It had to be the tranny. After I tore it down, I discovered the dig gear and top shaft gear were scarred from the three attempts I made to slowly throttle up and check the pinion, idler and slipper gears. I feel that during assembly, something went wrong and I believe that just re-assembling the dig unit will cure it. Hopefully. I will definitely buy a new dig and top shaft gear.

But before I go any further, I have another problem that I need anyone with the knowledge of the dig tranny to help solve. When I re-assembled the tranny this morning, I decided to check out the dig transmission to see if works properly. When I pushed the dig shaft into the tranny (front dig mode), I got resistance from the spring and then a click. When I turned the idler gear, the front output shaft (I've removed the drive shafts) rotates and the rear doesn't. But when I pulled the dig shaft out (rear dig mode), I didn't get the resistance from the spring on the opposite side of the dig gear and I didn't get the click. Also, the travel from centered (four wheel drive mode) to rear dig mode was longer than the travel from centered to front. And when I rotate the idler gear, both output shafts rotate.

Does anyone know what's wrong with my tranny? I've checked every component using the manual's exploded drawings. I believe everything's in it's place. But I could be wrong.

I'm open to any questions to get me closer to my first attempt to crawl.

Kabuki
RC Crawler from Clovis, New Mexico

[Jay Robinette]

I'll try to make this as short, but descriptive as possible.

I was finally ready to make my first attempt to put this truck on the rocks this weekend.

I did the bind thing and set up the esc. When I pulled the trigger slowly, with the crawler elevated, I got this horrifying sound come out the tranny and the wheels weren't turning. It sounded like gears were stripping. I then disconnected the drive shafts and checked the axles for binding. Fortunately they were good. It had to be the tranny. After I tore it down, I discovered the dig gear and top shaft gear were scarred from the three attempts I made to slowly throttle up and check the pinion, idler and slipper gears. I feel that during assembly, something went wrong and I believe that just re-assembling the dig unit will cure it. Hopefully. I will definitely buy a new dig and top shaft gear.

But before I go any further, I have another problem that I need anyone with the knowledge of the dig tranny to help solve. When I re-assembled the tranny this morning, I decided to check out the dig transmission to see if works properly. When I pushed the dig shaft into the tranny (front dig mode), I got resistance from the spring and then a click. When I turned the idler gear, the front output shaft (I've removed the drive shafts) rotates and the rear doesn't. But when I pulled the dig shaft out (rear dig mode), I didn't get the resistance from the spring on the opposite side of the dig gear and I didn't get the click. Also, the travel from centered (four wheel drive mode) to rear dig mode was longer than the travel from centered to front. And when I rotate the idler gear, both output shafts rotate.

Does anyone know what's wrong with my tranny? I've checked every component using the manual's exploded drawings. I believe everything's in it's place. But I could be wrong.

I'm open to any questions to get me closer to my first attempt to crawl.

Kabuki
RC Crawler from Clovis, New Mexico

Check your e-clips that hold on the dig forks, maybe this is the issue with your clicking. http://www.horizonhobby.com/Products/Default.aspx?ProdID=LOSA3179

As for the dig sticking look at the shaft that holds the forks. It slides in and out of the gearbox and might need to be lightly sanded for smooth operation.

If it still sticks, running it will loosen up the areas that stick.

And make sure your screws that hold the gearbox together are not cranked down. Snug them down and then loosen them a little so the gearbox has a little slop.

[Clovis Crawler]

Thanks for your help Jay. I'm at lunch at this time, but I'm going to try the sanding tonight. I may have the screws on the transmission set too tight. I'll try your tip to back the screws out. That may fix the noise I had. Maybe that's why the upper shaft gear and dig gear were scarred. Tightening the screws too tight may be causing the problem.

[Clovis Crawler]

Update on my problems.

I've tried Jay Robinette's suggestions, and I'm afraid they are for the dig transmission. That can wait. Remember, the Comp Crawler doesn't need a dig servo to run this truck.

My main problem is that when I install the motor to the idler gear and start to throttle up, I'm getting that "stripping gears" noise. The pinion, idler and slipper gears are rotating fine. The top shaft and dig gears? Since they are inside the transmission housing, I can't visually inspect them. However, when I pull them out, they're both scarred like they never meshed. Why is that?

Folks, this has been very frustrating. I think I'm going to walk away from this, for now. I really think the only way out of this is to buy the components to build a complete transmission. From scratch. I know I can do it. But why do I have to?

I really want to crawl...

[Robbob]

just out of curiosity have you taken your slipper apart?

it sounds more like that could be the noise your hearing and more of a common problem amongst LCC owners.

You may just need some adjusting of it or possibly a small shim to help adjust it better.

[Casey Peck]

Hey Clovis don't give up....when you have had enough you can send it to me if you like and will go thru it for you.

[K_B]

Update on my problems.

I've tried Jay Robinette's suggestions, and I'm afraid they are for the dig transmission. That can wait. Remember, the Comp Crawler doesn't need a dig servo to run this truck.



This may be your problem. I tried to do a quick test run with mine without a servo in place for the dig. The dig mechanism would "slip outta gear" under load. Without the servo, or something to at least keep the dig mechanism centered, I got the same nasty sound that you describe.

[Clovis Crawler]

I appreciate your generosity in helping me with my problem Casey. Even going as far as physically checking out my tranny. That's what makes the rc car hobby so great. Ten years ago I raced 2wd off road at the grass roots level. I always helped fellow racers (especially the young ones) anytime. The rc community is a close one. It was as much fun meeting new people with a common interest as it was to race when I went out of town.

Actually the suggestions Jay Robinette gave me were great. Especially about backing out the screws. That fixed the sticking problem with the dig. At first, common sense told me that backing out the screws was wrong. However, I was wrong.

Robbob, I'm going to check out the slipper. I did take it apart. Does the Losi team have a suggestion for adusting the slipper?

When I first encountered my problem K_B, the dig servo was connected.

I believe I might have the problem fixed. However, I need to make a purchase or two. And I don't have the money to do now right now. I will post later with the good news.

Finally, I want to thank all the Losi team members and the junior members of the Losi forums for all your advice and concerns. I'm glad I joined. I will crawl this truck. I promise. I can't wait to show everyone my Zegers painted body.

[Clovis Crawler]

Update: I'm crawling now! The rig is amazing! Once again, thanks to everyone for all your advice.:)
Kabuki the Clovis Crawler