T-maxx Idles/Revs but wont move.

[Rolex]

Big time congrats on the fix! It's a great feeling, isn't it? The wrenching and troubleshooting is a major part of a great hobby.

 

[Bill]

That's great!
That one of the reason I took out my reverse gears ,by doing so ,it relieved some of the rotating mass inside that relieved some of the tension
& pressure on the pins inside of tranny.
Also a lot has to do on the tension that your spur is set on the terrain you run on.
When I run my Mt out in the street ,I will loosen up my spur alittle because of the high torq. & high grip of my tires.
Too much on an off throttle out in the street with high torq & grip with out something giving will eventualy shear a pin!

But anyway ,I'm glad that you decided to dive off into it ,ts the best way to learn ,you also learn on any future issues
that may come.

Yea, that's great information. I figure I can also gain a little more power on the top and bottom end if I free up those reverse gears. Think I will ditch that little reverse servo/linkage as well. Everything counts, right?
That would make sense about the tight spur gear. Before the last outing I'm sure I over torqued my new spur gear which I'm sure helped snap that pin.

 

[cbaker65]

I couldn't wait until tomorrow. I HAD to know! The cars were out of the garage so I fired little monster and away it went! Ran excellent, lots of torque and super responsive with a good little idle. Nice smoke as well. Busted out some donuts until the garage got too toxic and shut it off.
Looking forward to getting it out into the open ASAP.

Will most likely be purchasing the forward only kit here in the near future.

While I had the transmission out for the 3rd today I replaced the single disk brake with a vented disk brake. Excited to see how braking improves.?.

Cheers!

SUWEET!

I'm glad that you got it going ,as some people will throw in the towel an lose intrest!...

 

[Bill]

Big time congrats on the fix! It's a great feeling, isn't it? The wrenching and troubleshooting is a major part of a great hobby.

Thanks much! It was most certainly a WONDERFUL feeling.. My fingers really hurt tonight.
I love wrenching on real cars/trucks but there is something about taking this little beast down to the chassis on the living room coffee table; that gets me.
Its a hobby that I hope to pass along to my kiddo on the way.

 

[Rolex]

We have quite a few father/son members here. My back can't take wrenching on real cars anymore and besides, I could never do that in the comfort of my living room.

 

[Bill]

Got to stretch the legs on the Tmaxx today.. I'm pretty sure I royally screwed up the shift point. I remember torquing down the little screw inside before reassembly..
Looks like I'm ordering a new primary clutch assembly and a forward only conversion.

 

[cbaker65]

Got to stretch the legs on the Tmaxx today.. I'm pretty sure I royally screwed up the shift point. I remember torquing down the little screw inside before reassembly..
Looks like I'm ordering a new primary clutch assembly and a forward only conversion.

Lol...I did that on my mgt.,I tighten the screw all the way down an it messed up the tiny spring.
It now has a bic lighter spring in it now,works great!

 

[hamz9561]

Lol...I did that on my mgt.,I tighten the screw all the way down an it messed up the tiny spring.
It now has a bic lighter spring in it now,works great!

Sometimes, improvising a replacement part like your lighter spring works better than a OEM part.

 

[Bill]

Lol...I did that on my mgt.,I tighten the screw all the way down an it messed up the tiny spring.
It now has a bic lighter spring in it now,works great!

Yea, I didn't know what I was looking before I started screwing it in ALL THE WAY.. lol

I wounder if a Bic spring would work for my application.?.

 

[cbaker65]

Yea, I didn't know what I was looking before I started screwing it in ALL THE WAY.. lol

I wounder if a Bic spring would work for my application.?.

Its trial & error ,I think it took me 2 or 3 times to figure out what size to cut down
the little spring ,but it eventually worked.
It should work ,the traxxas hub looks similar size to the Mgt one!.

 

[Bill]

Its trial & error ,I think it took me 2 or 3 times to figure out what size to cut down
the little spring ,but it eventually worked.
It should work ,the traxxas hub looks similar size to the Mgt one!.

Nice! Well I will give it a try this weekend.
I just ordered a new primary clutch assembly off Amazon and picked up a fwd only conversion from my local HS.
Will report back this weekend.

 

[cbaker65]

Nice! Well I will give it a try this weekend.
I just ordered a new primary clutch assembly off Amazon and picked up a fwd only conversion from my local HS.
Will report back this weekend.

In my tranny ,I really never had any type of major melt down or gear damage.
Just the usual pin snap ,sprung spring.An I did fry a o-way bearing once ,which was my fault do to
spraying wd-40 in tranny.
O-way bearings absolutely DOES NOT like any lube on them!
I run a greasless tranny.

 

[Bill]

Swapped out the reverse gear setup,for the forward only gearing today.
Wow! There sure are a lot of pieces that come out. All of which, add weight and create more drag on the engine.

I can't wait to get some nice weather and test everything out.
Should be seeing a nice little difference in power, right?

 

[Rolex]

Should be seeing a nice little difference in power, right?

Just not in reverse.

 

[Bill]

LOL!

 

[olds97_lss]

Turned out to be a small pin that went through a gear and the shaft and was secured with a metal clip..
After a victory lap, I headed down the local HS and got myself a replacement pin and gear.
Part #: 5396X https://traxxas.com/search?type=All&keyword=5396&items_per_page=40

That's the same one my OS21TM has sheared off in my revo twice already.

I ended up getting RRP gears as I could see the pin gouging into the plastic of the gear (and I sheared the teeth of the main input gear once already), so guessing that started it to bend or put weird leverage on it. Also, I didn't have a spare pin, so I made one, which was a total pain. I found some hardened pins at my hardware store in their small nuts/bolts cabinet. I used to use them for my savage cvd's as they held up longer than what came in those. I had to put it in a dremel and grind it's diameter down some. You can see the original size on the fat end. I just cut it to length with the dremel after getting the diameter down to fit.

The first run, it broke loose again and I thought for sure the pin just sheared again, but it seems I didn't make it short enough for the clip to hold it. So, I shortened it a bit more, compressed the stupid c-clip a little and heat shrunk it for good measure:

I only ran a handful of tanks through it after that before it got too cold out to run such a new/expensive engine, but it held up so far. Next spring I'll figure out how well it really holds up.

 

[Bill]

Those RRP gears looks sexy AF! Hopefully they hold up for you.. Do the gears weigh significantly more than the OEM? I will rock my setup until goes real bad or until I get tired of replacing pins. lol

You know what the difference between the black and grey transmissions at all?

 

[olds97_lss]

Pretty sure on a t-maxx, the "black" trans was the old style, the grey was more revo'ish and stronger with a better reverse mechanism.

The RRP gears are heavy and they do add some rotational mass, but it wasn't very noticeable on my 21TM revo. Might be more noticeable on a 3.3/2.5 engine.

I ran it through break-in with the stock trans, spun the teeth off the main input gear, then ran another tank or two and sheared that pin, replaced the gear/pin and ordered the RRP and sheared the pin again before the RRP showed up which is why I had to make one for the RRP gears. I run RRP in my LRP28 revo as well. I think I pieced it together though vs buying the full gear kit that replaces all of them. It had a slayer trans and at the time, I didn't know they differed, so my primary output gears are plastic in it, but they are the slayer gear ratio which is higher gearing than a revo. This makes me run a larger spur so the engine sits more upgright. Seems to hold up ok though.