TMaxx 2.5 Engine Problem

[Poncho92]

Hi, My name is Alfonso i am new to the forum. I got a question about my TMaxx Classic. So today i was using it and doing some jumps but then i did a fast jump got like 7 feet in the air and it landed right on the engine block (should of bought a roll cage) and the engine instantly died. I went to check what happened and saw some minor scratches on the head but no cracks. So i tried to turn on the engine and it turned on but it wouldnt move forward. All i hear is a spinning-clanking sound. The transmission in fine. Any Idea on what it might be and if i can replace it?


Short Version: Truck landed on engine block from 7 feet after jump, engine starts but it wont move forward. what might be broken? Transmission and drive is fine.

Thank You.

 

[ohsnap]

Does the engine idle fine - sound fine?
When does the "spinning-clanking sound" start - at idle or when you give it some gas - also what part of the truck is making the noise ?
Does the engine provide power to turn the spur gear?
Are your driveshafts intact?

You could have one of several problems - including - but not limited to a broken motor mount or clutch shoes or drive-shaft problems or transmission issue or the spill may have messed with your clutchbeel/spur gear mesh or who knows what.

Have you pulled the engine from the truck and if so, does it seem to be OK?
If you roll it forwards and backwards - does it seem to work right or does it make funny noises?

 

[Poncho92]

Havent taken it out because I'm new to nitro cars (not the first day i ran this).It does not idle by itself. I give it gas and the spur gear does not spin but the gear is fine. i forgot to mention that the "gear" behind the gear the spins the spur gear (confusing, big/thin gear) is worn out on the whole right side ( it wasn't like that before the car i think). Maybe the shaft that spins the gears from the engine is broken. is that possible?

Things that happen when engine is started:
High Rev on low throttle
Stall after a few seconds
No power to transmission

 

[ohsnap]

Not sure what you mean by "the "gear" behind the gear the spins the spur gear..." - but you've got broken parts (from the sounds of it probably more than one).

Can you provide a picture or match up parts that look bad to part numbers in the diagrams (below)?
http://www.traxxas.com/PDF-Library/4910-08_tranny.pdf
http://www.traxxas.com/products/nitro/trx25/blueprints/050926_TRX25_explode.pdf

 

[StevoRevo]

Same thing happend to me twice..

First time it was a stripped spur gear ( the big gear that is attatched to the tranny that sipns with the clutch (the clutch gear is attatched to your engine near your fly wheel))

Second time it smashed the reverse gear inside the tranny which spat little teeth everywhere and jammed all the gears.. This senario is more difficult to fix..

And yes.. Pics wld be a great help

Goodluck

 

[Poncho92]

Not sure what you mean by "the "gear" behind the gear the spins the spur gear..." - but you've got broken parts (from the sounds of it probably more than one).

Can you provide a picture or match up parts that look bad to part numbers in the diagrams (below)?
http://www.traxxas.com/PDF-Library/4910-08_tranny.pdf
http://www.traxxas.com/products/nitro/trx25/blueprints/050926_TRX25_explode.pdf

Alright i really dont know what happened but i took the engine apart to look for any broken parts, i couldnt find anything but i did notice that the flywheel (the gear that i was talking about, finally found the name) hit the chassis and lost grind it up a little. but after putting the engine back together i decided to run it and it worked. what do you think the problem what?

Same thing happend to me twice..

First time it was a stripped spur gear ( the big gear that is attatched to the tranny that sipns with the clutch (the clutch gear is attatched to your engine near your fly wheel))

Second time it smashed the reverse gear inside the tranny which spat little teeth everywhere and jammed all the gears.. This senario is more difficult to fix..

And yes.. Pics wld be a great help

Goodluck

yeah i also checked the spur gear and its a little worn out but i will be replacing that soon. any tips on what to look for in a spur gear and the pegs?

 

[StevoRevo]

When you say a little worn...What exaxtly do u mean..??
Are all the teeth still in good shape..??

And as for replacments i wld just stick to the stock spur and pegs.. The amount of teeth u get is up to to..Also depends on how many teeth your clutch bell has..

I dont recommend a steel spur(not even sure if you can get steel spurs for the Maxx now i think about it) if you do the next weakest point will be your tranny gears and are alot more hassle to replace.. plastic spur will strip first and save u alot of trouble

 

[Poncho92]

When you say a little worn...What exaxtly do u mean..??
Are all the teeth still in good shape..??

And as for replacments i wld just stick to the stock spur and pegs.. The amount of teeth u get is up to to..Also depends on how many teeth your clutch bell has..

I dont recommend a steel spur(not even sure if you can get steel spurs for the Maxx now i think about it) if you do the next weakest point will be your tranny gears and are alot more hassle to replace.. plastic spur will strip first and save u alot of trouble

it still has all its teeth just little flakes of plastic here and there.

 

[cwal1774]

Sounds like to me when it hit the transmission got knocked in betweeen forward and reverse and got hung.

 

[Poncho92]

Sounds like to me when it hit the transmission got knocked in betweeen forward and reverse and got hung.

maybe, but its working again. ill make sure to remember these things just in case it happens again. thanks.

 

[StevoRevo]

does your reverse still work...?
Cause wen my reverse got stripped and it spat teeth inside my tranny it stopped working for a while then all of a sudden it worked again... The teeth got dislodged and it moved foward again...But no reverse..!!

 

[Poncho92]

does your reverse still work...?
Cause wen my reverse got stripped and it spat teeth inside my tranny it stopped working for a while then all of a sudden it worked again... The teeth got dislodged and it moved foward again...But no reverse..!!

i did notice a delay in the time switching to reverse but it still works. i will have to dissemble the transmission to look for any damage, but so far i only see cosmetic damage on the flywheel. will that effect performance?

 

[StevoRevo]

well honestly then...
If everything is working ok.. I wloud leave it like you said untill something goes wrong...

Goodluck

And if/when something goes wrong that u can't figure out..
Remember just ask here...
someone will be able to help..

 

[Poncho92]

well honestly then...
If everything is working ok.. I wloud leave it like you said untill something goes wrong...

Goodluck

And if/when something goes wrong that u can't figure out..
Remember just ask here...
someone will be able to help..

alright thanks a lot! i think my engine wont last very long, would you recommend i upgrade to 3.3 when it dies?

 

[StevoRevo]

Definatly yes...
My GF just upgraded her Maxx 2.5 to a 3.3 and she loves it...
I'm sure anyone will tell you the same...

Off eBay it wont cost you much more to by a 3.3 rather than a 2.5..

Trust me you wont regret it..
What makes you say the 2.5 wont last much longer...???

Oh yeah and remember...
IMO All TRX engines need to be sealed...
Check out some old posts on here and youtube on how to do it...
Very easy once you have done it once

 

[Metalhead Matt]

The gear you are referring to is the spur gear. The flywheel is attached to the crank shaft on the engine, and the clutch bell is attached to the flywheel. It's much easier to help if you take the time to get some basic terminology down. Do a forward only conversion(foc) to the tranny before upgrading the engine. Reverse makes the tranny weak, and anything bigger than the 2.5 will exploit this.