Tmax clutch replacement?

[shahav]

It seems that i have a problem in my transmission.

The truck refuses to move :-( but when i hold
it in the air the wheels role.

I did check the spur gear, it is not damaged, and it is well
engaged with the bell comming out of the engine.

I also checked the bell clutch, it also function properly.

So, it seems to be gear. since the wheels are turning while
not loaded, i think it is probably the cluch system within
the gear.

Where is this clutch placed within the gear? How do i replace
it? What should i replace?

Any help is apriciated.
R.

[wolfy2386]

Are if your talking about the clutch in the transmission then I don't think thats your problem. I have a 5 year old T-maxx and I never had to replace the clutch in hte transmission. How did this happen? Did the truck stop moving while you were changing from forward to reverse? Or did the truck gradually get slower?

[shahav]

Are if your talking about the clutch in the transmission then I don't think thats your problem. I have a 5 year old T-maxx and I never had to replace the clutch in hte transmission. How did this happen? Did the truck stop moving while you were changing from forward to reverse? Or did the truck gradually get slower?

I wish i knew, i gave it to my friend, and he says that it just stoped rolling. Any way i enjoy fixing it more than driving it.
R.

[4DMNYC]

Check to make sure your slipper clutch is set correctly.
Make sure your not stuck between foward and reverse.
Check and see if you have any broken drive shafts.

[wolfy2386]

Yeah i was going to say stuck between gears, that happened a lot to mine. Start it up and switch switch gears and see if it will pop into one. If you have the idle set to high it won't go in or out so make sure its set low enough.

[shahav]

I finally got my car back. now i can c the problem, well it is kind of
stucked between the gears, i.e. front vs reverse, but i can shift the
gears manualy.

The problem still persists, it refuses to role . some how somthing in my
gear is damaged. Any suggestions?

Note:when i hold the car in my hand, the wheels start to role slowly and
properly i.e. forward/backward based on my choise.

Should i disassemble the gear? or should i give it some expert? until now
i did all the maintanence, including some fixing within the diff'.

R.

[wolfy2386]

I would just take the tranny out yourself and check the parts. Once you get it apart the first time and see how its works its actually pretty simple. There is a exploded view here (http://www.traxxas.com/products/nitro/maxx/tmaxx/blueprints/051123_tmaxx25_tranny.pdf). There are two gear that have clutches in them. They are number 4997 and 4998 in the diagram. The larger black Ring(4990) is what the clutches engage. Basically all the shifter does it move the ring over one of the two gears to engage it in forward or reverse. I would check those gears and that ring and eensure that nothing is broken or anything. Easiest way I've found of taking the tranny out (I've done it too many times) is pop the servo horn off the throttle servo, Disconnect both driveshafts from the bottom of the tranny then unscrew the 8 screws on the bottom. just make sure when you get it back together you get the servo horn back on properly.

[shahav]

OK, i got your push, i'll take a part.
Regarding the exploded view, actually this view scared me at the begining :-)

Still, based my "sypthops" do think it is the cluch or some worn gear?

I'll let you my findings
10x a lot.
R.

[wolfy2386]

From the how you explained it sounds like the internal clutches are worn, which is weird because I have had my T-maxx for a 5 years and never had a problem with them. and for niether to work it would mean that both are worn. The reason the wheel move when you pick it up is because the gears touch the larger ring slightly and will make it move even when not engaged. If those parts are worn though it will be a cheap fix as they are around $7 each on tower. If you have any trouble determining what the problem is, if you can post pics and I'll help you as best I can.

[ofnaravager9]

did u check the engine at all? same happened to me it was the engine i gots a new 1

[Duster_360]

That sot of thing happened with my 1st one - I could shift in manually, but once running, if I shifted it into reverse, it would stop and I couldn't get it back into fwd either until I turned it off and manually shifted it.

What fixed mine was re-centeringteh shift servo, then rotating the servo horn slightly so it would have more travel moving into the trans. If I remember it was not but one or two splines worth either. Worked after that.
If you can shiftit manually, try adjusting the servo horn like I did and see if that solves it.

[ofnaravager9]

try taking it apart the servo, possible problem

[shahav]

guys, the problem in certainly in the gear. I have already checked the spar gear, engine, bell cluch, diff's. It is some how related to the front/rear drive mechanism, still it is not
the servo who control back/front drive.

I didn't have the time to take it apart, yet.

10x all 4 the help.
R.

[mxermadman]

Does the throttle servo move when you give it gas?

[shahav]

Does the throttle servo move when you give it gas?
yes, the stearing works fine as well.
R.

[shahav]

I got it fixed.

I did open the gear, and noticed that a small pin
was broken.
The pin is M3/12 in part # 4995 in exploded view:
http://www.traxxas.com/products/nitro/maxx/tmaxx/blueprints/051123_tmaxx25_tranny.pdf

That was the whole story. it cost me absolutly nothing :)

Half of the pin, the threaded part, was still in place, this is why the
wheels would still role while not loaded.

btw - the gear is all made of plastic :eek: there is no lubrication like
in the diff's, it is plastic :(
10x All
R.

[wolfy2386]

There is an advantage to the plastic gears with no lube. They're lighter weight and cheaper to replace, and with out the lube there is less drag on the drivetrain. So its not such a bad thing unless your running a huge motor.

[ofnaravager9]

jw for a .21 engine, would u use plastic or metal?