James c harrell

My Feedback: (18)

I got me a t-maxx to try and keep up with my son. He has a 3.3 and mine is a 2.5 so I expected his to be more powerful. I didn't expect his to have so much more top end. A little more,O.K. but this was ridiculous. I had a 72 T metal gear spur on mine that I changed to a 68T plastic but I was still embarrassed. The 2.5 I am running has a Traxxas resonator pipe on it and I am not sure If it is holding my top-end down or not. I counted the teeth on my clucth and there were 20. That's stock right? Befor he blew the 2.5 on his it had alot more speed and power than the one I got. I first figured maybe I just got a wore out engine but the compression stays good even hot. I did the carb slide check to see if it was going to wide open and it was. One of my stupid ideas was the tranny. I had a primary gear fail and went in to replace and discovered that I have the old style primary gear. Is that tranny geared lower that the newer style. It is a two-speed with reverse black case. I got the funny feeling I am missing somethig with the pipe. Any special tunes I need to try with a resonator pipe?

Snook Man

Are you both running the same (black) tranny? (Changing the forward primary from the old style to the new does not change the gear ratio and all black trannys will have the same output ratio with or without reverse (unless I got ahold of it).

The 20T bell and 72T spur is stock for the .15 and 2.5 Maxx. What CB and SG is the sons Maxx running? Is he running reverse as well?
There are other things to consider when it comes to top speed as well. Tire size and weight, overall weight of the truck, engine tune, any binding in the drive train will slow it down, and is the engine strong enough to pull the gears you have selected.

James c harrell

My Feedback: (18)

Yea snook I can't get a grip on it. He has the same tranny, tires and clucth bell. I have a 68 t spur and he has a 72 t. I had figured with that set up, I did both, we should be pretty close at top end. I know he would be alot faster getting to top. But he makes me look like I am sitting still. I have the steel axles and driveshafts with the c/v boots and an aluminum frame and shock towers but other that there's just the engine. Got to be the engine not turning the right RPM. I also did notice I run out the tank twice as fast so may-be I am way to rich. But my luck with leaning these things down is not good. Hey, if I do blow it ya reckon the wife will feel sorry for me and let me get that Picco at the HS. Now that's funny, I don't care who you are. Heck lets find out I'm going back to factory sets and start turning in. Be back in a bit

Snook Man

If your going through a tank of fuel twice as fas as he is with a 3.3 you are running really rich or have a fuel leak.
Tune her up and see how it goes. You may just not be producing the power to pull the 68T spur to the high rpm range.
The 3.3 will get there quicker but top end should be close.

cenracer1

James.. tuning and not sure if the 2.5 will pull that gear either.. there is a big difference in the output power of the 2.5 vs 3.3 engines... I know you are hesitant to lean out the motor, but maybe just a bit will help... How is it shifting now? If it winds out first, shifts into 2nd and winds that out, then its gearing.. If it won't wind out second, then its tuning and or gearing.. Too tall a gear for more speed doesn't work if the engine can't deliver the power to turn it...

James c harrell

My Feedback: (18)

Well , tuning it was, I went to put it back to factory settings and it was already there. Took her outside and ran it,BLAH, Gave her a half a turn on the HSN and Hey this is better. Did two laps and started the 1/8 turns in. By my count I did 1-1/4 turns in from factory 4 out. She ran the best it has but I was scared to go more till all of a sudden it lit up like a rocket had been lit under it. Actually stood up on the rear. And then it was out of fuel. probably could go leaner from the sudden power at the end af the tank but I think I will leave it there for now. The 68T spur does good. It shifts a little early but that is O.K. I guess. Winds out second fine. Well the boy is home from school. Time for dad to get schooled.

rcslsafut

now thats funny .......
amazing how much better they run when they are tuned correctly!!
my son's best friend bought 3.3 t maxx. my son got 3.3 s maxx.
the friends t maxx goes through more fuel than,my savage,his s maxx,and my old t maxx with a os tz in it!!!

James c harrell

My Feedback: (18)

Hey you wanna know what happens when two T-maxx collide? Daddy gets a new set of lower control arms!! Just get the thing running so he can't catch me so easily so he head ons me. That's O.K. Integy makes a real cool looking set of em! This is fun.

rcslsafut

almost everyone say's to stay away from integy!!!!!!
unless you want your truck to sit on a shelf.
i would go with rpm myself!!

piddlefoot

Definately RPM arms.
Funny thread, glad you got it running good.
So what gunna happen , buddy, when son figures out, ramming dads car get him a new one and dad the old one ! hahaha

cenracer1

James.. glad you got it sorted out.. I wouldn't recommend aluminum arms at all, just transfers the impact elsewhere, especially the bulkeads and chassis.. stay with the stock ones or RPM.. I run the stock as the RPM have too much flexibility for my taste, but they are popular and work well.. either way, I'd rather break a plastic cheap arm then an expensive pain in the rear bulkhead...

James c harrell

My Feedback: (18)

Hey folks. Just got back from running our trucks and figured I would sit down at the computer before I started to fix em. I hear you about the flex thing with the arms but when I called the HS to get a replacement the chain HS was closing so I called my buddy that runs a small HS,kinda ma and pop store, all he had was a set of integys'. He let me have them at half price and even opened up after hours to help me out. Any- way, they did fine but my tranny didn't. First I tore out a Primary. Replaced that and evidently I didn't get the tranny tight or tightened it to much. It came loose and shreeded the spur. I put the 72t metal one I had on there and found out the screws in the tranny wouldn't tighten, stripped. Pulled out the screw can and found some sheet metal screws that tightened up nice. I set the metal spur at 1/2 to 3/4 turns out. I am scared of those metal gears. Made just about a whole tank of see who can do the best jump with the boy and toasted the brand new primary. At least that is what it sounds like. Man those things break alot. I just about know that tranny with my eyes closed. No problem though, I will fix it. Think I will get about ten of those primary gears as hard as me and my son are on these things. The only thing he broke today was a glow plug. I thought I would ask if you guys knew any tranny tricks or something I may be doing wrong. I seem to have some realo bad luck with these trannys'. But I did learn how to do a back flip. get going real fast, turn and hit the brakes, when it spins around punch it. When it grabs traction it will flip right over backwards. Cool Huh. Wonder why I can't keep a tranny in it? I'm puzzeled.

Snook Man

Get ride of reverse and the tranny will be much stronger but doing the backflip like that will kill any stock trany gears.

James c harrell

My Feedback: (18)

Yea I know. I really didn't mean to do that. I was racing down to the next mail-box and back against my son and figured the only chance my 2.5 had against his 3.3 was the turn around. Would have worked to if it hadn't flipped over backwards one, two, maybe three times. I think that is what got my first primary today but I purposely set the spur gear loose to try and save the new one. Maybe the new steel spur is supposed to be set different, I don't know. The steel gear was on it when I bought it. It didn't have any of the pegs in it at all. I changed it out with a plastic 68t with the pegs. That's the one that stripped when the tranny came loose. So I put the steel one back in with the pegs. Are the steel gears supposed to have pegs. It has the holes for them so I figured it does. I just remembered soimething else I did to it. The spring in the clucth was loose. It would pull all the time even at a real low idle. I took and shortened a little and it appeared to work fine. Don't know if that has any thing to do with it tearing the brand new primary or not. Guess if I got it to tight and it revs up to high befor engaging it could but I really don't think it was. I bought a forward only tranny and it should be here Monday. Maybe I will have better luck with that one. I was kinda hopeing snook could tell me how to make one bullet-proof. Or may-be I should say idiot proof. Either way if any-one would know I figure he does. My best guess is that every-thing is going to have a weak link some-where. The primary may be designed to be this trannys' weak link. I know between mine and my sons I have already changed 5. And we haven't had a truck but since Christmas. Sooner or later I should be getting better at it.

tj107us

does anyone know where i can get the aluminum Robison Racing reverse primary ive broke at least 4 or 5 of those suckers? I can find all of the steel gears to make a trans almost bullet proof but cant find that gear. Thanks for any help!!!!

Snook Man

<p class="MsoNormal" style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial; FONT-SIZE: 9pt">Bullet proofing the tranny can get expensive quick (real expensive) and when running the 3.3 it's not a necessity IMO. When you start using more powerful engines there are many different ways to beef it up to handle the extra torque. A full set of RRP gear for the tranny is around $150.00 and if you choose the OTB/UE nitro gears (slipper shaft and gears and 1st &amp; 2nd primary gears they go for around $100.00+ used so it can add up quick.
With the stock gears, reverse will always be the weak link and due to the extra weight of the output clutch bell and F/R output gears it’s hard on the forward primary. Installing a FOC in the tranny is the cheapest way to make it stronger. I run .28's with it and with a properly set slipper I have little problems. Making sure the bearings are in good condition and shimming the end play out of the shafts if needed goes a long way in keeping the internal gears meshed properly.

</p></span></p><p class="MsoNormal" style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial; FONT-SIZE: 9pt">

 </p></span></p><p class="MsoNormal" style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial; FONT-SIZE: 9pt">I’m working on a 3 speed version of that tranny right now which has a much stronger forward primary and forward output gears, larger primary shaft and did I mention faster[X(]</span><span style="FONT-FAMILY: Arial; FONT-SIZE: 9pt"> </span></p>

Snook Man

http://www.robinsonracing.com/catalog/tmaxx25.html
Bottom of the page Part # 8522

Looks like this

tj107us

yeah thats the gear im looking for and i saw it on there website but you have to go through a middle man to get it but cant find one that has it.

Snook Man

If your LHS does not carry them or will not order, click the order tab on RRP's home page and they list a few places that carry them.

tj107us

yeah i tried that too, but there dont carry it for some odd reason.

tj107us

I found the gear on stormer hobbies.com

James c harrell

My Feedback: (18)

Any- one who has been following this thread check this out. I ripped another tranny. Got me a forward only tranny to replace it. put it in and guess what, dern thing goes backwards. Reverse is lower than forward, that is why my son was smoking me on top-end. Reverse is weaker than forwards and that is why I am ripping the gears out. Something is reversed and I have been running forward in reverse gear. Some-one tell me how too fix it. PLEASE!!

Snook Man

You got PM.

Wo81

Your diffs could be installed backwards.

Mopar Or Nocar

Thats what i was thinking too... good luck man! I can't wait to get my t-maxx out again