2.5 to 3.3

[xsd916]

Looking at doing a swap. I have an older 2.5 that I'm needing a new engine and transmission for so I was going to get the 3.3 engine and transmission. Is there any other parts i need to make this work? I heard everything works with all the 2.5 stuff but I might need to change the driveshafts.

 

[insaneatvs]

Should just drop in there. I went from a .15 to a 3.3 and need to change the throttle linkage and brake set up. set transmission, same axles

 

[RusTLeRx350]

Funny you mention, my dad's 3.3 just got here today too! He's upgrading his 2.5 to a 3.3 too. I'll let you know how it goes, but as far as I know, it should be a direct drop in.

 

[surgemaster1970]

Assuming you have the Classic Narrow Maxx 2.5 with the black transmission you're going to have to get a suitable rotary carb that will work for the 3.3 if you dont change the transmission because the carb slider will hit the spurgear spindle before wot unless you flip the carb and do something different with the linkage placement and design.....If you do change out the black transmission for the grey case one you will also need the throttle/brake linkage setup complete to work for the Classic 2.5 Maxx .If you want to use the beefier drive shafts with brake rotor they must be shortened to work.With that much power in the classic design truck the chassis braces, bulkheads and bulkhead mounting holes on the chassis plate dont hold up too well with the ultra thin frame ..Dont be surprised if you eat-up spurgears and drive axles from the power and torque increase also when the thin chassis flexes from jumping and landing hard.I suggest swapping out the chassis and braces for the beefier 4909 chassis plate or even the 4908 extended design but that wouldnt look or handle too good unless widened ..Even the narrow Maxx looks good and drives even better widened..

 

[ohiofordfan]

i went from black trans to grey one. everything works except front driveshaft. the plastic one might, i don't know. i had cvd's and it was a little to short. kept popping out. if someone knows what cvd fits a 2.5 chassis with grey trans i would appreciate it. it was so close i bet the plastic one works.

 

[surgemaster1970]

Heres the swap done with a 3.3 and the black transmission in under an hour and a half on the Pro .15 Classic Maxx that I widened and already beefed it up with 3.3 drive axles...

To get it to fit and work with the black trans I had to flip the carb and make a revo style type throttle linkage with a lil ingenuity utilizing an extra throttle pivot post from a 4909 model I had laying around and a futaba servo horn with two thin self tapping screws...After flipping the carb I had to move the carb inlet to the rear nipple port,added an extension boot for the intake,flipped the brake activation lever and reworked the rods to work with my new design...

I went for weight savings so I used a Tiger drive to crank it and went with a 24 tooth clutch bell to match the large spur gear better..The engine was given to me by a friend for free...its only 3 weeks old and has about a gallon of fuel burnt through it beleive it or not....He couldnt get it to run cool enough so he drilled holes and cut slots in it hoping it would work...The cooling head is beat up badly and looks like sheez but it runs good now after I found the carb inlet fuel port on the carb body wasn't large enough to supply the engine adequately enough at WOT so I drilled it larger.Now its my test pigeon to make the Classic Maxx scream..

 

[xsd916]

I found a rolling body for a newer tmaxx, I might just get the parts i need for that and just build that up instead of having to make things work with the 2.5 body. thanks for all the help guys.