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center diff in a 2.5r

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rckid91

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ok guys what do i need to get for this truck to put the rear brake and center diff setup in it can i trim the chassis or do i have to get the 3.3 chassis

i would like to trim my chassis if possible because i like the wheelbase

thanx guys,
nathan
 
u can trime the chassie it cost me around 75 bucks for the conversion

chassie 50
steering rod 5
cv joint 5

plus i need a heaver weight oil for the diff 15bucks
 
I'm going to do the same thing in my revo 2.5R. i have the center diff and rear break. I'm just trying to get myself a 3.3 tranny and plan on triming the chassis
 
yeah any idea how much the chassis must be shaved?? can i get a template??
 
You don't need to get a complete 3.3 tranny. You do however need to get the newer tranny case halves if you wanna use a rear brake. All 3.3's and some of the last 2.5's had these newer case halves (which have the mounting tabs for the rear brake molded on). The set of case halves cost under $10.00. The part # is TRA5391X.

http://www.amainhobbies.com/product_info.php/products_id/7043

To use the center dif in a 2.5 you need the traxxas center dif output shaft. That's part # TRA5416.

http://www.amainhobbies.com/product_info.php/products_id/7259

So....you will need the center dif kit (which comes with an FOC kit BTW), the center dif output shaft, the rear brake kit, and the tranny case halves.


You might as well convert to a 3.3 chassis while you're at it. They can be found cheap on fleabay. If you want to keep the 2.5 chassis you can trim it for the rear brake though. I've got the traxxas link somewhere...


Here it is. It's within the traxxas rear brake instructions!

http://www.traxxas.com/PDF-Library/5417INST Rear Brake.pdf
 
you can trim the rear of the chassis with a dremel.
I trimmed mine with a pair of needle nose vice grips.
it was a nasty looking job. but my dremel was out of
commition at the moment.
 
ok so i need the center diff kit a 3.3 tranny case and the rear brake kit

is there a template i can get to use for trimming the chassis?
 
bob24 said:
ok so i need the center diff kit a 3.3 tranny case and the rear brake kit

is there a template i can get to use for trimming the chassis?
Click to expand...

According to the Traxxas rear brake kit instructions you need to trim the tranny cutout back 10mm. That's about .4 inches. Looking at the instructions (click the link in my above post), you just move the existing cutout back 10mm (maintaining the same profile as before).

Just make a few measurements back 10mm from the existing cutout and draw the existing profile with a sharpie. I doubt the exact shape is critical. If you must have a template you could probably print out the instruction sheet from the PDF and cut it out as a template. The Adobe reader lets you change the size percentage easily...
 
if u buy a rear brake kite u'll need a 3.3 tranny case it come with a guide to cut it out
 
o cool thanx guys so this will be my nexy 100 dollar project
 
bob24 said:
ok so i need the center diff kit a 3.3 tranny case and the rear brake kit

is there a template i can get to use for trimming the chassis?
Click to expand...

you dont need a template.


once you try to install the parts you will plainly see what
material needs to be removed.

it is not difficult
 
cool thanks guys if any1 has any of the tranny cases that i cna get for cheap lemme know
 
ok i just got myself a 3.3 tranny off ebay, i already have the center diff and rear break kit. what else do i need to complete this for my 2.5R chassis.

do i need the 3.3 center driveshafts? or anything else besides trimming my chassis?
 
2.5 cv are ok cause ur staying 2.5 but i will suggest u to buy a screw set cause the screw that the rear brake kite come with are a little to short and some times drag
 
Mattyfats, Please let me know how you make out with the conversion. I have been wanting the 3.3 just so I could play with the center diff and brakes but I wanted to stay with my 2.5R wheelbase. I didn't know you can retrofit.

What I am looking for is a final shopping list of what exactly you needed to make the mod. or at least confirm what the others posted already.

Moding the frame is no problem I just need to know just what to buy for parts.

I assume this mod makes it rear brakes only?

Are you guys happy with the mod? Is it tighter on the track?

Thanks, Bill
 
Last edited:
i will keep you posted blackbird85, actually keep an eye out for my thread in the member project part of the forum. ill try to do it step by step for people who would want to do this in the future, I'm going to be installing an OS18TM, 3.3 tranny W/center diff and rear break, and the RPM True Track rear conversion all on my 2.5R chassis. i did order myself the 3.3 chassis just in case it doesn't work out or i do something wrong and screw it up.
from what I've learned from working on cars and RCs is to always have a back up plan ready just in case it doesn't work out the way it was originally planned.
 
Thanks. I get real impatient and anxious when it comes to my Revo. It's just so pretty all covered in track dirt. At 37 you'd think I'd have better self control.

I think I got the list of everything I need from Tower Hobbies to do this as well as a few other things like locking the rear differential and adding a 40MM flywheel for my starter box. I defenitly think it would be good to make a DIY step by step thread. Maybe even kit the parts together and sell it as a kit with your instructions.

I'll keep my eyes out for your new thread.

Bill
 
Blackbird85 said:
Thanks. I get real impatient and anxious when it comes to my Revo. It's just so pretty all covered in track dirt. At 37 you'd think I'd have better self control.

I defenitly think it would be good to make a DIY step by step thread. Maybe even kit the parts together and sell it as a kit with your instructions.

I'll keep my eyes out for your new thread.

Bill
Click to expand...

i know what you mean. my revo always looks its best after a nice race =]

as far as making my own kit and selling it with instructions. i dont think traxxas would approve lol.

maybe one day ill have enough money to make my own parts and stuff. but for now all i have is imagination. and that will only take you so far haha

ill definetly do a step by step, but I'm sure i will be here asking questions along the way....as always =]
 
OK so I am too lazy to research it myself. Does the 3.3 tranny take all the same guts as the 2.5R tranny. I have a complete 2.5R but need the 3.3 for the rear brake setup. Can I use the guts from the 2.5?
 

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