T-Maxx 2.5 to 3.3 upgrade, need drivetrain advice

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suhbliem

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Have a 2.5 maxx, upgraded to 3.3 engine. Rear diff gears already need replacing after about 6 hours of driving. What do I need to buy and replace on the stock driveline to give it a reasonable amount of durability so I'm not fixing the drivetrain after every bashing session. Also, are there any other additional tricks I can do to protect the drivetrain from the increased power?
 
4908 carriers, axles, turnbuckles and diffs. For center shafts, pick up 2 4908 rear center shafts. They'll fit the front and the back of your short Maxx. A properly adjusted slipper clutch goes along ways towards keeping your drivetrain together.
 
4908 carriers, axles, turnbuckles and diffs. For center shafts, pick up 2 4908 rear center shafts. They'll fit the front and the back of your short Maxx. A properly adjusted slipper clutch goes along ways towards keeping your drivetrain together.

Hi Metalhead Matt, thanks for the quick response. I am still fairly new to the hobby and don't have all of the jargon down yet.

before I go to the lhs, just want to make sure I have the right parts, here is my shopping list so far:

all parts 4908
1. carriers (2) - i am unsure what this, do you mean bulkheads?

2. turnbuckles (4) - I assume these are the black plastic pieces that join the wheel, driveshaft and a-arms together right?

3. differential (2) - can i get away with just replacing the gears inside the housing or do i need to buy 2 new 4908 diffs?

4. driveshaft (2) - 2 rear center shafts (4908)

5. driveshaft (2) - 2 for front 2 for back (4908)

am I missing anything else? thanks for your time.
 
Your diffs should hold up for awhile. The carriers are the parts that bolt to the a-arms at the wheel side. They house the bearings which "carries" the wheel/tire. You'll need 4 of them; one for each corner of the vehicle. The turnbuckles are the metal bars that hold the wheels straight out back. They attach at the bell crank and the carriers in the front. The bulk heads bolt to the chassis, surrounding the diffs and holding them in place. I recommend finding the parts on Ebay to save some money, but supporting your hobby shop is always a good thing to do. Maybe find everything you need on ebay first, tally the prices up, then price them at your lhs. Just to get an idea of the difference.
 
shouldnt you also replace the trans? i know you dont need to but if you got a 4909 trans would it work out it would have better brakes better spur gear set-up and more. i got a 4908 trans not knowing its the wrong one no one seems to sell 4909 parts on ebay?
 
People have been running big blocks on Maxx's for years. The strength of the old and new trannys are comparable. The new slipper is far superior to the old one though. The old one holds up fine though with all new pegs installed and a proper setup. There's also a kit that allows you to mount the new slipper on the old tranny.
 
not doubting that just looking for the grey updated trans in my 2.5 to 3.3 conversion almost everything is 3.3 i use the vantage carbon chassis which was built for the 3.3
 
I would like to add a little something to the conversation as far as the tranny is concerned. I didnt see it in the thread and if I missed it sorry for repeating. A way to beef up the tranny some is to install a FOC Forward Only Conversion. Who needs reverse anyway?? lol
 
Right on hipluther. That's a big one to miss! The forward only conversion is a must in either tranny if you want them as strong as possible. Easy, $10 mod. Best bang for the buck mod you can do to a Maxx, really.
 
already have this done in my 2.5 trans so it will hold up perfect with the 3.3??? i still want the new tranny becuase of the brake system and spur set-up
 
already have this done in my 2.5 trans so it will hold up perfect with the 3.3??? i still want the new tranny becuase of the brake system and spur set-up

There is a FOC for the 3.3 that is from RRP. Its an all metal gear conversion as well for around $100. You do that and you can out WHATEVER you want behind it.:D
 
Thank you everyone for your very helpful advice. I combined what I learned here with the recommendations from the hobby shop and came up with this set-up to handle my new engine and so far it is holding up very well, I really do not let up on the throttle much and everything is still in tact and not bent out of shape. Here is what I ended up doing (budget was a factor):

1. Removed front wheel drive shafts and diff
2. FOC in trans
3. Rear Diff Gear replaced with 3.3 diff gears and rebuilt using losi 30,000 diff oil
4. loosened slipper clutch 1/2 turn out from seated

all parts together cost $11 and about 2 hours of work has resulted, for me at least, a very sturdy and reliable transmission and without the four wheel drive, I swear the handing has improved 100%, perhaps b/c the front wheels are free spinning now.

In any case, if anyone is trying to figure out how to get their trans to hold up so they are not breaking things constanstly, the above steps work great and improve the responsiveness of your truck for only $11!
 
Why did you remove the front drive parts? Four wheel drive is what makes these trucks fun. Did your hobby shop recommend this for the sake of it holding up to the power of the 3.3?
 
the drive shafts in the front center broke while I was going through some high traction grass so I just took out the rest of the drive shafts to see how it is. At first I liked it and was raving about the handling, but I went back to 4wd and am much happier with it that way.

So I've got about 40 hours of driving on this car since I did those drivetrain mods and am happy to say that not a single problem has occured (knock on virtual computer wood) and I drive pretty hard. Friend and I both got wheelie bars and practice who can do the longest wheelies at the highschool astro turf field and I know that is murder on a drivetrain but so far so good!

Thanks everyone for your help!
 
What is the RRP website? Me and my son are from Fulton, Ky and we just got a couple of tmaxx's. Does Paducah have a track or place for people to run? Thanks, Joey
 
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