Trucks T-maxx 3.3 My Steel Center Shaft Kit Doesn't Fit 4949r

Scott Marshall

New Member
I recently acquired a very nice and gently used T-Maxx 3.3 with a big box of parts. The truck runs fine, but the u-joints were a tad sloppy, and it had Traxxas 5451R halfshafts and an (almost) complete RPM chassis kit still in the packages with it. I rebuilt the stock driveshafts with the included ujoint kits, installed the True-Track rear end kit and the rear half shafts. All this fit the chassis fine, and I ran it while waiting for the missing RPM front control arm and Traxxas 4949R steel center shaft kit. It runs and handles nicely, but still needs a few bugs work out.

The parts showed up this Am, so I just started to complete the "freshening upgrading" and discovered the 4949R Center shaft kit is not only too short, but has no way to drive the brake rotor. In addition, it calls for 2 pieces .5mm teflon coated washer to be installed on each pinion and if you do so, the CV joint pin hole won't line up. (you CAN make it work with 1 shim).

The back of the shaft kit says "Driveshafts, center (steel constant-velocity) front (1)/ rear (1) (assembled w/inner and outer dust boots, for T-Maxx w/optidrive transmission"

I know the T-Maxx is an old design, and has probably been thru many changes, and I vaguely recall reading something about an extended chassis version, and I know there is a (popular) no reverse model. That would explain the length problem, but not the brake rotor issue. The rotor on this model floats on 2 pins mounted on the front transfer case/transmission yoke.
The kit comes with a blue anodized hollowed out hex that looks similar to the wheel drivers. I'm thinking some models use a hex drive brake disc?

I understand these have been made for 20+ years now, but I have no idea how old this truck is, there are no identifiable model numbers except a tag on the chassis (KA2246-R00) and one one on the transmission (C15001943). It has Optidrive, reverse, a 58t spur, 22t clutch, Steering servo is a 2055, Shifter servo is a 2060, and the Steering has been replaced with a Savox SA-1256TG if that helps identify it.

Sorry about the long post, just trying to make it easy to help me. I've got a cool $32 paperweight right now....

I am probably overlooking a obvious issue, but am currently at a loss. I'm thinking it's a mis-marked part, or maybe I have a Revo with a T-Maxx body or something weird like that, but it's most probably something I've done wrong or missed.

Thanks in advance for any guidance you can offer.
 

Tony

Staff member
If you don't have inboard cantilever shocks, then it is not a revo. I'm thinking that either 1, your truck is newer and the parts you ordered are older, or, and they did make one, this has the extended chassis on it for a longer wheel base. As for the brake disk, I remember there being two if I'm thinking of the correct model. One with a round hole with two flats 180º from each other, and the other having the hex. I think I have only had models with the hex. What brake setup does your truck have?

And if you are running the smaller spur gear, then you likely have the newer transmission as well. Stock spurs for the older trucks are something like 72 if I remember correctly.
 

Scott Marshall

New Member
Mine has the brake disc with the round hole and 2 pin holes (floats on the transmission output shaft and drives with pins in the u-joint yoke). I put the stock driveshafts back in for now, and put in the rebuild kit. Seems tight enough, but was hoping to install the steel and not have to worry down the road.

The shocks are all upright and look like any T-maxx I've seen.

I ordered all the parts using numbers from the Traxxas exploded drawings for the current model T-Maxx 3.3 shown on their site. There is a classic shown as well, but I believe it's a 2.5? so figured the current model would be the safe bet. The driveshaft is the only part that didn't fit.

I was just on the phone with Horizon and forgot to ask them (bought a set of Proline sand tires to match the pair that came with the truck and the new ones are glued with such bad runout they are unusable).

If you know of anyone who can use the hex disc driveline kit 4949R, I'll sell it (unused and uninstalled for $20 plus ship) - I'm not going to try to return it to Horizon if it's my fault for ordering the wrong part..

Thanks for the help.
 

Scott Marshall

New Member
This is the disc, the roll pins in the drive yoke go thru the slots on either side of the center hole.
 

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Scott Marshall

New Member
It looks like this is the model I have. It's called the T-Maxx 3.3 which is deceiving. There are several versions of the T-Maxx which have the 3.3 engine (plus the electric versions), but this is MODEL 3.3. They couldn't have made it more confusing.

Looking at the Traxxas "showroom" page, there are only 2 current models of the T-Maxx (Nitro) - the "T-Maxx Classic" which is equipped with the 2.5 engine and the "T-Maxx 3.3" which is equipped with the 3.3 engine, is 30mm longer and has a larger brake disc of different design than other T-Maxx models. The 3.3 also has larger wheels and a different non-chevron style tire.

The Traxxas page on the T-Maxx 3.3 says it has a wheelbase 30mm longer than a standard T-maxx. That's about how short the driveshaft is. The whole Model number is 49077-3
T-Maxx 3.3: 1/10 Scale Nitro-Powered 4WD Maxx Monster Truck with TQi 2.4GHz Radio System, Traxxas Link Wireless Module, and Traxxas Stability Management (TSM) | Traxxas

For anyone else with this truck here is a link to the Traxxas parts page. RC Parts | RC Car Parts | RC Truck Parts | Traxxas

I'm still in search of the correct steel driveline kit, but am getting closer and learning a lot about Traxxas and RC trucks in general. It's part of the fun, for me anyway. If they don't make a longer kit for the T-Maxx 3.3, I may end up simply making a longer shaft to fit the CV joints in the kit. The complicated part is the brake disk drive, but that's do-able as well.

Merry Christmas all!
 

liquid1

Member
The 3.3 Tmax is a mixed bag. within a certain year there was a change and its hard to match up correct parts, I blew my reverse out doing revers wheelies the transmission replacement would not work with the steel driveline I was using so I had to modify a newer style plastic slide shaft. Love this truck it will flat rip ride a wheelie full football field with a little fine tuning with a temp laser gun . Hits 2nd gear and gone.
 
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