(9) Long Ext Chassis Trucks / 2.5 Differential / Rear / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(9A) Rear

Hpi 101064   .140"

Traxxas 5153

5

(9B) Rear

Hpi 101360   .175"

Hpi 86082

2

(9C) Rear

Hpi 101360           

Hpi 86276

2

(9D) Rear

Hpi 101360           

Traxxas 5153R

5

(9E) Rear

Hpi 101360           

Traxxas 5153

5


(3) Short Chassis Trucks / 2.5 Differential / Rear / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(3A) Rear

Hpi 103664   .125"

Traxxas 5153R

5

(3B) Rear

Hpi 103664           

Traxxas 5153  

5

(3C) Rear

Hpi 86056     .175"

Traxxas 5153R

5

(3D) Rear

Hpi 86056             

Traxxas 5153  

5

(3E) Rear

Hpi 86152     .196"

Traxxas 5153R

5

(3F) Rear

Hpi 86152             

Traxxas 5153  

5


Some dog bones have larger shaft diameters than others and may be more suited for extreme use. The matter of choice maybe the availability at the time needed. 

To identify, 3.3 pinion collars are straight with a raised support bar.  2.5 pinion collars are offset. Flats on 3.3 pinion shafts are cut flush to the bearing. 2.5 pinion shafts have a noticeable shoulder. 

(1) Short Chassis Trucks / 2.5 & 3.3 Differentials / Front & Rear / 2.5 Plastic Drive Lines:

Traxxas currently makes two different versions of the T-Maxx, 2.5 and 3.3 ext (long) chassis.  Current 2.5 trucks share the same differentials as the first Pro15's and the discontinued 2.5R and 3.3 short chassis trucks. The diff case was also upgraded from a two screw to a four screw configuration during this time.  When the extended chassis T-Maxx was introduced, it was upgraded with stronger drive lines and stronger differentials, i.e. 3.3 diffs. But because it is a T-Maxx and most parts are interchangeable, it is impossible to assume that everything is still original.  3.3 differentials can be fitted to short chassis trucks all the way back to the first one made. Another possibility, the truck was a short chassis originally, but later upgraded with the extended chassis. Now the truck has a long ext. chassis but with 2.5 differentials. The possibilities are there and it is very important to follow the instructions and charts for this conversion to work as described.

Plastic Center Drive Line Assemblies:

​(4) Short Chassis Trucks / 2.5 Differential / Front / Drive Line Assy.​

   Position

Dog Bone     Dia:

Drive Cups

Washers 3981

(4A) Front

NA

NA

​NA

> This chart will be updated when more information becomes available.

Long Ext Chassis Trucks:

(7) Long Ext Chassis Trucks / 3.3 Differential / Rear / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(7A) RearHpi 101064   .140"
Hpi 86082
0
(7B) RearHpi 101064           
Hpi 86276
0
(7C) RearHpi 101064           
Traxxas 5153R
3
(7D) RearHpi 101064           
Traxxas 51533
(7E) RearHpi 101360   .175"
Hpi 86082
0
(7F) RearHpi 101360           
Hpi 862760
(7G) RearHpi 101360           
Traxxas 5153R
3


Differentials 2.5 or 3.3

(8) Long Ext Chassis Trucks / 3.3 Differential / Front / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(8A) Front

Hpi 86057   .175"

Hpi 86082

0

(8B) Front

Hpi 86057           

Hpi 86276

0

(8C) Front

Hpi 86057           

Traxxas 5153R

3

(8D) Front

Hpi 86151   .196"

Hpi 86082

0

(8E) Front

Hpi 86151           

Hpi 86276

0

(8F) Front

Hpi 86151           

Traxxas 5153R

3


​​​

Each Drive Line Assembly front or rear consist of one dog bone and one package of drive cups. Some dog bones are sold 2 to a package, only one is needed for that assembly, the extra is a spare. Traxxas washers (3981) are 10 to a pack and used to properly hold the pinion and bearing in place.

(6) Short Chassis Trucks / 3.3 Differential / Front / CVA Drive Line

Position

Drive Cup

Rebuild Kit

Driveshaft

Drive Cups

Washers

(6A) Front51625129518751530

Note: This front drive line assembly will only work with 3.3 differentials.

It will not work with 2.5 differentials or long chassis trucks.

Use one package of Traxxas part# 5162 (Drive Cup), 5129 (Rebuild Kit), 5187 (Driveshaft 55mm) and 5153 (Drive Cups) for the complete assembly.

Use the extra parts as spares. No washers needed.

A simple way is to first cut the tube end to the length shown below. Cut and trim the rod end until the tube meets the shoulder. 

(5) Short Chassis Trucks / 3.3 Differential / Rear / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(5A) Rear

Hpi 103664   .125"

Hpi 86082

0

(5B) Rear

Hpi 103664           

Hpi 86276

0

(5C) Rear

Hpi 103664           

Traxxas 5153R

3

(5D) Rear

Hpi 86056     .175"

Hpi 86082

0

(5E) Rear

Hpi 86056             

Hpi 86276

0

(5F) Rear

Hpi 86056             

Traxxas 5153R

3

(5G) Rear

Hpi 86152     .196"

Hpi 86082

0

(5H) Rear

Hpi 86152             

Hpi 86276

0

(5I) Rear

Hpi 86152             

Traxxas 5153R

3


(1A) If the truck has been upgraded with 3.3 diff's and using 2.5 drive lines, a small modification to the 4928x yoke is needed to fit properly. Cut drive lines to the same length as above. On the differential end, grind off enough of the raised area so the screw pin can intersect the pinion shaft hole.

For a complete set of new front and rear center drive lines, use one package of Traxxas 4951x and two packages of 4928x  to complete. Assemble and cut the drive lines to the approximate lengths shown. Lengths shown are the max distance.


In the charts below are the different combinations of dog bones and drive cups that are proven to work with this conversion.

To understand, say we have a short chassis truck with 2.5 diffs and wanting a metal drive line assembly for the rear. Look at chart (3). We have 6 possibilities to choose from, (3A) - (3F). The hobby store only has the Hpi 86056 & Traxxas 5153 part numbers. (3D) is a match, the HPI 86056 dog bone & Traxxas 5153 drive cups will work together for this particular setup. Also as seen in the chart, a package of 3981 washers are needed for proper spacing.

(2A) Using larger 3.3 drive lines with 2.5 style differentials needs 2 washers 3981 between the bearing and yoke.

The brake yoke can be reused with some modification. The brake disc pins have to be cut and ground flush to the plastic . Also the hole has to be rounded about 1/16" deep until the screw pin will pass through the transmission shaft.


Note:  E-Maxx differentials (3903, 3905, 3908 models) have the same outside dimensions as the 3.3 diffs. Meaning, that for center drive line selection and fitting, they are the same as 3.3 differentials. Although they share the same housing & ring gear/pinion, the diff carrier and spider gear assembly are stronger than 3.3 diffs.

For extremely strong builds and abusive power, E-Maxx diffs are the differential of choice.

​Metal center drive lines specifically made and sold for T-Maxx trucks do not work with this conversion. The electric transmission's position on the chassis + the output shaft diameter on some nitro transmissions are different. Below are other options using HPI dog bones and HPI / Traxxas drive cups.

(10) Long Ext Chassis Trucks / 2.5 Differential / Front / Drive Line Assy.

Position

Dog Bone     Dia.

Drive Cups

Washers 3981

(10A) Front

Hpi 86057   .175"

Hpi 86082

2

(10B) Front

Hpi 86057           

Hpi 86276

2

(10C) Front

Hpi 86057           

Traxxas 5153R

5

(10D) Front

Hpi 86057           

Traxxas 5153

5

(10E) Front

Hpi 86151   .196"

Hpi 86082

2

(10F) Front

Hpi 86151           

Hpi 86276

2

(10G) Front

Hpi 86151           

Traxxas 5153R

5

(10H) Front

Hpi 86151           

Traxxas 5153

5


Metal Drive Line Assemblies:

3.3 drive lines can be used at their current length. The brake yoke will need to modified or can be replaced with a 5458x yoke. The rear drive line can be moved to the front without any modifications if a metal drive line assembly is used for the rear.

Center Drive Lines (Axles):

It is possible to use current parts from both front and rear assemblies and make one front drive line. Drive line yokes used on the nitro transmission have a smaller inside hole and will not fit the electric transmission. By taking the differential yoke (4928x) off one assembly and exchanging with the transmission yoke on the other we now have a drive line with differential yokes on both ends. After this it will need to be shortened to the length show below. Using plastic drive lines in front and metal drive lines for the rear works well with this conversion as the rear takes most of the abuse. See Metal Drive Lines below for options.

(2) Long 3.3 Ext Chassis Trucks / 2.5 & 3.3 Differentials / Front & Rear / 3.3 Plastic Drive Lines:

MyElectricTMaxx