This is part 2 of finding a solution to the Losi Speed-T horribly made gear differential.

If you aren’t familiar with my previous post I outlined a common problem with the Losi Speed-T locker differential in the transmissions where the main diff gear strips or eats the center spokes of the gear due to high-end torque that the brushless motor produces.

None the less… for a solution… possibly?

Last night was the first night running the brand new Losi Speed-T for a full battery discharge and the thing is blazing now.

The Losi Speed-T is basically an XXX-T tranny except with a gear diff / locker pads.  You have the option to purchase the Carbide Differential Balls and the Diff Grease to make it a ball differential.

After much research we realized that the ball differential would most likely still melt/destroy the diff gear just due to the nature of the vehicle and it’s brushless power.  So we decided to purchase a Robison Racing Hardened Aluminum Diff Gear and Idler Gear to replace the existing plastic gears inside the gear box.  Let me say, plastic gears DO NOT belong in a brushless motor powered gear box.  PERIOD.  With a combination of the ball differential conversion and the metal gears we think we finally have a pretty solid Speed-T transmission.  Due to the vehicles suspension it’s definitely runs different than say the “Rustler VXL” which does uncontrollable wheelies constantly.  The Speed-T still hugs the ground and is definitely street ready even with a ball diff.

The one thing that is still pending in our head is why doesn’t 1 wheel spin the opposite as the other wheel since it’s a ball diff?  Possibly gearing differences?  Maybe we’re doing something wrong?  The car is running but we’re not sure if it’s running the way it should in a ball diff conversion.

Here are the aluminum tranny gears we upgraded to: (Tower Hobbies Pricing)
LXXGM3     Robinson Racing Hard Steel Idler Gear XXX/SPD T      1      $12.99 (Purchase)
LXXGM1     Robinson Racing Hard Aluminum Diff Gear XXXT     1     $16.29 (Purchase)

Robinson Racing Idler Gear (RRP9402)

Robinson Racing Diff Gear (RRP9400)

Here are the carbide balls and diff grease from Losi:
Losi Diff Lube TEAM LOSI – LOSA3065 – $3.31
Losi Carbide Balls 3/32 – LOSA6951 – $10.78

Reference / Pricing / Purchasing:
http://www.losipartshouse.com/servlet/the-21175/LOSA3065-Losi-Diff-Lube/Detail

Losi Carbide Balls 3/32 (LOSA6951)

Losi Diff Lube (LOSA 3065)

We’ll keep you posted on the progress of things to see if we find out more about certain tweaks we can make to improve the performance of the vehicle and it’s stamina! Any comments are always welcomed!

-jfr

Hello!

It’s been quite a long time since I’ve posted on this blog but figure I’ll jump back in with my new R/C ventures.

My buddy just purchased a Losi Speed-T Brushless 1/10th truck.  The car is setup for street driving from the factory and is also geared for it.
The truth is though – that the diff gear from the factory is not really capable of staying intact with that high of torque and strips out usually within 10-15 minutes.

There are a couple of options to help prevent this from happening.
You can do a Ball Diff conversion kit which requires several parts which I will list at the end of this blog entry or you can simple go with a 17T Pinion Gear / 88T Spur to help and leave the locked diff in place.

The benefits to the locked diff is it’s capability to keep control at higher speeds but is not the greatest if you plan to do any off-roading.  The ball diff is also known as “DT” or Desert Truck Diff is designed for off-road and dirt races.

Here is a picture of what commonly happens to the diff gear on the Speed-T: