.....just flip a one-way diff you say? Sounds simple enough...

[Kingfisher]

 So, I took the advice of flipping a one-way diff to give my RWD TT02 some front brakes while maintaining RWD. First, I installed the diff and tried it out. I had 4WD going forward and only RWD going backwards. Ok, this is the part where everybody told me to flip it. This is also the part where my brain stopped working. So, I took it out, flipped the whole thing around, and put it back in. Thinking to myself, wow, that really was simple. Time to test it. Now, my rear wheels were going forward and my front wheels were going backwards. The car looked like it was trying to implode itself.    That's when I realized that I don't flip the whole diff. I flip the one-way bearings!  

 

Here's the one way diff that I got. It's also my first encounter with a one-way.

 

 

Up until now, I had all of the front drivetrain out of the car and was using the M-chassis freewheel axles up front. They fit the TT02 knuckles and bearings perfectly.

 

 

The one-way bearings were pressed in. No amount of bare-hands force was going to get them out.

 

 

 

Using the big-socket / little socket trick, I was able to push them out.

 

 

Next, I mocked things up. Turn the back wheels forward, driveshaft turns this way, diff spins this way,  power is applied in this direction, so bearings have to be this way in order for this to work. Got it! I was certain that I had the bearings facing the correct way, and pressed them back into the housing. I put the diff in and rotated a rear wheel by hand. Something wasn't right. I was back where I started. After I mocked them up, I set them on the table one way, and picked them up the other way. I figure that's where I went wrong.  So, I put them right back in the same way I took them out.  

 

Repeat the process and I got it right the next time around. 

 

 

Pretty neat the way it works. I have a rear wheel drive car when going forward. The front wheels just free-spin. When I go backwards, I have 4WD reverse, and I have 4 wheel brakes when going forward.

 

Also, the bearing grease that they used on this diff is one of the worst smelling greases I have ever seen. I've washed my hands 3 times now and still smell it. If you get this diff and choose to take it apart, wear gloves. 

 

 

[MadInventor]

Congrats on persevering with it. If you'd flipped over the rear diff as well you could have avoided pushing the bearings out though All four wheel would have moved in the same direction, just in reverse rotation to normal, which could have easily rectified by swapping the motor leads over.....

 

[Juggular]

Now, this is a learning moment.  

I have a one way bearing for TA01.  I did not like the fact that I had only 2WD when I'm in the ditch, where I DO need 4WD to back out.  Interesting how people thought to make it 2WD forward + brake!   

[Kevin_Mc]

I’m going to buy one of these for my TT-02 Capri. Cheers for the photos

[Juls1]

So the question is, how does it drive? More specifically what’s its steering like off power but not on brakes? Since the front end is now a spool off power/on brakes I’m wondering if it causes push under engine braking/coasting??

[Kingfisher]

6 hours ago, Juls1 said:

So the question is, how does it drive? More specifically what’s its steering like off power but not on brakes? Since the front end is now a spool off power/on brakes I’m wondering if it causes push under engine braking/coasting??

Haven't had a chance to run it yet since putting this in, but the car is built for the top speed thread. It's meant to hold a straight line more than it is for turning. Trying to stop a 60mph car with foam tires on concrete, and only rear brakes wasn't easy. That's also the reason why I have had to do another body shell. The other got destroyed. 

[Juls1]

Yeah rear brakes only, is great for initiating a drift. But stopping, not much good. I’m doing a Build with the flipped one way but not for speed running. Purely utility in the scale build

[Kingfisher]

On 10/21/2018 at 7:56 AM, Juls1 said:

Yeah rear brakes only, is great for initiating a drift. But stopping, not much good. I’m doing a Build with the flipped one way but not for speed running. Purely utility in the scale build

I'm tempted to get another one and use it for its intended purpose, just to see how it works and what changes with it. I have a TT01 built as a touring car and another TT02 built as a rally car. Any idea where it would be most useful between pavement or dirt?

[Kevin_Mc]

What exactly is it’s intended purpose?

[Juls1]

In a 4wd drifter it has its greatest purpose because it gives you basically a hand brake. In rally if your running on a very tight circuit at relatively low speeds. It could be useful in a touring car the ability to basically hand brake turn could make switch backs more manageable. 

Some belt driven kits have a front one way pulley instead, this is so you still have a open diff under power. Usually a front one way diff gives you a spool under power.