Torsen University special differential

[Gourav]

Will anyone pls care to explain the setting of side gears & washers (6 of them) in torsen university special 012000 differential?? What are the dimensions of cut inside the housing & any clearances, if any?? The drawings on site didn't help much.

[Hector]

I'm pretty sure all the information you need is there, though you may need to combine dimensions from the main drawing and the B-B' section view.

I made a one-piece billet diff using nothing but this drawing a few years back so I say this with confidence.

[Gourav]

May be, you are right but still is there any clearance required between the washers & side gears? And what do they mean when they talk about REWORK THICKNESS of the washer?
Again, the id of washer is 30 mm (as given in pdf) but the dia of splines on inner surface of side gears is ~37 mm. How do you decide the o/p shaft then (or rather pass a 37 mm od shaft through a 30 mm washer!!! I guess, rework dia has to do something here, Has it??)

[Pico]

If you look closely at the drawing you would notice the MAJOR DIAMETER of the splines is 23mm. You should reread the drawing carefully because all the information is there and correct.

[Hector]

Pico is correct. Take another look at the drawing. The largest part of any of our stubs (at the time) was 25 mm.

Do you mind me asking what you're doing? My guess is you're trying to machine your own housing. In that case, you're going to need to order a diff so that you can take it apart to use the gears. You might as well order it now, so that you can actually hold the housing in your hand and see the dimensions in 3D real space.

[Gourav]

Thanks Hector. And u r right - We r on our way to machine our own custom housing. Were just trying to figure things out. Any other critical suggestions for custom housings anyone?

[Hector]

Are you going for a one-piece housing or will it be several pieces that bolt together? The two most challenging parts on ours was trying to perfectly index the diff 120 degrees so that the windows would be evenly spaced, and machining the sun gear thrust washer bores on each end. We ended up making a custom tool that would insert in one end of the diff, then allow you to attach the correct cutting tool on the end.

The depth of the sun gear bearing reliefs was by far the hardest dimension to get accurately. The first year we "snuck up" on the depth very slowly. We'd take a little off one end, flip the diff, then take a little off the other end, then try and fit the sun gears in. This is time-consuming and it's hard to keep the diff concentric when you flip it that many times. The issue was compounded by our custom tooling not being stuff enough - it's hard to hit a tight tolerance with flex tooling!

My solution to the problem was to machine one side as close as you could, then flip the diff and do all the "sneaking up" on this end. Take a little off end #2, try and fit the gears, take a little off end #2 again, keep doing this until the gears fit. In the end, the sun-gears aren't quite centered in the diff (though still concentric!) but you can shift them a bit axially with no issues.

For your questions about clearancing, there really is no issues on this diff. Just cut three windows with the length and width in the drawing as deep enough to hit the center axis of the diff. Drill your bores on each end, and it's done. Everything will fit.

[Gourav]

More help than expected!! Thanks.

Are Taylor race halfshafts made to custom orders as well? If not, how do we adjust their length to our requirements??

[Hector]

TRE shafts come in several sizes which you must then cut to length, a process that can be rather difficult depending on the equipment you have access to. I highly recommend TRE as they are very supportive of FSAE and have an FSAE representative, Scotty, who is also a member of this forum. You'll see him poke his head around from time to time. If you have any more questions about TRE products just give them a call and ask for Scotty.

[scotty young Taylor Race]

I thought I heard my name.....Thanks Hector
We have two versions of the Torsen stub
The 0200418 is the 86mm bolt up housing version
And the 02004181 Tulip stub. They have 5 inches of spline on the shaft so they can be cut to fit in you housings.


scotty

[Gourav]

Thats Ok scotty....I have seen the drawings on your site...but can you please elaborate about cutting the shafts/splines to required sizes? What machines...what process & what precautions to be observed as recommended by TRE.

[scotty young Taylor Race]

You can part them off in the lathe with a parting tool . or use a chopsaw with some type of coolant Just don't get them too hot when you cut them.

scotty

[Gourav]

We are making an aluminium custom housing but have serious apprehensions about the leakage proof ability of the housing. We are considering using O rings in a few ways but are not sure of the results. Will someone please tell how you make the housing leak-proof??

[The_Man]

Make sure you face the aluminium surfaces(that are to be sealed) quite carefully as the last step of your manufacturing process and have the proper sized grooves for your o-rings(have 2 if you can).

[scotty young Taylor Race]

We use O-rings as well as bushings in our TRE diffs. There are also numerous double lip seals that will work in these applications.