Harder than mild steel?

[shithotfast]

Here's a question for all you metal-heads! My clutch set-up is rather unusual in that I dont use the 911 swing arm for the trust bearing. It sits on a small plate I had made to hold the thrust bearing assembly. The plate is about a qtr inch thich but bends slightly over time putting the thrust assembly out of line. So question is whats the hardest substance I can get the plate made from? Mild steel isnt strong enough, and I cant make it any thicker due to clearance issues...?? It is quite a complex shape so needs to be machined to exact shape and thickness.

[G Man]

In tube try cromoly or T45 steel, I don't no if it is available in plate

G MAN

[Allen-GTR]

Well, you have a couple of choices I'd think...
If the part needs to be machined:

H-13 tool steel
Carbon Steel
Chromoly steel
Nickel Steel
Titanium
Or possibly some of the harder aluminums like a 7075 T6 but have a low resistance to wear and abrasion.

Low carbon steels like "mild steel" are generally flat or rolled stock.

If the part has to be "bent" and not machined, then a quenched/tempered approach may be needed. (HSLA steels)

I would say any machine shop would be able to help you find a alloy that would be stiffer (albeit more brittle) than the Mild steel you are using now.

Allen

[andygtt]

paul
have you got pics.... I recently bought a G50 tripple plate kit for my car and have an internal hydraulic bearing kit which replaces the original sleeve withing the gearbox.
You may be doing it an alternative way and so could swop over to this setup type.

[steve_D]

Stainless steel of the same thickness would be stiffer and readily available in local machine shops.
Is it possible to include a stiffening web at right angles to the plate that is bending?

Steve

[shithotfast]

thanks guys.. I am doing my winter strip down now, so will post some pics. It was some time ago we put this system together, my cousin used this setup in a GT Ultima which was in the GT championships about 5 years ago... had a bad off at 150 at Castle Coombe and the car is no more. I have the gbox and clutch now, and although it works, it is a bit heath robinson!

[marky p]

andygtt said:

paul have you got pics.... I recently bought a G50 tripple plate kit for my car and have an internal hydraulic bearing kit which replaces the original sleeve withing the gearbox. You may be doing it an alternative way and so could swop over to this setup type.

I have done the same thing, change your pull type slave to a push type which sits inside the bell housing, use a saab slave.

>> Edited by marky p on Tuesday 28th December 12:02

[shithotfast]

Mark.. thats exactly right! I am using the same ( a saab 900 unit) How have you nailed it on? the three bolts from the unit sits on a plate on mine, which in turn is attached via two flat head screws into the bell housing. The plate (between the saab unit and the bell housing) is the issue for me. When you put it all back together the clearance is minimal. I took the back edge off the saab unit to gain an extra few thou.. The fixing plate if not thick or strong enough can bend, which in turn misaligned the saab unit. Still works but I get some strange noises as the saab unit can touch the main shaft.
Is your in place yet? Have you had the same issues?

[andygtt]

Seems the SAAB unit is popular as I understand mine is too.
However my plate replaces the original sleeve on the box so has quite a lot of meat on it. have you got pics?

[mrloudly]

tainless steel of the same thickness would be stiffer

errrr I think not... To be technical its "Modulus of "E"" is about 15% less than basic mild steel.

[gtrclive]

These people sell T45 Tubeing and the Equivelant bar and flat plate of the same grade. They also stock 4340 "Moly" tubing etc. They sell to Pro-Drive and Ascari etc, so these are the boys to know about High tech metals.

There not cheap but it is the Dog's Dangles of Steels, and it's helped save me 50Kgs on my Mini frame..

www.elmdonmetals.ltd.uk/stocklist.htm

>> Edited by gtrclive on Saturday 1st January 14:39

[steve_D]

mrloudly said:

tainless steel of the same thickness would be stiffer errrr I think not... To be technical its "Modulus of "E"" is about 15% less than basic mild steel.

I stand corrected. Or was that slapped, difficult to tell.

Steve

[shithotfast]

Ok, got pics of the clutch set up and the problem... for those of us who still use steam driven devices.... how do I put pics up with a reply??

[mclark]

When you go to the reply option there you'll find Formatting Codes.

You can then embed a picture as long as is hosted from your webspace.

Haven't seen any other way.

[WilldJ]

Consider heat treating the part after machining, if done right should significantly improve long term stability. I also wouldn't rule out some stainless materials, like 15-5 and 13-8. Suggest you talk to metalurgical heat treat experts (which I am not). Please share what you end up doing with the group.