Would ETD 150 be a suitable material for a drive shaft on a non model T cone clutch car? It's a Chevy 490 and the clutch is rather smooth for a cone clutch. Please no comments about shoddy Chevrolet Steel. We all know it to be fact. So Cherry Hill George Mills, Les Schubert, I want your input or input of guys with similar knowledge Thanks.
Ted Dumas is a metallurgist, hopefully he will see this and comment.
Thank you Royce.
If it was my car I would start with a piece of 4140 Q&T ground shafting. Machine it without overheating it. Install when finished
I'm not a metallurgist, just a engineer with almost 50 years of experience
Les 4340 is the king of shaft material. Scott
Thank you Les, I'm apprehensive about using 4140 because it's simply more labour(British English grin) intensive. Basics question: do the properties of ETD 150 MEET basic requirements in your opinion to provide a satisfactory shaft? An Etd shaft is almost guaranteed to be strait, you can leave the raw material finish of it alone and it's simply seems to be the more trouble free solution to building a suitable replacement shaft .I've worked with high yield 4140 in the oilfield and seen in distort like crazy once the entire shaft length outside diameter was brought to size.
I would use T G P Stress Proof Shafting. It is pre hardened and is made for torsional stresses and easier to machine than P H 4140 or 4340.
Machine to spec. and install.
ETD 150 is a 4140 steel that has been heat treated tempered and drawn such that it has a tensile strength of 150 ksi. I would think it would be just fine. I am not a metallurgist either but an engineer like Les also.
Stress proof is an old favorite aamongst me and my best fellow machinist. I'm inclined, perhaps erroneously, to think etd is tougher. Well there's been no nay saying about the etd so I'm feeling good about using it when the time comes. Further opinions encouraged and welcome.
Thank you Ted. Oh, the old post drill you gave me will soon be in service with my kid running it, or that's the idea. <grin>
I think this a question with more than 1 acceptable answer. Mine is what I have used in the past and can buy easily. I respect all the other options
4340 is not difficult to machine. Stress proof is very easily machined, and will not get brittle with flexing or twisting. I think either would work well, but if it were mine, I would use 4340. I am not a metallurgist, but have a lot of experience making stamping press repair parts. I have seen stress proof work where everything else failed. I am not familiar with EDT.
Are you making a new drive shaft to adapt a Model T pinion (and ring gear) to the 490 rear end?
I have never looked at it under a microscope to know exactly what it is (running bond, Flemish bond, staggered bond...oh wait that's bricks! lol)
Go for it...ETD150 is a 4140 modified in terms of chemistry. What is modified? #1, there is no range tolerance on Carbon %. The % is 0.40 exact. The mills can do this and have been able to do this for years...they just don't unless it was a boutique steel. Generally speaking an alloy steel that has a Carbon range...say...0.37-0.41 WILL behave totally differently when at the 0.37 and heat treated v. the 0.41 and heat treated with the exact same heat process. Close enough for grenades perhaps in all but exacting applications. Presumably, there is NO detectable carbon difference in any stick of ETD 150
The manganese is controlled to a lesser range than 4140, clipping off the lower end...and then just leaves the chance for 'soft' natural hardness at the curb by never including the lower % of Mn in the first place.
The chrome moly part is basically the same and would be hard pressed to see any differences.
BUT...ETD150 is MADE with mid-range natural hardness throughout, where 4140 has to be post heat treated to achieve any hardness other than near 'silly putty' (Rc 32). You post heat 4140 it can check and twist on you...not so with ETD150.
How do they do it? 4140 when hardened is heated, then quenched. What that does is 'freeze' the state of the matrix crystals on the surface, and lets the inside cool out at a secondary rate. This is why 4140 can have an Rc 32/33 core if not careful. ETD 150 is a bake out right as a part of the making of the alloy. They claim it controls nitrogen to achieve the uniformity...but the real influencing factor is an extended bake at high temperature so that every grain is near identical in growth...any impurities do perc out and not get caught under the 'skin'...and then they slowly bring the temper down. That's what makes it also a bit 'tough".
I deliberately left off the 4340 anaologies as that is a different ball game for a different solution...it achieves its toughness by the inclusion of nickle that draws the heat effect well past any chances for minimal surface hardness and throws the heat transition zone deeper into the alloy.
My only caution, if any, is that with near 50 years experience in specialty steels and boutique steels you can't get everything without a trade-off somewhere. Higher hardness/tougher machining...too fast a quench and you get soft centers...pay 5x-10x per ton to get everything you want without too much compromise? Doable...yet to the best of my knowledge, ETD 150 is being sold at or near at 4140 with a mild heat treat price?
Since there never is a magic metal that does it all and also at a buck+/- a pound, (Example...SA649 has near infinite fatigue life in minor constant bending in the billions of billions of revolutions, the surface can be taken to Rc 61 a full 3/8 deep via induction and rapid quench without checks and cracks, and it can be machined, heat treated and then ground finish at respectable heavy creep feed cuts...but goes about 10 bucks a pound...when you can find it!)
I suspect the fly in the ointment on ETD 150 will eventually reveal to be elongation and/or yield strength creep, which shouldn't happen in your application as your yield 'ceiling' should be way below that, unless you go rad n overly custom.
[Sorry Harold, that's the least amount of 'words' I can use ]
oops...one more thing...
They claim the 'easy machining' of ETD 150 is the result of having some really weird trace materials tossed into the pot. Not sure what they might do until looked at under the scope...I'd half suspect that there is some raw ore out there in huge amounts that has these somewhat rare materials in it...and they got lucky.......
Mark, no .On the 490 the drivers side outer wheel bearing makes noise, particularly when coasting and when there no one but me in the touring. I don't hear it when it's loaded with people. My axles were replaced by my father sometimes in the past but I doubt the drive shaft was. I was thinking I need to tear the rear axle apart to see why that bearing is noisy. (I've greased it) if I'm gonna do that I might as well build a new drive shaft out of good steel . I noticed you on the chevy forum the other day. Do you have an early Chevrolet? Would you happen to know how to get the outer bearing out of the axle? I used to be in the vcca until the local failed and I had no job . I couldn't get reliable tech info from club members or their forum. Not about this issue anyway.
Hey George thanks a bunch!!
I helped a friend pull a hub on a 28 Chevrolet. All we had to use was a knocker, It worked but did not damage the bearing as far as we could tell. I did not realize it until later that we were hammering on a ball bearing. I hope you have a puller of some sort as I don't think using a knocker is a good idea.
Could your noise be a pinion bearing rather than a wheel bearing?
Ted, the 490 rear end is almost exactly like a T except I think it may be considered 3/4 floating. The outer bearings are like Hyatt's but they're shorter. Not the same axle as a 28 Chevy. I know that one too the 490 hub has a boss on the inside that fits in the Hyatt. Kinda like a model a. So the housing takes the weight instead of the shaft.
It might be the pinion, which is not a roller type but caged ball but I really sounds like its coming from the left rear wheel.
I've got a hub puller, we used knockers when I was a kid and I badly damaged the hub cap thread .Years later I built a chase nut to fix those threads. Thread files might have worked but the chase nut was fun to build and it worked well.
No not right now. I did have a 28 commercial chassis many years ago but never got that far into it. I started posting on VCCA because I was doing some motor work on a neat 24 runabout.
This might be of some help if you don't have it now;
You can tell George is the metallurgist! He used more words than the engineers!
Thanks Mark and everyone else!
Yea! Jerry the engineer. Lol
George, Thanks for the information on the different steels. It was really helpful when choosing which steel to use.
Saw a T-Shirt at Old Car Festival that I really liked. It had a very nice image of a fly-ball governor on it with the words, "Mechanical Engineers, Society of Extremely Dull Gentlemen". Wish I could find a copy.
(P.S. I know some gals are ME's too, I guess they're just not as dull as the guys are.)
You mean this?
It's a club of just 4 members... We're just nerds that like old stuff.
YES! EXACTLY!!! I love that shirt!