left front door hinge

[Jason]

My left front door hinge currently looks like this..

30447

It's my understanding that the part isn't available anywhere.

Does anyone know if a part made out of aluminum would be strong enough? I have a small CNC mill and could machine a new part from aluminum fairly easily. If not aluminum what material would be best?

Also, how would I separate the two hinge pieces? It looks like the hinge shaft is press in. Is the shaft just a single diameter or does it taper or have a cap or something on one end? If I were to try to press it out does the direction matter?

Thanks

- Jason

[David T]

The part may no longer be available NOS but if you look someone will have a good used one.

[Ryan King]

My left front door hinge currently looks like this..

30447

It's my understanding that the part isn't available anywhere.

Does anyone know if a part made out of aluminum would be strong enough? I have a small CNC mill and could machine a new part from aluminum fairly easily. If not aluminum what material would be best?

Also, how would I separate the two hinge pieces? It looks like the hinge shaft is press in. Is the shaft just a single diameter or does it taper or have a cap or something on one end? If I were to try to press it out does the direction matter?

Thanks

- Jason


If I were you, I would find an experienced local metal shop to try and reinforce it/weld it back up for you.

[Nicholas R]

If you think you can make a new one, I'd give it a shot. Thats pretty rough. I'm not sure I'd make it out of aluminum using the same dimensions. The original isn't the best metal to begin with, (pretty sure it's just cast steel), but thats likely a little stronger than aluminum would be. Can you machine something like ASTM A36 steel?

[DMC5180]

I'm guessing a certain vendor will eventually figure a way to reproduce them in SS. But until then there should be a reasonable supply of cars being parted out to find one.

[DMCMW Dave]

I've seen them successfully welded, (it is a steel casting) but a parts car part is your best bet. They are out there.

No real reason to do it in stainless, I think machining something of steel will be the ultimate solution if people stop parting out cars and more break.

At this point in time the need is very low so the supply (parts cars) and demand (stuff that breaks) is about in equilibrium.

----------------------------------------------

Actually I'm not sure it's steel as I've never seen one rust. Hard to believe it's a nickel alloy (typically not very strong) but that's what it looks like. It would be interesting to know for sure.

[Jason]

If you think you can make a new one, I'd give it a shot. Thats pretty rough. I'm not sure I'd make it out of aluminum using the same dimensions. The original isn't the best metal to begin with, (pretty sure it's just cast steel), but thats likely a little stronger than aluminum would be. Can you machine something like ASTM A36 steel?

This is what I've come up with so far.

30465

I added more material where there was clearance.

I could do A36 steel, but it would require a lot more work, and probably cost a lot more, as I never done steel before (other than small holes and slots), so I'd likely mess up the first couple of parts.

[Nicholas R]

I'm guessing a certain vendor will eventually figure a way to reproduce them in SS. But until then there should be a reasonable supply of cars being parted out to find one.

I would not want this part to be made out of stainless. If you replace this this part with a SS replacement, and you don't replace the roof box with stainless, all you're doing is creating a nice electron conduit that will increase the corrosion rate of the roof box every time it rains. I know in my car, every time it rains, water ends up in the torsion bar area; if not from leakage, then just when opening the door. That's all you need for some nice galvanic corrosion. The hinges will last forever, because they have the roof box to act as an anode.

[Jason]

I would not want this part to be made out of stainless. If you replace this this part with a SS replacement, and you don't replace the roof box with stainless, all you're doing is creating a nice electron conduit that will increase the corrosion rate of the roof box every time it rains. I know in my car, every time it rains, water ends up in the torsion bar area; if not from leakage, then just when opening the door. That's all you need for some nice galvanic corrosion. The hinges will last forever, because they have the roof box to act as an anode.

What about 7050 aluminum?

[Delorean Industries]

I would not want this part to be made out of stainless. If you replace this this part with a SS replacement, and you don't replace the roof box with stainless, all you're doing is creating a nice electron conduit that will increase the corrosion rate of the roof box every time it rains. I know in my car, every time it rains, water ends up in the torsion bar area; if not from leakage, then just when opening the door. That's all you need for some nice galvanic corrosion. The hinges will last forever, because they have the roof box to act as an anode.

Challenge accepted.

[Nicholas R]

Challenge accepted.

Yea but roof boxes are the worst to replace, even if you're replacing it with stainless. Patrick C and I tried replacing one with Cliff Schmucker once without success. It was terrible to try to get it to fit right. If you do make them, the pieces almost need to be stamped with a die, instead of just made with breaks. They have to fit perfectly.

[Delorean Industries]

At this point every car is different. The last batch we made had a little extra meat on the bone for fine tuning. It takes 40+ hours to fit one correctly start to finish.

[djdogbone]

can someone 3D print this thing in aluminum/Steel/SS? I saw Turbos being printed for cars on 3D printers, why can these?

[ALEXAKOS]

Or just contact James ( member eagle-co94) for a used spare;)

[Jason]

Prototype in plastic to check the fit.

305163051730518

I'm still not sure what material to use for the real one.

[Nicholas R]

At this point every car is different. The last batch we made had a little extra meat on the bone for fine tuning. It takes 40+ hours to fit one correctly start to finish.

That was our experience as well. However I guess we never put in the full 40+ hours because we never got Cliff's SS roof box installed.

[Josh]

I would not want this part to be made out of stainless. If you replace this this part with a SS replacement, and you don't replace the roof box with stainless, all you're doing is creating a nice electron conduit that will increase the corrosion rate of the roof box every time it rains. I know in my car, every time it rains, water ends up in the torsion bar area; if not from leakage, then just when opening the door. That's all you need for some nice galvanic corrosion. The hinges will last forever, because they have the roof box to act as an anode.

This is a bit far fetched. What about the huge stainless steel door the hinges are attached to? This isn't causing corrosion issues with the hinges and roof box.

[Nicholas R]

This is a bit far fetched. What about the huge stainless steel door the hinges are attached to? This isn't causing corrosion issues with the hinges and roof box.

Yes but the water flows down in the traugh, not up to the door. Not to mention, there are a lot of roof boxes out there that are rusting out on their own, let alone with stainless hinges bolted to them. I will say that truthfully, using stainless bolts would likely accelerate the corrosion much more than the hinges themselves. The roof box and hinges at least have the paint and coatings to insulate them, but the threads of the bolts are metal to metal.

EDIT: Course on that note, you probably wouldn't want to use stainless steel bolts just based on their strength. Not sure if the originals were 8.8 or 10.9 but either way, a stainless metric bolt is typically less strong than even an 8.8.

[Jason]

I ended up making a hinge out of 7050 aluminum.

30564
30565
30566
30567
30568
30569

[Domi]

Amazing work done, it's beautiful :thumbup:

[Nicholas R]

That looks awesome!!, way to go! :thumbup:

[djdogbone]

Holy crap, that's awesome!

[cybercusp]

Well, mine just broke. Looks like I'm in the market.

[Sidaries]

My car's LF door hinge is broken now. Were there any changes in the past few years? Do anyone know the exact material it is made from? I am planning to reproduce the door hinge (430 euro for a used one is a bit too expensive for a used part, which can break any moment), and it will be good to know, what material I should use.

[DMC5180]

What do you mean by any changes? AFAIK, none of the vendors has stepped up to remanufacture them due to low demand and there are enough parts cars to meet that demand. While I would agree 430 euro is a bit steep for a used part, think about the used price of the Torsion bar that mates with it. The last I checked they were double that amount. I have yet to hear of anyone who had replace that hinge with a used one, have second failure. It certainly could happen, however the risk is likely extremely low.

The guy who posted earlier made his from 7050 aluminum. If you’re
worried about strength, I would find a local machine shop with A Rockwell hardness tester and have them test the broken arm of the hinge. This will give you a minimum number to meet for material grade selection and improve upon if desired.

A conservative shoot from the hip material would be 4130 or 4140 steel.

When examining the fracture of the broken pieces, is their any rust present from a long term developed crack or was it a clean fracture?









Sent from my iPhone using Tapatalk

[Sidaries]

I meant exactly, what you describer. Maybe a new stock or anything.

The crack was not a clean one. As it seems, there were a previous crack. I send a few pictures.
One of my friend says he can reproduce the hinge, I am eager to see the quality of it.

[Bitsyncmaster]

Your material will depend if you cast it or machine it from bar stock.

[David T]

Your material will depend if you cast it or machine it from bar stock.

For all of the work you should be able to find one less expensive from a parts car. Very unusual for a hinge to break. Something weird must have happened to it. Was the door ever replaced? Maybe the car was in an accident or it was driven into a garage with the door open.

[Sidaries]

The car was not in an accident, as I know. At least not in the past 10 years, since I own it. I said in our forum, that I should check the door this spring, because it seems, that it is not aligned well. Now I see, that I was right, so this break was not without antecedent.

The reason is a bit more mysterious, but I think, this was my fault. About 5 years ago, we aligned the door at home, and maybe we made some mistake. Or this happened because I like to drive occasionally with the door open. Very rarely, but sometimes on rough terrain. I don't know, but actually it doesn't matter, I will fix it and enjoy the car even more.

Finding a hinge from a parts car is not easy here. We don't have any Deloreans in Hungary, so it will be easier to fix or reproduce the part. Or buy the one from Ed for that horror price, when everything fails.

[Sidaries]

It is fixed. This is how it looks like now. It will be painted, then measured, and a new one will be created. And then I will see, which one is better.

[delornut]

For all of the work you should be able to find one less expensive from a parts car. Very unusual for a hinge to break. Something weird must have happened to it. Was the door ever replaced? Maybe the car was in an accident or it was driven into a garage with the door open.

My left front hinge broke shortly after I bought the car new in 1981. I've seen several left front hinges broken over the 32 years I owned the car. No idea why but it was always the left front

Bruce Benson

[Sidaries]

So we made two new hinges. On the picture, he left one is the fixed original, and the two other, we made. It seems very good, soon I will put one new into the car.

[Patrick C]

So we made two new hinges. On the picture, he left one is the fixed original, and the two other, we made. It seems very good, soon I will put one new into the car.

Very nice! The new one looks much beefier around where the torsion bar inserts. Well done!

[Sidaries]

Very nice! The new one looks much beefier around where the torsion bar inserts. Well done!

Yes. It is stronger there. This was an important request to be done.

[TTait]

I had the exact same crack last winter. A friend was able to straighten it, weld it and build it up a bit to make it stronger. Works like a charm so far.

I suspect the reason the part is out of stock is that its a more common problem than anyone may have caught on to. Certainly the drivers door cycles more often than the passenger one, but there may be subtle differences in the original castings too.

[Bitsyncmaster]

I had the exact same crack last winter. A friend was able to straighten it, weld it and build it up a bit to make it stronger. Works like a charm so far.

I suspect the reason the part is out of stock is that its a more common problem than anyone may have caught on to. Certainly the drivers door cycles more often than the passenger one, but there may be subtle differences in the original castings too.

Where the torsion bar fits into the hinge is a pretty sloppy fit on the OEM hinges. So it may be the 6 sided bar puts more pressure on the casting than the 4 sided bar.

[DMC5180]

Metallurgically speaking, I’d say the main reason for failure is partly due too the sharp corner in the bottom of the milled slot. This creates a nasty stress riser which is a big no no for a highly stressed part like this. Those new parts have a nice radius too spread the load.


Sent from my iPhone using Tapatalk