Pin drive bolts splitting Help Please

[David Kirkham]

Originally Posted by Ant

David brilliant job, I normally look indepth at components to see if they are engineered correctly, but wouldnt have thought to on the pin drive nuts.

We have machined all our hubs from 4140 front being similar to original with press in pins and retaining nuts so not a problem there, but on the rear we made adapters similar to Trigo, I tested the Trigo adapters before I sold them and they are just normal soft free machining steel from memory so I wasnt happy with them even though that type of steel is probably adequate for the job.

I am using Cap screws and the Trigo Pin drive bolts on the rear, but now have major concerns with the small seating ring area, and I have had two of these trigo pins have approx 3/32" chunks of metal break off the inner sharp taper just with assembly maybe the metal is quite hard or brittle!
I will consider machining the correct taper or making new ones, we used to make them with two flats which isnt as nice to work with as the internal 12pt or if anyone is supplying a better product I would be interested.

Ant,

Hard does not always equate to brittle. Think of a really high quality steel that is properly heat treated. I once saw a F1 1/2 shaft from a crash that was bent at 90 degrees! It didn't break! It didn't even have a crack. But, that junk "free machining steel," "leaded steel," and other such abominations can be quite soft and the lead inclusions will make it brittle. Perhaps that is why we have seen so many of the threads torn and broken. I would have to do a chem and hardness on the pins, but I don't know if I want to spend the 100 bucks on the test.

As for making you pins, that is no problem.

David

[Ant]

David,
thanks for your experience, that makes sense, and with the quality of your cars the right metal for each job is so important, as you mention hard can still equate to elasticity.
Will keep an eye on this post, and when suitable I would like some pins made.

My hubs are drilled for 1/2" which could have been 3/8" but I am stuck with that size! Interestingly enough I was looking at some single seater race cars Lola T332 and others they have a thin drive flange and piddly little drive pins transmitting 500bhp through their massive rear tires, but they are quite light, so its how the car is engineered.

Originally Posted by David Kirkham

Ant,

Hard does not always equate to brittle. Think of a really high quality steel that is properly heat treated. I once saw a F1 1/2 shaft from a crash that was bent at 90 degrees! It didn't break! It didn't even have a crack. But, that junk "free machining steel," "leaded steel," and other such abominations can be quite soft and the lead inclusions will make it brittle. Perhaps that is why we have seen so many of the threads torn and broken. I would have to do a chem and hardness on the pins, but I don't know if I want to spend the 100 bucks on the test.

As for making you pins, that is no problem.

David

[cdnus]

After reading butz999 post about runout on his adapters I thought I would spend a little time checking mine out.
1st.
I removed 1 nut & checked the angle- 60deg taper(or 120deg total)
still confused on the correct termonology.
The taper was FULLY seated as indicated by the dulling of the entire surface.
The countersunk hole was similarily dulled indicating a correct matching of the nut & adapter angle. (120deg.)

2nd.
Mounted a dial indicator & measured runout @ the outward end of the snout--Hub 1-.003, hub2-.007
Measured the hubs that the adapters are mounted to & they had .003 runout on the mounting face.

3rd.
Measured the pin location by positioning the indicator to measure the outside location of each pin while rotating the hub through 360deg. (hope I have splained that correctly)
Hub 1--4 pins .000-.001, 1 pin +.005
Hub 2--3 pins .000-.001, 1 pin +.005, 1 pin + .007

4th.
Measured with dial verniers the pin location from OD to OD of 2 pins working my way around untill all 5 were measured-- Max variance was approx. .003.

Conclusion:

Vintage makes & supplies a excellent product & is very good dollar value.

My only complaint was the original nuts supplied in 2005 were too soft & the hex stripped very easily. Bob replaced them with a improved version N/C immediately & after making up the tool to install & remove them(mentioned earlier in this thread) I have had NO problems & my car runs very smooth at any speed.

Craig

P.S.
I checked the front only--too lazy to do all 4.

[Larry N Johnson]

Originally Posted by cdnus

After reading butz999 post about runout on his adapters I thought I would spend a little time checking mine out. (VINTAGE WHEELS)
1st.
I removed 1 nut & checked the angle- 60deg taper(or 120deg total)
still confused on the correct termonology.
The taper was FULLY seated as indicated by the dulling of the entire surface.
The countersunk hole was similarily dulled indicating a correct matching of the nut & adapter angle. (120deg.)

2nd.
Mounted a dial indicator & measured runout @ the outward end of the snout--Hub 1-.003, hub2-.007
Measured the hubs that the adapters are mounted to & they had .003 runout on the mounting face.

3rd.
Measured the pin location by positioning the indicator to measure the outside location of each pin while rotating the hub through 360deg. (hope I have splained that correctly)
Hub 1--4 pins .000-.001, 1 pin +.005
Hub 2--3 pins .000-.001, 1 pin +.005, 1 pin + .007

4th.
Measured with dial verniers the pin location from OD to OD of 2 pins working my way around untill all 5 were measured-- Max variance was approx. .003.

Conclusion:

Vintage makes & supplies a excellent product & is very good dollar value.

My only complaint was the original nuts supplied in 2005 were too soft & the hex stripped very easily. Bob replaced them with a improved version N/C immediately & after making up the tool to install & remove them(mentioned earlier in this thread) I have had NO problems & my car runs very smooth at any speed.

Craig

P.S.
I checked the front only--too lazy to do all 4.

David Kirkham

Terry Stapley kindly lent his adapter. It can be delivered this morning as promised if you like. Even though the Vintage setup has excellent tolerances, the new Kirkham pins would still be easier to install w confidecnce as the "wrenching" is on the outside rather than inside. Plus the studs would not have to be trimmed.

LNJ

[CNGreen]

Is there any value to me trying to measure the depth of the pin holes in my Trigos?

[Larry N Johnson]

Originally Posted by CNGreen

Is there any value to me trying to measure the depth of the pin holes in my Trigos?

Both a Trigo and Vintage wheel were delivered last week.