The lower threads in my front axle are worn pretty bad and I need to helicoil them. What size threads are they and what helicoil size do I need? I really appreciate all the help I get from you T owners - thank you in advance!!!
I suppose you are using new spindle bolts. If you don't get an answer or even if you do, take the bolts to the store when you are getting the helicoils
See if you can find someone with the Steven's front axle tool. If they don't have the thread inserts, have them contact Dan Hatch.
If you decide to use Helicoils, the size you need are 1/2-20. You might have to do some searching, in my area most auto parts stores only carry 1/2-13.
Bill: The size of the spindle bolt is 1/2 inch national fine threads (1/2-20 NF) they are not a common size at most stores. They can get them for you or find them on the web. If you decide to use the "Stevens" tool (if you can locate one to use) It will use a special insert for the top hole if needed and a insert for the bottom. The special "Stevens" style inserts are available thru the vendors. If you just use a standard heli-coil, remember that it must be installed inline with the upper hole or you will never get the spindle bolt to thread into your new insert. I have done it several times using heli-coils, by being very carefull to watch the alingnement of the drill bit and tap. good luck ....
One other tip on Helicoils - the insert will be longer than the threaded hole it fits into, so you will have to trim one end of the insert enough so that both the top and bottom of the insert are below (not flush with) the top and bottom of the threaded hole. The ends of the insert must have some room to "dig into" the threads in the hole so that the insert won't try to thread back out when you install and remove the spindle bolt.
Thanks for the input, friends! Has anyone ever used the Timeserts instead of Helicoil?
Bill I was just looking at an axle with loose threads. I use Timeserts all the time and they are the best thread repair you can do. There is plenty of meat in the axle to use them. Helicoil is the cheapest and weakest thread repair you can do. It is just a wire loop. Timesert is a complete body and the pulling load is spread evenly. Why eat Spam when you can have a steak? Scott
Scott, can you tell me what size Timesert to buy for the axle?
You buy them based on the thread you are repairing. So get ones that are 1/2-20 NF, if you check out Timeserts website that's kit #0122.
There is nothing wrong with using Helicoils in this particular application. Aerospace and Military use this product in everything from armored tanks to the Space Shuttle and other launch vehicles (meaning new production, not repairs) typically in soft materials like aluminum. By virtue of its design, when in service, the load is spread into the parent material in a wedging action, unlike a solid insert which relies simply on shear strength of the two materials (insert and repaired part). When used in soft, or some sintered materials, the resulting threaded joint is often many times stronger than a non-inserted joint of the same material, and is certainly fine in an axle repair such as this. As an example of a new part made from aluminum (for instance), any durable part will have a helicoil or a tangless insert as original manufacture rather than simply tap a hole in the part and leave it at that.
With a helicoil you will be removing far less material from the axle, which will provide for an additional safety factor over the alternative of making the hole large enough for an insert.
The additional bonus is a complete kit for this repair is 1/2 the cost of a Timesert.
I have no connection to either product, but to state that heli-coils are cheap and weak (meaning inferior) does a disservice to the product and flies in the face of industrial use in production worldwide. Frankly, for their simplicity and serviceability, Helicoils are a remarkably clever invention.
Stevens Front Axle Tool. "Ask the man that owns one"
Scott, The body of a Timesert is very thin, not like some of the inserts. The axle takes a beating, thats one of the reasons that they go bad. If Iam using a soft material and want a better thread Helicoils are ok as the whole part is frail. But for something that has your life in its hands do a better job. By the way Iam not trying to slam you. Having used both my new Helicoil kit is still unopened and will stay that way for the next 20 years like it has been. Scott
Scott is absolutely correct. Our shop manufactured magnesium turbo prop engine housings for Pratt & Whitney many years ago. Every thread was Heli-Coiled. The use of Heli-Coils in airplane engines speaks well enough of their durability, safety & ability to protect human life. It's being made out of a "wire loop" is what gives it the unique ability to "expand" into the parent hole when stressed.
Jerry, We all know that Magnesium is the weakest material there is. Maybe Balsa wood is less. So you need to do something about the weak threads. The end of a T axle hanging out 6 inches and two little nubs holding a spindle, wheel, and tire going over ruts, pot holes and what ever else they saw is a HUGE difference that a round housing. Why do the cheapest, weakest thread repair there is? There is a place for Helicoils, but in a T axle? But you do what you wish, Scott
Robert, I don't believe your evaluation of the Helicoil. You're entitled to your opinion but I agree with Scott's evaluation and proven true during my tenure in heavy industrial applications.
For you to state as a fact to someone looking for advice is a disfavor that is often seen here on the Forum.
Thanks for posting
Sorry, folks, but every time I see this, I can't help thinking that it is a Front Axle Thread thread....
The vendors came out with a lower axle thread repair kit. Are they still available?
If the threads on the bottom are gone, the taper on top is wore out as well. You need to fix the entire problem, not just half of the problem. A Stevens tool does this the fastest and most economical.
When aluminium and magnesium are used in high spec situations such as aircraft manufacture, fitting helicoils will undoubtedly add strength to the thread. The manufacturers do this as a matter of course. It does not mean that it is the best solution. More likely it is the most economical solution which meets requirements.
I prefer threadserts. In Austrelia the brand is Keysert. They come with different OD's for a given internal thread, so they can be used in badly worn holes such as those in T axles. I find them easier line up and fit than helicoils, and they never wind in or out when the kingpin is fitted/removed.
Just my experience.
Allan from down under.
I agree with Dan and Andy that the Stevens tool is by far the best method to repair the front axle. It can be done on the car, and you repair the thread's on the bottom and the top that is also worn oversize. Dan has reproduced every thing except the main body of the tool to do this job.
O.K., this may be a little late and it may be a dumb question (which is probably why I didn't mention it in the original posting)but are the threads on the lower part of the front axle supposed to go all the way through? The threads on the lower part of the opening are fine and still hold the new Kingpin when I insert it from the bottom up, but there are no more threads left in the upper half of the lower part of the axle. Does that make sense? It's like only half the threads are worn away. Or were they originally only in the bottom half of the opening?
Does this help?
So judging by that diagram, the threads only go half-way up the opening. In that case, I don't need to re-thread my axle after all! And here I thought half the threads (the upper half) were missing - silly me! Thanks for all the input anyway.
Perhaps we should warn Pratt & Whitney, Rolls Royce & General Electric that they're making engines out of the weakest material there is. While we're at it, we also need to tell every auto manufacturer on the planet not to make magnesium wheels any more.
I don't care what you use for thread repairs but don't pontificate on topics that you are not versed in.
Glad you got your question answered. Sometimes, when a kingpin appears loose in the threads, just installing a new kingpin will help. In other words, the axle isn't the only part of the assembly that experiences wear.
There is no taper at the top, it's a straight hole, but your point of there being wear up there is well taken.
Jerry, Can you come up with a weaker material? It takes power and fuel to get planes off the ground. The more it weighs the more it cost to fly and the pay load is smaller. So what part of this do you not understand? If the material will do a job good. But that does not make it the strongest. Mag wheels are an alloy. A mixture of different materials to set the strength up. Please understand a topic before you jump in. Scott
"Mag wheels are an alloy."
So are magnesium aircraft engine housings. Did I ever say that magnesium was the strongest possible material? I don't believe I did.
I'm done here. Enjoy your Model T.
My mistake after 9 hours at work and 5 hours out in the field shocking oats, my mind and hands didn't communicate quite right. I meant a tapered insert is used to fix the wore out hole on the top.