I'm in the process of rebuilding my front axle and was wondering what is the best method for installing the brass kingpin and spindle arm bushings?
The best method depends on how many special Model T tools you have, want to buy or can loan
The usual steel spindle arm bushings are easy, you just cut the old ones with a saw blade, punch them out and press in the new ones in a vice. Usually no reaming needed. Bronze bushings may be a better choice - haven't had vendor supplied bronze tie rod bushings on hand so I don't know if they need reaming.
The old king pin bushings are hard to get out.. I first tried with a home made split punch without luck. The only method that worked for me was threading them with a suitable tap, then screwing in a fitting bolt, turning the spindle around and punch the bushing out with a bigger hammer and punch.
The vendor supplied king pin bushings are sometimes a tad too thick - spindle bodies have been cracked on occasion, so measure first and check so they have reasonable press fitting.
When pressing them in they contract and needs to be line reamed with an expensive tool from the vendors: http://www.modeltford.com/item/2713RM.aspx
Then you'll have to fit the spindle to the gap in the axle - and the axle may need some filing/machining to be square in the upper area where the spindle bushing goes and the weight of the car rests. There is another expensive tool, a face cutter for fitting the rebushed spindle to the axle: http://www.modeltford.com/item/2713T.aspx
If you want to try alternative methods you may reduce the cost for seldom used tools.. I was lucky and had new spindle bolts with an already good fit into new bushings.. Hated to press them in and loose the good fit, so I made a fixture out of a bolt and some washers to mount the bushing in the drill press as a primitive lathe, filed off enough on the outside while rotating for a slip fit into the spindle body, then checked fit in the axle - some adjustments needed, then I filed off the excess thickness easier while out of the spindle, without any face cutter. Final assembly involved some epoxi to get the bushings fixated while the king pins held them in line.
I remove/replace my spindle bushings with that relatively inexpensive tool from one of the vendors. Works very well. Once the new bushing is in it usually needs reamed, but I prefer to take it to my local machine shop and have it honed, as that apparently results in less wear on the spindle bolt than reaming does. Don't know for sure, but was told that. And he gets the tolerance right on the mark, and is very affordable.
Luckily when I did my front axle I had access to the specialty tools needed to build an axle. Some folks aren't so lucky, but this is why we have clubs. I'm sure there's another T'er in your area who has the tools you need. Ask around. Finding a simpler way to do it would be handy, but it's so much easier to do it when you have the right tools.
One thing I have found when installing bushings is, that if they fit the shaft before being installed there is a good chance they will fit if pressed in instead of being pounded in with a bushing driver if the OD of the bushing is the same/close to the ID of the hole the bushing is going into. They may still need a little cleanup but may be minimal.
Here is what I have done:
Tap the old bushings with a 9/16 - 12 tap.
Thread in a bolt and knock it out with a punch.
Clean up the spindle inside and out.
Anti-seize never hurts and usually helps.
Use 7/16 all-thread with some heavy washers to squeeze the new ones in place.
Reamer to size the hole.
I was advised to change out and ream one bushing at a time using the other bushing as a guide for the reamer to keep the holes in line.
JD (and everyone else)
Thanks for the great photos and advice - the removal/install went beautifully!
If both old bushings are out, the vendors offer an alignment tool that temporarily fits in one side of the spindle to guide the reamer for reaming the first new bushing, it works well:
You can then use the first newly reamed bushing to guide the reamer for the second new bushing.
Mark thanks for posting that tool. Missed that one when looking through the new catalog.
The first response from Roger mentions a VERY IMPORTANT detail--many modern bushing are too large in diameter, and will split spindles, even if very carefully pressed in. Bill, yours are in so this is for others contemplating the install. Measure your spindle bore, and then measure the bushing. You only want a few thousands interference fit (the bushing being slightly larger than the hole it is going in). I did mine in a lathe, and while at it, I measured the length of the spindle and opening of the axle, and also turned down the face of the bushings to match (took most off the bottom bushing, since the top one takes most of the wear). I then had them honed to fit the bolts at the local auto shop. Since I knew them at the time, they did it for a favor (some adult beverage or other thanks is always helpful--if he/she is a non-drinker, a Lemon Pie does amazing things).
Y'all knew I had to fit a pie in here some wheres!
Press fit on the Brass bushings are not over .002 thousandths, and not under .001-50 thousandths.
Herm, thanks for the accurate specs--I was using a "rule of thumb" for mine (and just the other day I heard that "rule of thumb" is derogatory to females?? I can't figure that one out.--so no downers meant from me). It's been a few years since I did mine, but I think the "out of the box" was more like 8 to 10--I KNEW that was way too much!
Rule of thumb? Now you can't really do much damage with that can ye? Maybe it should be "Rule of wrist".
The "rule of thumb" comes from old English law. One was able to beat their wife or dog with a stick. But, it had to be no thicker than ones thumb. Maybe more info than you wanted.
Lol Michael I was quoting "The Boondock Saints" where one of the characters says "rule of thumb" and it makes this huge woman really angry and so she says the same thing you said. In jest, he holds his thumb to see how big the stick would be and says the line I quoted above, then holds his wrist to show how much bigger the stick would be. He's just joking but then she gets mad and starts a fight, it's pretty hilarious.
Seth...that's pretty funny...I don't know how much truth there is in 'my' etiology.....but never ruin a good story with the truth, eh? lol