On ebay now is a KRW transmission fixture for rreaming bushings. Sure would like one, but next best is knowing someone who has one that allows use...
On ebay now
Last one used was owned by a buddy, sure like that instead of paying $$$ for one of these nifty tools.
Did a quick check of the CPI Inflation calculator. That KRW ad with price of $60 dated 1924.
Here is today's value if you could get a new one at the Ford dealer supplier
CPI Inflation Calculator
Has the same buying power as:
$794.46 in 2011.
Many of the drums we find have been turned down or need to be because they are tapered or cupped. I am curious how the fixture would work with smaller drums. I see the fixture has a slot so it will compress some but I wonder how much. I was thinking about bidding on the one listed but that fact plus not knowing the condition of the reamers makes me pass it up. Neat tool to have but I wonder how practical.
Current bid 3:20 p.m. p.s.t. 12-15-11.....
Looks like it's still a bargain even though it's "used".
IMHO a nice shelf setter but I'd rather turn them on the lathe between cones with the bushing removed -- using a tool post grinder to restore the original ground finish, then put the bushings in and ream the busings on the lathe, then finish them on my Sunnen hone.
I'd sure like to have it to set on the shelf, tho.
I cant understand looking at this tool is how it can center a drum if it is used? for the wear on the drum will alter the center?..no? Just wondering
I believe in that CPI buying power stuff...really do, but the advert says the universal standard price for a tranny rebuild was also 4 bucks! Now, to find tranny rebuilder who would today do it for $52.97 complete with new and reamed bushings...now, that would be the trick
Only the second one I've seen in over forty years of playing with this stuff !
I totally agree.
Nice bench art, but of limited practical value.
In my opinion your way of doing it is the next best thing to perfect and that is finishing the bushings using the gear pitch circle to index the drum.
Ron the Coilman
I dunno how to do that.
That $4 mentioned in the KRW adv is for labor only.
If you go to the Ford Service book, rate for overhaul transmission was listed as 1hr and 50min. So I gather that $4 is the labor of 1hr and 50min in 1924
Here is what is common today:
Repair bills are high because parts and labor are expensive. The average hourly labor rate charged by new car dealerships can run anywhere from $35 to $60 per hour or more because large dealerships usually have a lot of overhead. Independent repair garages, service stations, tire dealers and other types of repair facilities usually charge less, but even so still get $25 to $40 per hour for labor.
Not too far off...for the avg mechanic to get that CPI 2011 of $52.97 you posted!
I'm hearing dealer labor rates of $125-150/hr.
Like so many other KRW tools this tool also assumes you bought a new transmission drum from a Ford dealer, installed new bushings and then you had a fair chance of getting the bushing reamed concentric with the gear pitch circle.
Placing new bushings in 90 year old transmission drums and using the outer drum surface as an index to insure a bushing hole true to the gear pitch circle is questionable at best.
The Stevens transmission drum bushing reamer made a stab at using the gear pitch circle as an index for reaming the bushings.
You cannot easily back up on a 90 year old part and expect top get a good bushing job with the KRW tool. The same is true of triple gear bushings.
The very knowledgeable Dan McEachern has written at length on using the gear pitch circle and it's relationship to triple gear and transmission drum bushing concentricity here.
I am convinced this problem is why so many "rebuilt" Model T transmissions lead to trouble.
I will say it again, at $762 this is nice "bench art", but of limited practical value.
Look for the Stevens tool for this job.
Ron the Coilman
And I did not even discuss the reamers!
I think there is a common misunderstanding about how KRW tools were used in the Model T era and can effectively be used today?
Some of them in their original form are of limited practical value because we do not have access to the new parts they required.
The classic example is the KRW combination machine. In it's original form and without significant modifications it is useless today.
That tool assumed you re-babbitted the block and bought new babbitted caps from a Ford dealer. It used reamers, where do you find good usable reamers today? I know one fellow who, at significant expense, paid a reamer manufacturer to bring his reamers back to standard and he uses his milling machine for horizontal feed.
Otherwise you will have to adapt a cutting tool boring bar for making the bearings. The KRW Acme thread feed works was fine for reamers, but not for a cutting tool. One of the best feed works I have seen adapted for boring bar tool bits is a Tobin Arps self contained infinitely variable feed works.
Here is a photo of one.
If you're planning to buy these tools as a collector go with my blessing, but if you plan to use them be sure they can practically be used to produce a quality job.
On the other hand one original Model T era tool that is indispensable if you run original ignition coils is the hand cranked coil tester.
Ron the Coilman
I just looked and realize I know the fellow selling this KRW tool.
I am sure he will appreciate my comments? Grin
Ron the Coilman
I just realized I may have misspoke about "Stevens" transmission reamers.
Perhaps it is another name? I will find out the correct name and report back with photos here soonest.
Ron the Coilman
Ron, I can tell by the shelf, and bench art, that you have never had a chance to use a Wilson Transmission Reamer set. The first thing that I have to disagree on is that New Ford Transmission drums, tail shaft, triple gears came from the factory with out bushings. Not True, I have had at least, over a hundred pieces, of N.O.S. Trany parts, and all had bronze already in them, and already reamed to size, and I still have enough pieces for two of my own cars. The Stevens reamers, are not as good an the Wilsons with the Jig. The stevens follow the bushing hole, always, and that has nothing to do with where the hole should be, and there is no way to change it. With the jig, and the reamers, the Jig holds the drum, regardless of were on the drum. I have never seen a wore drum that the Jig could not grab on to , and not bore the bushing an a 90 degree angle, and that is what you should be after. In the Wilson picture of the drum, and reamer, the drum is pushed back to a machined surface in the jig, and then the jig centers it, by clamping the drum to keep it there, and there is a clamp on both sides, to keep it pulled back tight in alignment. The Wilson reamers, unlike Stevens, and there are others, bore the hole where the hole should be, rather then a Stevens type following the hole is the bushing, like a drill bit, in which does you no good.
Reamers can be made, and the Wilson reamers can be sharpened several times, and you don't sharpen any thing but the tapor end only. We use cutting oil, and a mix of a tap fluid. We also suck the shavings with a shop vac, and it really prolongs the reamer life. When the bushing are reamed, we put the drum on a K.O.Lee expanding mandrel, and check trueness, and true the out side of the drum, the gears always check, as long as their isn't drum damage.
The bushings should be trued the first thing, and then true the drums, NOT the reverse of that, as you have to make sure the bushing hole is right first, and the gear centralization then you work out of the bushing hole, to true the drum.
For getting the bushings true, and at a right angle, and the right clearance, nothing I would trade for, and I have all that stuff also. Herm
I have a great deal of respect for your opinion, but I stand behind my position; It is the gear pitch circle that rally counts when reaming transmission drums and triple gear bushings.
Ron the Coilman
Here's a thought. First, it just makes clear sense that indexing off the gear pitch circle is the way to go. However, there is no way I know of to do that without special jigs that would cost a small fortune to make. (Or to acquire a Dearborn transmission reaming machine that has such jigs. See p. 13 of the MTFCA publication "The Ford Transmission".)
So here is what I am thinking.
If we knew exactly how the piece was held when the gear teeth were cut, we could index off that surface. If the inside diameter of the sleeve were held on a spindle when cutting the teeth, then the inside surface would be concentric with the gear pitch circle. If so, the inside surface of the bushing pressed in to the drum would also be concentric with the gear pitch circle. This is assuming the bushing is made correctly so that the thickness is uniform and that it compresses evenly when pressed into the drum.
If all that is true, then its a pretty simple matter to index off the inside of the bushing when boring on a lathe, or reaming the bushing in a fashion that follows the existing hole and doesn't wander.
All this assumes the hole in the gear sleeve is what Ford used to hold the sleeve when cutting the teeth. If the hole was bored out after the teeth were cut then the whole analysis fails because there is no guarantee the cut hole is concentric with the gear pitch circle.
Continuing this thread of thought, if the outside surface of the gear sleeve is what Ford used to hold the sleeve when cutting the gear teeth, then by holding the sleeve in a lathe and boring the bushing, the inside surface of the bushing would be concentric with the gear pitch circle. This assumes that any final grinding of the sleeve done after the teeth were cut was done evenly so the final surface of the sleeve continues to be concentric with the gear sleeve circle.
Now that I think of it, the outside surface should be concentric because the drums telescope off the gear sleeves and the gear pitch cirles must be in alignment to work correctly.
So by holding the drums in a lathe and indexing off the sleeves, one should be able to bore the bushings concentric with the gear pitch circles.
I have commonly been accused of making perfect the enemy of good enough, but here are my thoughts.
We will probably never know the exact machining sequence of the transmission drums and triple gears, which surfaces were precision machined and which were rough machined and the procedure used to index the pitch circle for bushing machining.
Given the design of the Model T transmission with it's myriad gears, drums and shafts running in (theoretically) concentric circles the importance of precision machining of each transmission part must have clearly been understood.
The Dearborn transmission drum reaming tool is the one I trained on. I will try to dig up a photo so all readers can see how the Dearborn tool uses the gear pitch circle as an index.
Stan's method sound intriguing, but having worked on many rough machined starter mounting brackets and found the reamed bushing bores "all over the map" I wonder how the drum holes were machined?
How many running Model T transmissions have you listened to that sounded like a wheat thrashing machine? And how many new engines have you seen with a fine paste of metal filings floating around in the oil or transmission screen? My theory is most of that comes from improperly machined transmission parts?
Guy Z. once invited me to drive one of Ford 100 year anniversary Model T's. The first thing I did was use reverse gear and listened to the transmission. I was completely stunned at how quiet it was. Those transmission gear sets had had been modified, but it always made me wonder what a brand new Model T transmission actually sounded like when running?
Ron the Coilman
I suppose it all comes down to what you want or need out of your car. If you are in the business of rebuilding Model T transmissions, then I would agree that you should split all the hairs mentioned above. But if you are a do-it-yourselfer, all the jigs and fixtures are not necessary to get a workable transmission. It may not be as quiet. It may not be as smooth. It may not win a Montana 500, but it will be serviceable and reliable. I did mine with a combination of hones, reamers, and Timesaver. Cost me less than $100. Runs just fine, at least to me it does. Maybe I don't have very high standards?
Again, I understand why professional builders go to the pains they do, but don't feel like transmission building HAS to be done by a professional. If you are mechanically inclined, have the MTFCA transmission book and some tools, and the desire, you can do your own transmission without all the expensive machinery.
I have arranged to obtain several good photos of the Dearborn Transmission Drum and Triple Gear Reamer and post them here so interested folks can better understand how it indexes the reamers on the pitch circle of the gear and contrast that with the indexing method used by the KRW tool.
Ron the Coilman
I came across one of the kr wilson drum machines, the price was right for a conversation piece, for shits and giggles I reamed an original outside spec drum, It was with in .002 on center. I still use a lathe to cut the bushings but it was interesting of how accurate it was. On drums that had been turned down you figure out the difference and add shims to the outside of the drum then tighten down, now that one .005 now was that because of who turned it or drum? Like I say it is a good conversation piece!
I just received some excellent close up photos of the Dearborn Transmission Reamer and how it works. I need to get a few more shots to fully make my point about how this tool is superior to the KRW Transmission reamer.
Here is a teaser photo of how the Dearborn Transmission Reamer indexes the triple gearset pitch line for precision reaming of the bushing.
Ron the Coilman
Sorry here is the photo.