I purchased a new repop driveshaft from Chaffins and a Funprojects spool from John Regan. The bearing cone appears to be a C2 fit on the new shaft, which seem a bit loose. What fit should I expect between the Tapered roller bearing cone and the drive shaft?
I just got through installing one of John's kits using an original Ford drive shaft. It was very snug, I had to oil it up and tap it in place with a light hammer. I would call that a perfect fit.
Royce, That is what I would expect but am not getting. The shaft measures about .0005 under size.
The bearing slips on with no force at all. Any thoughts what to do?
I started going through my axle, and just the drive shaft, spool, and bushing need replacement. I decided to wait until John's new driveshafts are available to do the job. The car won't run this year anyway
I have a reproduction driveshaft that I purchased from Lang's. I also have a Funprojects Spool. The driveshaft measures 1.000.This is the same Dia. as a stock Ford shaft according to the Axel book written by Glen Chaffin. The Funprojects roller bearing inner cone surface where it slides over the shaft measures 0.998 The Bronze outer race where it meets the shaft is 0.995. according to John Regan as per the instructions that come with the kit... "slide the spool onto the shaft" "It is normal for the roller bearing cone end to be tighter on the shaft then the brass sleeve end"
In this case a 0.002 fit between the shaft and the roller bearing cone is good one. What are your measurements?
Charles, the shaft OD is reading .09997 and the cone ID is 1.000. From what I read is that you have .002 interference. I have no interference with enough clearance between cone and shaft that the cone slides on the shaft with no resistance.
My fear is that under load the cone will spin on the shaft with not so good consequences.
This is exactly what is wrong with new shafts from the vendors.
John Reagan has just begun selling new shafts that are not undersized.
Yes, unfortunately I did not buy one. My bad! To add insult to injury, when the spool is bolted tightly to the drive shaft tube, and pinion is tight, the u-joint hole is off by 1/4".
But, no biggie. I staked the drive shaft with prick punch to solve the loose bearing problem, and I will run the U-joint unpinned. If I have a problem, I will replace the shaft with a Regan shaft.
Too many wasted cycles on this problem already.
You should pin the u-joint. If not pinned you may cause damage to the 4th main.
A floating uni joint doesn't worry the 4th main ball cap, if the uni bottoms out into the drive plate, it doesn't touch the babbitt bearing and there is still about 3/8" clearance between the cap and the uni as well.
What did John and Glenn have to say about your situation when you contacted them about it?
I have not been contacted but I am going to wade in here anyway since what is being contemplated is a very bad idea. The bearing cone is and always has been 1.000 and the drive shaft if made correctly must have a light press fit in that bearing or the bearing race will wear on the shaft since it is much harder than the shaft material. Likewise the stock sleeve would be loose too. The new shafts are reporting in as being undersized by those with accurate micrometers. You cannot "prick" the shaft and expect that to hold since the bearing forces will quickly loosen that up. The ujoint hole may be off too on some of those shafts and I don't know when that problem returned or if it ever left us. The bearings are not larger and are from the same batch that we have been shipping for more than a year. Please contact me off line if you are having a problem. I have new shafts that are made correctly if you need one and you must NOT assemble a loose roller bearing fit on the shaft and not pinning the ujoint is a very bad idea since that pin keeps the ujoint concentric with the perimeter of the outer ball housing that pivots in the back end of the motor. Ujoint must pivot on the exact same pivot radius inside that housing are things will bind up and the ujoint will be squirted in and out with force. Someone now gone from this earth began the idea that it was OK to not pin the ujoint. Terrible idea but nobody would listen and I gave up trying to reason with folks who think this is OK.
Mark, I haven't contacted them yet. It's pretty clear to me that I have a shaft problem, which has been fairly well documented here before.
Those reproduction drive shafts are trouble. It is a classic case of an offshore vendor using the closet metric measurement instead of using SAE dimensions for the diameter.
As far as the location of the hole for the rivet it is inexcusable to keep accepting driveshafts made incorrectly for years.
Stupid I phone spell check. The word is closest.
John Regan, I PM'ed you. Please let me know how can get the shaft from you...
Great description, now I know why not pinning the U-joint is a bad idea. I never thought about the varying point of pivot radius--that makes great sense!
I also agree with the question of why have we put up with improperly manufactured parts--a question I have had for some time. One vendor told me, "The Street Rodders don't care!" Uh, since when is that a design criteria??
The spec for the Ford Drive Shaft is 1.000-1.001 at the pinion end and 0.993-1.001 at the U=Joint end. I never knew there was a difference but that is what the Ford print says. A new Snyder's Shaft in stock measures 1.001 at both ends.. I wouldn't worry about 0.001 in.
Both the drive shafts I have gotten over the last few years from Snyders have had no issues, U-joint pin hole lined up. One was setup with stock pinion bearing the other John's kit.
So I did some research and discovered something!
The shafting material is supplied by Round Ground Metals, in Illinois who specializes in precision finished shaft stock of several materials and grades.
If the material being used by the parts maker is RGM's standard product, then their tolerance for 1" nom. ground and polished shafting is: +0/-.0005, so undersized shaft stock meets their specs.
One will notice that the original Ford shafts have a rough mill finish with bearing surfaces finish ground down to size.
The repops are ground and finished the whole length, because that's how the shafting comes to the parts maker, that is, as 1" "finished" stock.
If in fact 1" nominal shafting is being used then this would help to explain the diameter variances, but it doesn't explain why the U-joint hole is bored in the wrong place!
My driveshaft and rear axle rebuild is scheduled for this Fall. I would hate to have waited until that time and then discovered problems with the shaft like those encountered here in this thread, I made a decision and emailed John to purchase one of his shafts. Knowing what I know now I can rest easy with that decision.
Interestingly, a lot of areas on a T are not too awful critical when you think about, but apparently the driveshaft is.
Now I'll try to return my reproduction shaft to the vendor from which it came for credit.
If that's the nominal tolerances for 1" shafting, then the shafts should be made out of a slightly larger shafting with the end finished to the 1.000" + .001/-.000 standard on the pinion end and 0.993-1.001 on the U-joint end.
That, of course, will raise the price of driveshafts, probably considerably.
I went through this when you only had one manufacturer. I ended up taking it to a machine shop and had the shaft knurled. This really tightened the bearing,taking a lot of pressure to press the bearing on, to much for my liking, now I wonder if there was any damage to the bearing, guess I will eventually find out.
I have decided to purchase a new drive shaft from John Regan and start over. Perhaps if John can build a better "mousetrap" the driveshaft "issue" will just become another anecdote in the quest for Model T perfection!
John, What are you using to measure the diameter of the Drive Shaft and is it properly calibrated?
If you actually are 0.0005 undersize it is nothing to worry about. I would be more concerned about having to drive the bearing on. A slip fit is perfectly acceptable and you can always use locktite if it bothers you..