Use of Speedi-Sleeve for Shaft RepairWhen I went to replace the oil seal on the belt pulley shaft on my 1942 AC-B, I found the shaft had a spiral groove in it under the old seal. The sealing surface of the old seal was leather that was about 1/4" wide that rode on the shaft on top of the spiral groove and covered the end of the spiral. The groove was intentionally machined into the shaft to assist in retaining oil in the pto housing. It is machined spiralling in (ccw) while looking at the pulley end of the shaft. The shaft rotates cw from the same vantage point.
Here's a photo of the spiral groove:
I was unable to locate a replacement leather seal. All I could find in that shaft and housing size was a rubber lip type conventional oil seal. Such a seal would not ride and seal properly in the area of this spiral groove. The dimensions here would not permit me to move the actual sealing point of the lip out far enough to clear the end of the groove. The shaft also begins tapering rapidly beyond the end of the groove.
Here's a photo of the old and new seals. The old one is on the left:
The ID of the new seal is smaller because the leather on the old one is expanded to the shaft OD and the lip on the new one is spring loaded to a smaller ID. This lip will expand as needed when slipped over the shaft.
In order to use the rubber lip seal on the spiral-grooved shaft, I used a Speedi-Sleeve made by Chicago Rawhide. These sleeves are intended to repair shafts that are grooved or worn by seal action over time to the point where a new oil seal will not work. They are made of stainless steel and come in many different sizes for use with different shaft diameters. They are a slight press fit onto the shaft.
Here's a photo of the Speedi-Sleeve and the installation tool that comes with it. The tool is on the left:
The thickness of the sleeve is only a few thousandths of an inch so the same lip seal that would otherwise ride directly on the shaft can be used. The height of the seal I used for a nominal 1-3/8" shaft was about 9/16". The flange is for installing the sleeve on the shaft and can be left on or removed as needed. If it is necessary to remove it, it can be peeled away with wire snippers along a pre-cut line that is on the sleeve. For my purpose, I just left the flange in place since it did not interfere with anything.
For manufacturer's information on these sleeves, go here:
http://www2.chicago-rawhide.com/speedi_sleeves.htm
I found the installation tool provided with the sleeve worthless for my purpose. It has a blind end so it can only be used if the sleeve is to be installed close to the end of a shaft. I used a short length of pvc pipe to install the sleeve. About anything can be used as long as the end contacting the sleeve flange is cut square. Of course the ID has to go over the OD of the sleeve working area with some clearance while at the same time being less than the OD of the sleeve flange.
Here is a photo of the sleeve ready to be installed on the shaft:
And here is a photo after installation:
My pulley shaft was NOT a standard size but undersized from a standard 1-3/8" diameter shaft. As it turned out, the shaft was right in between two standard sizes of Speedi-Sleeves. One was too small and the other was too big. The Speedi-Sleeve for a 1-3/8" shaft is recommended to be installed on a shaft diameter between 1.371" and 1.377". My shaft measured about 1.368". I decided to go with the 1-3/8" Speedi-Sleeve. It would not slip on the shaft freely but it was less of an interference fit than recommended. I decided to install it using Loctite RC-620 retaining compound. This is the green semi-liquid that can fill gaps up to 0.015" and has a 3000psi shear strength when cured. I think it used to be called "stud and bearing mount". I have found it to be useful anytime you have a loose fit that is supposed to be tight. Great stuff. Just be sure to degrease all surfaces before using it.
Here's a photo of the final seal installation:
When installing such a seal, always lubricate the rubber lip well. I also like to use a thin coating of Permatex #2 sealant on the OD that presses into the housing.
The particulars on this seal are:
Speedi-Sleeve = Chicago Rawhide part #99138
Lip Seal = Chicago Rawhide part #13865
I suspect there are other ways to deal with such a problem. However, mine is a working B and I needed a fix that could accomplished without removal of the shaft from the housing. That would have required removal of the pto housing assembly from the tractor, something I did not want to get into. Even though the sleeve is kind of pricey at about $25 for this size, it was well worth it to avoid additional work.
Rod (NH)
