Update - I completed the job
1.) Preparation of the flange nut removal tool It was difficult to source the appropriate wrench to remove the flange nut. A custom tool had to be fabricated from a 2-5/8" spindle nut tool wrench (
performance tools). This tool is readily available on amazon for $20 under ASIN
B000N34ANM. The conversion of 2-5/8" to metric equates to 66.7 mm, therefore approximately 3-4 mm of material was removed from the diameter to ensure a proper fit inside the flange cavity (see previous post with calipers measuring flange nut clearance). A rotary tool equipped with a stone grinder removed the excess material from the spindle nut wrench. The removal of excess material took many hours but proved worthwhile,
Figure 1.
2.) Removal of the flange nut . With the transmission in place, the prop shaft collar was removed and the flange nut was exposed. A breaker bar could not loosen the flange nut due to the
engine turning over - even with the transmission in
gear. A torque wrench indicated that the transmission would turn the piston past top dead center with approximately 60 ft*lb of torque applied at the flange nut. Therefore, a different approach was required. A 1/2" impact driver was purchased from Harbor Freight Tools (
Chicago electric) for $45 under the SKU number of
61173. The impact wrench was able to remove the nut with ease and to my surprise, did not impart any torque upon the transmission output shaft (i.e. the shaft did not turn. Conversely, I could tighten the flange nut using the impact driver with the disassembled quill shaft in my hand and the impact driver would not spin the shaft). It was my first time using an impact wrench and I was impressed!
3.) Inspection of the output shaft flange. With the transmission still in place, the flange was removed from the spline. This was a surprise, since It was not evident from my interpretation of the diagrams in the repair manual. In fact, the
images from the manual show the flange nut on the opposite side of the output shaft - completely backwards,
Figure 2. Red silicone
sealant coated the spline,
Figure 3. I took note of the presence of
sealant and also applied some during the reassembly of the flange. I'll talk more about why I decided to use sealant later on in this post.
4.) Inspection of the front oil seal mating surface. Inspection of the flange revealed that the mating surface for the oil seal was worn,
Figure 4. To ensure an adequate seal, the mating surface would have to be repaired. The average diameter of the mating surface was measured with calipers and determined as 2.555" +- 0.001" (n=3). The closest fitting sleeves were either SKF 99254 or SKF 99253. I made the decision to use SKF 99254 which is meant for shafts no smaller than 64.92 mm and no larger than 65.07 mm. The reason for choosing SKF 99254 is that the ZF/Hurth manual specifies that this shaft is 65 mm nominal and therefore I decided to use this size sleeve despite my measurements (2.555" = 64.90 mm which is only 20 microns smaller that specified by SKF). Two sets of SKF 99254 were purchased from amazon for $40 ea. under the ASIN
B00CLIN7BI.
5.) Sleeving the front oil seal mating surface. The SKF sleeve was installed by hammering the sleeve unto the flange with the provided tool in the SKF speedi-sleeve kit. I opted to retain the speedi-sleeve brim and keep it on the flange,
Figure 5. The fitment was tight and satisfactory; however, the sleeve protruded significantly past the flange - a detail that I had overlooked,
Figure 6. The solution was to trim the excess material as close to the flange as possible because the flange forms a facial seal to the spline shaft,
Figure 7. Any imperfections in this facial seal (i.e. scratches, antiparallel faces, etc.) will cause transmission fluid to leak past and weep along the spline shaft. This is the reason why the previous repair attempt used silicone sealant on the spline and which is why I too applied sealant to this facial seal and along the spline during reassembly. The sheared edge of the sleeve was de-burred with 80 grit sandpaper and smoothed with 220 grit to prevent tearing of the oil seal.
6.) Inspection of the rear oil seal mating surface. To gain access to the rear oil seal, the transmission was removed from the engine and split open. The rear oil seal mating surface is integral to the output (quill) shaft and located at the aft-most portion of the output shaft. Inspection the
surface finish revealed large dimples likely due to
corrosion,
Figure 8. The shaft diameter was measured with calipers to be 2.556" +- 0.001" (n=3) and the remaining SKF 99254 speedi-sleeve was used to repair this surface.
7.) Sleeving the rear oil seal mating surface. Steel reinforced
epoxy (
JB Weld) applied as filler onto the shaft ensured that no gaps would negate the
interference fit of the speedi-sleeve,
Figure 9. While the
steel reinforced
epoxy was still tacky, the SKF speedi-sleeve was installed with the provided tool. Excess epoxy was removed from the quill shaft with a clean rag. The excess sleeve material was trimmed and the sheared edge of the sleeve was de-burred and smoothed to prevent tearing of the oil seal,
Figure 10.
8.) Oil seal installation and shaft reassembly. Two oil seals were sourced form Basic
Power Industries using the product ID
ALT316406. The lips of the seals were lubricated copiously with Teflon grease. The sheared edges of the speedi-sleeves were also covered in Teflon grease and the oil seals were installed on their respective mating surfaces taking extreme care not to rip/tear the seals on any protruding speedi-sleeve material (think of newly opened tin can). Once both oil seals were installed, a small amount of silicone sealant was applied to the flange facial seal and to the spline shaft of the output flange. While the silicone was still wet, the flange was mated to the output shaft and the ring nut was installed with finger tightness. After 15 minutes, the ring nut was tightened with impact driver and improvised ring nut tool,
Figure 11. The output shaft was placed back into the transmission case, both halves were bolted together, the transmission was mounted to the engine, the prop shaft collar was installed and the prop shaft was secured. Transmission fluid filled to the mark on the dipstick and then I walked away and poured myself a drink.
9.) Testing Now the big question, does it hold up? Well, I motored around for 30 minutes and didn't catch a drop of transmission fluid on the oil adsorbent pads. I'll keep you all posted on how this repair holds up with time.
I hope that this write-up inspires others to repair their own V-drive transmissions when the time inevitably comes. If you find typos, broken links or incorrect information in this post, please let me know so I may edit it accordingly.
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