Front output flange seal
Posted: Tue Jul 07, 2026 11:05 am
Hi folks, so after fitting a used gearbox last year I noticed the front input shaft seal was dripping oil. With one thing and another I finally got around to changing it a few days ago. On taking it apart, the flange diameter that the seal is in contact with had some light pitting. I thought that I could get away with a polish.
Unforunately that didn't work, so resorted to cylindrically grinding the diameter. Put it back together tonight and all went well, when originally taking out the flange the split pin on the castellated nut was perfectly in line. The nut came off a little too easliy for my liking (battery impact gun) so when re-assembling I torqued it up to the correct figure (85ft/lb) using two nuts and bolts with a large screwdriver as resistance. The nut and washer were now further onto the shaft, and looking at it the split pin hole it was just before the end of the catellations, I managed to get one leg of the split pin in and wraped it around the nut. Trimmed the other and did similar. Small test drive last night and no drips from that area, still needs a clean under there though.
Unforunately that didn't work, so resorted to cylindrically grinding the diameter. Put it back together tonight and all went well, when originally taking out the flange the split pin on the castellated nut was perfectly in line. The nut came off a little too easliy for my liking (battery impact gun) so when re-assembling I torqued it up to the correct figure (85ft/lb) using two nuts and bolts with a large screwdriver as resistance. The nut and washer were now further onto the shaft, and looking at it the split pin hole it was just before the end of the catellations, I managed to get one leg of the split pin in and wraped it around the nut. Trimmed the other and did similar. Small test drive last night and no drips from that area, still needs a clean under there though.