311 Tach Oil Seal Section-Part 1
From an online discussion between two forum members comes the following great information. We have all had a leak around the tach cable at one time or another. Here is the solution.
Ray B. says "In front of me I have a nos transmission repair kit which lists the speedometer pinion oil seal as 32709-14600. The oil seal inside the box is exact same one as measured for the tachometer pinion and has same manf name and number. Nismo has them listed for $2.
The 7/8" diameter o-ring which fits over the threads of the pinion assy ,which screws into the casting, is 32710-14600. This joint never seems to leak ,so I wouldnt bother getting a spare one.
You could probably also get an over the counter alternate oil seal from your local bearing supply house by supplying them with the inside diameter of the pinion sleeve,outside diameter of pinion shaft and the thickness of old oil seal. (also bring your old one with you)."
Erik S. asks how it is done and if there are any parts that might come flying out.
Ray B. responds with the following:
"No loose parts should fall out. Unscrew the pinion housing nut and the pinion should stay in the distributor base with its shaft sticking out. On the pinion housing nut you removed, notice that there is an "o-ring" on the threads. This o-ring rarely leaks. Look inside the counterbored hole on the cable side of the pinion housing nut and you will see the small black oil seal at the very bottom. The flat side of the oil seal is facing towards you at the cable attachment end of the housing nut (the grooved side faces towards pinion shaft).
Remove oil seal using dentists pick (or seal hook),using caution as not to scratch inside the housing nut bore. (The seal is pressed in pretty tight to the bore, so it might take some tongue to get it out.)If you get some minor scratching on the inside you can give it a quick light hone with some 400-600 emery paper and wash of any grit residue.
Put some motor oil/wheel bearing grease on new oil seal and install with grooved side facing towards bottom of the pinion housing nut counterbore. Use a piece of hardwood dowel (with a squared off end and is same size as the outside diameter of the seal) and push the oil seal into the bottom of the housing nut counterbore until "seal seats square against the bottom of the hole".
Put some oil/grease on the housing nut o-ring and pinion shaft and re-install pinion housing nut to distibutor base. Re-attach tach cable...and you done and no more leaks.
The speedo cable oil seal at the transmission end (under the 90 degree speedometer adapter) is done in same manner, but if I recall correctly, the pinion shaft wants to drop out when the pinion sleeve is removed."
Erik S. responds:
Took me 1/2 hour total including battery removal, getting the camera, customizing a tool to remove the old seal etc.... Cheapie dental picks aren't up to the task to pull the seal. It was fairly stubborn but it came out. One other note, a 11mm deep socket works great to press the new seal in. Just use the 3/8" side against the seal and you are all set."
And there you have it-the proper parts and steps to repair that leaky tach seal. Thanks guys for sharing!