Slip Yoke Spline Grease?
I recently pulled the drive shaft on my 65, 289 fastback with a C4. Before reinstalling, I cleaned out the splines on the slip yoke with some brake cleaner, lubed the splines with some assembly lube (thinking that would be good enough until trans fluid worked its way into the splines) and put a very thin coat of silicone grease on the outside of the yoke.
Well something got me thinking? Did Ford recommend putting lube on the slip yoke splines and if so what type? Short answer is yes, lubricant part number B8A-19589-A. It appears to be some sort of molybdenum grease. The Ford shop manual states that the grease will not be washed out by transmission fluid due to an internal seal in the tail of the transmission that seals it out. That's news to me. I was always under the impression the rear outer seal on the back of the transmission tail sealed the fluid in the transmission which allowed transmission fluid to lubricate the slip yoke splines. My gut is telling me to pull the drive shaft and coat the slip yoke splines with some molybdenum grease. What's your experiences with this?