I've notice a bit of fluid leakage from around the transfer case rear seal, and when I grab the driveshaft close to the transfer case and wiggle it, there seems to be a good amount of play. I've also noticed the where the tailshaft assembly mates to the transfer case might also be weeping fluid.My research on the site has lead me to believe I can pull the tailshaft from the transfer case, and re-seal them using RTV silicone.I also plan to freshen up the rear seal, but my question is about any bearings or bushings which I could inspect/replace? Or do I have to replace the entire tailshaft assembly?
Anyone else been down this road?

 

If there is play in the driveshaft, you've worn out the bushing in the tailshaft assembly. You'll have to replace the whole thing unless you're friendly with a transmission tech you can get you just the bushing. Replacing the rear seal will not fix anything. A common reason for the bushing wearing out is a driveshaft that is too short. If your truck is lifted I would recommend having a 4x4 or driveshaft shop make sure it's the right length.

If you do not replace the bushing, the driveshaft will rattle around while driving and could cost you u-joints, pinion bearings and eventually a whole new rearend. Trust me, BTDT.

I think the tailshaft assembly is around $200 from Ford. It comes with the bushing, a new rear seal and a new output shaft sensor. I would imagine it comes with a new gasket as well, which should clear up the other leak you're having.

Good luck

 

Thanks for the advice.
My truck is lifted and I recently had the driveshaft lengthened because the slip yoke was pulled out too much, but I had been driving it like that for months, and figured that the tailshaft bushing was going bad.Guess I'll go see the stealership when I'm out of town on friday.

 

When you had the driveshaft lenghtened did they make sure your slip yoke was still in good shape? Here's what I went through with mine.

I drove with a driveshaft that was too short for too long. The tailshaft bushing went bad, and I continued driving it. That cut a bunch of grooves into my slip yoke, which had to be replaced. The vibrations from this destroyed my pinion bearings. I didn't pay enough attention to this and eventually it cost me a ring and pinion.

So I got to get a new driveshaft, slip yoke, tailshaft housing, and gearset/bearings. Very expensive when all I had to do was have my driveshaft lengthened in the beginning.

I would make sure that your slip yoke is in good shape. If it's not, replace it with the tailshaft housing or you'll probably run into the same problems again a bit down the road.

 

I actually had a new driveshaft built and did the install myself. I was sure to check the condition of the slip yoke, as I was/am having a new vibration in the driveline. Once I had the longer driveshaft, the vibration was lessened, but still there, and only noticable at take-off,up to about 40km/h. The slip yoke appeared fine to me, no noticable damage to either the outside of it, or to the splines. But I will check it again, never be too careful. Stealership here says it's $312 cdn for the unit.Got to order it in though, so I'll haveta pull it apart next day off.
Once again, thanks for the advice.