Should I grease Slip Joint of Driveshaft [1996 Ranger XLT Standard Cab 7ft bed 4cyl 2wd Manual 170k miles]

[borori]

I've got a mystery to solve.

Truck is listed in the title. Everywhere I read, someone says something different. No luck on Fords website or the manual.

Attached is a photo of the driveshaft in question. The part circled in red has splines on the inside of the column, and this goes INTO the transmission and seats onto a shaft.

Do I apply grease to these splines, and if so what kind of grease?

HAYNES manual says to grease the slip yoke. This obviously isnt a slip yoke [edit: this is an encased slip yoke] , and some people say to not add grease into the transmission for fear of ruining it [which is fair].

However, there are videos on YT of people adding grease to this exact style of drive shaft [single solid shaft with two ujoints, one end inserting into the transmission]

There is a bit of a catch/bump/clunk whenever I accelerate or decelerate. Mounts are fine, replaced fuel system, throttle/ari system looks good. Sounds mechanical and coming from under and behind, but not so far back. Simply sounds like play in the driveshaft, like its binding somewhere. Read that this part needs to be greased.

So do I? Or would that ruin my transmission.

 

[19Walt93]

I would polish the rust off with steel wool and then apply a very thin wipe of grease on the yoke. Some Rangers had the slip-bump problem caused by the enclosed slip yoke needing lube, it's a different set up with the slip yoke covered by a boot.

 

[Curious Hound]

I agree. Clean it good and apply a thin layer if grease. A good lithium grease or even just some wheel bearing grease.

 

[sgtsandman]

I would recommend molybdenum grease if you can get your hands on some. The molybdenum imbeds into the metal making a more permanent lubrication to the joint.

Otherwise, the above is good recommendations. For applications like this, I like synthetic wheel bearing grease for boats since my source for the molybdenum type has dried up.