Slip Yoke Clunk

has anyone drilled a relief hole with any success?

 

How has the Ford PTFE held up? Others have gone with lithium-based moly grease. Any idea which lasts the longest?

 

my 2021 makes an awful clunk when coasting and stepping on the gas. it's very consistent and annoying. i've been thinking it was the torque converter but this makes more sense. I feel like it was never greased from the factory. shouldn't there be a grease zerk so we don't have to take the driveshaft apart to grease it?

 

Yes, there should have been a zerk. My 06 4runner had one and no clunks once greased. My manual for 2013 double cab says "Propeller shafts Spider Lithium base chassis grease, NLGI No.2." Nothing about the slip yoke. Hence I am wondering what grease has lasted the longest. Ford or a lithium-based moly grease. I haven't got a definitive answer.

 

great. guess i gotta drop the driveshaft or pay the stealership to do it. doubt they will do it for free. "we don't cover routine maintenance". guess i gotta find the best possible grease so it lasts a while.

 

If you have bumper to bumper warranty i'd give it a try, you just have to word it as a noise from the midsection of the truck or something of that sort. If he owners manual doesn't explicitly state that as a maintenance item it can be wrote up as a noise concern. You just can't go in and specifically say you have x issue and y needs to be done because then they can push it back as not warrantable... dealerships are quasi very political, it's all about how you word things

 

anyone got a guide on how to remove the slip yoke to grease it?

 

If your slip joint(s) are covered with rubber boots/clamps, be sure you have the correct replacement clamps & clamp ear-ring tool on hand before you remove the current clamps. (Most clamps are not designed to be reusable, though some people manage to re-use them.)

Paint-mark both driveshaft flanges & mounting plates so you can re-assemble them in the same bolt hole locations later.

Drop the driveshaft completely (unbolt both ends) and remove it from the vehicle.

Paint-mark both halves of the driveshaft at the slip joint so it can be re-assembled in the exact same spline locations. (Although some, or ?? maybe all shafts have index splines anyway, it can't hurt to paint-mark.)

The two parts of the shaft come apart without tools, just by pulling on them with bare hands. Clamp one part lightly in a vise if available.

Clean out the old grease with brake cleaner & rags and nylon bristle brushes until bone-clean.

Apply a modest amount of your preferred slip-yoke grease. I tried the Ford/Motorcraft XG-8 light-blue-colored PTFE grease that many people recommend and have been satisfied with that.

Don't overgrease! The joint is long & and deep and it's not easy for excess grease at the far back to get squished out. I'd estimate maybe a maximum of 1 tablespoon of grease for the whole joint. (I overgreased mine the first time, which caused considerable excess clunking during normal driving for maybe 500 miles or so until the excess probably did eventually get squeezed out into the boot.)

Reassemble everything, being sure to match up your painted index marks. (Take time to be sure the rubber boots & clamp rings are correctly installed on the shafts before re-assembly.)

Torque to spec and Bob's your uncle.

 

For my 2012 I used the white Ford grease in the tsb kit. It completely fixed the clunk and then it came back the exact same about 250 miles later, will take it apart again and see what it looks like and then possibly drill a hole with a zerc. The truck only has 90k, the driveshaft looks excellent but clunks bad.

 

Try a calcium sulphate moly grease, I don't remember the mileage I was at but I know it was well over 30'000kms ago based on my road trips since. So far still quiet.

Also make sure you "massage" it into the splines, not just lay it over like toothpaste