How much play did you have in the slip joint? I just had my rear end rebuilt, which took most of the slop out of my drive line... but there's still a tiny bit left.

Consequently, I lube the splines regularly, but the prev owner didn't even realize that it needed to be done. How much play is acceptable there? (I'll have to re-lube to see if that takes some of the play back out.) Trying to get an idea of how much play is acceptable.

Still have a tiny bit from the rear end too. (I'm in love with my true-track... works like a charm and it's buttery smooth, but want to make sure the rear end was shimmed correctly.) I've never heard of the true-track (being an all-gear limited slip) causing any extra play.

 

Arise, zombie-thread!

Just bought a 2000 Ex, low miles (86K) with exactly the same problem Monstaa described - feels like "lash" in the driveline being taken up. So, how does one "lube the splines?" I've not done that but I'm not afraid to turn the wrenches (having a second vehicle makes such projects much less stressful!)

 

If only "lube the splines" were as enjoyable as it sounds... it is however as easy as it sounds... so the 2nd vehicle won't be necessary for this one.

Abridged version: Park on a relatively level surface, engage parking brake, blocks under tires, remove band clamp from the rubber shroud over slip joint, drop part of the drive shaft at the u-joint so you can slide slip joint off (might want to use PB Blaster or have something to tap with), grease the splines, re-install section of drive shaft, replace the band clamp (or use a hose clamp) to secure the boot / cover, remove blocks, take out of park... go for a clunk-free test drive.

The whole job won't take more than an hour or two. (Edit: Two or three if you decide to add a grease fitting... or the whole afternoon if you take it apart... and realise that you need a trip to the hardware store for a drill bit, tap and grease fitting because you didn't plan ahead.)

A lot of guys (myself included) also decide to drill and tap a hole for a grease fitting to make it easier to grease next time... without taking apart. There is some controversy over whether or not this is a good idea... and even the placement of the grease fitting, but it's worked out pretty well for me so far.

Edit: Here is a link for your convenience... with pictures... because we like pictures...

https://www.ford-trucks.com/forums/8...tting-mod.html

Also - I think it might already have been mentioned above... but while you're in there - check the whole drive shaft and u-joints for play. With the truck parked, parking brake engaged and wheels blocked... put the transmission in Neutral... and turn the drive shaft back and forth by hand... checking each joint for play.

 

Thanks, that is on the agenda for this weekend, along with replacing all 5 door actuators. Any particular grease I should use? I'm 99% sure that the slip yoke is the problem, the "thump" feels like it is right under the center console and that is just about exactly where the yoke is when I peeked under the truck.

It feels exactly like my old boat trailer (with surge brakes) when it needed the tongue greased for the surge brakes, which is pretty much the same principle as the slip yoke, as I understand it.

 

I had this exact problem and greasing the splines solved it. Took maybe 30 minutes (not adding the grease fitting). I used some BelRay waterproof motorcycle axle grease I had lying around until I decide if I will add a grease fitting or not. Worked awesome with instant results (no clunking!).

 

Ford makes a specific teflon grease for this job. It is availabe from the Ford dealer for around 10 dollars. Plan ahead and order it. That will be the right material for the job.

The same grease can be used for rub points between two pieces of interior plastic to stop squeeks.

 

Called my local FoMoCo dealer, he said the part number is D2AZ-19590-A and they could only get it in a 1 lb can for about $35. Some quick googling led me to Motorcraft part number XG-8, which is a 3 oz tube of the same stuff, for about $8 at the local parts store.

 

XG-8 that's the stuff you google fiend!