81 f150 4x4. I was replacing my front wheel bearings today and turning the hub by hand I noticed a little bit of play in the axle u joint. Not much, and not every time, but enough to notice. How much is too much?

Replacing them sounds pretty do-able but if I'm going in that far I should probably do ball joints huh? And what else? I'm really not wanting to do this job right now, but winter is almost here and I dont have a garage, so if I need to do it I should get on it. Any tips? Thanks guys.

 

U-joints should move freely, but not have any noticeable freeplay, so it sounds like yours is well on its way out.

Getting the spindle off is the toughest part of the job, at least up here in the rust belt. Once you get down to the bare spindle (which you already have if you're replacing bearings) it's "just" a matter of removing the 6 (?) nuts (which always seem to come off easily) and then pulling the spindle off (which doesn't go so well in my experience). I made a puller that works for me, but I guess you can rent / borrow pullers from auto parts stores as well.

If you're just replacing the U-joints at the steering knuckles that'll get you as far as you need to go. You can take the right side out back to the slip joint pretty easily. The driver's side will pull out too (but be careful putting it back in not to push dirt into your diff).

If you decide to replace the U-joint in the center of the right side I'm pretty sure you need to go inside the diff to remove a C-clip. It's been way too long since I've done that to remember anything about that process though.

 

One thing to keep in mind about bearings or similar things like u-joints or tie rods, drag links and so on - the manuals will have the go/no go specifications that sometimes sound awfully small - .001" or .005" or whatever the case may be.

And, it takes years sometimes for a part to reach that point. BUT, thing is, once they DO start to get close it goes REALLY REALLY quick from there to the "Holy $&%#!" territory. Keep an eye on things - and if they are original it may be good practice to just replace them on a high mileage truck on GP, even if they seem tight.

One thing I've been meaning to do, is add a simple safety chain or strap around the driveshaft on my trucks. It doesn't happen very often but when u-joints let go in front they can sometimes catch on the pavement or whatever, and launch any truck into the air or flip them instantly.

Good driveshaft service means vibration levels will be minimized, bearings will last a lot longer and the ride will be quieter and smooth. I would imagine it keeps leaks from forming at the gearboxes and things like that too.

 

I bolded the part that tells you if it's too much.

 

Thanks, I'll see about renting a puller. I went ahead and gave those 6 bolts a healthy dose of pb blaster to loosen them up some. We don't actually salt the roads here in AK ( too cold for it to work ) so our vehicles are in suprisingly good condition, rust wise, though they've usually been pretty beat up. Sounds like a job I can tackle. Found a couple videos on YouTube of the process too but they seem to skip over the part where you actually pull the spindle off which is the only part im concerned about!