Rear End Question??
 

Hey Guys,

I have a 1990 Ford F-250 7.3L 5 speed Manual. Well I was driving the other day and my Rear U-Joint Broke, Which It happens, Its a wear Part.Older ones dont Have the Grease fitting, but my new one does. Well I replaced that so I could get it Home and It drives Fine. My Question is, When my U-joint Broke when I was replacing it.... I noticed that the Knuckle(?), where the drive shaft and U-joint Hook to on the rear end if you know where I am talking about. Anyways is that Part suppose to have a little Play in it? Or is it suppose to be Tight? It does not have a lot of play but a little when I move it back and forth. I didnt think it was normal to have a little Play in it but I know nothing about rear ends, And I have never tried to wiggle that thing back and forth. Just let me know some thoughts if you guys have any. I been driving it since the U-joint Breaking and no problems, Just wanting to know if I am gonna have more problems.


Thanks Guys you guys have been a great Help in the Past!!!

You need a little free play.

Mine is under 1/8th turn, probably more like 1/16th turn.

I got ya. You are talking about turning it, I mean just pushing on it, Putting some pressure on it. It is just a little bit back and foth.

i broke my ujoint doing a burnout

it has to move some to keep it from snapping the drive shaft when your workin the suspension.think of it like you put a 10 inch lift on the front of your truck and not the rear with a stock drive shaft it would be pulling on the drive shaft.get where im goin?hope so cause sometimes i confuse myself.lol o wait i just re-read your post you mean on the yolk on the rear end?

get it right i have 11inchs of lift lol

Mark are you saying you can move the pinion in and out?
That is not normal.
The pinion preload should not let it move in and out at all.

The yoke is known to wear out, which causes rotational movement, which can cause the pinion nut to loosen, which would change the preload.

You can pick up a little info here and see a few pics.
Ford 10.25 & 10.50-Inch Axle Tips | Four Wheeler Magazine Article at Automotive.com

As for grease zerks, you can buy lifetime lubricated or greasable joints for replacements.
If you go with greasable, do it often.
Mine is on a 1500 mile schedule for driveline lube.

Joe, running a lift changes the driveline angle at the U joints as well as the driveshft length.
Transfer case to driveshaft angle and driveshaft to pinion angle, the higher these angles are, the more stress the U joints have on them.
Also that much lift would mean longer drive shafts required.

Did you lift it or was that the previous owners work?
Given how he hacked the wiring, I have to wonder how hacked the driveline is if he did that as well.

The splines on the pinion seem to wear on the Ford rearends. So then they will rotate just a little bit, and that seems to loosen the large nut in the middle, which starts aggravating the whole problem.

Mark the position of the large nut and take it off, slide the yoke off, and look down in the ID at the splines. On the one I was messing with, you could see the wear in the splines, since there is a spot way up inside that the pinion shaft doesn't contact and wear.

By the way, the stronger u-joints do not have grease fittings. Hollowing out the u-joint for the grease passages makes the u-joint weaker.