So I developed a squeak under truck towards rear end. It started about 200 miles ago. The squeak can be heard as soon as you take off and is hard to hear after 20mph. Makes no difference when brakes are applied. It used to squeak when I first purchased truck, but only in reverse. Now the squeak in reverse has diminished quite a bit, but the squeak traveling forward has started.


Today....Jacked up rear and ran it in drive. Squeek appears to be coming from drive shaft, towards rear. Hard to pinpoint but as close as I can tell it is coming from driveshaft near rear about 1 foot from rear end. Squeek seems to travel forward through drive shaft


What has happened about 200 miles ago (1 month ago)?....new front pads, new front brake lines, rotors turned, rear brakes adjusted and new tires and used Alcoas installed on all 4.


Also, it rained pretty good down here a couple of weeks ago and truck went through some deep puddles!


Squeek developed about 4-5 days after rain. .


I researched this forum and found that it could be u joints.


How are u joints inspected and tested for bad?
How are they replaced? Special tools? Tips/tricks to install?


Thoughts on what this might be?


Thanks!

 

I would suspect the hanger bearing, ie the center driveshaft support bearing, maybe they call it the carrier bearing. Anyway the bearing that supports the driveshaft between the transmission and the differential.

With that long wheelbase two wheel drive, I'm sure you would have that bearing. Usually when they replace that bearing, they replace the outside metal housing, the rubber cushion and the bearing as a unit.

I would suspect that over a U-joint. But it would be hard to pinpoint, as you said noise travels through the drive shaft.

 

88n94 could be on the right track ... in my experience, u-joint noise starts as a tick, or click, progressing to a knock or clank ... not a squeak ... but since you asked, u-joints are checked by firmly grasping the drive shaft near the joint ... try to twist it and shake it , looking for any slop in the joint. any visible slop means that it needs to be replaced soon.

the re and re is basic wrenching, no special tools . just mark driveshaft and yoke so that they go back the same way they were so as to avoid putting it out of balance.

 

I totally agree with joey's method of checking U-joints, but I must add something. Park the truck where it can't roll or firmly block the wheels, that part for safety purposes only. PLACE THE TRANSMISSION IN NEUTRAL, this applies to either a manual or an automatic transmission. Now the driveshaft won't be holding the weight of the truck. The driveshaft will turn slightly from the play in the differential, somewhat of a moot point but FYI. Watch for play in the U-joint as the driveshaft comes against it's stop each way. Obviously each U-joint must be checked separately.

 

That's been my experience too, til my F-250 started squeaking It was a continuous sound that went from high to low pitch as the driveshaft went thru 180° of rotation. Like you, I'd never heard a u-joint do that before so I let it ride til I couldn't stand it. Couldn't figure out what else it might be so I replaced the u-joint and all was well. The old one was a bit dry but didn't look all that bad.

 

I've had several u-joints squeak as the first symptom. If there's a zerk on the u-joint, grease it...

 

Which u joint went bad? Are there two.......rear one near rear end and one in front of carrier bearing near trans?

I can't tell if it's a u joint or carrier bearing?

Only the carrier bearing has a zirc fitting; u joints do not

 

U-joints are a basic maintenance item.

Replace with ones that have a Zerk fitting and pump them full until you see grease at all four caps each time you grease your tie rod ends/pitman arm and king pins/ball joints.

I usually do this every other oil change since I'm under there anyhow.
Greasing too often is not going to harm anything, unlike letting something run dry.

 

so, replacing u joints (are there one or two) does not require any special tools?

Anybody done this on a crew long bed? Is there a process to follow.....

1. center support being first; 2. rear u joint second; 3. front u joint last?

Thanks

 

You need to take the shaft out and do both of them at the same time.

How do you expect to press the caps out of the driveshaft yokes under the truck with the other end of the shaft attached?

ETA, special tools?
Depending if they are inside or outside caps you may need a pair of snap ring pliers.
You might want a large vise and a set of sockets so you can press the caps out, and in.

 

It was the rear one. That truck didn't have a carrier bearing as far as I can remember.

 

Trying to shake the driveshaft won't tell you if the joints are dry.. which is what happens first before they wear enough to become sloppy, you'll need to remove the driveshaft from the truck to really see what's going on.

 

If you don't have a large vise, and it will need to be a very big vice with about 6" or more of throat, a heavy, large C clamp will work too.

I have an old school forged 8" C clamp that my Dad used for years that I use for these types pf projects. This isn't a cheap shiny threaded one, it is heavy with the threads straight cut (like a spiral staircase, not pointed) and are about 3/4" diameter.

Priced in between the heavy duty C clamp and big vice is an entry level hydraulic press from Northern Tool or similar...in case you need justification to get one.

 

I took a good look under the truck this evening.

It has 3 U joints......

1 just back from trans
1 just back from center support bearing
1 just in front of rear end.

There is also a small portion of shaft (between the two main shafts) that has a zerk fitting. What is this part called? When I pushed grease in it, grease came out of the u joint just back of this small shaft.

So it looks lie I would....1. remove the clamps at rear u-joint....2. remove center support bearing... and then 3. shaft should pull out from trans. Are these the correct steps for removal?

I mic'd the diameter of the shaft the passes through the center support bearing and it is 1.378". There is a center support bearing part this size. Apparently there are two different ones (larger one at approx 1.5").

The u-joints I am not sure what size is needed. How do I measure these?




U joint at trans





U joint just behind center support bearing





U joint just in front of rear end

 

Your second photo is the slip section of the driveshaft.
This is what allows the suspension to move.

I see grease at the slip yoke, but there is none at the universal joint cups.
The other two look dry as well. (externally)

You don't even need a vise or a clamp.
You can just use sockets and a BFH to tap them into place.