1993 2.3L vibration + chirping in rear

[Killing Hours]

Hello all-

I'm a bit stumped here and I know where to ask advice when I'm at a loss. I've read quite a few threads on the u-joints in hopes of helping to pinpoint this issue... however, they've left me with more doubts than confirmation.

Over the past few days I've tried to monitor the vibrations & tapping/chirping I'm hearing coming from what seems the rear of the truck so that I can provide the best description to you. Here's what I've noticed.

Truck is a 5 speed (manual).

1. The sound is intermittent.
2. When the sound occurs... it happens in two forms. A light tapping at the beginning of the gear and as the engine revs.. so does the sound until it is gone. (sounds like someone is taking an extension and tapping on the axle...almost a clicking sound)
The sound sometimes also comes back at normal driving speeds but when it does, it sounds like a cricket chirping. (this seems to only happen at higher speeds)
3. Usually in 4th or 5th gear at around 50 - 60mph... I can feel and hear a low vibration/rumble through the entire truck. This only happens when gas it applied or held steady. (sounds very similar to how a bad front bearing does when it's on it's way out)

So in an attempt to narrow the issue down... I've pulled the truck out of gear @ 60mph on a very smooth road to see if the vibration continues without the engine/tranny being engaged. It does not. It seems that the only time I hear the sounds/vibration are when I'm giving it gas or keeping a set speed.

I've had a buddy who has recently pulled his DS and replaced his u-joints (similar model) take a look at mine but he seems to think they are ok.


In your opinion... do all these signs point to the u-joints or is there something else this could be pointing to?

I also started to think that the rear wheel bearings might be causing this vibration... but if I pull the truck out of gear @ 60mph... the vibration "should" continue if I'm not mistaken. Really at a loss here...

Here is a snapshot of the rear where it connects to the diff. I noticed on the flange (not sure what that's called) that it has what appears to be grease on it and I'm not sure where that has come from.

 

[Tbars4]

...It does sound like u joints but the rear bearings and also the brakes could make a similar noise...

...The vibration leads me toward the u joints, rear end, or rear bearings...Possibly even a pinion bearing going bad..:scratch:

...If it were me, I would block the front wheels, lift both rear tires in the air at the same time, throw it in neutral and manually spin the rear wheels forward and reverse listening for even the smallest of odd sounds...

...U joints are easy and cheap to change...Just remember to mark both ends of your driveshaft for orientation as your shaft is balanced and must sit in it's yokes the same way it comes out...Others have forgot to do this and wound up with a vibration after changing u joints...

 

[Killing Hours]

Tbars4, thanks for the reply.

I'm agreeing with you that I honestly think it's all pointing to the u-joints. I went out yesterday after I posted this and crawled under my truck to see if I could wiggle the u-joints at all.

What I noticed when I did this was at the rear u-joint... when I held the flange with one hand and twisted on the shaft with the other was no play at all in that u-joint... however, when I did the same for the front u-joint... I had about 1/8 or 1/32 (very little but noticeable) play in the front u-joint.

I had planned on replacing the u-joints regardless tomorrow just to eliminate them as a cause. Like you said... easy and cheap and probably need to be done anyhow.

Thanks for the advice on marking them... I did my homework yesterday and watched/read quite a few videos/threads on replacing u-joints which all made that point very clear. (hooray for expertvillage on youtube)

When you say the "rear bearings" or the "pinion bearing"... are you talking about the bearings in the differential itself? (I'm not sure of the names of positions of bearings in the rear end)

I'm trying not to buy parts that are not needed... but since I'm working from the tranny backwards replacing parts... if the u-joints aren't the cause... wouldn't the pinion bearing be the next in line right behind the flange and could that also be why the flange appears to be wet with oil?

Thanks for your help & time in this.

 

[Tbars4]

I'm trying not to buy parts that are not needed... but since I'm working from the tranny backwards replacing parts... if the u-joints aren't the cause... wouldn't the pinion bearing be the next in line right behind the flange and could that also be why the flange appears to be wet with oil?

...The location of the squeak and vibration would be the next in line...Jacking it up and locating the noise first would give you a place to start and save you time and money on parts...

 

[Scott B.]

The oil on the flange is probably due to a leaking pinion seal (the seal just behind the flange.)

Check the oil level in your axle, but as long as oil is not puddling under the axle when you park, you should be OK.

 

[Killing Hours]

@Tbars4, clever reply... I concur. ;-)

@Scott B., That is what I've read as well... the oil level is good (checked) and there is no puddling.

I'll report back after the u-joint change. Thanks for the insight guys!

 

[Killing Hours]

Update

Here's the update for future seekers.

Bad cup in the front u-joint.

One bad apple spoils the bunch.

 

[Tbars4]

...Glad to see you were able to locate and fix the problem...:biggthump

 

[Killing Hours]

Thanks for the reply!

The only trouble I had putting it back together was breaking 4 of the roller bearings while pressing the new cups in. (they fell down and I didn't notice till I heard the snap crackle & pop)

Note to future seekers***

DO NOT TOSS YOUR OLD CUPS UNTIL YOUR ARE COMPLETELY THROUGH!! If you break any of the new ones... just pull some of the old roller bearings from the old cups, clean them off good and replace the broken ones.