My son's truck has a squeak almost like a brake tab telling you when it's time to change pads/shoes. However, it seems to be coming from the transmission right at the Ujoint. The sound is a rotational squeak that increases in frequency with speed and gets louder under load. It is quite loud in the cab and is definitely coming from the front side of the drive shaft/back side of transmission.

I am going to dig a little deeper tonight but where would you start? What does a Ujoint sound like when it goes bad? Any other things to look at?

Thanks in advance.

1995 F150
4.9l I6
139k miles
Automatic Transmission

 

hmmm well to me it sounds like an issue with either your blinker fluid reservoir or maybe an exhaust bearing. i would try doing a full camshaft delete and transmission belt alignment. upgrading to the high volume blinker reservoir is always a good thing as well.

 

All fine ideas and I thank you for the quick and studious reply. However, we only use synthetic blinker fluid and always grease the exhaust bearings at each oil change. The transmission doesn't use a belt on this model, it's a chain and the tensioner is only at 3cm.

 

Sounds exactly like the old u joint I just replaced. It made an "eeek eeek eeek" sound that increased in speed directly relating to vehicle speed. I thought it was the rear wheel bearings or axle seals but after some testing I determined it was the rear u joint.

Try standing on the brakes (so wheels don't move) while stopped and shift into drive then reverse. Repeat as needed. If you hear the squeak and are sure the wheels didn't move then it's definitely in the drive line.

The most definitive way to diagnose the noise is to put the rear on jack stands and put the truck in "1" (1st gear). Crawl underneath and listen. Mine was squeaking at the top of the rotation so the sound was bouncing off the bed, making pinpointing the location difficult.

If in doubt, replace the u joint anyway. They're cheap, relatively easy to replace and it probably needs to be replaced anyway.

 

Awesome write up thank you. We will take a look tonight. Not sure It it has a grease fitting or not. Tht would be too easy though I'm sure.

 

That's how I do it too. Prop it up on some stands, make sure it's in 2wd, and chock the front wheels to make sure she ain't going anywhere. Also a great way to adjust rear drum brakes!