I'm going to replace the u joints on my F250 driveshaft. One squeaks in reverse sometimes and when you hit a certain speed as of today you can hear a slight hum. When you replace these on these trucks should you replace all of them at the same time? I noticed there's four. Also do you have to rebalance the shaft before putting it back on. I've never done that before so I don't know quite what it entails. Thanks in advance.

 

Sense you have the shaft out and take the age of the joints into account
if may be better to just do all of them.

When you say 4 are two of them very close together with a part in the center?
If yes that is a double cardan joint and should be done as an assembly.
You can see what one looks like in this image.




Before you start place reference marks on the shaft and where it mounts on each end.
This will save having to have it balanced in most cases.

 

Ok, is this a part that needs to be OEM?

 

Spicer is the option I happen to like.

 

Any good drive shaft shop should be able to fix you up and Spicer is the way to go.

 

Oem shaft is made by Spicer

 

Seems like there is a short shaft then the carrier bearing then a long shaft. So three U joints. I'd assume you replace all three?

 

I would. It's less of a pain to only pull that shaft once.
When you put it back in make sure that the carrier bearing
is aligned correctly or you will be pulling it out to do that
bearing. It should be 90º to the shaft centerline.

One thing I won't do is use any greasable joints do to the
grease in the cross sometimes getting hard and not allowing
the fresh grease to get into all the caps and they also create
a point where the cross can snap do to torque loading. Just
stick with a good quality solid Spicer joint. Don't go cheap.

 

I found a kit that has a carrier bearing too. Anything special I need to know about putting one of those in?

 

So when I'm on a hill in the driveway and I put the truck in park sometimes it acts like it doesn't quite lock and then rocks and locks into park with a clunk noise. A couple weeks it started acting like the neutral safety switch was going bad because I had to put in in neutral to start. Bosses truck is the same way. Are the two issues related or does it go back to U joints?

 

Your reverse lights may also not light when you are in reverse.

Just a punt, but start by chocking your wheels.

Then with the key on and engine off, lay down on the floor under the column.

Use a flashlight to look for a loose bracket against the firewall while moving the shift lever. Some fords have a bracket that gets loose. Sometimes not noticeable until one of the two screws falls out and gets lost. T25 or T30 heads IIRC.

Also, not sure, but look for broken plastic bushings in the shift linkage near the transmission.

 

Thanks. I will do that this week when I pull it in the shop.

 

+1 on spicer u-joints. I bought a couple Moog premiums when I did mine. I couldn't even get them installed without issue, but the spicers went right in.

 

I found the kit on eBay but am a bit leery about buying truck parts off there. Is there any other good online source that someone has bought from?

 

Amazon, rockauto, or riff raff are all better than ebay.