Should I replace front driveshaft u joints?

[Reece’sPieces]

Hey everyone,
I’m not sure if this is in the right category. Anyways, I noticed the u joint between my front diff and front driveshaft is a little loose. I’m wondering if I should even bother replacing it since I don’t use 4 wheel drive often. So technically the front driveshaft never even spins unless I use it right? My truck is a 91 btw.

 

[Shran]

It spins when your hubs are locked in (assuming manual hubs.)

Guess I'd replace it. Two new Spicer u-joints are only about $20 total plus an hour of your time... better to fix it than listen to it bang around when you need 4 wheel drive or break and destroy the shaft and possibly other vulnerable things in that area... oil pan, exhaust, wiring, fuel lines, etc

 

[Curious Hound]

I'm not clear about which ujoint you're talking about. Between the diff and the druveshaft coming from the transfer case? Or one of the u-joints between the diff and the wheels?

Either way. I would want it fixed in case you ever need 4wd. That way you know you can depend on it. That's just me. Otherwise, as long as you stay in 2wd and don't lock the front hubs, it doesn't matter.

 

[Reece’sPieces]

The one between the diff and the driveshaft. I’m gonna replace them all eventually. I just don’t have the time and money right now and wanted to prioritize the most important ones.