I have a 1998 Disco I that broke the back U-Joint on the front Prop shaft. I have removed the front shaft and am in the process of replacing the U-joints.

I did notice though that when I put the Rover in gear (diff not locked) it doesn't go into gear (can't go forward or backward and engine just winds up). When I lock the diff, it goes into gear and I can go forward and in reverse.

Does anyone know of any relationship between breaking a u-joint and the t-box not operating correctly? Any other ideas of what may be going on here?

 

It is operating correctly since the d/s is out.

Go check out the sticky that explains how the open center diff functions.

With CDL unlocked, power go to path of least resistance. Which is the front, your yoke is spinning but there is no shaft to transmit to the front.

Lock the cdl and both front and rear get 50/50 split of power. Rear driveshaft turns rear wheels, your yoke that attaches to the missing front drive shaft is spinning as well but you are now rear wheel drive! You can drive like that temporarily.

That is CDL 101. Welcome to the Wonderful World Of Discovery! Now it is time to replace all your u-joints not just the broken one as the others are not far behind failing like it did!

 

You should also go ahead and drain all the diffs and replace the old fluid.

Consider when were your wheel bearings last serviced? Or would you rather wait until one of them fails?

 

Thanks, that is good to hear. Will get back to replacing the u-joints.

 

In the tech section is a nice short video on how a diff works, the transfer case is a differential.

 

Also, don't just let the captive bolts on the Transfer Case flange flop around. Throw some washers on there and put the nuts back on to keep the holes from opening up or the bolts from wearing.

 

Make sure you replace all your u-joints at the same time and make sure you grease them at every oil change.

 

To be clear for a new Rover owner, the transfer is a lot more than a differential. Technically speaking, the center diff is one component of it.

 

Yes, you are 100% correct, thank you.

 

Being a new owner, I encourage you to thoroughly learn the vehicle so you can enjoy it to the maximum with the minimum of damage from lack of understanding. Most of the older ones have been neglected to some degree. If you find a gem, you are lucky.

I encourage you to stock up on things like PB Blaster and Rotella 15w40 by the jug. It takes more than 1 for an oil and filter change.