The large belt that goes over several pulleys is not broken, the huge round thing attached to a rod broke off, there are no screws , it would have to be welded or replaced. I need to see a picture to show what is broken. It will not steer, but starts

you should be able to turn it by hand or with a socket and ratchet broken crank means broken car if you broke crank which is rare you would not have a running engine sounds more like stretched timing chain if it feels sloppy

I assume you are replacing both and not just the rod. Reason for breaking the rod comes down to one of two things to my knowledge.
First reason, someone tried to tension the belt and didn't release the locking bolt that holds the inner setting of the tensioner as the rod IS NOT MENT TO HOLD THE TENSION. That bolt is a 10mm hex key bolt.
Second reason, rubber from tensioner has let go and shifted so that inner shaft sits to close to tension rod bracket on such an angle that it snaps of.

Removal...
Loosen 10mm hex key tension bolt at front of tensioner and remove belt. Once the belt is off, remove water pump pulley. Powerstering pump also needs to be unbolted so that you can move it somewhat to the right. you should be able to see several bolts holding the bracket that the locking bolt goes through. In addition there is a shockabsorber on the tensioner that is attached to the engine. once all them are undone/removed you should be able to remove the tensioner. The locking bolt is the longest and it lets you line everything up on reassembly. BUT DO NOT FULLY TIGHTEN UNTIL YOU HAVE TENSIONED THE BELT WITH THE ROD. Once you have tensioned it with the rod, tighten the locking bolt and just slightly undo the tension rod to take the stress of the thread. Remember the tension is held by the pressure of the lockingbolt against the inner steeltube of your tension assembly NOT THE ROD. If you are unsure of your steps for reassembly, take pictures with your phone step by step of the removal so you can check where goes what by the pictures.
Have fun

find the bolts attaching the bracket to the engine (possibley2 or 3) Buy a genuine replacement assy and fit get a new belt as the old one may have suffered damage. Replace where you removed the broken bit and adjust the belt to the correct tension

Check with Autozone and discuss your problem. They know what they are talking about and have always come up with the right parts or belts for me. I used to be a mechanic in my youth and I never go anywhere else.........

Hi:
Your car will always start with out the alternator belt, as long as the battery is charged. The first thing to figure out is why the belt broke. With the engine cold, and not running, try to rotate all of the pulleys that you can, and see if you can find one that is stiff or binding. It could be the alternator, the tensioner pulley, or something else. If you find the culprit, that is what broke the belt. Once you fix that, you can check out other things. If you had other symptoms, such as overheating or something else, that is another problem, but a broken belt doesnt point to those things yet.

you could adjust your tensioner to fix it, but most likely your power steering pumps pulley is not completely parallel with the the crank pulley

a bad belt tensioner leaving too much slack in belt causes it to break.

The Tensioner is Located at the Top Front of the Belt Routing System. It has A Large Circle that resembles a Doughnut with a Nut or Bolt Head in the Middle of it. Just Below that there is a Smaller Round Pulley that has an Arm attaching the two Together in the Back of them. The Belt will either go over or Under the Second or Smaller Roller. Look at the Factory Sticker Under the Hood for Proper Belt Routing. Get a Ratchet and Socket that will fit the Bolt on in the Middle of the Doughnut Shaped OR First Pulley. It will be Tight But, it will turn left or right and the Smaller Pulley will let Tension off of the Belt for Removal. Let me know if ya got any Probloms!

On the Inside of the Engine Compartment you will find the Routing Sticker for the Belt to Reinstall. Locate the Tensioner (Will look like a Pulley that has one Round Pulley Under the Belt and One larger Round Pulley Mounted Above that. In the Middle of the Large Pulley there is a Bolt. Get a Wratchet and Turn it. It will Lower the Pulley under the Belt and Loosen the Tension Off of the Belt. Remove the Belt. Follow the Diagram Under Hood to Reinstall.

Sorry, I don't have access to a Bentley now. There are 4 belts, 2 for alternator etc, 1 for aircon and 1 for pwr steering.
The power steering belt goes round the power steering pump & crank pulley only.
The paired belts go round crank pulley, alternator and water pump.
The aircon belt goes round crank pulley, aircon compressor and tensioner.
Alternator / water pump pair are closest to the engine.
Power steering is in the middle (with aircon) or closest to the bulkhead (without aircon).
Aircon (if fitted) is closest to the bulkhead.

(1) If you do not have an AC compressor, skip this step and go to step 2. If you dohave one, begin by cutting any cable ties that hold the main wiringharness to the AC hoses. Lift the harness up and over onto the camcover until it's near the PCV valve, and is now out of your way.

All nuts & bolts in this step are 13 mm.

Then, slacken the 2 bolts attaching the AC tensioner pulley mount (athick triangular steel plate) to the head. Use a long box wrench (ringspanner, in English ).

Using a deep-wall socket (or an offset ratchet wrench, or plain wrench)on the adjuster nut, back it off until there's no more tension in thebelt (you won't be able to remove the belt yet, though).

Now, remove the upper of the 2 mounting bolts and its washer, and pivot the tensioner down; remove the belt.

Remove the lower bolt, and lift out the tensioner. Look the triangularplate over for cracks, and spin the pulley to see if its bearing issmooth and quiet. (If you find problems, the pulley is about $15 and www.eeuroparts.com sells the entiretensioner assembly for something like $70.) Back off the adjuster nutuntil it's about 1/4" (1/2 cm) from the end of its threaded rod (usevise-grips to clamp the rod's other end onto the triangular plate, orput the whole thing in a vise).

(2) Slacken the bolt and nut holding the power steering pump to thehead and to the RH engine mount, respectively. Slacken the adjuster nut(yes, anotherthreaded-rod type thing) by about 1/2" (1 cm). You can use a normalwrench for this, but it takes forever--so I made a special tool bytaking a cheapo 13 mm open-jaw wrench and bending it to a 45-degreeangle just below the jaws (cut it to length if it's too hard tomaneuver). Loosen the mounting nut until it's almost off (but not completely off,or you'll lose the bolt it screws onto--this bolt was designed to fallout when the nut is removed). Pull the nut end of the threaded rodtowards the firewall to get it of the adjuster fork. Push the pumptowards the engine centerline and pull its belt off (you may need topry with a screwdriver to get it out of the pump pulley completely).

(3) Slacken the 16 mm nut on top of the alternator. Back off the alt.adjuster's 10 mm nut about 1/2" (1 cm)--a ratcheting wrench helps here.(This is the last threaded rod--I promise.) Completely remove the 16 mmnut, and pull the adjuster towards the firewall until it's out of thealt.

Now for the clever part: Cut yourself a wedge from a piece of wood (2 x4 is perfect), with a rise of 3" (8 cm) and a run of about 12" (30 cm).Push the alt. towards the engine, and shove the wedge in between theside of the alt. and the coil-spring tower (master cylinder mountingbracket works, too). Keep pushing the alt. and driving the wedge downuntil the alt. is so close to the engine that it's compressing thelower heater hose.

Pull the outer belt off the alt. pulley. Working from the RH side ofthe car, lift the belt off the water pump pulley and then disengage itfrom the crank pulley. Now, pull the inner belt into the outergroove of the water pump pulley. Go back to the LH side of the car, andmove the inner belt into the alt. pulley's outer groove. Try removingit from this pulley; if too difficult, either wedge the alt. closer tothe engine or try pulling the belt off the water pump pulley from theRH side of the car (a helper is very useful for all this).

(4) Install the new inner belt by fitting it into its groove in thecrank pulley first. Work it into the outer grooves of the alt. andwater pump pulleys, then into the inner ones. Install the outerbelt--again, first onto the crank pulley, then the water pump and alt.pulleys.

Remove wedge. Insert tensioner into alt. making sure the threaded rodsettles into its fork, and refit its 16 mm nut--but don't fully tightenit yet. Tighten 10 mm adjuster nut until belts can be pushed in only1/2" (1 cm) by thumb pressure (applied 1/2 way between water pump andcrank pulleys).

(5) Push PS pump as close to engine centerline as possible, andfinger-tighten its mounting bolt to hold it there. Fit a new beltaround the crank pulley first, then work it into the pump pulley groovefrom the bottom of the pulley until it pops in. You may need to use both hands, and/or carefully pry the belt on with a screwdriver.

Loosen the bolt you just tightened. Pull the pump away from enginecenterline, insert threaded rod into its fork (you may have to back theadjuster nut off some more), tighten the mounting nut (but notcompletely), and screw in the adjuster nut until the belt deflects asdescribed in (4) above.

(6) Start the engine. Blip throttle, watching the belts deflect as theengine speed goes up and down. If the "blur" you see midway down eachbelt is over 1" (2 cm) wide, tighten the belt(s) until it isn't. Tighten the PS pump mounting nut and bolt, and the 16mm nut on the alt.

If your car doesn't have AC, your belt replacement is over!

(7) If you haveAC, reattach the tensioner to the head with the lower bolt only (andleave this bolt finger-tight). Fit the new belt around the crankpulley, then around the compressor pulley and, finally, around thetensioner.

Reinstall the top tensioner bolt and its washer. Be careful and patienthere--you're threading a steel bolt into aluminum, so make sure it goesin straight. You may have to back off the tensioner nut a little. Leavethis bolt finger-tight.

Screw in the adjuster nut to get the deflection as described in (4)above. Start the engine, and blip the throttle. Watch belt's "blur" on LHside of engine. Adjust as in (6). Switch on compressor, and repeat.

If satisfied, tighten the 2 tensioner bolts. Return wiring harness toits original position, and re-secure with cable ties if needed.