Replacing a front diff

[Les Henson]

This thread is how to replace the front differential without having to strip the hubs down to the stub axles in order to remove the driveshafts. Ideally, you need two jacks and two axle stands, but just the one jack and two axle stands will be enough, which is what I have used in this thread. If you have standard brake lines, then they would have to be disconnected probably, but this vehicle has +2" Goodridge hoses, which are long enough to allow the hubs to go out far enough for the driveshafts to clear the diff assembly without disconnecting the braking system.

The pinion bearings are worn, so this is a replacement item, which is second hand, but in good condition - from a 110V8.

The diff nose seal has been leaking for some time, and the drive flange will move up and down - indicating wear of the the pinion bearing/s.

Drain the diff first - the level plug and drain plug are both the same and a 1/2" drive bar is perfect for removing them.

While the oil is draining out - disconnect the front prop (propshaft tool and 14mm spanner), and tie it out of the way.

Place a jack under the radius arm and remove the wheel. Steering link rod first - this is a 19mm nyloc nut, but maybe a castellated nut and split pin. Remove the nut and then strike the hub arm with a hammer as shown and the joint will seperate. On the passenger side, the link rod has to be disconnected as well.

The +2" brake line - long enough to leave connected.

There are 7 x bolts that hold the swivel ball to the axle tube. They are very tight, so a close-fitting 14mm x 12-spline ring spanner to undo them. I lock another spanner on them as shown in order to increase leverage. Undo and remove 6 of them, but leave an easily accessible one in place for now.

Put the wheel back on - the wrong way round. This is to increase the amount of room there is avaiable behind it to undo the remaining bolt - secure it to the hub with 2 or 3 wheel nuts.

Manipulate the jack/axle stand until the tyre is just touching the ground, then undo the remaining bolt. As it seperates, keep an eye on the gap top-and bottom, and adjust the jack as necessary.

Once the final bolt is removed - slide the wheel/hub assembly out. When the driveshaft leaves the diff - it will drop down, as you can see in this picture. Then move to the other side and do the exact same thing. Both driveshafts are now clear of the diff and it can now be removed.

The nuts holding the diff to the axle case are all 14mm nyloc - remove them, position yourself underneath and manipulate the diff so that it comes off the studs. Once free, lower it to the ground.

A few important things -

Devise a way of keeping the brakes on before the wheel is removed, the hub will rotate until the heaviest part of it is at the lowest point, which will put a lot of strain on the brake hose. A bar jammed between the brake pedal and the seat box is favourite.

Once the diff has been replaced/repaired, the wheel has to be removed in order to move the hub assembly so that it will mesh the driveshaft with the diff. The swivel pin will keep the driveshaft vertical, and with some careful manipulation and swearing - the shaft will slide back in.

This method means that the swivel ball/axle tube gasket cannot easily be replaced. You can cut a new gasket, put it in place, then add a blob of sealant where the cut is, or put a thin film of sealant over the old gasket and bolt it all back together.

Les.

[ciderman]

The nuts holding the diff to the axle case are all 14mm nyloc - remove them, position yourself underneath and manipulate the diff so that it comes off the studs. Once free, lower it to the ground.

Mine are 3/8 UNF Les

I see this is a simplified way of changing a Front Diff ,But I still prefer to use the traditional way , hubs ,stubs and shafts off , Gives you a good chance to inspect the other front axle components ,such as wheel bearings , Cv joints .

[andyb]

Excellent thread Les....but as always there are more than one way to skin a cat.

With normal length flexi hoses I have removed front brake pads, undone top swivel pin bolts so as to remove brake pipe bracket, undone caliper bolts and then carefully moved the caliper so that it can be zip tied to the coil spring. A jack under the hubs end will support it so that you reduce oil leakage from the swivel oil seal. You will also have to re-torque these bolts.

I have modified my brake pipe bracket so the bolt holes are now slots, so you can just back off the swivel bolts and slide the bracket out.

I realise that you have to be careful with copper brake pipe cracking, but my method reduces the chance of stretching a flexi hoses it you mis-judge the weight of a complete hub and the need to rebleed the brakes.

Neither method is without it's short comings, but I thought an alternative view was useful

[nicks90]

The nuts holding the diff to the axle case are all 14mm nyloc - remove them, position yourself underneath and manipulate the diff so that it comes off the studs. Once free, lower it to the ground.

dont you mean:-

"manipulate the diff so that it comes off the studs. Once free it will fall out of the hole - completely surprising you at how heavy it is and crush half your rib cage, roll off your chest (leaving multiple bruises as it goes) and land on the soft fleshy bit of your bicep and armpit and then roll onto the drive."

[Les Henson]

also - " leaving blobs of EP80/90 as it goes."

Les

[bishbosh]

Nice thread Les as usual.

On a serious note, I think it should be made very clear that the diff is a very heavy 25kg. Not only that, but it is not well balanced when it comes out and can really take you by surprise as already said.

I say very heavy because of the combination of the actual weight, the unballanced distribution of weight, and the fact you are lying on your back with it just above your chin .

[upnover4x4]

Curious how difficult it was getting the halfshafts back into the diff on reassembly? Or havent you got that far yet?

Good thread, been thinking about this job today & couldnt really think of an easy solution...well done

Adrian

[TOR4x4]

Curious how difficult it was getting the halfshafts back into the diff on reassembly? Or havent you got that far yet?

Good thread, been thinking about this job today & couldnt really think of an easy solution...well done

Adrian

Easy enough to get back in, but you'll be there a while if you try doing it with the wheels on

[Les Henson]

You won't get the shaft back in with the wheel on. You remove the wheel, grasp the hub and manipulate it until the shaft slides into the diff. I expected it to be really fiddly, but they went in pretty easily really. Taking the weight of the hub takes a bit of effort though, so if it takes a bit of time, you will quickly tire out.

Les.

[JST]

good thread Les

i do it as above but take the wheels off and with +2" brake pipes theres enough flex in them to get the shafts out without complete removal.

lying on your back with it just above your chin .

use of all chins will help balance it too.

[Les Henson]

Bit of a rubbish tech thread - now I've studied it a couple of times. In my defence it was tipping with rain and I had to wear my 'hot 'n' sexy' wet suit

If I do the same job again - I'll do a better write-up and replace this one.

Les.

[gsr341]

replaced my front diff a few weeks ago using this method , just i used 4 axel stands and took the wheels off before starting the strip down , made it a bit more ''airy'' round the hub

[streaky]

I fitted front and rear ARB lockers in the Disco this week and was surprsied that I had to drop the front anti-roll bar to enable removal of the diff from the axle.

Is this normal? It was touching by 8mm on the right side only.

Also....other than banging seven bells out the diffs casing....is there a simpler way to break the 'seal' between the diff and the axle? My workshop had used a black rubberised sealant that acted as glue...!

Thx.

[missingsid]

Les,

Great thread and excellent pictures yet again.

I use this method minus the wheels and I could change a front diff and get back racing with out losing too much time.

The best time saver I learnt years ago was the use of the hammer to remove the TREs. At a trial my mate bent a drag link in the morning and was acout to give up for the day until I showed him how to get it off in double quick time.

I like the ida of keeping the wheels on and using the brakes to stop the hub from spinning around and hitting you on the head!

However I usually take the calipers off to safe guard the brake pipes so Im not sure of the best way.

As said before its all a trade off what ever you decide to do.

PS do you keep braking bits on a regular basis or are you in the trade and giving away secrets to help the members?

Marc.

[Les Henson]

I'm in the trade Marc (mobile mechanic). I repair all makes of car, but quite a lot of Land Rovers.

For some weird reason - I quite like repairing them. Local garages hate them, so pass jobs onto me

Les.

[missingsid]

I'm in the trade Marc (mobile mechanic). I repair all makes of car, but quite a lot of Land Rovers.

For some weird reason - I quite like repairing them. Local garages hate them, so pass jobs onto me

Les.

Les,

That sounds like a perversion to me

I quite fancied starting a business with LR work but there are too may independent garages around my way allready (one of them's a mate).

Marc.

[bobtail4x4]

I fitted front and rear ARB lockers in the Disco this week and was surprsied that I had to drop the front anti-roll bar to enable removal of the diff from the axle.

Is this normal? It was touching by 8mm on the right side only.

Also....other than banging seven bells out the diffs casing....is there a simpler way to break the 'seal' between the diff and the axle? My workshop had used a black rubberised sealant that acted as glue...!

Thx.

stick a jack under the nose, and lift it slightly.

[streaky]

That may be a remedy to break the seal Mike...but what about clearing the drop-arm of the anti-roll bar? Does tilting the nose of the diff help solve that little problem as well?...I wouldn't have thought so but would like to hear more.

Thx.

S.