MGB MK1 (Banjo Axle) Differential and Half Shaft Replacement & Rear Axle Oil Change

A step by step guide to removing and refitting the half shafts and differential housing in an early MGB. I'm really trying to push my KZbin channel forward for 2020, if you like the videos it would help me immensely if you would be kind enough to subscribe to my channel.
Any questions are always welcome, this video is covers the early MGB with a banjo axle, the later Salisbury axles are different. Some procedures are similar such as draining the oil and removing the brake drums. I have added some bookmarks below so you can skip directly to the parts you need.
02:37 Removing the brake drums
03:58 Draining the axle
05:56 Removing the half shafts
10:17 Removing the differential housing
19:30 Re-fitting the differential housing
32:37 Re-fitting the half shafts
35:59 Re-fitting and adjusting the brake drums
40:59 Re-filling the axle

[@davidsheppard1133]

Great idea soaking the paper gaskets in light oil.

[@davidrussellwilks]

Thanks for watching!

[@RichardChynoweth]

I found a wee hack for filling the rear axle up if your petrol tank is preventing you from getting the bottle at the correct angle: Use a a hand soap dispenser top to squirt it in. Worked a treat for me.

[@davidrussellwilks]

That's a great tip!

[@TheBoxerdog22]

Great informative video i have a 1966 car so seeing it removed in video helps big time.

[@davidrussellwilks]

Glad you enjoyed it David, the process is pretty straight-forward if you ever need to do it.

[@callumtbjones]

You’re an excellent teacher. Thank you

[@davidrussellwilks]

You're very welcome!

[@tedsmith_photography]

I always enjoy your energy in these videos. You always seem to relish these tasks. Makes me chuckle how something that most of us would consider major work seems to be like a walk in the park to you. "The diff broke in a race last week so I'm going to replace it" :-) I'd be crying into my chips! Re the refil task (we spoke about this via e-mail) : it is indeed trickier with the fuel tank in the way, but I used a pump as I did for the gear box. Makes life much easier for only £7. Also, I notice you mentioned you had "a road MGB"...be interesting to see that one day, as all your videos feature the race one. Obviously no issue with that but I'd just be intrigued to see it.

[@davidrussellwilks]

Many thanks for your message Ted, with the diff failure I was happy that it happened on the warm up lap rather than the start, so in all honesty I think I got off lightly with it. Also having tackled the job a few times I know it's fairly straightforward, a big engine failure and no oil pressure would certainly make me far less chipper! Glad you managed to refill the gearbox ok, having a pump tool really is very useful. I sold the road MGB GT I had a few years ago now and put the money into the race car. I'll email some pics to you.

[@stevencowan5599]

As l have the 1979 MGB it was still very good to watch David and as always very very informative. Cheers Steve

[@davidrussellwilks]

Thanks Steve, glad you enjoyed it.

[@57dhay]

Great video that inspired me to do the same on my 66 Roadster. One complication that I encountered was that I have 2 battery boxes and that meant getting the axle as low as possible and removing the diff with a quarter turn anticlockwise before it would squeeze through the gap between the battery boxes. Ended up being a 2 man job to get it back. Hope this helps anyone in the same situation. Love all the videos. Keep up the good work!

[@davidrussellwilks]

Thanks for your message David, on my car having only one battery box and the fuel tank in the boot does make access quite a lot easier. Delighted to hear you managed to get the job done.

[@mattkilbourne4654]

Love your videos. Always well done.

[@johncooper7242]

Another great video guide ....when you were pulling off the diff and the car was swaying from side to side my heart was in my mouth.! From the beginning I thought it would be safer to put the axle stands under the diff tubes rather that the narrow flats of the springs where the car can easily slide off sideways. I always make sure I have a secondary support like additional axle stands, or tree stumps or railway sleeper blocks or even a trolley jack just in case .

[@davidrussellwilks]

That is a very good point John, I thin the car was fairly well located with the springs in the middle of the axle stands, but as you say, far better safe than sorry.

[@johncooper7242]

@@davidrussellwilks I think I must be getting more and more cautious in my dotage David...One upon a time I was quite gung-ho overtaking long chains of cars on the road with foot flat to the floor all the time. The needle on my stripped out 67 MGB GT used to go right round to the ignition light on my journeys back and forth from Bath to Oxford on the M4

[@SteveDentonClassics]

Great video as always mate, annoying that your diff when on track, but I suppose that's racing, and what you have to be prepared for.

[@davidrussellwilks]

Thanks Steve, luckily it was on the warm up lap rather than failing on the start line, the half shaft failed two weeks later!

[@bshnabel]

Another detailed and informative video, beautiful car, cheers Barry

[@davidrussellwilks]

Many thanks Barry, delighted that you enjoyed the video.

[@can-cruiser]

Great video. Quite helpful indeed! Thanks for posting and sharing..

[@davidrussellwilks]

Many thanks, I'm glad you enjoyed it.

[@jacktorrance8677]

Thanks David great video, and lots of good info and tips, I’m doing my MGA which is almost identical to the MGB diff set up.

[@davidrussellwilks]

Glad it helped

[@stanbest3743]

Thanks, I'm going back to the banjo axle on my car so very useful. You probably have the later 4 synchro gear box on your car. You wouldn't win many races with the appalling ratios in the earlier car.

[@davidrussellwilks]

Thanks for your message Stan, you are quite correct that the car has the later 4 synchro 'box. It uses a straight cut close-ratio gearset rather than the original one.

[@neilwalker3643]

Your car is in beautiful condition, did you restore it yourself? Great videos, excellent information and very well presented.

[@davidrussellwilks]

Thanks for your message Neil, I certainly had a lot of help when I built the car but I can say it's largely my own work. I didn't build the engine, gearbox or differential though. Glad you enjoy the videos

[@donthuis]

What I miss from this story is the fact the banjo axle has its outer bearings lubricated by the same hypoid oil in which the diff turns. The end caps to the hubs, together with the seals at the inner sides assure no oil is lost from these ends. BUT: after any removal and reassembly of these half shafts the space behind them will no longer carry any oil inside. I myself finalised the halfshaft and oil filling procedure by lifting first one side of the axle high up and then the other, letting oil from the center pour outwards. And then rechecked the oil level in the axle, which did not need any additional refill after this action, since the shifted amount was small. Still: better safe than sorry.. BTW the OEM filler plugs with their square drives sit deeper inside the tapered holes than the latertype with hex drives. For jacking the rear of the car up under the axle I prefer a flatter surface so went back to the OEM plugs.

[@stevenserabian7366]

Another great video David and thanks for posting! Love how clean your car looks especially on the underside. How would you suggest I clean and paint the rear end in my 72 MGB (sand/media blasting, wire wheel brush, etc)? What type of paint is typically used?

[@davidrussellwilks]

Many thanks for your kind message Steven, the whole of my car was painted with a 2K or 2-pack type paint. With the 2 part paint you end up with a harder and more resilient finish than cellulose. You paint on the 2k with a brush, you will need to appropriate hardener to go with it. I would say that sand blasting would be the best method, but be careful if you have a rubber type stone chip. You will find the sand gets everywhere too, for small areas a wire wheel type brush may be the better option. In an ideal world I would strip the car to a bare shell and have it acid dipped, I can understand that time and cost involved make this prohibitive though.

[@stevenserabian7366]

@@davidrussellwilks many thanks for the reply and the specifics on the 2K paint and process!

[@hankpb1]

hi how easy is it to remove backlash ?

[@windmill1965]

Interesting video, with a clear view on the differential and axles. I have an 1964 MGB (thus banjo type) but haven't touched any of this yet. I have some leaks though, so it is time to look at things. There is some oil dripping from the differential at the point where it connects to the drive shaft. I guess that there is an oil seal there which needs replacement. Also, one of the brake drums gets greasy on the inside, thus that brake isn't functioning perfectly. Is there an oil seal on the half shaft and is that easy to replace? I don't have a well-equipped workshop and only have access to some basic hand tools. If access to the oil fill hole is limited it might work to use a large size syringe with a piece of hose attached to push the oil from the syringe into the differential. Oil spillage might be limited with this method.

[@davidrussellwilks]

There is an oil seal on the front end of the differential, the differential will need to be dis-assembled to access this though. The ones on the half shafts are much easier. There is an o-ring and a paper gasket that are easy to swap. The hardest part may be removing the half shafts, if you have a pry bar or similar though you should be able to persuade them out. Best of luck!

[@windmill1965]

@@davidrussellwilks Thank you for your reply to my questions. Watching your video it indeed seems easy to replace the O ring and paper gasket on the half shafts. About the half shafts: I noticed on drawings that these also do have an oil seal. This oils seal sits on the half shaft between the wheel bearing and the differential. Would I need to replace that as well, or is replacing the O ring and paper gasket sufficient? I found the location of the oil seal on the half shaft a bit confusing: it means that the wheel bearing is not lubricated by the oil in the differential. Maybe my understanding is incorrect: I haven't seen a half shaft in real life yet, so I might be misinterpreting the drawing.

[@davidrussellwilks]

By all means send me a link to the drawing. As far as I know the only oil seal for the half shaft is by the bearing. There is a metal spacer and the O-ring followed by a paper gasket on the half shaft. I'm fairly certain the bearing receives oil from the axel itself, it certainly seems this way when I remove the half shafts.

[@marvin151173]

Hi David, sorry I'm late to the party on this, but, as ever, another fantastic and informative video. I have just started on my journey in building and Appendix K MGB (with a view to racing in Equipe amongst others) and am now just starting to dismantle the rear axle. Whilst dismantling i have sheared off one of the check strap brackets (research suggests this is a common mistake), I've noticed that you don't run check straps, is that the case? I'm minded to not replace the broken bracket and possibly go as far as removing the other one (weight saving), what would your advice be, the research i have done gives mixed opinions.

[@davidrussellwilks]

I used to run with check straps but was told by a knowledgeable racer not to bother. I've certainly not seen any issues at all in not having them.

[@marvin151173]

Thanks David. Another couple of questions, I see you have uprated half shafts, who’s did you use? Also, did you upgrade the rear hub bearings, if you did who’s did you go with? Thanks in advance.

[@michaelannen4168]

"R" on tire mounted on the left side

[@davidrussellwilks]

R for REAR

[@hankpb1]

hi again, woukd yoy say a 4:1 is the best mediun for acceleration and top end ?

[@davidrussellwilks]

Is this with a non-overdrive gearbox? You may find the 4.1 a little short, a 3.9 is the most common choice.

[@hankpb1]

@@davidrussellwilks hi no overdrive.. but engine is 2500 Essex v6

[@hankpb1]

@@davidrussellwilks my diff has atb7182 on it

[@hankpb1]

hi is backlash easy to fix on banjo axle ?

[@davidrussellwilks]

It's not something I have tried myself, at the very least you will need a shop press, a dial indicator with base, and a small torque wrench. One good thing with the banjo differential is that the whole unit can be removed and then given to a specialist to rectify.

[@hankpb1]

hi how do you get the oil seal out on the half shaft..please

[@davidrussellwilks]

Do you have a banjo or Salisbury axle?

[@hankpb1]

@@davidrussellwilks banjo

[@davidrussellwilks]

@@hankpb1 With the oil seal on the banjo axle it's in the hub carrier with the bearing, it should just lever out.

[@hankpb1]

all new nuts and bolts ?

[@davidrussellwilks]

I bought new fixings from Moss when I built the car. More recently I have been changing these over to titanium where possible