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MG Midget and Sprite Technical - Stuck Axle Nut

Hi, not sure why the photo is upside down, but anyone got any suggestions for getting that axle nut undone.
I thought it would be easier to undo it when the car was on its wheels and the handbrake sorted.
Want to replace the oil seal.
Have tried a little heat, penetrating fluid, electric impact gun. Longest bar I can get on it.
Trouble is I can’t get a long bar on it unless without a lift.

Can I use more heat in that area? Could that melt the old oil seal and make a right mess?

Any tips would be very welcome.

Thanks

James


James Paul

I knocked this up using 1/4 x 1 inch mild steel bar. Take the diff out, attach the steady bar to 2 opposing holes in the flange. Place on the floor and then use a socket and as long a breaker bar as you can find. Easy-peasy.

David Smith

I did a similar arrangement to Davids. Before you loosen the nut mark the nut orientation so that you get it back to the same torque setting. Helps keep everything aligned internally.
Martin

I shaped up a large piece of flat steel to fit around the pinion nut so I can fit a couple of bolts into the flange - same basically as David's but mine is one piece.

If the car is on stands the bar would react onto the ground - I did mine in the bench vice.

You can borrow it if you want to save making one.

R.
richard b

I have done it with the diff in the car, but as David said, it's much easier out.

Mark the position of the nut in relation to the pinion, so you can tighten the nut to the same position once you have replaced the seal, without loading the bearings.
Dave O'Neill 2

Ok think I get! Thanks for your help

I don’t know why but didn’t think about removing the diff

Richard I’ll message you if that’s ok to borrow it?

Thanks
James Paul

David Smith's anchor bar is so elegantly simple it would take a lot less time to fabricate one than going to collect Richard's. And with the price of fuel even a short trip is going to cost more!
GuyW

Guy
He's in walking distance - oh its a bit heavy !

R.
richard b

LOL.! I knew he was close. But how long does it take to drill 4 holes in two lengths of flat bar? James will have to walk quite briskly! 🤣
GuyW

Guy,

You're assuming that James has the bar stock to make one. ;-D
Martin

Martin, but doesn't everyone have bits of old metal, bed frames, bar? I have bits like that, that I have hung on to for 50 years on the chance that one day they will come in useful! 😁
GuyW

Guy,

Yes, many of us do but there is the odd chance that someone may not have exactly what is needed. My wife complains about my collection of odds and ends until I use one of those odds or ends to fix something. But then, my wife is mechanically challanged.
Martin

Don't worry Martin. I am not being serious. But I do like the simplicity of David's device.
If I lived as close to Richard as James does, I would still make one like that, if only because I am desperate to use up some of the scrap iron I have accumulated over the years! Then I would pop round to see Richard for car natter as he is a top bloke.
GuyW

Be carefull if you're doing it with the car on stands,- Instead of having the bar pushing against the ground, feed it through above the right side spring to undo it, that way the torque is going onto the spring instead of trying to lever the car off the stands-
If your nut gun didn't move it there's a chance that someone has loctite'd the nut, if so, get your foot against your powerbar or whatever you're using to undo it and hold a heap of constant pressure on it, if it has been locktite'd you'll feel it let go after a few secs of constant pressure-
William Revit

Two months ago I did have plenty of spare metal and enough to make this tool. Whilst the car was at the paint shop I decided to have a clear out and took all the spare old metal to the scrap yard, thinking why would I need any of that!

Did the same for my wood pile as well. 🤦🏼
James Paul

James

These videos might be helpful: https://www.youtube.com/watch?v=yug-eaCaldo &
https://www.youtube.com/watch?v=H9yKWKV8poc

Cheers
Mike
M Wood

James,
I also have a 3/4” drive socket set (metric) but can sort that and it has Man sized Breaker bars !!!

Also somewhere. 240volt impact driver but the 3/4” should gain a submission!!!

R.
richard b

I had to replace the flange and oil seal on my Capri, and did it on axle stands as willy describes.

1st pic undo, 2nd pic tighen up back to scribed mark.




anamnesis

Great! Thanks
James Paul

Anam,

Did you check the torque required to rotate the pinion after changing the flange. Unless the new flange is machined precisely the same as the original from the nut face to the face that contacts the bearing I wouldn't expect the same preload to be maintained by putting the nut back to the same position.
David Billington

Hi David. No I didn't check the torque, but did measure the flange. It was supplied new to me by a diff rebuilder, and he confirmed that the dimensions were the same. It was done in 2017, and so far, so good. 😄.
anamnesis

I would consider selling the Capri, could go wrong anytime now... ;)
A de Best

Lol. Exactly my thinking Arie. 😄

It is pretty much for sale, I just haven't advertised it yet. Wanna buy it? 😅

anamnesis

if only it was a lhd... ;)
A de Best

lol
Arie, couldn't help myself--he'll take cash

William Revit

👍. Quickest conversion ever.

Ha ha. Yep cash says it all Willy. 😁
anamnesis

Cheers Willy. 🙂.

Just to confirm it, ---- 😅




anamnesis

Got to admit it, its a pretty, stylish car! Speaks of its age, and I dont mean in condition!
UK style of the 60's was so much braver than any attempts since then.
GuyW

I agree Guy. I thought when I bought my first one back in 1972, it looked quite futuristic. But unfortunately for Ford, they left it too late, and it was a commercial flop, with only circa 20000 sold. It took too much from 50's america, just when the US was dropping the fins. It's cousin the Classic did better at 40000, but the shorter length 105e Anglia sold way more at over 1 million by the end in 1967. And the mk1 cortina which wiped out the Capri and Classic along with the Corsair, sold over a million too in just about 4 years.

But the shape of the Consul Capri is what makes it.

As for condition, mine does show it's age. But then I like old cars to look their age, as long as they still go properly that is. 😁
anamnesis

James,
If you still want to borrow the bar let me know so we can arrange it.

R.
richard b

Here's one for you at the Wem Vehicles of Interest event Anam.

Not one that's on my wanted list but it looked to be in excellent condition throughout.

C

C Mee

Very nice. I'll see what I can find out about it on the facebook group.
anamnesis

Hi Colin.

It's a 1963 Capri 1500gt; a genuine one not a copy, which makes it very rare -- maybe 1 of about 50 surviving..

Belongs to a chap in the Consul Capri Club. It was his first car, and he's owned it since 1983. Not for sale but in today's market would probably make circa £20k.
anamnesis

Sorry to bring this back to more mundane things, but thought you might be interested to know that I borrowed Richard's bar and it worked perfectly off the spring.

When I did the nut back up to 140 lb/ft I noted that it went a fraction passed the marks I made, so assume it wasn't done up as tightly as it could have been in the first place.

The old seal was very brittle and old so definitely needed replacing.

No more leaks for while!

Thanks for all the advice once again.






James Paul

James,

140lb/ft is the torque to do it up with a new crush spacer, when replacing the seal it should be done to the marks not the torque as the spacer is already crushed. Might be worth checking the torque required to rotate the pinion to see if it's in the right range but you'll need to pull the halfshafts, or back the nut off back to the marks.
David Billington

Hi David,

How do I know if it was ever torqued up to the correct setting in the first place?

Most things on this car seemed to have been bodged.

Thanks

James
James Paul

James,

The only way to know if the pinion bearing preload setting is correct is to measure the torque to rotate the pinion, ideally on it own. I did help a neighbour with his Morgan and we fitted a new CWP and the rebuild data included the torque for just the pinion, pinion crownwheel and diff, and pinion crownwheel diff and halshafts. That was a different axle so the values wouldn't be applicable but maybe someone has the values for the A axle and can post them.
David Billington

Jamrs you will only know now if you have exceeded the torque, when your pinion bearings start rumbling. Hopefully they won't, but it doesn't take much to over crush the spacer.
anamnesis

Ok thanks,

So the best option is for me to assume the original torque was correct and loosen the nut to the markings. Yes?

Over tightening the nut could be more problematic for me.
James Paul

Unfortunately I don't think you can do that. The crush spacer won't spring back to the original length.

The nut doesn't need to be 140 tight.

It only needed circa that, to crush the spacer initially.

But if you loosen the nut now, the spacer will likely be 'rattling' loose between the two inner races, and leave you with no torque tightness on the nut at all.

But how much past the scribe did you go? If only a gnats cock's worth, you may get away with it if you just leave it as it is, and see how the bearings take it.

How much do you use it?

You could back the nut off enough to use some thrrad lock, and then tighten the nut back exactly to the scribe mark. And then also use a punch on the nut in a few places, belt and braces, to prevent the nut from coming undone.
anamnesis

Difficult to be prescriptive of what is best when doing a repair on your back under a car !

The seal was well leaking - general wear or made worse by pinion moving about ?
Could pull the shafts and see if it feels tight/ draggy ?

Could back off to marks and stake the nut as Anan suggests.

How accurate are the torque wrenches used originally to set up if measuring of bearing preload was not checked and seal previously replaced ?

Before I was ‘educated’ in marking the nuts I have ‘in the day’ replaced seals and torqued nuts and seemingly got away with it.

Bit of a lottery if not bench rebuilt with new parts and measuring tools.

Bit sitting on the fence I know !

R.
richard b

James
You 'must not' back it off
It looks like you only went past the mark a little bit which is what i'd normally do---I go up to the marks then a tiddle just to make sure
If you've gone 140ft/lb and only gone that far past the mark i'd be happy with that
Just grab hold of the flange and give it a good workout up and down to make sure you haven't got any up/down-in/out movement---if that's ok then rotate the flange by hand, it'll be a bit stiff because you're turning the axles,brakes etc but if it turns ok then there is a spot where you can rock it back/forward where it'll move roughly about 1/2" on the outside of the flange where the rest of the internals aren't moving.
Using that spot to work with place your thumb on one edge of the flange and two fingers on the opposite side--with your fingers like this you should be able to move the flange radially in that 1/2"ish spot without any real binding, there will/should be some resistance but should move smoothly with just them fingers like that in that short area- If that's how it is then all good--

and just for correctness's sake, the nut's correct name is a pinion flange nut--can be confusing as some cars (MGB) have nuts on the end of their axles(drive shafts)which is what you'd usually refer to as axle nuts

willy
William Revit

Just looked at the picture you posted James. As Willy says, you haven't gone far past the mark, and it could well be ok, if you leave it as it is.

These are taper bearings, and they wear in, which reduces preload a little. With the small amount you've gone past, you may only have just nipped up that wear.

Question.
Did you also count the number of full turns to remove and replace the nut?
anamnesis

James. Not saying that you don't fully understand it, but just in case, follow this link to a pretty good basic explanation of pinion preload and how to set it.


"What is preload in a differential?
Preload is the amount of force pressing the tapered roller bearings, mounted on the ends of the differential, together. Preload is used to pre-compensate for wear in the bearings (prevents the bearings from getting loose as they wear), and is defined as the amount of rotational drag induced by the load on the bearings."

https://stretchmaster.co.nz/council-of-experts/often-asked-what-is-pinion-bearing-preload/
anamnesis

Who am I to question this:
"Preload is used to pre-compensate for wear in the bearings"
Doesn't sound very convincing to me! Are you supposed to accept that the thing isn't set up properly until it has part worn out?

Ages ago I read what, to me was more convincing. The pinion expands as it warms up, increasing its circumference. But so does the big ring gear and that, being bigger, increases more. The 'tightness' of the pre-load is to compensate for this expansion as the diff warms to its operational temperature. No need to wait for it to wear out!
GuyW

Just checked the flange and it doesn’t wobble around.

Checked the rotation and there is the, and as was before the backward forward movement as you describe Willy.

I can turn the flange and the wheels rotate as they did before.

I can’t hear or feel any additional noise or grinding.

Thanks for all your advice. I’m definitely learning on the project and I do welcome all the lessons,

Many thanks

James
James Paul

Guy, I see it as not so different to taper wheel bearings. When they wear, you nip them up a tad.

On taper wheel bearings it's easy, tighten and back off a tad, repeat until worn out.

Not so easy on a diff. The preload is set, and will gradually reduce, lasting until the bearings are worn out.

But in the case of the diff pinion, you also have the constant 'on off' action of the pinion gear against the crown wheel gear, and the preload is to compensate for this too.

https://www.freeasestudyguides.com/pinion-bearing-preload.html
anamnesis

James,

"Checked the rotation and there is the, and as was before the backward forward movement as you describe Willy."

It's not just the presence of that small amount of movement (backlash), it's the relative 'stiffness' and smoothness of it.

It's hard to gauge that though, if you haven't felt it before or don't have another diff to compare it to.
anamnesis

an
the way I see it is--
James' nut is a tiddle tighter than it was before
He has no movement evident at the pinion
He can rotate the whole assembly by hand at the pinion flange
He can move in that backlash area with a couple of fingers smoothly
I'd say he's right to go-not too loose(nut's tighter than before) and to tightness spec---not too tight if he can move it with 2fingers- he'll be fine

willy
William Revit

Yep I agree with you. I'd keep it as is now too.

Here's a question Willy.
If a spacer was used, could it be put on a well fitting round bar, and hammered flat again, and reused? I know they are cheap, just curious if they could be reused.
anamnesis

Yeah ,I've done that once or twice, you don't have to hammer it flat though, just enough, evenly to make it grow a few thou.
A better move if you can't get one and have to reuse it is to fit a shim in with it and just retension- or better still go for a solid spacer and shim to suit
William Revit

Ok thanks Willy. Shim the spacer, didn't think of that, really good solution if you do go too far.
anamnesis

This thread was discussed between 28/06/2022 and 25/07/2022

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