Fitting an Ashcroft ATB to my Salisbury axle

[Peaklander]

I'm having a good afternoon then. Thanks.

Now I'm 'off it" for 24 hours as got other more pressing things this afternoon and the morning, so there's plenty of time for more advice! In the morning I have to go to Buxton - just when some snow is forecast, so that could be fun. #wintertyres

Unless anyone has a contrary opinion I think that I should leave it. There's the chance that fitting the bearings to the ATB and the crush washer to the pinion will alter things. I know that's not supposed to happen but...

If I remember in the morning I'll put the ATB in the freezer. It will need some sort of weight spreader otherwise I'll squash something. Bearings on the Aga too. Even so, they are a tight fit.

Oh yes, @ashtrans confirmed this morning that their ATB shaft spec. is 57.2mm +0.02 +0.03 (thanks Dave), so that is the same as the carrier that has come out and my machinist was being unduly cautious.

[Gazzar]

Superb thread, thanks for taking the time to share your pain. 

[Peaklander]

😀 it isn’t quite done yet.

I think when it is,  I’ll want to close the case before lifting down from the workbench and back to the vehicle. I will need to get some additional muscle from somewhere. There’s no room to use the crane.

[ianmayco68]

This is great , I’ll need this when I do mine thank you 👍.

[Hybrid_From_Hell]

On 2/29/2024 at 12:31 PM, Peaklander said:

So, I have looked at the contact pattern and will post some photos.

The situation is that the pinion is in, now with a Timken bearing and the shim that was there is now under a Timken cup, ground undersize so that I can remove it if needed. That will be changed to a pressed cup at the end. The book suggests the pinion should be over 10 thou lower than it is, due to the +9 marking, so that is more out of mesh. However, give or take the Koyo - Timken change, it is in the same position as before.

The ATB is in with dummy bearings and shims as detailed above. There's now a total of 0.103" and there was 0.105" with the old final drive fitted. The bearing caps are fitted but not torqued.

Backlash is under 0.011"; it varies a little on the rotation.

There's no measurable run-out.

Here are the photos. I have posted several as the shadows and angles really affect what you can see:

Drive side (convex)

 

 

To my novice eye, that looks good. Central up and down and not on the edge or down in the root.

 

Coast (concave)

 

 

 

 

Ok,

Bear in mind the bearings etc are new, but the CW&P is not and may have done Moon Miles (and back  ) 

As such you have to accept wear, and that the blue check run out back lash may be close or even out of "Spec".

We tend to start this final process "by Feel" helps when you do it every B day you do get "a Feel" for where things are

Then we rotate and jiggle it about and see if its quiet - if it not quiet the blue check is rather irrelevant !

If there are no tight spots and it sounds and feels smooth then and only then do with get the Dial Gauge out and measure, for us its more checking we are where we think we are, minor adjustments, and a quadrant check etc, and then we check again for run out and tight spot and that its quiet.

 

Finally if we are happy with all of the above we blue check it, even then you can be caught out with weird patterns from previous wear / damage, but what you are hoping for is more confirmation thats the previous steps are all good and so too the blue check

 

I think that is a good pattern, if there are no tight spots and it sounds quiet I would stick with that . - There is always the ability to fiddle some more and end up with it worse

 

....been there done that, ......prob do it again, so run with it if it all seems ok

 

Nige

[Peaklander]

OK well on the strength of the positive feedback I have decided to continue!

Into the cooler 🥶

[Snagger]

32 minutes ago, Hybrid_From_Hell said:

 

 

I think that is a good pattern, if there are no tight spots and it sounds quiet I would stick with that . - There is always the ability to fiddle some more and end up with it worse

 

....been there done that, ......prob do it again, so run with it if it all seems ok

 

Nige

Likewise on the Rover diff I built with an ATB and the 4.1 gears I bought from you, Nige.  I initially tried the  pinion with the original shims from the 3.54 setup and got the head depth from the bearing cap flats matching what was engraved on the pinion.  Once I set it all up, the pattern looked pretty good as far as I could tell using oil paints (try finding decent engineering stuff here!) but it all seemed to easy, so I then tried thickening and thinning the shims, all with worse results.  Wasted several hours with that, but on the plus side, it did give me more confidence, given that this was the first full diff build up that I had done, rather than just swapping pinions and diffs complete on a Salisbury without changing shims.

[ianmayco68]

Did you have to ask permission to put the ATB in there @Peaklander ? Or did you sly it in without the boss knowing? I only ask because her indoors would have had a hissy fit 😱 if I’d have asked to do that or been caught doing it. 

[bishbosh]

16 minutes ago, ianmayco68 said:

Did you have to ask permission to put the ATB in there ?

I think we all know the answer to that question Ian!🤣

[ianmayco68]

Well yes , but I thought it polite to ask 😁.

[Peaklander]

Ahem, it's like a lot of things, you need to get your timing right. 

[ianmayco68]

Oh yes , timing is everything usually when they’re out shopping or at a friends and a get out of jail plan is always wise.

[Peaklander]

Pressing the bearings onto the carrier didn't go well. I could not get my press to push vertically and twice got the first bearing on cock-eyed. Nothing I can do will get it to start straight and I used the clamshell puller to get it off (very easily).

I dislike this press enormously and if I continue with this kind of hobby I will need to either throw it or severely modify it so that it does what it's supposed to do. The ATB is back in the house and I hope that the frost on it will evaporate quickly. Maybe the freezer isn't such a good idea and I would be better properly heating the bearing.

I think I'll move to Plan B and jump in the car on Monday to Mister Gearbox. 

 

I can concentrate on the pinion instead. The outer race was also in the freezer and now that is in the case in front of the shim (yes I did remember to put it back). So I can add the crush washer and set the preload, which needs to result in a torque of 34.5 - 46 Kgfcm which has to be the weirdest non-SI measurement. I will check it with a spring balance and a short bar and I will show my workings here. 😜

The old and new crush washer are only 1mm different in length (27.9mm v 28.8mm) although the new one varies a little on that length (about 0.4mm) measured to different points around the circumference. It's obviously not a precision piece.

I have a new seal ready to go in. It's the leather type, which must have been appropriate for the mid 1990s builds.

I went to the local garage and  I borrowed one of their brake pipe flare kits. The guy there (long time, experienced mechanic and sole trader alongside his better half), was having a bad day. I caught him cursing a front hub that was in the process of being demolished dismantled with such anger, that he was wearing ear defenders.

Anyway I was clearly so happy myself that it rubbed off and he told me to go and get the box and I was off. I need to replace the brake pipe across the axle, as stupidly I managed to snag a union and in the semi-darkness I had twisted the pipe instead of turning the union around the pipe.

I also need to service my Eberspacher D2 heater. So there's plenty to do in advance of Monday morning. I can even lift the axle back into place and fit the new brake pads and be ready to do that final install of the ATB from underneath.

 

[Snagger]

14 hours ago, ianmayco68 said:

Did you have to ask permission to put the ATB in there @Peaklander ? Or did you sly it in without the boss knowing? I only ask because her indoors would have had a hissy fit 😱 if I’d have asked to do that or been caught doing it. 

You have to work on your presentation.  They see the benefit when you point out that it’s cheaper than than buying all the new original spec parts, will take less time, need less tooling, will be more certain to work correctly and also happens to make the car more capable should she need to use it in snow or floods., and that the time and money saved could be better spent with her…. You have to work the angles, Ian! 😉

[Peaklander]

I set-off this morning with great intentions to get the pinion installed and the axle fastened back in / up. First job was to make a bar to brace the pinion, so that the pre-load can be accurately set. That was easier than I thought because I had a spare length of wall plate tie-down bar. I drilled out a couple of holes that were already in the correct place and then ran the flap disc on it to give clearance for the socket which I think is 27mm.

 

 

The outer bearing must go into the case first, with oil applied and the oil seal has to go in the correct way round but it would fall out if reversed. I even oiled the leather that seemed very brittle. Presumably that was the correct thing to do.

 

Somehow I got involved watching Mike's video of the same job and before I knew it, the seal had been knocked nicely into place. Then I looked on the bench and saw the oil splash washer thing that I had missed out. He doesn't mention fitting it though. The seal doesn't come back out without damaging it, so now I will be going to Paddock's to get another but at least I'm ready to take all the unused shims back. I have £11.82 in total so by the time I have driven there and back with a new seal I'll be +/- nothing probably.

This afternoon I'll get the axle onto the floor and start to put the hubs and brakes back on, hopefully with no mistakes.

 

[elbekko]

21 hours ago, Peaklander said:

So I can add the crush washer and set the preload, which needs to result in a torque of 34.5 - 46 Kgfcm which has to be the weirdest non-SI measurement.

I'm guessing that comes from some non-metric-knowing American that just threw ft*in into google... It's just 46 Nm.

[Hybrid_From_Hell]

I am looking at that bearing puller ! 

 

Whilst we no longer work on Salisburys I am wondering if that might do for other bearings - the short nose head being an absolute bugger to remove ...

 

Could you please measure the OD and ID of a salisbury carrier bearing and let mr know - I think I can lathe up collars / spacers if need be, the kit I looked at also comes with 3 x bearing adapters ......I see a plan forming possibly !

 

Post up when you can after you've dug out the old ones lol !!

Nige

[Peaklander]

1 hour ago, elbekko said:

It's just 46 Nm

No I think it’s 46/9.81 Ncm. Not very much of a turning force.

Or my head is scrambled.

1Kg force = 9.81N

Edited March 2 by Peaklander
Added clarification??

[Peaklander]

@Hybrid_From_Hell the Salisbury carrier bearings are Timken 387A/382-S

These are imperial bearings measuring

OD 3.8125”

ID 2.25”

[Hybrid_From_Hell]

3 hours ago, Peaklander said:

@Hybrid_From_Hell the Salisbury carrier bearings are Timken 387A/382-S

These are imperial bearings measuring

OD 3.8125”

ID 2.25”

😎perfick - that’s tomm 1st jobbie 😎😂

[elbekko]

14 hours ago, Peaklander said:

No I think it’s 46/9.81 Ncm. Not very much of a turning force.

Or my head is scrambled.

1Kg force = 9.81N

... then the internet lied to me as well But you're right, inputting it correctly it gives this:

[Peaklander]

I get that.

1Kg force is that experienced by a 1Kg mass under acceleration due to gravity (9.81m/s/s) which is  9.81N

thus 46 Kg-f is 46 x 9.81 =  451 N

So 46 Kgf-cm is 451 Ncm which is 4.51Nm

My spring balance is marked in Kg anyway, representing increasing 1Kg forces when a pull equivalent to gravity acts on it.

So I can just pull at 46Kg at 1cm away from the pinion centre of rotation. Something like 15cm would need 46/15 = 3Kg on the spring balance pulled with a short bar.

I'm glad to get that off my chest.

Edited March 3 by Peaklander

[Snagger]

5 hours ago, Peaklander said:

I get that.

1Kg force is that experienced by a 1Kg mass under acceleration due to gravity (9.81m/s/s) which is  9.81N

thus 46 Kg-f is 46 x 9.81 =  451 N

So 46 Kgf-cm is 451 Ncm which is 4.51Nm

My spring balance is marked in Kg anyway, representing increasing 1Kg forces when a pull equivalent to gravity acts on it.

So I can just pull at 46Kg at 1cm away from the pinion centre of rotation. Something like 15cm would need 46/15 = 3Kg on the spring balance pulled with a short bar.

I'm glad to get that off my chest.

All correct.

[Peaklander]

I have made progress today but wow this axle is a bit of a beast to work on.

Firstly I walked into Mister Gearbox yet again and even though it was Monday morning, I had a brief catch-up and then Richard got to work on the carrier bearings. I had been careful to separate the shims across the two sides, can't have a mistake there.

What a lovely press. It has a fixed head, the pump is fastened to the header and there's nothing flapping around, unlike my hobby one. There was no heat or cold involved; they just pressed-on easily.

 

 

Then I had a reasonable drive to Paddocks where I picked up another pinion seal and the hub tab washers that I had forgotten and a stock of propshaft 3/8"unf nylocs.

Then I set-to with the pinion final installation, this time remembering to locate the oil plate thing and the paper gasket too.

 

 

The seal needs a big bearing race or something to knock it in. A hub box spanner works but is a bit small. I used a bit of Hylomar around the mating surface.

 

Then it was on to the pinion installation and setting of the pre-load. Now I have read about this and I have seen Brit. Rest's video. Even so, I would say that nothing prepared me for the difficulty in getting that crush washer to move enough to create the pre-load.

I started confidently with my holding steel on the the flange and started with the 1/2" long breaker and 32mm socket. It gets tight way before there is any preload. In fact there is no preload until just a smidgen before it comes on.

 

Before that though I had moved to 3/4" tools and it continued to get very tight.

 

Then this happened

 

So I searched for something else and found a better shape.

 

These bracing bars are located with a couple of nuts and bolts but they need to be secure and this means that each time you want to check the preload, they need to be undone. The weight of the steel interferes with the turning resistance unless it is vertical maybe. I just thought it better to eliminate it. A better design would allow it to be held into the flange but quickly removed.

Before the crush happened, I was leaning hard on a 1m pipe and the axle was trying to lift up and wander. It was a huge torque going on in fractions of a turn before I felt the pre-load and one check later it was done. About 2Kg at 20cm which I make as 40Kg-fcm.

 

The flange is stiff to turn with your hand. That's how much pre-load it is.

Next I need to install the carrier and check the mesh now that the bearings are fitted. Hopefully it is still OK.

 

[Snagger]

It is surprising how stiff the bearings are once set up - I went back and double checked the figures on numerous sources when I did that Rover diff.  Well done for getting so far!

It is a bugger to get that much torque onto the pinion nut.  I was a bit suspicious that the bar you used might not take it because of all the holes, but I didn’t expect that much of a bend.  The general principle of pushing down on the breaker bar with an extension is going to be the easiest, though you are limited by your weight.  A longer bar will still multiply that torque, though, if you end up dangling from the extension.  You really want the bar on the flange to be horizontal, not vertical, onto a block.  That way, its force from the pinion turning it will be straight down into the ground and the axle will be stable; if you have a diagonal or near vertical bar, the axle is going to want to walk across the workshop.

You must be very pleased to have got this far.