K Series Spigot Bearings - There must be a better way!

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revilla
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K Series Spigot Bearings - There must be a better way!

I've probably posted on this subject before...

Getting old spigot bearings out of K Series crankshafts.

When putting them in you need to heat the crank and freeze the bearing and spacer sleeve. By the time they're banged in and the temperatures have equalised they are SERIOUSLY tight.

I've tried three leg bearing pullers. It was just a question of which broke first, the back edge of the bearing or the puller.

I've tried all the hydraulic tricks with thick grease or even wet bread; you pack the space behind the bearing with something then hammer a close-fitting bolt or shaft into the centre of the bearing, the pressure being transferred to the back of the bearing driving it out - in theory, I've never managed to move one at all.

I've tried slide hammers, no joy.

I must have done seven or eight of them to date. Had to do another one yesterday. I was determined to get this one out with resorting to the usual levels of extreme violence, so I fitted a slide hammer into the bearing, put a heat gun on the end of the crank until it was far too hot to touch, then turned an air duster spray upside down and squirted propellant into the bearing. That gets you about -30°C or something, you need to wear gloves to avoid serious frostbite. The plan was to try to shock cool the bearig to loosen it a bit. I then went at it with the slide hammer as quickly as I could.

I counted 200 strokes of the slide hammer (with occasional cooling topup shots) before it broke. I was going at it as hard as I could. In the end the expanding collet on the end just chewed and bent. The bearing still hadn't moved at all.

So in the end I had to use the same technique I've ended up resorting to on every other one I've done (apart from the one where I tried to cut it out with a die grinder and cost myself a crankshaft).

Basically I used a sharp chisel and hammer to smash the front face of the bearing casing until I could get the mangled needle roller cage out, then used a cold chisel and a hammer to cut a groove down the length of the casing of the bearing, trying to avoid cutting through the spacer sleeve into the crank metal, which is hard when you're giving it hell with a big hammer and sharp chisel. In the end you can weaken the bearing case enough to allow you to hammer a sharp spike in between the bearing case and the spacer sleeve at several points until it partially collapses inwards until the mangled bearing case can be extracted.

After than you hammer the spacer sleeve inwards until that too collapses and comes out.

After that it's a case of cleaning out the hole, taking off any rough edges with wet and dry and hoping that you haven't done too much damage!

Having done a few, in this case there was only a bit of superficial marking behind the bearing and after a cleanup it was fine to install a new sleeve and bearing.

I've got it down to a fine art but I absolutely HATE having to do it! It really doesn't feel like the right way to treat a crankshaft.

I haven't yet found a better way they works though.

Any ideas beyond the standard tricks?

Thanks,

Andrew

paul richards
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Hydraulic method using tiny pieces of newspaper soaked in water. Works for me. 

Paul Richards

LADS Joint AR  Drink

I thought 2020 was the year that was going to give me all I wanted. It turned out to be the year to make me appreciate what I've got.

aerobod
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With the hydraulic extraction method, ensure the crankshaft you are extracting from doesn't have an oil galley plug at the bottom of the spigot recess. I'm not sure if any engine used in a Caterham has, but certainly with some GM engines that is the case (specifically the Corvette engine and other small block v8s). Using the hydraulic extraction on that type of crankshaft will destroy the oil galley plug or worse still cause it to leak all engine oil out through the spigot bearing, when the engine is started after the clutch has been refitted. Will most likely require a crankshaft out repair, possibly a new crankshaft if that plug exists and is damaged.

James

ECR
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I haven't done that many, but as I recall, smashing the bearing out isn't too much of a problem, it's getting the sleeve out without damaging the crank that's difficult.

If I had to do many I might look at turning up a drill jig to locate on the spigot on the end of the crank and bolted to the crank to stop it moving. The jig would have 2/3 holes in it just covering the edges of the sleeve. I'd then try a small end mill in a drill to cut c shaped slots in the sleeve thus weakening it as you do with the chisel method but by using a jig removing the possibility of crank damage

If it worked, relocating the jig a few times would nearly machine the sleeve out....

This assumes that the sleeve isnt hardened of course
.

Don't know if it would work and it requires a bit of investment in a jig to try it

oilyhands
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I usually lever out the needles and then use a Dremel to cut a slot down through the bearing case and sleeve, a fine tipped screwdriver does the rest.

Oily

Bricol
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I would have thought something along the lines of 

https://www.sykes-pickavant.com/products/pullers-and-separators/mechanical-pullers-and-kits/856

But use the "pulling unit" not the slide hammer.  Pull it out, not shock it out.  If you're doing a few, a bespoke arrangement to sit securely on the end of the crank might be in order.

I'm more used to slightly large bearings in my designs - had to remove, without damage, a pair of rather large taper rollers (2 grand plus each) - two bent pullers later, a more bespoke design took 15 tonnes to get 'em out.  Eased out slowly and damage free - phew!

GPBox
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I've replaces 2 over the years...both occasions used this (I think) First motion shaft...kindly donated on a visit to Road and Race for a gearbox refresh a few years back.....pack grease into the hole w/Spigot bearing....insert shaft couple of good smack....comes out very easily (the 2 previous bearings in the pic too....very cool ...it's a bit heavy but happily post if would help...

 

 

 

 

 

 

Livin' the R400K 'screamer' dream....

revilla
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An update:

I had to cut another one out today.

I tried packing it with grease. I borrowed a first motion shaft as described above. Not a chance of it moving. I tried a(nother) slide hammer. Hammered until it broke. Nothing moved. Tried a bearing puller. No joy. So had to resort to violence again:

The reason I had to remove it is because I fitted it for somebody else and he then found that his first motion shaft wouldn't actually fit into the bearing, it was too tight. Luckily he used an old first motion shaft as a clutch alignment tool and found the issue before he actually tried to drop the engine into the car.

So I took some measurements to find out what was going on:

The Ford (INA) bearing is (as close as I can measure with vernier calipers) 21.08mm outside diameter. This fits with Ford quoting 21.00m for the hole in the crank. That leaves a 0.08mm diameter interference fit.

However, the inner diameter of the sleeves I'm using is only 20.90mm, which increases the interference to 0.18mm which is a lot. Ordinarily the sleeve may stretch a bit, but looking at the interference between the sleeve and the crank, the situation is even worse.

The crank hole inside diameter as best I can measure is 21.80mm (I measured across a few cranks). The spacer sleeve outside diameter however is 22.16mm leaving 0.36mm interference.

All in all, using a standard 1.8 crank, a good Ford/INA bearing and the sleeves I have here there is about 0.54mm too much metal one way or another. If you heat the crank end with a heat gun and freeze the bearing and sleeve, they still go in with a bit of effort but once the temperatures even up they are hopelessly tight, to the point where they crushing the bearing until it is tight on the first motion shaft and almost impossible to remove.

A friend remembered that the wall thickness of the spacer sleeve was originally 0.5mm. I measured mine at around 0.60mm wall thickness. Cross-checking this with half the difference between ID and OD that came out as 0.63mm.

So it looks like the spacer sleeves currently being supplied nowadays (through Redline, I guess sources via Caterham) are just too thick, which is causing me all of these problems. Older installed bearings probably will come out with the various tricks suggested above, but ones I've installed will not in a month of Sundays.

For now I'm going to try spinning the sleeves on a mandrel and sanding them down to a more reasonable fit.

Any thoughts?

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

Bricol
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Can't imagine sanding with reduce them concentrically or true - they need grinding properly.

I've only ever bought and fitted one sleeve and bearing - I can't remember where from, but I will try to look it up - it went in with no particular hassle, no heating of crank.  Maybe I just have a bigger hammer?  But then no issue with the gearbox either.

elan_fan
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Isn't it one for a twincam? Try one from qed. Also the early fords had a bronze oilite bush. Wonder if one made like that would be ok. The od was bigger on the bronze bushes. I machined the id on one for my dad on his Ford Classic and it was good for many thousands.
 

best regards 

Mark

revilla
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@elan_fan Good call on QED ... they are about 4 minutes from my house! I'll nip round and see if I can pick one up and measure up to compare, thanks.

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm