No Oil Pressure - AJP8 Auxiliary Drive Shaft Failure

[ukkid35]

I now have what is probably the last oil pump housing available in the country

I suspect that if anyone needs one in future, the only possibility will be buying a complete pump mechanism from an AJP8 that is being broken for parts due to a cracked block or similar

I reckon that will then be £1500 or so, however despite the possibility of electric ancillaries, that would probably be the only realistic option, and still likely to be very hard to find

If anyone suffers a seized oil pump in future, I recommend finding someone who can drill out the shaft from the oil pump end

The setup required in order to hold the piece (with the water pump casing still attached) would be quite a challenge/expensive/specialised, but almost certainly the best option

The problem was that the Woodruff key didn't simply get sliced in two as I've seen elsewhere

Instead the shaft became enlarged with debris, so when I attempted to press the shaft through the pump, the housing simply split

All for the sake of a £6 spring - which I had replaced within the last couple of years anyway

[ukkid35]

Rufus Roughcut said:

Did you manage to save the Impellers? ....every cloud and all that.

Small nic in one of the impellers sadly

I doubt it will cause any significant imbalance, remember that the oil pump rotor outer is an eccentric, so I will forgo the opportunity to spend another £240 on a replacement

[ukkid35]

Jhonno said:

Have you thrown the cracked one away yet?

Next time I get some stuff blasted and coated, I'll add it to the batch for cleaning - and then it will make a perfect paper weight

[ukkid35]

Pleased with the work done by the mobile welder, but did all the finishing myself to save money

Getting the surface perfectly flat was more time consuming than I expected

[ukkid35]

[ukkid35]

spitfire4v8 said:

Elegant it ain't.

Only because of the coupling to the ZF PS pump

If they had designed their own PS pump and mated it directly to the oil pump using the same shaft then that would be very elegant, but a significant extra cost

It is also essential to protect the PS coupling from debris that can fall in and jam the mechanism, that is most definitely a design fault

[ukkid35]

I like the concept

Here it is used on what I think is a Ford Cosworth DFV, admittedly belt driven

[ukkid35]

gruffalo said:

How did you deal with all the scoring?

There was a little scoring on the rear most part of the oil pump housing, which is also the PS bracket, I was able to polish that out

Everything else that was damaged is new except for the drive gear

[ukkid35]

Here's a Judd AV from 1989 that I think was used in the Indy 500

This appears to be either chain or gear driven

[ukkid35]

Jhonno said:

Didn't fancy going electric PS whilst it was all apart Paul?

The PS pump weighs but a few ounces, a pound at most

The Saxo pump weighs nearly as much as me, and requires a lot of additional cabling, and takes up ten times as much space

Using power from the alternator, and then converting it back to mechanical energy probably means a loss of at least 50% efficiency relative to a direct mechanical drive

Sorry, but I'm not a fan

However, I will make sure to use the PS coupling cover that a very generous PHer sent to me

[ukkid35]

Jhonno said:

Yeah the Saxo pump is a bit bigger, but only requires 6 wires, and a relay.

I would say, given that manufacturers are all switching to electric PS in the name of efficiency, that they are are probably better compared to mechanical pumping losses.. They aren't a massive drain on the alternator, I will have to measure mine now!

But aren't they mainly electrically operated steering columns, rather than hydraulic racks with electric pumps?

And I bet it's nothing to do with efficiency, and all to do with cost

[ukkid35]

Jhonno said:

there is a fuel saving in the region of 0.3 l/100km (or an extra 3.75 MPG)

I feel sorry for anyone who converts a Cerb to electric PAS expecting a 20% improvement in fuel economy

I had had the dubious pleasure of driving home from Zolder with no PAS, and there was no perceptible difference in fuel economy

I do appreciate that on a small engined daily hydraulic PAS, aircon, heated seats etc are all going to affect economy

The Cerb fuel economy is so poor, that when I brought the Cerb back from Germany on the back of a truck, the truck used less fuel carrying the Cerb than the the Cerb would have done by itself

[ukkid35]

This is the best possible protection from Aux Shaft failure





Not my work, this was made by a very generous PHer who sent his prototype to me FOC

[ukkid35]

mrniceguy351 said:

How is that attached?

It's simply a spring fit

It's been in place for several years so I'm confident that it works

[ukkid35]

My neighbour (and his wife) are doctors who work in the local hospital

I don't know what their specialisations are, but he has been working in ICU

We sometimes chat in the garage because he has the space next to me where I am often under my car

The pic was from a few hours before we spoke, the crane is in his parking space



Last Thursday evening I asked how he was finding work, and he was obviously somewhat fatigued

He said three things that I found very interesting

1. There was currently no problem with PPE where he works
2. Nevertheless, he was still very concerned for his family's health as the continuous exposure to affected individuals not only raised the likelihood of him becoming infected, but more importantly the viral load would make it more serious and potentially life threatening despite his age/health profile
3. He was aware of a case of re-infection

The last point is a massive worry if true and not a mistake or simply a rumour, I didn't press him for details as I didn't want to seem skeptical and potentially rude

If true though it really is a total game changer

[ukkid35]

My gf helped me put the engine back in a couple of hours earlier

Still needs a lot of work putting the gbox back and fitting exhaust, cooling, and induction

Wonder whether my preferred MOT centre will still be open by the time it's finished

[ukkid35]

Not taking any chances with the Reverse Switch wiring after it melted last year



But I haven't replaced the release bearing even though I have a spare bearing

It spins freely, but there is lot of wear where it presses on the fingers

I didn't want to disassemble the entire assembly as I don't have any spare seals and didn't want to risk damaging them

I hope I don't end up regretting that

[ukkid35]

More heat shielding, this time for the PS hoses

[ukkid35]

pmessling said:

I'm here if there is enough interest. Just got to finish off stainless steel fuel filter and fuel pump mounts.

I definitely like the look of that pump mount, but I need to ensure that I can include some rubber mounts as the original fittings welded to the chassis are damaged on my car

I would be wary of any additional sleeving that might increase the chance of it overheating

Please PM me with a price when you have a chance - thanks

[ukkid35]

A new gearbox/clutch fixed the starter motor

Perhaps if I'd tried cleaning the old mechanism I would have saved myself £70