No Oil Pressure - AJP8 Auxiliary Drive Shaft Failure

[CerbWill]

Ingenious!

[ukkid35]

Not sure what to do now though

Can't get the PS coupler off because I can't reach either the large or small grub screws which are opposite each other

Perhaps I can double nut the studs, remove them and turn the housing to expose the grub screws?

[ukkid35]

TwinKam said:

Well done Paul!
Did it take a lot of force?
Rik

Not a silly amount, I didn't check but I would guess about 15-20 ftlbs

I was using a 1/2" wrench about 10" long to tighten the M10 bolts

The only thing holding it was the sleeve that you can see in the last pic but one, whose only purpose seems to be to fit in the seal that I've already removed from the front part of the pump assembly

Not sure why it is separate to the shaft itself - it's not part of the water pump seal assembly

https://tvr-parts.com/tvr-parts/part-details/tvr-e...

So what is it, and where do I get one, assuming I need to replace it?

[ukkid35]

[gruffalo]

Bigger, what are your options?

Are pumps available new?

[Rufus Roughcut]

Is it the bearing in this photo that has failed?




causing the shaft to wobble and chew the housing.

[gruffalo]

It sounds like it was a broken part of a pressure relief spring got in there.

Not sure if they are available anymore.

[gruffalo]

ukkid35 said:

The gear like part of the pump is available.

Looks like the rest needs welding to build it up and then machining back.

Or try the usual breakers.

[CerbWill]

Hmmm. Electric PAS has been done. Aide has an electric booster pump for cooling and I'm (fingers crossed) about to see how a bigger pump fares as the sole coolant pump when my car goes for mapping. I wonder if an electric oil pump could supply the needed pressure.

[Rufus Roughcut]

I've had a quick scout around the internet, certainly there are pumps for water and oil that are more than capable of doing the job.

Haven't looked into the cost of such devices though

[TwinKam]

All those electric pumps need feeding and that will entail an upgraded alternator for a start, in an area where space is already tight. Plus the wonderful thing about engine driven oil and water pumps is that they by very definition increase flow proportionally without the added complication of controllers...
So I think this is over-thinking and over- complicating the matter somewhat. KISS! There are surely s/h pumps (and parts of pumps) lying around under benches at places like Powers and Readman Racing...

[Rufus Roughcut]

I agree, 25A water pump, 25A oil pump, 30A power steering all adds up.

I was bored.

[Jhonno]

Electric water/ps pump fair enough. Not sure I'd trust an oil pump..

Running an uprated Denso alternator in my Cerb and no issues with charge, with my electric PS.

Waterpump to go fully electric, look at TinyCWA and the Pierburg CWA400..Aide runs a CWA200 as a secondary pump successfully, but it wouldn't have the capacity to run by itself. Would have the advantage of getting rid of temp spikes.

[CerbWill]

I've got a CWA400 as the sole coolant pump. I upgraded the alternator to a 120A item just incase. When I get round it I want to add some sort of current logger so I can see what the power draw of the pump is in various scenarios but I suspect when driving normally it is quite low. PAS pump demand would, I think, be quite low but an oil pump would obviously be a continuous large power draw.

Either way I think the easiest and cheapest option is a 2nd hand mechanical pump.

[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

[Rufus Roughcut]

Nice one Paul,

Fingers crossed it doesn't happen to anyone else, I'm guessing spark erosion would have got that shaft out without damage to the housing.

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

[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

[Jhonno]

Ouch Paul! Bad luck there..

I'm just wondering if the housing could be recreated..

Have you thrown the cracked one away yet?

[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

[Byker28i]

I have a couple of holed pistons I use as a pen pot on the desk. I did make a desk lamp from a 2.8i Cologne camshaft I wore the lobes off but that got sold as my wife thought it was too much.