Thread: Why do 2.7 cranks break?

Originally Posted by BradC

How are you measuring the O-ring? I'm measuring it by closing the calipers until there is a slight drag on the jaws. Confirmed by looking for light between the O-ring and jaws. Otherwise I can just squeeze it down with the calipers. Measured like that, the OD of the new and unused MAHLE filter O-ring I have here is 11.05mm and the Ford is about 11.0.

We really need the orifice it inserts into to be measured to be meaningful given the Spigot measures ~10.07mm.

Undersized would be good wouldn't it? It allows the seal to expand a whisker when tightening & I see that as a good thing.

Originally Posted by 4bee

Undersized would be good wouldn't it? It allows the seal to expand a whisker when tightening & I see that as a good thing.

Not really. It's an internal O-ring seal, so you want the ring to compress into the hole to provide the seal.

I've popped out the Mahle O-ring I have here.
Spigot :
ID : 7.28mm
OD : ~10.1mm

O-ring :
OD : ~11.05mm
ID : ~7.2mm
Thickness : 2mm.

That shows my measurements must be off as 7.2 + 4mm > 11.05mm

Originally Posted by DiscoDB

Received the MANN oil filter today. The OD measured across the o-ring on the spigot was 11.1mm

Removed the MAHLE filter - oil had already drained to the level of the drain hole (which is meant to be plugged by the spigot). But was happy to see it was completely flooded above the anti-drain valve.



By the way - this is fresh new oil that is already black from less than 1 hour of running - just shows how much oil is left behind during an oil change.

The OD of the MAHLE filter o-ring was 10.8mm.

This difference is only a fraction of a mm but exactly what people reported on Lr-club.com.

The MANN filter locked in nice and firm when fitting. Will have to get a Ryco filter next time to compare.

Normal 4 secs for oil light to go off first time, and then on re-start goes out as engine is cranking. After the weekend will park the car up for a few days to see if there is any change with the oil light off time.

Meanwhile some more photo’s.

First is the hole in the housing just below the rubber seal. When you open up the filter 4-5 turns this not only lifts the filter element up and out of the drain hole, but this small hole in the housing is also exposed and allows air in so it drains off.



Next is the blocked filter bypass. As Brad suspected it does appear to be in the top of the housing cover itself. Does not look to be serviceable.



The photo is difficult to see, but it does look like a match for a typical bypass valve, but would have to pull out to truly know.

Interesting - this is getting good. Yes the filter housing only drains to level of the bung so there’s half a cup of black left over and you never see the NRV inlet submerged under it.

So, theoretically, if the filter was blocked the bypass would allow pressurised oil surrounding the filter into the middle section at the top where the opening of the spear is to complete the circuit?

I just remembered my new oil cooler came with a new filter cover and filter I dumped in a box. I used the old filter cover and a new Mahle filter because the old cover has the yellow LR markings on it whereas new one is black. Here’s what I found;

The 3 Amigos - when I extracted the filter out of the housing the bypass widget actually pulled out with it. Maybe a good choice reusing the LR original. Same bypass spring design as the NRV on the inlet side.



Widget top view



Widget side with galleries to allow oil flow from outside to the centre as per the theory above.

This are the tangs that grip onto the top of the filter. This butts right up to the open top of the spear that the filter sits over.



Inside housing sans widget. A series of teeth that clip into the top of the widget.



Filter can slide right up to top of widget collar.



When you undo filter cover it withdraws to this point then lifts up filter. This is what you are fighting to prise it out of the cover each time you change it.

Originally Posted by BradC

How are you measuring the O-ring? I'm measuring it by closing the calipers until there is a slight drag on the jaws. Confirmed by looking for light between the O-ring and jaws. Otherwise I can just squeeze it down with the calipers. Measured like that, the OD of the new and unused MAHLE filter O-ring I have here is 11.05mm and the Ford is about 11.0.

We really need the orifice it inserts into to be measured to be meaningful given the Spigot measures ~10.07mm.

I agree it is hard to compare measurements taken by different people, so assuming you are consistent it is the absolute difference that is more telling.

In my case, I adjusted the verniers until I could pass over the o-ring with just a slight grab on both sides.

So where I was getting contact on both sides at 11.1mm with the MANN, there was an air gap with the MAHLE and I had to reduced to 10.8mm to get the same “feel” in contact.

At best these values would be +/-0.1mm and as you previously noted could all just be within manufacturing tolerances.

The real test will be to see what happens after being parked up for 3-4 days. 🤞🤞

When you pull out the old filter it does feel like you are going to break something.

So if the widget (I like that name) was accidentally pulled out and thrown out with the old oily filter, then someone not understanding how this is set up could refit a new filter with no bypass valve at all, meaning you would always get oil bypassing the filter.

Something else Ford forgot to warn it’s customers about when it wrote up the technical manual.

Originally Posted by DiscoDB

with the MAHLE and I had to reduced to 10.8mm to get the same “feel” in contact.

How long had the Mahle been installed for?

Originally Posted by PerthDisco

Interesting - this is getting good. Yes the filter housing only drains to level of the bung so there’s half a cup of black left over and you never see the NRV inlet submerged under it.

So, theoretically, if the filter was blocked the bypass would allow pressurised oil surrounding the filter into the middle section at the top where the opening of the spear is to complete the circuit?

That looks about right. Same on a spin-on with the relief valve is at the far end of the media. See, lots of valuable teardown information in this thread. Was your replacement cooler a Nissens?

Any chance you have a set of verniers and could measure the hole the spigot on the filter pops in to?

Originally Posted by BradC

Not really. It's an internal O-ring seal, so you want the ring to compress into the hole to provide the seal.

I've popped out the Mahle O-ring I have here.
Spigot :
ID : 7.28mm
OD : ~10.1mm

O-ring :
OD : ~11.05mm
ID : ~7.2mm
Thickness : 2mm.

That shows my measurements must be off as 7.2 + 4mm > 11.05mm

Aaahh, ok.

Thanks Brad.