Onto the conrod bearings (TDI)

[manic]

I've got the sump off, dropped the ladder frame (200 TDI), looking at the big end bearings.

With a motor that's done ~500k and starting to get low oil pressure at hot idle, I am mentally preparing myself for an engine out rebuild. But if I am lucky and crank is in good nick this will be a sump off/on job to get back on the road ASAP.

I have big end shells #1 and #4 out, and so far so good. Certainly over due, but crank is smooth. I know there are measurements to observe but I'm on my back without a micrometer so I am going to go by eye/feel/sound on this one.

Now waiting for the replacement bearings to arrive.....

Should I need to take the engine out I will do it all by the book, BUT whilst I have sump access is it worth replacing just the lower MAIN bearings on caps 1 - 4?
https://www.aulro.com/afvb/images/imported/2018/06/216.jpghttps://www.aulro.com/afvb/images/imported/2018/06/217.jpg

[bee utey]

You can usually get the upper shells out too, just refashion a suitable split pin to fit into an oil hole in the crank and stick up about 3mm, then rotate the crank to push out the shell. Same maneuver to get it back in.

[rangieman]

Do em all one at a time[wink11]
I did my 300 in situ i just pushed them out from the opposite side enough to grab with some pliers easy as to do[thumbsupbig]
And i mean the (Big Ends) the main`s should be fine as they don`t cop a hammering like big ends[wink11]

[roverrescue]

My only concern with playing with the mains is disrupting the flaky rear main seal/ t-seals
10:1 if you don’t have a leak now you will soon after!

I’ve only stripped a few high mileage 300s and on them the Conrod big end shell wear far exceeded the mains. In light of minimal wear on the shown shells I would be thinking of not touching the mains

Steve

[manic]

1 and 4 conrods done. Onto 3 and found this (see photo)

First four shells out the bag were as expected and fit fine (plastiguaged), the last four have a hole in them. What have I got here?https://uploads.tapatalk-cdn.com/20180623/d72f1e8798934f39e915a1d8f317a913.jpg

[donh54]

First things first, never replace one half of a bearing! All the oil will tend to migrate to the loosest part, and starve your nice new bearing shell of lubrication, ensuring its' early demise.

The hole is for oil to flow through onto the bearing face.

The tab is to locate the bearing shell within the conrod big end. If you are only replacing the bottom shells (bad idea!) then those shells are for the top side. Push a conrod and piston up the bore a bit, and you should see the cutout and oil hole in the existing shell. The shells can only go in one way, due to the tab.

[manic]

Erm, look at my earlier photo of 1 + 4 bearings removed. No holes top or bottom.

The last four shells in the bag were inline to service conrods 2 + 3, but they have bloody holes in them. Ive got the wrong set clearly.

[manic]

OK so I ordered RTC2993 for my TDI but it looks like I received bearings for a 2.25 diesel (RTC7139)

The 2.25 bearings have the hole on the upper bearing shell, the 2.5's are solid uniform.

Supplier is telling me that I have the best bearings for the job, that the hole is of no consequence, and that I should install the holed bearing in the bottom position.

What do you lot think?

[gromit]

First things first, never replace one half of a bearing! All the oil will tend to migrate to the loosest part, and starve your nice new bearing shell of lubrication, ensuring its' early demise.


In a hydrodynamic bearing the shells shouldn't touch the journal, the load is carried by the oil between the surfaces.
The only time it should touch is on startup (no oil pressure). A worn shell bearing creates a bigger gap so the oil flows out more freely so you run lower oil pressure, plenty of lubrication but might be possible for the surfaces to make contact.
The 'white metal' (Babbitt) surface is soft and any particles get embedded, long term the white metal is worn away down to the copper backing.
The Science Behind Modern Performance Engine Bearings (http://dsportmag.com/the-tech/the-science-behind-modern-performance-engine-bearings-simple-complexity/)

But I'd agree, you only change both halves of the bearing.


From the supplier's comments the 2.25 has oil squirters in the conrods hence the hole to let oil up the conrods, doesn't the 200TDI have them ?? Looking at your pictures it doesn't so the supplier has suggested putting the ones with the holes in the caps so you get a full surface area in the highly loaded shells in the conrod. If they are exactly the same size I can't see a problem.


Colin




Colin

[justinc]

Its of no consequence in a tdi... however in a 2.25 that hole MUST be there😅

[manic]

Tdi shells fit backside dry, journal side lubed. There is no need for a hole in the bearing shell, they are oiled by a hole in the journal.

So it seems wrong to fit the 2.25 bearings with the hole, but supplier is convinced they are equally effective..

[manic]

Its of no consequence in a tdi... however in a 2.25 that hole MUST be there[emoji28]Hmmm. If truely no consequence, why did landrover delete the hole in the bearing, they could have continued using the old 2.25 bearings?

[bee utey]

Hmmm. If truely no consequence, why did landrover delete the hole in the bearing, they could have continued using the old 2.25 bearings?

Cost.

[manic]

Ok ok. I was trying to dig up alternate opinion, but it seems the supplier is entirely right. Im still miffed I was given 2.25 bearings when I ordered OEM for tdi.

Final check, no one disagrees with this statement:

Swapping an OEM TDI bearing shell for the 2.25 bearing with a hole punched in it will effect absolutely no change in oil pressure or rate of bearing wear, is no more likely to fail or score the journal when flogged, and the hole is not going to allow oil to get behind the shell in a way that might cause any adverse effects.

[gromit]

Tdi shells fit backside dry, journal side lubed. There is no need for a hole in the bearing shell, they are oiled by a hole in the journal.

So it seems wrong to fit the 2.25 bearings with the hole, but supplier is convinced they are equally effective..

Both the 200TDI & 2.25 are supplied oil through the hole in the journal. On the 2.25 the hole in the shell bearing is to supply oil up a drilling in the conrod to squirt oil up the bore/under the piston.
The hole should have no effect in the TDI but as suggested put the shell bearings with the hole into the caps not the conrods (shouldn't really make a difference anyway). The only difference is the loss of surface area due to the hole so less white metal to collect dirt particles.

Have the TDI shell bearings been discontinued or is it to do with supply & demand ? If the only difference is the hole then as time goes on the economics of producing two different sets of shell bearings when one covers both applications comes into play.


Colin

[manic]

Have the TDI shell bearings been discontinued or is it to do with supply & demand ?


This is my next question also. The supplier claims it is harder to get the 2.5s in lead copper. But they rebuild both engines so I can see why they would be happy to only buy in the 2.25 bearings.

Im now on the hunt for lead copper bearings for the 2.5 RTC2993. Ive been led to believe the best option are the King Bearings made in Isreal (not india).

[gromit]

Best of luck, most supplier don't seem to list where they come from.

King Big End Con Rod Bearings CR4405CP STD For LAND ROVER 2.5 DIESEL | eBay (https://www.ebay.ie/itm/King-Big-End-Con-Rod-Bearings-CR4405CP-STD-For-LAND-ROVER-2-5-DIESEL/112567408071?hash=item1a358a55c7:g:j3kAAOSwL5BZvtE O)

Turners list them as well.

Colin

[manic]

Best of luck, most supplier don't seem to list where they come from.

King Big End Con Rod Bearings CR4405CP STD For LAND ROVER 2.5 DIESEL | eBay (https://www.ebay.ie/itm/King-Big-End-Con-Rod-Bearings-CR4405CP-STD-For-LAND-ROVER-2-5-DIESEL/112567408071?hash=item1a358a55c7:g:j3kAAOSwL5BZvtE O)

Turners list them as well.

Colin

Turners are sending out 2.25 bearings even if you order the 2.5, I've told them to update their site.

Since last post I received OEM RTC2993, genuine King, supplied by Bearmach which I was assured would be confirmed as copper lead before shipment. But no, I received the aluminium variant - CR4405AM. Got to keep them with a refund. Any one want them?

[gromit]

Turners are sending out 2.25 bearings even if you order the 2.5, I've told them to update their site.

Since last post I received OEM RTC2993, genuine King, supplied by Bearmach which I was assured would be confirmed as copper lead before shipment. But no, I received the aluminium variant - CR4405AM. Got to keep them with a refund. Any one want them?

Need some for a 2.25 but don't know the size until I drop the sump.

PM sent.

Colin

[manic]

Hey Colin, will see what I have left over when jobs done. I might still use the copper 2.25 king bearings for the 300tdi seeing as Turner Engineering are doing it. Right now I only have the aluminium king 2.5 bearings to give away. STD size

For anyone interested a simple graphic shows merits between the two:

Aluminium based as supplied OEM Bearmach:
K-783http://www.kingbearings.com/material-type/aluminium-based/

Copper based as supplied by Turner Engineering
K-794http://www.kingbearings.com/material-type/copper-based/

Pros and cons there, but for my 200tdi, this time round at least, I'm keeping it copper.

Seeing as bearmach label them OEM and have seen them listed here in Auz for over $100, I guess they should be good enough for a couple of hundred thou. Any one want them?

[manic]

I finally got the bearings I was after.

Purchased from Lithuania, made in Isreal, you might find the listing on ebay if you search for CR4405CP
King confirmed as authorised re-seller. Looks legit, heavier than the aluminium bearings.


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