BIG END BUSH REPAIR . IS IT POSSIBLE ??

[gofer]

hi folks.
i'm 64 and grew up in an era when there was room to work around an engine in a car :-))
pre computers etc.
my old man was an "a" grade mechanic, did everything. not like todays specialists.

so, imagine a td5 stopped on side of road in middle of nowhere. driver pulled up because of a loud knocking noise. he has loads of spares and tools etc for "just in case " - "murphys law "
no mobile signal. thank you telstra.
goes through all the possibilities etc and concludes that a big end has gone. ( the why doesn't matter )

is it possible to change over big end shells working from below ?? my memory cells tell me i did something with leather as a temp repair many many moons ago.

on the same note, is it possible to change over a piston /conrod etc working from below ? ?
i'm not talking about the crankshaft bearing etc. that would be impossible me thinks.

food for thought.

thanks
gofer. :-)

[alien]

Have good look at the harmonic balancer /damper as they are known to break and make bad rattle.
Use the search box down the left bottom of the page to find previous threads on the subject.

[PhilipA]

I think it's a "hypothetical"

Regards Philip A

[p38arover]

is it possible to change over big end shells working from below ??

Dunno about the Td5, but I've done it on the V8.

[Pippin]

Dunno about the Td5, but I've done it on the V8.
You can, Sump, Oil Pump and your there.

[gofer]

You can, Sump, Oil Pump and your there.

ok. thats the easy bit.
what about piston / conrod. ?? i've done it on diesel engines in boats. can it be done in td5 ?
gofer. :-)

[Pippin]

ok. thats the easy bit.
what about piston / conrod. ?? i've done it on diesel engines in boats. can it be done in td5 ?
gofer. :-)
No it has to go out the top.
Nick

[p38arover]

what about piston / conrod. ?? i've done it on diesel engines in boats. can it be done in td5 ?


Why would you want/need to remove the piston/conrod assy to change the big end bearings?

[bblaze]

rolled a set of crank bearings in more than once on bigger diesel but never a td5, just put a T shaped split pin in the oil gallery and roll the crank until the old shell comes out and then wind the new one in.
cheers
blaze

[kelvo]

You can replace the big end bearing shells from underneath. That is how the LR workshop manual tells you to do it. The engine stays in the car and the head doesn’t need to be removed.

I’ve been contemplating replacing mine as a preventative maintenance measure (It has currently have 295,000Km), but I’ve never heard of a big end failing on a Td5.

You would need to remove the head and the sump to remove a con rod or piston.

[Pippin]

You can replace the big end bearing shells from underneath. That is how the LR workshop manual tells you to do it. The engine stays in the car and the head doesn’t need to be removed.

I’ve been contemplating replacing mine as a preventative maintenance measure (It has currently have 295,000Km), but I’ve never heard of a big end failing on a Td5.

You would need to remove the head and the sump to remove a con rod or piston.
You have now! I pulled down a TD5 engine yesterday that I replaced with a spare to find little of the bearing left on No.4140352

[Tins]

I've certainly done it from underneath on other engines. Thing is, if it's truly knocking it's probably too far gone to be fixed with new bearings.

I agree about checking the balancer. They really make a racket.

[Tins]

You have now! I pulled down a TD5 engine yesterday that I replaced with a spare to find little of the bearing left on No.4140352

Ouch. What's the journal like?

[theelms66]

I reckon your pushing it all uphill from here

[Pippin]

Ouch. What's the journal like?
Not good but the rest of the engine is very good including the piston and cylinder. I think a replacement crankshaft if it can't be saved and con rod and it will be good to go.
Nick

[Tins]

Not good but the rest of the engine is very good including the piston and cylinder. I think a replacement crankshaft if it can't be saved and con rod and it will be good to go.
Nick

A bearing that's run like that one would have caused a loss in oil pressure. What are the others like?

[kelvo]

You have now! I pulled down a TD5 engine yesterday that I replaced with a spare to find little of the bearing left on No.4140352

Not much left of that one :eek2: How many km on the engine? Any loss of oil pressure?

[JDNSW]

Many years ago (1963) I ran across a bloke driving round the gulf country in a Holden that seemed to be running very rough. I asked him about it, and he pointed out the piston and conrod on the back seat - it did a big end, so he pulled it out and kept oil pressure by wrapping the journal with a bit of a tin can and binding it with tie wire.

[Pippin]

Not much left of that one :eek2: How many km on the engine? Any loss of oil pressure?

I bought it with 265K on it very cheap with what I thought was a bent rod. Oil pressure was still good amazingly, perhaps because the oil way was sealed by the bearing that the rod was turning on. I must admit I'm surprised how good the rest is.
Nick

[djam1]

Back in the 1960s a friend of my father in law repaired an old morris or similar on the side of the road by making big ends out of a saucepan it worked fine and continued its journey around Australia.
When it was pulled down it was in amazingly good condition with the alloy embedding itself into the scored crank.

The pressures in a TD5 will be vastly different than a morris engine though

[Roverlord off road spares]

I reckon your pushing it all uphill from here

best find a nice grade on a slope, then it's down hill all the way, better than pushing uphill.

[87County]

Many years ago (1963) I ran across a bloke driving round the gulf country in a Holden that seemed to be running very rough. I asked him about it, and he pointed out the piston and conrod on the back seat - it did a big end, so he pulled it out and kept oil pressure by wrapping the journal with a bit of a tin can and binding it with tie wire.

I have seen an engine which evidently had a similar problem - in the case I saw they packed a leather patch on the crankshaft where the missing big end went and held it in place with a jubilee clip around it. It worked this way on a farm for many years apparently.

[lyonsy]

Very few engines will let ya pull a piston and rod out from underneath as they have counter weights on the crank you cant get the piston past. Really old cars quite often dont have counter balancers on the cranl that will allow you to drop a puston out the bottom.

But a lot of stuff you could do back in the day wont work now as engines have much higher compression putting too much load for stuff like leather bearings

[JDNSW]

Not so much the compression as the high engine speeds and better breathing. Highest loads in any engine are from the power stroke and the reversal in direction twice per revolution. Compression load is much lower - remember that the pressure in the cylinder, and hence the load on the piston and big end is much less at the end of the compression stroke than it is a short time later when the fuel is burnt to increase the pressure for the power stroke.

Another factor that increases the load is the modern tendency to put turbochargers on everything - this enables more charge in the cylinder and as a result, increased combustion pressure.

[Bigbjorn]

Very few engines will let ya pull a piston and rod out from underneath as they have counter weights on the crank you cant get the piston past. Really old cars quite often dont have counter balancers on the cranl that will allow you to drop a puston out the bottom.

But a lot of stuff you could do back in the day wont work now as engines have much higher compression putting too much load for stuff like leather bearings

To get the piston and rod assembly out of many pre-war engines you had to drop the bearing cap, push the rod and piston up the bore and remove the piston pin, take the piston off , and then remove the rod from underneath.

If you wish to test your ability as a fitter or engine builder, try putting an Offenhauser together having never seen one before and being presented with a crate of pieces stated to contain "three racing engines". These are beyond the ability of most A Grade Motor Mechanics. Like most aero engines.

[JDNSW]

To get the piston and rod assembly out of many pre-war engines you had to drop the bearing cap, push the rod and piston up the bore and remove the piston pin, take the piston off , and then remove the rod from underneath.
.......

This applies to the Series 1 engine, and probably the six as well. To further complicate matters, you have to turn the assembly 90 degrees to access the gudgeon pin via the sloping top of the block and the exhaust port!

These are not a pre-war design, strictly. While the patents date to 1940 (obviously the design was earlier), production started post war, with the Landrover being the first to appear with them in 1948.

John

[lyonsy]

Well i would love to see ya pull a head off an offy. But then it was also designed to have the pistons taken out the bottom

[101 Ron]

I have a tool which lets you take a worn crank journal down to the next under size on most small engines with out pulling out the crank.
I dont think they are made now..........but still a great time and money saver if you know how to use the tool.
You just then fit a over size big end bearing and all is good again.

[Bigbjorn]

Well i would love to see ya pull a head off an offy. But then it was also designed to have the pistons taken out the bottom

Head and block (called "case" in Offy talk) are cast in one. No separate head. They were methanol engines with compression ratios up to 16:1. No head gasket to fail. To remove pistons and rods one has to lift the block off the crankcase.

If you want a detailed study of these engines buy Ken Walton's most excellent near academic quality work "Offy, America's Greatest Racing Engine". This is the closest thing to an Offy workshop manual ever produced. Fred Offenhauser and later Lou Meyer and Dale Drake sold race engines to race teams, They assumed these guys didn't need to be told how to build and/or repair engines so no workshop manual

Edit- The book is available from the author direct. He lives just outside Kansas City. contact kenwalton@waltoncues .com

[lyonsy]

Yeah hence why i said i would like to see ya pull a head off one

[JDNSW]

Block and head in one was one of the standard layouts for engines up to the 1920s, although some manufacturers had detachable heads earlier - Ford was the first to mass produce engines with detachable heads.

[Bigbjorn]

Block and head in one was one of the standard layouts for engines up to the 1920s, although some manufacturers had detachable heads earlier - Ford was the first to mass produce engines with detachable heads.

Very common in veteran cars but pretty well gone by mid 20's. Big side valve engines with screwed in plugs above the valves so the valves could be installed/removed.