crankshaft main bearings.

[Phil Read]

Is it possible to fit main bearings to a 3A engine without removing the engine?

[Rob Salisbury]

Not the set nearest the flywheel unless you remove the gearbox and flywheel first.

 

[Chilliman]

1 hour ago, Phil Read said:

Is it possible to fit main bearings to a 3A engine without removing the engine?

Yes it is - all of them, I've just done it with engine in situ.

[Motorsport Mickey]

+1

Mick Richards

[BlueTR3A-5EKT]

Just don’t take them all out at the same time.

[Phil Read]

I am a bit confused by the contradictory answers, does the gearbox have to be removed to get the rear bearing off? if so I might as well take the engine out.

[Rob Salisbury]

How do you get the rear main cap with the ali oil reverse scroll past the flywheel? ,....I couldn't do it on my 4A, maybe the flywheel is different on the 3's and 4's?

Cheers Rob  

[Chilliman]

Rob, he engine I did the bearings on a couple of months ago was a 4, once the bell housing bottom cover plate is removed the rear main can be pulled downwards (I use a very basic homemade puller to do this cleanly) first to the limit of it's travels  & then slightly angled inwards towards the front of the engine to roll the attached oil sea out around the block edge.  Assembly as they say is the reverse process plus your sealer of choice.

[Rob Salisbury]

Hi John,

       Thanks for that explanation, however when  tried to do exactly that, no matter how I maneuvered the combined cap and oil scroll it jammed against my flywheel, so I gave up and took the gearbox and flywheel off.

Cheers Rob 

[Chilliman]

That's interesting, can't really offer an explanation other than different flywheels? I wonder if removing the forward thrust washers may have enabled a critical few extra thou on the crank & flywheel?

[stuart]

3 minutes ago, Chilliman said:

That's interesting, can't really offer an explanation other than different flywheels? I wonder if removing the forward thrust washers may have enabled a critical few extra thou on the crank & flywheel?

Lightened flywheel, probably where its been scooped out has given you the clearance?

Stuart.

[Chilliman]

Sounds likely Stuart, it would be good to hear from anyone else with experience of doing this. The engine I was working on certainly did have a light weight flywheel fitted.

[Lebro]

Could it be that a modified crank to take the Landrover seal is easier to do as the crank is a smaller dia where the seal goes ?

Bob

[Chilliman]

In my case Bob it was a stock crank that still had the scroll in place & one of Christians oil seals so in theory at least the sizes were the same.

[Phil Read]

Thanks for the replies. I will remove the sump to investigate the state of the crank before my final decision regarding engine removal. On start up the pressure is 80psi at 2000rpm dropping to 50psi on tickover, when hot it drops to 45psi and 15psi on tick over. The big end and mains do not rattle or grumble on start up.

[stuart]

2 hours ago, Phil Read said:

Thanks for the replies. I will remove the sump to investigate the state of the crank before my final decision regarding engine removal. On start up the pressure is 80psi at 2000rpm dropping to 50psi on tickover, when hot it drops to 45psi and 15psi on tick over. The big end and mains do not rattle or grumble on start up.

In that case TBH I would keep driving. You could always adjust the PRV a little.

Stuart.

[Ian Vincent]

Alternatively fit a high capacity oil pump?

Rgds Ian

or a new one?

Edited May 31, 2023 by Ian Vincent

[ianc]

It's flow of oil which matters - no need to worry if the pressure when hot is somewhat lower than the 70psi which everyone seems to worry about.

My TR4 shows similar trait, has done so for years, and I don't worry about it because it rattles slightly for only a short distance from a cold start.  Years ago, Neil reassured me, saying "we fit them a little loose".

If it were my TR, I wouldn't be doing anything to the engine if the car is performing well.

Ian Cornish

[Ralph Whitaker]

Sounds perfectly acceptable to me, mine starts at 80 when cold and continues to work at 60 to 70 when hot depending on revs and drops to 20 on idle when really hot after a good run. Mine had new bearings 5000 miles ago.

Different oils can make a big difference, what are you using?

Ralph

[Phil Read]

Hi

The oil I use is Smith and Allen Select XL 20/50. I use it in all my classics.

[Ian Vincent]

3 hours ago, Ralph Whitaker said:

Sounds perfectly acceptable to me, mine starts at 80 when cold and continues to work at 60 to 70 when hot depending on revs and drops to 20 on idle when really hot after a good run. Mine had new bearings 5000 miles ago.

Different oils can make a big difference, what are you using?

Ralph

Mine is pretty much the same. I use Penrite Classic Light oil.

Rgds Ian

[BlueTR3A-5EKT]

Beyond a weak oil pump the only places oil pressure is likely to”leak out “ are crank big ends and main bearings plus the rocker shaft and rocker arm bearings.   Simple check for the rocker arms and shaft.  Simply slide the rocker side ways and check the shaft for wear with a thumb nail.  Big ends and Main bearings. Drop the sump.   Unbolt the centre main and one of the con rod big ends.  If brass is shewing renew. Oil pump to be checked for running clearance while you have the sump off. Use factory data.   Lapping the end plate fly will improve it a bit.  I have a Triumph NOS oil pump rotor set somewhere if you want to wait till July when I next go to the lock up. 

Edited June 1, 2023 by BlueTR3A-5EKT