• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

new t/w's, big ends, mains and no oil pressure.

Share this page

charlie74

charlie74

Jedi Warrior
Country flag
Offline
Just changed the big ends, main and thrust bearings on my 1974 TR6.Did the with the engine in situ, not difficult, but time consuming and a two man job.
Coated all new bearing surfaces with assembly lubricant and took special care to make sure the bearing shell tangs fitted properly.
Had to remove the oil pump, so cleaned it out. Refit everything, new oil filter (spin-on), which I also filled with oil and used new oil (20/50).
Turned the engine over with the s. plugs out for a few seconds, then put them in. It started right up, but after about 15-20 seconds of running at idle, there is no sign of oil pressure and oil does not seem to run out of the gallery, once the pressure gauge fitting is removed. aside from no oil pressure, it seemed to run smoothly with no unusual noises.
Absolutely stumped, has anybody any ideas? Do not want to remove the oil pan yet, I think the pump and bearings were assembled correctly (I have a shop manual). If the bearing assembly was wrong would suspect it would reduce oil flow and thus pressure. However, that seems the next step.
Have also read some posts about priming the oil pump, the manual does not mention that, but should I try it and how is it done?
Has anybody else has done this and what could I have missed?
Typically how long does it take to build oil prssure at engine idle?
thanks in advance,
c74
 
My suggestion is to take the plugs back out, and spin it for a full minute with the starter (or until the oil pressure comes up). If that doesn't work, I'm sure someone will be along to describe how to prime the pump by spinning it with a drill motor.

The pump doesn't work well at all with just air inside; plus it has to fill the oil filter before oil gets delivered to the galleries. I think you just haven't allowed enough time. Even on a TR3 where the pump is submerged in the oil, it can take more than 30 seconds for the pressure to come back up if the galleries, filter, etc. are totally dry.

But by removing the plugs, the load on the bearings and starter is very minimal, so extended spinning that way won't hurt anything. Also turns a lot faster, which helps.
 
Pull the plugs and the coil wire and spin the motor until pressure shows up
Another way is to pull the dizzy and spin the oil pump that way
 
Not to kick you while you are struggling a bit Charlie, but aren't you supposed to confirm oil pressure and prime the system before starting her?
 
It is possible (assuming I remember correctly... ) To put the pump in without lining up the tang at the bottom of the drive gear, and to push the shaft down into the actual oil pump gear. Hope this isn't what happened... Don't run it until you are positive that the pump is working, or you could un do all of your work.
 
Yes, pull distributor and slip long metal rod with flattened end into oil pump. Spin rod (correct direction) with electric drill until oil pressure comes up.
As others have said, don't run engine until you figure this out.
 
Little bit of a hassle, but spin the oil pump. Buy a cheap deep socket (12 mm maybe?) and cut a groove in it with a disc. Attach it to an extension and a strong drill and run it at high rpm counterclockwise. After a few seconds, you should see the oil pressure gauge register and oil flow out of your valve train. The socket acts like a drive dog. Chances are you put the bearing in correctly. Kinda hard to screw that up. Good luck.
 
Re: new t/w's, big ends, mains and no oil pressure

These are the pictures of what you need to remove to do what they are telling you to do. First take out the distributor, then remove the upper housing (do NOT destroy the gaskets under it, they are shims). This is shown in the first picture. Then remove the gear and you will see the slot that goes onto the oil pump drive. Make sure that you replace the gear in the same alignment as you removed it to keep your timing correct.

The gear is offset slightly, so mark the top of the gear before you remove it, to face the front or rear of the block, so you will know which way it goes back in. Lube it well before reassembly.
 

Attachments

  • 16630.jpg
    16630.jpg
    32.6 KB · Views: 244
  • 16631.jpg
    16631.jpg
    55.7 KB · Views: 240
  • 16632.jpg
    16632.jpg
    32.7 KB · Views: 240
  • 16634.jpg
    16634.jpg
    33.1 KB · Views: 245
Re: new t/w's, big ends, mains and no oil pressure

I had the same thing happen with my 6. I ended up dropping the pan, taking the pump out and backing the gears with vaseline. I removed the distributor and did the drill thing as others have described. I took a long bolt, cut the head off and used a dremel cutoff to make 2 offset cuts to the end of the bolt so I ended up with a tang to fit in the slot as pictured in Paul's pix. With mine anyway, I knew when I got oil pressure as the drill tried to twist out of my hand.

Scared the poo out of me too when it happened.
 
Re: new t/w's, big ends, mains and no oil pressure

I did the same job, in situ, about 3k miles back, for peace of mind.
I did what Cheseroo did, only with grease.
I used the starter. I don't remember how long it took to fill the pump and register oil pressure, but it didn't seem to take that long; maybe twice as long as it does with an oil filter change.
 
jessebogan said:
It is possible (assuming I remember correctly... ) To put the pump in without lining up the tang at the bottom of the drive gear, and to push the shaft down into the actual oil pump gear. Hope this isn't what happened... Don't run it until you are positive that the pump is working, or you could un do all of your work.
Click to expand...

Very possible to do actually. Especially if there was any resistance felt in tightening up the oil pump followed by sudden loss of resistance to tighten the bolts fully. Had the tang rotate on me once assembling an engine and had that happen. It didn't "feel" right so I took it back apart and discovered what had happened. If that happens, the oil pump doesn't spin at all.
 
Re: new t/w's, big ends, mains and no oil pressure

Oil pumps can cavitate for a lot of reasons,the trick then is to get oil into the pump(prime the sucker)On a tr the oil pressure relief valve is the most handy spot to force some oil into the contrary pump.But you violated the most cardinal rule of engine building by NOT spinning the motor without plugs to bring up the oil first.....BAD DOG!!
MarkC
 
Re: new t/w's, big ends, mains and no oil pressure

hi all
thanks so much for the advice, we ended up using the suggestions to get the oil pump turning by removing the dist. and spinning with a drill. the original triumph service manual which i have been using has no pump priming procedure in it, so we tried to get it going with the starter (plugs removed) and must have been pretty close. the problem is you never know how close you might be.
anyway, below is a pic with the old T/W's, a main, and a big end bearing and the tool arangement we came up with to get the oil pump spinning. now o/p is about 55 psi at idle w/ temps just below 1/2 way across the guage. no unusual sounds idicating throwing a bearing and no other indications of serious problems.
hopefully, with all of the assembly lube and the minimal run time (less than 15 sec's) we will have caused no grief to the 6, and we can get another 30 some years of meandering out of it.
cheers
c74
100_2125.jpg
 
Back
Top