TR2/3/3A rear main seal

[sp53]

I am trying to understand why the centering of the mandrel is so critical when installing a rear main seal on a Tr3. The rear main cap is pulled down tight and the oil scroll is going to throw the oil back into the engine once the RPM rise. I see how the rear seal on the cap lets the oil flow back into the pan, but that ultra-precision of the centering seems not too critical to me. The holes in the aluminum piece are not slotted, so how do I move it much anyway. I know I am not the sharpest tool in the shed, but understanding helps me. Anyways, I will most likely purchase one of Mad Max’s seals, but if I do not need the centering tool why buy it. I am still waiting for Art’s stock rear main to leak, but perhaps he is out of oil and does not know it. The last one I did leaked badly. Using too much Indian Head gasket sealer might have contributed to rear main leaking on mine because I fear the small hole feeding the oil back might have become partially plugged. I see one of Mad Max’s seals for sale EBay and I see that TRF has them. If I buy from the TRF, I will get their warranty on parts, so that seems the way to go.

 

[GerryL]

The one advertised on ebay is provided by Joe Alexander, who supplies TRF. I purchased it thru ebay and he was helpful in answering any questions that I had in regards to installation. The seal has worked and so far haven't had any drips.

 

[CJD]

To be honest, I had never heard of a "scroll seal" till I bought my TR3. With an engineering background, I naturally studied it intensely when I had the part off. As far as I am concerned, it is ingenious! It will never be absolutely dry, but on the other hand it also will never wear out or score the crank. I left it in when I reassembled, and have never regretted it.

The reason for the setting mandrel is that you are dealing with extremely tight clearances. If the2 scrolls do not lineup absolutely perfectly, you will lose oil, and possible cause one scroll to contact the crank...and lose oil. Setting the mandrel is the only downside with the original seal, in my opinion! But once done, forget about it for the life of the engine.

 

[tinman58]

I am like you. I want to understand why things work. Even thou the machined parts are not slotted, there is still some wiggle room. What I have learned is do it as the instructions say. It will eventually make sense. Make sure you check the length of the flywheel bolts. They tend to be a little long and can rub against the new seal, causing a very nice oil leak..... believe me I know....

 

[TR3driver]

The one advertised on ebay is provided by Joe Alexander, who supplies TRF. I purchased it thru ebay and he was helpful in answering any questions that I had in regards to installation. The seal has worked and so far haven't had any drips.

Joe also supplies to TRF. He is the only authorized importer in the US.

As noted, the clearance between the scroll part of the seal and the crankshaft is critical to the operation of the scroll seal. It is probably less critical when combined with the Viton seal, as it's a "belt and suspenders" arrangement; but you still don't want to have the aluminum seal touching the steel crank when it is assembled.

If you really, really don't want to buy (or make) a mandrel; I have heard tales of wrapping the crank journals with fine thread and using it as a mandrel. Hardy swears it worked for him (with the factory seal, back when). But if you are going to spend all that money on an improved seal, why not install it as the maker recommends?

 

[Got_All_4]

I have my engine out only to repaint the engine compartment. Although driving the car for 30 years I've had minimal problems with oil leaks but have been thinking of doing a conversion. One question first is how does the flywheel flange come off the crank? For a modern oil seal to work it will have to come off.

 

[tinman58]

The viton seal is split. the seam goes up towards the head when installed.

 

[TR3driver]

Right. So is the other conversion. The flange doesn't come off.

 

[martx-5]

... I am still waiting for Art’s stock rear main to leak, but perhaps he is out of oil and does not know it...

I see you've discovered my secret...no oil...

Actually, I think that most of these leaks from the original scroll seal are due to the fact that the dimension given in the workshop manual is incorrect. They show the dimension as 2.822" when it should be 2.818". To make matters worse, the tools that Moss was supplying measured 2.825". I don't know if Moss has gotten that straightened out, but any centering tool that you use should be measured carefully.

 

[TR3driver]

Actually, I think that most of these leaks from the original scroll seal are due to the fact that the dimension given in the workshop manual is incorrect. They show the dimension as 2.822" when it should be 2.818".

Another reason, I believe, is that it is difficult to assess wear on the seal and so many people reuse them when they shouldn't. Of course it is non-contact by design, but with worn main bearings and hard driving, the crank can contact the seal and wear away a bit. Only takes a few thousandths to make it leak badly.

Yet another reason (which mostly affects only later TR4 and 4A) is pressure buildup in the crankcase. Full throttle is when there is the most blow-by past the rings; and yet at full throttle there is no intake manifold vacuum to pull fumes past the PCV valve. The result is a momentary build up of pressure inside the crankcase, that overcomes the surface tension of the oil in the gap of the seal and blows it out. (TR4 didn't use the valve, but the small tube to the air filters can also allow pressure to build.)

 

[Kevork Erer]

Hi everyone need help Im a little puzzled on the removal of the rear oil seal cap on my 1959 tr3. I have the engine turned upside down and everything stripped on engine stand an only crank and rear seal and cap left, dont want to start hammering looking for Ideas on removing cap stii has felt stuffed

 

[Sarastro]

You'll need to rig up some kind of puller. Here's what I did, using parts from a gear-puller kit.

 

[Kevork Erer]

thanks i will give it a try

 

[charleyf]

I removed the 4 bolts from the seal plate. Then I used a drill to remove most of the felt and sealer. That helped. I also gently tapped the rear seal to get it to move.
Charley

 

[Kevork Erer]

Thanks for the Ideas, I used a steering wheel puller with 2 long screws into the seal plate similar to pic I pried it up with a long crow bar between the screws over a 2x4 across the top of engine block with gentle taps on seal plate came out like nobody's business

 

[CJD]

I have always used a rubber hammer to tap it out.

 

[Kevork Erer]

I bought my 59 tr3 during peek of covid came from North Carolina rolling car full of parts owner had the head done at a reputable machine shop just before I got it(looks great shiny new) but the motor was sleeping indoors for approx 15 years he debated on redoing it but never did. I’ve decided to redo it so I’ve opened up a can of worms it seems first glance looked just clean and new bearings should do has a Mahle 86.97 .040 marked on top and 86 in the piston, not sure what that means Mahle said these were made specially for the tr3s back then and new parts be hard to find. So my plan of honing the cylinders and getting new rings is not going to work, TRF and Moss has a 86 and 87mm liner and Piston set for approx $560 seems the most cost efficient can anyone shed some light on this long story please I’m in the dark is one better than the other I’m all ears

 

[bobhustead]

I bought a used set of 86mm .030 over pistons from another BCF denizen. No trouble getting rings. Two sets of rings because apparently the machine shop defined "clean pistons" differently than I. Turned out that I had to clean the lands with a back-blade hacksaw to get the carbon out. That carbon broke one of my first set of rings.
Bob

 

[charleyf]

I bought a used set of 86mm .030 over pistons from another BCF denizen. No trouble getting rings. Two sets of rings because apparently the machine shop defined "clean pistons" differently than I. Turned out that I had to clean the lands with a back-blade hacksaw to get the carbon out. That carbon broke one of my first set of rings.
Bob

I have opted to stay with the 86mm piston and liner sets. Reason being that I once had a head gasket fail at the rear of the block. So the 87 or even 89mm pistons just give us that much less space between the water passage and the inner cylinder.
Second - unless you are planning to race the car the extra cc's do not change every day driving.
I have stayed with the piston and liner sets to avoid any mismatching. I figure the extra cost is worth the peace of mind in getting a totally fresh engine when I am done.
When you put the head gasket on you will note that it can fit two ways. Make sure you place that gasket with the edge overlap facing up.
Charley

 

[Kevork Erer]

Good point Charley , previous owner apparently did race this car. I appreciate your input 86mm standard is what I've been leaning towards as well want to do this right Thanks

Kevork