TR2/3/3A Changing rear seal

I have a 1954 TR-2 that has been "Resting" for 30 years. The oil was in pretty good condition, considering the length of time the engine was idle. The car has only 32k actual miles on it.

The previous owner, elderly, remembers having some work done on the engine, before it took its 30 nap. After the rework, the rear seal leaked and, of course, oiled the clutch nicely. He parked it in 1987 with the intent of doing a total restoration.

I drained the oil, changed it and added a new filter. I took the plugs out and the engine turned over with no bad sounds. The compression is 165 on all four cylinders!! Question: I do plan on replacing the radiator, water pump, re-building the carbs and fuel pump and replacing the clutch and overdrive harness. I will have the engine on a stand. With the good compression I don't plan on pulling the head and replacing bearings, etc. What is the easiest way to change the rear seal? I do plan on buying a good one.

Dick

I think the seal is like a tr3. You need to pull the crank to change it. Leakage is standard with this seal, which is actually an aluminum casting with ridges designed to impede the passage of oil along the crank. There is no contact with the crank. There are upgrades about which you will hear soon here. These too require disassembly. Running the engine a quart low helps.
Bob

+1 on removing the crank. Both the stock scroll seal and the best "improved" aftermarket seal (IMO) require that the aluminum pieces be very accurately located with respect to the crankshaft. There is no easy way to measure that clearance with the crank in the way.

BTW, the mandrel dimensions shown in the factory workshop manual (and every other manual that I've seen) have an error.



Updated mandrels are available from TRF or Joe Alexander (his website is currently still down, email N197tr4@cs.com ). Either can also supply the aftermarket "Viton" seal along with the modified housing to hold it. Here's a copy of the instructions (also included with the kit)
https://drive.google.com/open?id=0B2H2NJt34OffM3dsRUotOEF2SGM

I had decent results setting the scroll seal by wrapping the crank with shim stock. I didn’t have a mandrel. I did have the engine upside down on a stand. In the car you would have to lift the crank to simulate it riding on it’s oil film while running.

Randall,
I tried to open the website, it said it would be a violation of Google Terms of Service??

Dick

Hmm, that's interesting. Apparently I somehow violated Google's TOS; perhaps because Christian put a copyright notice in the PDF file?
Anyway, try this instead:
https://www.tr4-racing.de/download/splitseal.pdf

Randall,

That one worked; not sure I want to attempt this though. I have a good shop nearby.

Dick

I wonder what the problem with seal and mandrel dimensions is all about. Years ago I machined off the scroll and converted to the "Rover" seal from Racetorations. There was a problem with getting the correct dimensions for the crankshaft seal area at that time. That conversion worked for a short while then leaked something awful, I was better off with the scroll setup. I recently disassembled the engine, the seal was hard and brittle.

TRMark said:

I wonder what the problem with seal and mandrel dimensions is all about. Years ago I machined off the scroll and converted to the "Rover" seal from Racetorations. There was a problem with getting the correct dimensions for the crankshaft seal area at that time. That conversion worked for a short while then leaked something awful, I was better off with the scroll setup. I recently disassembled the engine, the seal was hard and brittle.

Click to expand...

Yes, there were quite a few of those conversions that produced less than ideal results. No turning after the crank is ground. Also not to be confused with the Marx split seal which has worked out to be much better.
I still use the scroll with fairly good results but not totally drip-less.
And John, great idea with the shim stock as long as you can keep it tight on the crank.
Tom
Tom

I would suggest holding off on replacing the real seal until you get more use to it . On an original motor there is no rubber seal. The crank shaft has a threaded scroll that throws the oil back into the motor as the motor is running and on the back side of the block there are 2 aluminum pieces that help funnel oil that escapes back into the oil pan. That hole in the bellhousing is to let the oil drain out to the ground if too much leaks. Your car might not leak oil when you are driving; it just looks like lot oil leaked out after you stop and it sits and puddles up. I forgot the exact amount of oil the manual says they can use in general, but it was like a quart every 500 miles or something.

Moreover, I do not see why the oil could not be leaking from the felt seal on both sides of the last bearing cap or just leak out of the breather tube because these motors are open crankcase vented and leak.

I put one of those Mad Max seal on this last engine and have no leaks, but is an upgrade that leaves the original stuff in place on the motor. A very smart design I would add.

Anyways, I would not trust the replacing of the seal to just any mechanic these motors are old style and the guy would need to know the car. Plus like said the whole bottom end should come out and the engine out of the car. I have heard that people have put a mad max seal on the motor in the car, but those guys are very very good and can work in very tight situations. One more thing, people who drove these cars back in day would say --do not park on a hill.

You see the problem with the scroll seal was when going forward it threw the oil towards the engine. In reverse, however, it threw the oil out the back. So, use reverse as little as possible.

yeh right, how about down hill in reverse with the motor spinning clockwise?

I know I am different...and not the norm...but I absolutely love the scroll seal. It has no points of contact, so it cannot wear out unless you let your engine get so worn you would have no oil pressure anyway. It will always leak a little, but never more than a few drops per outing on the garage floor. What oil it does leak only hits the clutch cover and drops to the road. The draft tube makes much more mess on a regular basis. The only thing that can go wrong with a scroll seal is poor installation.

Dick, the engine seal could not have oiled your clutch, as it cannot leak through your flywheel to get there. If your clutch disk was saturated, then the culprit is the tranny input shaft seal.

And Mark...you had me blowing coffee out of my nose!! That was funny.

Redoakboo said:

...The previous owner, elderly, remembers having some work done on the engine, before it took its 30 nap. After the rework, the rear seal leaked...

Click to expand...

I agree that a proper scroll seal's usual drip is an acceptable thing given its overall effectiveness.

But it is possible that the OP's engine does not have a scroll seal. The 'rework' and subsequent leak may have been in the era when a modern seal replacement was on offer but the the specs for grinding the crank were faulty - resulting in a badly leaking seal.

I suppose there is no way to know what's in there w/o looking.

John,

I just got the tranny out, see oil at the seal area; another project! The tranny does have overdrive, but the wiring harness has just disintegrated and was in pieces.

CJD said:

I know I am different...and not the norm...but I absolutely love the scroll seal. It has no points of contact, so it cannot wear out unless you let your engine get so worn you would have no oil pressure anyway. It will always leak a little, but never more than a few drops per outing on the garage floor. What oil it does leak only hits the clutch cover and drops to the road. The draft tube makes much more mess on a regular basis. The only thing that can go wrong with a scroll seal is poor installation.

Dick, the engine seal could not have oiled your clutch, as it cannot leak through your flywheel to get there. If your clutch disk was saturated, then the culprit is the tranny input shaft seal.

And Mark...you had me blowing coffee out of my nose!! That was funny.

Click to expand...

I'm with you on the scroll seal, for what that's worth.
As for the clutch, I've seen severe rear main seal leaks that coated the back of the flywheel which acted as a slinger that made a ring around the inside of the bell housing and then dripped onto the clutch (or at least that's how it looked to me). Of course, a transmission input shaft seal leak is far more likely.
Tom

When I redid my engine during the restoration, I decided to use the original scroll seal. It leaked very little before the tear down, so I was willing to go with it. I made a mandrel according to the dimensions that Randall gave and used that to set it up. I have virtually no leakage at the rear seal. Every now and then a drop or three. Hardly anything to worry about.

We have been through this Art; you did not put any oil in the engine!

+1 for the original seal, though I’ve been using Chris Marx’s viton addition as a little extra. Where I’ve had a bad leak it was less the seal but more from worn rings and crankcase tank pressure buildup - wasn’t using a road draft tube.

OK, I'm puzzled by this thread. I thought the consensus was that the Viton seal from ARE (Joe Alexander) was the way to go? No need to shave off the scroll. Am I wrong, confused (is it my memory failing)?