View Full Version : TR4/4A Last question about original rear main sealTR3 TR4

08-02-2009, 04:52 PM
OK maybe I have more than one. When I removed my original rear main seal I thought all was original. After talking to some friends and BPNW I found that someone put a rope seal in the groove that I believe was ment as a drain(see picture). It seems like a good idea but it blocks the holes that are ment to drain the oil back to the sump (I think). Has anybody else seen this? Also I can see no wear on the housing of the seal. How can I determine if I need to purchase a new seal? Who has the best seal available? BPNW does not have them because the say they can't find one good enough to sell. Should I reuse the original, or get a new one?

08-02-2009, 05:31 PM

I was just looking original one in the garage earlier this weekend, and it doesn't have anything like that - what it has are inserts that look very similar to the thrust washers, but without that extra tang in the middle.


08-02-2009, 05:45 PM
Hi Randy

I have no idea of what I should be looking for in the shape and size of the correct seal. This is my first 4 Cyl engine rebuild. Could you please post a picture of the seal that you have. In case the picture is confusing, It's the two halves leaning against each other, with the rope seal pulled out of one.

08-02-2009, 05:58 PM

I looked again, and think I may have been full of bs when I posted earlier - what I mistook for inserts may in fact just be the old thrust washers. Everything was in the same old box I was given with some other spares when I bought the car.

Here's what I have:

The rear seal looks like yours, but no rope seal. I not sure if anything else runs in that groove. Hopefully someone else can clarify it for both of us!


08-02-2009, 06:47 PM
Thanks for the picture Randy. At least I know I do have the correct parts on hand.

08-02-2009, 06:57 PM
The rope is NOT original; but probably does improve the sealing, at least for awhile. Rope seals were fairly standard back then; worked reasonably well for 20-30,000 miles. In fact, I'm told that the Ferguson tractor version of the TR2-4 motor did use a rope seal, the scroll seal was an "improvement".

Assessing wear is difficult without the mandrel; With a mandrel you just put the seal halves together on the mandrel and look for any gaps.

Can't help with who has a good seal, as I've always just reused the old one (and lived with the leaks). But I trust TRF to offer the best available (Charles owns a TR3), so that is who I would buy from. YMMV and all that.

BTW, the mandrel dimensions in the manual are apparently wrong.

08-03-2009, 09:29 AM
Guys! I don't believe this! I might actually be able to HELP someone! That space is NOT a drain outlet. It is designed to hold a felt packing piece that slips in both the top half and bottom half of the seal. It's original part number is 58335. The car requires TWO pieces.

Now, if anyone wants to discuss the EFFECTIVENESS of the infamous Triumph rear main seal...

On my 1958 TR3, I had such a rear seal leak that I never needed to change the oil filter. I poured oil in the top and it ran out the seal. I drove the car from Washington, DC to Oklahoma City, in the dead of summer, and it took EIGHT QUARTS of oil. In Oklahoma City, there was a new product out, STP, so I decided what-the-heck. I put two cans of it in there, and it only took two more quarts of oil to San Diego, going across all that desert. Should I have run STRAIGHT STP???

I hope this helps,


P.S. I forgot to ad: you an now get your crankshaft MACHINED to your seal, which is supposed to eliminate the leak. I'll believe it when I see it.

08-03-2009, 09:43 AM
It's original part number is 58335. The car requires TWO pieces.I disagree, George. 58335 is a felt packing; but it goes in the channels in the bearing cap (not the seal), between the cap and the engine block.

08-03-2009, 03:41 PM
Whoops. My bad. I <span style="font-weight: bold">STILL</span> can't help anybody out.

08-03-2009, 07:16 PM
George thanks for the post anyway, and thanks to everybody else.

08-03-2009, 10:58 PM
I think that if you have the crank out, the new rear seal kit and the machine work total only 100$(just had one done), so......with 3$ a quart oil the leak from an old scroll seal will be 100$ in 3 years....DO IT NOW!!!!! Save the money down the road.
MD(mad dog)

08-03-2009, 11:12 PM
I dunno ... heard too many horror stories of people who had all that work done and it leaked WORSE than the original seal, I guess.
Our local club president had to get the crankshaft replaced, after figuring out there was a misprint in the instructions supplied with the conversion kit. In the meantime, no one would drive behind her TR4, for fear of getting their paint updated.

The scroll-type seal in my TR3A was still original, AFAIK, and leaked pretty bad. Meaning it was time to change oil when the level got down to the 'add' line <<GRAEMLIN_URL>>/grin.gif

08-04-2009, 07:49 AM
My TR4 leaves a good puddle on the floor. Eventually when it comes to full rebuild time I think I'll go the modern seal route - this leaking / misprint issue has been around a long while so my hope is if my research is done properly I cn get the crank turned to a proper diameter.

08-04-2009, 01:09 PM
My TR4 leaves a good puddle on the floor..

When it leaves a "bad" puddle on the floor, it will be time.

I know that Hado is meticulous, and his also leaves a good puddle on the floor, and he swears by the new seal/turning crank approach. I've heard so much about this issue that I'm afraid to do anything at this point. -wich is almost as good an excuse as any since I haven't touched my TR3 in months. When the time comes, I'm not sure what to do about the seal. You can always try to reset the original seal, but once the crank is turned too small, turning it again doesn't help.

08-04-2009, 07:24 PM
I wish Racetorations in the UK would release information on their new style seal. It should be out soon.

08-04-2009, 08:25 PM
I read that too about Racestorations - supposedly a much improved design. But I bet it won't be an improvement price-wise!

08-05-2009, 02:33 PM
I opted for the original seal and it leaks a little. But what the heak there is an open breather pipe right next door that also contributes to the puddle. Moreover, if you go with the new seal don’t you still have to build the dam at the rear cap with felt and gasket shellac? It seems to me that is as a big of problem as the seal. I would use the old seal half because, who knows, they might have carful matched the seal half’s to the engine. They do take very close bolts. Follow the instructions and clean everything good and let the oil thrower do the work. Keep it original.

08-05-2009, 02:53 PM
Just a little "more of the same..."
I am running the original scroll seal.
I get about 1500 miles/quart of oil.
That's not the 3000 mi/qt that I get out of my Volksy Eurovan with 225,000 miles on it -- but it sure ain't bad for a 50 year old car. I'm not complaining about my "leaky" TR3. It doesn't leak enough to complain about. :smile: