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Re: TR-4 Rear Main Seal

To: "Bob Nogueira" <nogera@worldnet.att.net>, triumphs@autox.team.net
Subject: Re: TR-4 Rear Main Seal
From: "Jack W. Drews" <vinttr4@geneseo.net>
Date: Tue, 03 Aug 2004 07:24:49 -0500
References: <004601c4790b$a490f120$0100a8c0@CarRoom>
I chased this problem for a couple of years, talked with BFE Moss, called 
the manufacturer in the UK, etc etc. Many engines go together and are dry 
but some leak like a sieve, my own included.

As a result of all my whining they increased the diameter to turn the 
scroll by .025. They did this because I discovered that the ID of the seal 
was 2.500 and they specified turning the crank to 2.500. Huh?

I still think the problem is insufficient lip tension. To verify this for 
yourself, take a new rear seal, put the spring in, and slide it over the 
newly turned scroll surface and feel the tension. Now, by comparison, do 
the same thing with the seal that goes in the timing cover, over the pulley 
snout. That little bitty front seal must have at least twice the lip tension!

The way I deal with this problem is to take the spring supplied with the 
aftermarket seal kit and shorten it to 8". I've measured the length of the 
spring from five new kits and found them to be anywhere from 8" to 8-3/8" 
Just snip it off with a side-cut pliers and bend a new hook on it. So far, 
it's solved the rear seal leak 100%.

However, i must point out, I do more vintage race engines than street 
engines. Therefore I can't vouch for longevity in street engines. Racers 
take things apart frequently so we don't get to see 50,000 mile checks. 
However, I've personally done it to every strret engine I've built after we 
stumbled onto this. My reasoning is that we TR owners seldom put more than 
5000 miles a year on our cars, and I'm pretty confident that this fix will 
last for many years at this rate.

At 10:37 PM 8/2/2004, you wrote:
>Several years ago I installed the "new improved type" seal sold by
>Restorations. It has always leaked however not as bad as the old scroll
>type. I read where they later said that the instructions for turning the
>crank were wrong and the it should be cut down less than what they
>instructed.
>Well the leak has increased recently.
>Anyone know if they have a "improved, new improved type seal for those of us
>who followed the instructions and turned too much off the crank?
>
>Bob Nogueira

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