View Full Version : 455 Rear Main Seal for the street
slobrd
03-07-2000, 07:00 PM
I will soon be replacing the rear main seal as per "Tight Lip 2" article in HPP and Taylor's SD build up. The problem is that NAPA's seal came with two small pieces included in the box. I can't find any reference to these pieces. Any advice?
slobrd
03-07-2000, 07:00 PM
I will soon be replacing the rear main seal as per "Tight Lip 2" article in HPP and Taylor's SD build up. The problem is that NAPA's seal came with two small pieces included in the box. I can't find any reference to these pieces. Any advice?
Michael G
03-08-2000, 09:38 PM
The Napa part number for the 472 caddi seal for the large journal crank is JV-600. All that came in my box was two seal halves.
I believe you will need to trim about .020" from one end of each seal as the O.D. is slightly large. To be sure mic the seal o.d. against the bearing housing and allow a few thousands for crush.
SLOBRD, Can I get more info on that article? i.e. Month/Year
KevinDush
03-13-2000, 10:31 PM
Tight Lip part 1 was December 1998 HPP, which outlined how to do the Caddy seal, whereas Tight Lip part 2 (February 1999) told how to install an OEM rope seal.
Later,
Kevin
What is the deal with the rear main on 455's? Why can't you just use the neoprene seal for that application?
slobrd
03-24-2000, 09:37 AM
I heard that the neoprene seal in the 455s has a tendancy to leak, especially if you run synthetic oil. For now I must follow Taylor's lead and use the rope seal.
By the way, is it supposed to require 2 dozen or so razor blades to cut the seal?
PROBRD
03-25-2000, 11:44 AM
I use the neoprene seal in my engines and have had no problem with leaks. The problem I have had is with the rope seal. I've broken two rear main caps when trying to install the rope seal. Not sure why? Just seems to fit to tight, which I see as more drag on the crank. I've never had to cut a neoprene seal to make it work either. Just my 2 cents.
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PROBRD
(probrd1@aol.com)
Tim Corcoran
03-29-2000, 04:35 PM
It has been my experience that the ole Pontiac rear main seal is doomed to leak no matter what seal type you end up with. The factory rope seal, if installed correctly will not leak. Except if the car is not driven regular the seal will dry up and leak. Many of our classic Pontiacs are not driven regular i.e. bracket cars, summer drivers only, week end drives only etc. Even if driven daily most would be very happy to get 40,000 miles prior to the rope leaking, of course there are exceptions.
The Pontiac crank has hash marks machined into the journal where the rope seal makes contact. The hash marks act like an oil slinger to try and push the oil back into the engine during operation.
The reason the neoprene seals usually leak is because the lip seal is designed for use with a smooth surface and not on the hash marks. I am happy that PROBIRD1 has a leak free neoprene caddy seal but he is certainly the exception. The neoprene seals seem to stay tight and dry for a short while then start seeping in less than a year. I would be interested how long PROBIRD1 has had that leak free lip seal in there and how many miles he has on it.
Tim Corcoran
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PROBRD
03-29-2000, 07:12 PM
Tim, It's a bracket car and is torn down every winter. The seal is on it's third season this year. I didn't see any reason to change it since it still looked good and hadn't been leaking. In other words not too many miles (but regularly abused) and is checked fairly often.
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PROBRD
(probrd1@aol.com)
[This message has been edited by PROBRD (edited 03-29-2000).]