Leaking rear main seal

[clinebarger]

Originally Posted by AZjeff
Interesting that some RMS leaks are slowed or fixed by HM oil or additives and some aren't helped at all. And one brand of HM oil doesn't work but another one does.


A lot of modern engines use PTFE crankshaft seals, There aren't many chemicals that PTFE will react to.

 

[Ben Boyle]

Google Hapco Tri-Seal. The only fix I've ever seen in a bottle that seems to help.

 

[Revving2Redline]

I ran the Liquimoly Motor Oil Saver #LM2020 in my Hyundai before Honda. Changed oil, idled for 5 minutes, added the entire bottle and ran it on the highway for 30 minutes. After that I went to PPHM 5w30 and added a small maintenance dose. Vinny at Liquimoly says once its sealed to cut back/discontinue as it can over swell. I would also consider Lubegard Oil Stop Leak too.

 

[AZjeff]

Originally Posted by clinebarger
Originally Posted by AZjeff
Interesting that some RMS leaks are slowed or fixed by HM oil or additives and some aren't helped at all. And one brand of HM oil doesn't work but another one does.


A lot of modern engines use PTFE crankshaft seals, There aren't many chemicals that PTFE will react to.


What would you consider modern? About when did use of PTFE seals (Teflon!) start?

 

[DoubleWasp]

Friend of mine had a Yukon that would put 2 quarts of oil on the ground in 10 minutes. ATP-205 reduced that to about 2 droplets over one hour.

Mind you, we went into this doing it as a complete Hail Mary pass, with no faith at all.

Another person I know did it to his Denali with zero change at all. Depends, depends.

 

[Trav]

Originally Posted by clinebarger
Originally Posted by AZjeff
Interesting that some RMS leaks are slowed or fixed by HM oil or additives and some aren't helped at all. And one brand of HM oil doesn't work but another one does.


A lot of modern engines use PTFE crankshaft seals, There aren't many chemicals that PTFE will react to.


Yes they are very common and many get damaged by careless/improper installation, installing dry with an installation sleeve is a must. You are spot on that almost nothing (that I know of anyway) effects them chemically.
FFKM seals and O rings are resistant to almost everything also, strangely many German cars even later model ones were using Buna-n which will blow up even looking at it wrong. Esters really have an effect on this type.

 

[clinebarger]

Originally Posted by AZjeff
Originally Posted by clinebarger
Originally Posted by AZjeff
Interesting that some RMS leaks are slowed or fixed by HM oil or additives and some aren't helped at all. And one brand of HM oil doesn't work but another one does.


A lot of modern engines use PTFE crankshaft seals, There aren't many chemicals that PTFE will react to.


What would you consider modern? About when did use of PTFE seals (Teflon!) start?


The first one's I ever saw were on 2nd design Cadillac Northstar engines & all GM LSx engines have them.