98 Old 88 - Flush or Drain ATF?

[Lubener]

Originally Posted by atikovi
Originally Posted by Lubener
Never use RTV especially on an oil pan and don't use it along with a gasket.


You might want to ask yourself then, why have most of the major car manufacturers gone to RTV instead of solid gaskets.

Cheaper, plain and simple. One less part for the plant labor to inventory, handle and install, muliply that by many gaskets. That RTV is dispensed from a hose and not a sqeeze tube. I have seen it myself doing work at Ford. Only a naive person would believe that auto makers use something like RTV because its better. It's all about producing cars for the least amount of money as possible. The sealant usually outlives the warranty period which is all that matters.

 

[kschachn]

A good RTV is better than a gasket. As someone who owns old vehicles (one being 26 years old) I have observed that a properly made assembly using a good RTV such as Toyota FPG or Honda Ultra Flange II will last much longer without leaks than any gasket.

And this is far longer than a warranty period which is another silly argument. Maybe for some less reliable brands but it obviously isn't a general truism as my vehicles have demonstrated. RTV failure is most likely due to improper application and not following instructions or just they just don't care and want something to complain about later.

 

[atikovi]

Originally Posted by Lubener
Originally Posted by atikovi
Originally Posted by Lubener
Never use RTV especially on an oil pan and don't use it along with a gasket.


You might want to ask yourself then, why have most of the major car manufacturers gone to RTV instead of solid gaskets.

Cheaper, plain and simple. One less part for the plant labor to inventory, handle and install, muliply that by many gaskets. That RTV is dispensed from a hose and not a sqeeze tube. I have seen it myself doing work at Ford. Only a naive person would believe that auto makers use something like RTV because its better. It's all about producing cars for the least amount of money as possible. The sealant usually outlives the warranty period which is all that matters.


You can do as you please but I've been under a late model BMW and VW with 120K and over 150K miles and they were bone dry. When I get under a 10 or 15 year old Cadillac that uses gaskets on the pans and with less miles for example, the underneath is covered in oil or transmission fluid.

 

[atikovi]

Originally Posted by Lubener
The sealant usually outlives the warranty period which is all that matters.


And it outlives the gaskets it replaced as well, which is why they use it.

 

[caprice_2nv]

I've used just a gasket, just RTV, and a gasket with RTV on different occasions and none of them leaked. I usually try to use both because that's what I've been told by more than one technician that I've worked with. I used just RTV on the thermostat I replaced last week... No issues with it so far and just the supplied gasket when I did the transmission service. The original gasket was not leaking and the new one is good so far. The last transmission pan drop I did last summer, I'm sure I used both, no leaks so far.

I'll stick with using both if I have both available.

Come to think of it the reason I only used RTV on the thermostat is the Canadian tire I went to that weekend didn't stock a thermostat gasket for my 2005 Silverado and the new stant thermostat didn't include one. That tells me right there that everyone is just using RTV on them.

 

[clinebarger]

Originally Posted by atikovi
Wasn't taking the chance of reusing a 25 year old gasket no matter how reusable they say they are when RTV gives a superior seal. The only reasons techs don't like them is because it takes more time and effort to use it; cleaning off both surfaces and a steady hand to apply.


GM specifically states not to use RTV on any of their transmissions, Other than some issues with 4T80E front pump seals & 5 speed Allison 1000's.....They seal up very well using factory gaskets.

Chrysler used RTV on many units & are notorious for leaking.

 

[caprice_2nv]

Originally Posted by clinebarger
Originally Posted by atikovi
Wasn't taking the chance of reusing a 25 year old gasket no matter how reusable they say they are when RTV gives a superior seal. The only reasons techs don't like them is because it takes more time and effort to use it; cleaning off both surfaces and a steady hand to apply.


GM specifically states not to use RTV on any of their transmissions, Other than some issues with 4T80E front pump seals & 5 speed Allison 1000's.....They seal up very well using factory gaskets.

Chrysler used RTV on many units & are notorious for leaking.



I think you're supposed to clean both surfaces no matter what. The techs at the shop I used to work at used RTV in some cases, I was told to look for permatex "aircraft" RTV or something like that. I couldn't find it and used somehow different (just for my thermostat since I couldn't get a gasket for it) but they may be using it only because of gasket availability also.

 

[Trav]

Originally Posted by Lubener
Originally Posted by atikovi
Originally Posted by Lubener
Never use RTV especially on an oil pan and don't use it along with a gasket.


You might want to ask yourself then, why have most of the major car manufacturers gone to RTV instead of solid gaskets.

Cheaper, plain and simple. One less part for the plant labor to inventory, handle and install, muliply that by many gaskets. That RTV is dispensed from a hose and not a sqeeze tube. I have seen it myself doing work at Ford. Only a naive person would believe that auto makers use something like RTV because its better. It's all about producing cars for the least amount of money as possible. The sealant usually outlives the warranty period which is all that matters.


Spot on! Those steel core laminated gaskets are expensive even at the manufacturing level compared to RTV. The parts are brand new, never seen fluid, the unit is upside down with a robot is applying the schmoo. Even then the crap can leak as Clinebarger pointed out.
RTV is crap in many applications, many a Subaru engine has been toasted when someone used RTV to seal the oil pump, when properly cleaned and an anaerobic sealer used instead there are zero issues with RTV breaking loose and going into the oil passages or leaks.

RTV is my least favorite product and one I rarely use unless its absolutely necessary eg gap filling on some intakes where the OE used it.

 

[JTK]

Originally Posted by atikovi
Originally Posted by Lubener
Never use RTV especially on an oil pan and don't use it along with a gasket.


You might want to ask yourself then, why have most of the major car manufacturers gone to RTV instead of solid gaskets.


Like said above, it's mostly cost driven and it can be a very reliable seal when it's applied in the factory, super consistently, by a machine when the surfaces are clean and free of oil, etc.

I do prefer a metal bonded gasket for pans and diff covers, but for applications like OHC timing covers, block sections, etc.. what manufacturer isn't using an RTV type stuff today or 25yrs ago?

 

[atikovi]

Originally Posted by JTK
Like said above, it's mostly cost driven and it can be a very reliable seal when it's applied in the factory, super consistently, by a machine when the surfaces are clean and free of oil, etc.


I have no problem making the surfaces clean and applying consistently.

 

[caprice_2nv]

I've had leaks while using a gasket because I didn't get the surface clean enough. So I try to get it as clean as that pic anyway... And the last diff cover reseal I did was last spring using RTV just like that. So I guess only time will tell if it's leaks or not.

 

[Lubener]

Originally Posted by caprice_2nv
I've had leaks while using a gasket because I didn't get the surface clean enough. So I try to get it as clean as that pic anyway... And the last diff cover reseal I did was last spring using RTV just like that. So I guess only time will tell if it's leaks or not.

I would bet the reason your gasket leaked was the pan was dimpled out at the bolt holes and wasn't flat.

 

[clinebarger]

Originally Posted by caprice_2nv
Originally Posted by clinebarger
Originally Posted by atikovi
Wasn't taking the chance of reusing a 25 year old gasket no matter how reusable they say they are when RTV gives a superior seal. The only reasons techs don't like them is because it takes more time and effort to use it; cleaning off both surfaces and a steady hand to apply.


GM specifically states not to use RTV on any of their transmissions, Other than some issues with 4T80E front pump seals & 5 speed Allison 1000's.....They seal up very well using factory gaskets.

Chrysler used RTV on many units & are notorious for leaking.



I think you're supposed to clean both surfaces no matter what. The techs at the shop I used to work at used RTV in some cases, I was told to look for permatex "aircraft" RTV or something like that. I couldn't find it and used somehow different (just for my thermostat since I couldn't get a gasket for it) but they may be using it only because of gasket availability also.


For GM & to a great extent Ford as well...OE gaskets work very well without sealants of any kind.
If you're unfolding a gasket out of a box....You're using a junk aftermarket gasket!

 

[caprice_2nv]

Originally Posted by Lubener
Originally Posted by caprice_2nv
I've had leaks while using a gasket because I didn't get the surface clean enough. So I try to get it as clean as that pic anyway... And the last diff cover reseal I did was last spring using RTV just like that. So I guess only time will tell if it's leaks or not.

I would bet the reason your gasket leaked was the pan was dimpled out at the bolt holes and wasn't flat.


Could very well be. It was likely my 2004R in my Cutlass I've had for almost 20 years, so it's a 34 year old pan.

 

[caprice_2nv]

Originally Posted by clinebarger
Originally Posted by caprice_2nv
Originally Posted by clinebarger
Originally Posted by atikovi
Wasn't taking the chance of reusing a 25 year old gasket no matter how reusable they say they are when RTV gives a superior seal. The only reasons techs don't like them is because it takes more time and effort to use it; cleaning off both surfaces and a steady hand to apply.


GM specifically states not to use RTV on any of their transmissions, Other than some issues with 4T80E front pump seals & 5 speed Allison 1000's.....They seal up very well using factory gaskets.

Chrysler used RTV on many units & are notorious for leaking.



I think you're supposed to clean both surfaces no matter what. The techs at the shop I used to work at used RTV in some cases, I was told to look for permatex "aircraft" RTV or something like that. I couldn't find it and used somehow different (just for my thermostat since I couldn't get a gasket for it) but they may be using it only because of gasket availability also.


For GM & to a great extent Ford as well...OE gaskets work very well without sealants of any kind.
If you're unfolding a gasket out of a box....You're using a junk aftermarket gasket!


I did have to unfold the rubber gasket that came with my trans filter for my 4L60E, so far it's dry as a bone but it's only been a few weeks. If it leaks, I'll replace it with an oe gasket. The factory gasket on the 2013 at work (also a 4L60E) leaked at only 100k miles late last year. The 2005 was dry (except the cooler lines which just got repaired) right up until I had the pan off.