ATF RTV?

[Rick Anderson]

Someone was wondering whats different about Chrysler ATF+3/+4. Chrysler came up with their own specific ATF for their 41TE/A-604 4spd Electronic Trans, the first version was 7176 Fluid. That trans had all sorts of fielding problems and burned itself up a lot, mostly because people used DexronII in it, instead of the Chrysler Specific Fluid (Chrysler sorta had a hand in that mess up as well). Chrysler kept improving the fluid to fight the chronic trans problems they were having with the 41TE/A-604, and they changed the name to a more user friendly one, probably to help people remember what fluid they are suppose to use.

As far as the fluid properties, the first version 7176 (ATF+1) had greater friction modifiers for quicker and better clutch engagements (since the electronic controlled 4spd had no bands, just clutch packs and shifting was purely an electronic affair controlled by a solenoid valve). The later versions ATF+2/+3 had improved properties like greater oxidation and corrosion resistance, greater heat handling capabilities and less likely to foam etc, basically just better fluid all around based on what little I could find on it. The fluid was so good, they recommended it as retro-fit for just about all Chrysler Transmissions.

Finally Chrysler came out with ATF+4, which from multiple accounts I've seen, its Synthetic ATF with all the improved properties of the previous ATF+'s. Chrysler has started to use ATF+4 as Power Steering Fluid and Manual Transmission Fluid for factory fill as well, as well as ever other Chrysler trans past and present. So, Chrysler may be cutting costs and using one fluid or maybe ATF+4 is such a high performing fluid that it can actually meet the specs PS and Manual trans as well. I suspect its a little of both, ATF+4 is a great ATF that can actually meets the demands for PS & Manual trans, but Chrysler is still cutting corners, because its the best ATF out there, BUT you can probably find better PS fluid and Manual Trans fluid than ATF+4, even though its probably adequate at least.

Sealants, my $0.02, I have had the best lucky following exactly what the Factory Service Manual recommends, well for other vehicles, I don't have a FSM for my Jeep. Only exception has been pan gaskets for transmissions, fluid is always dripping from the trans pan area, you get trans fluid mixed into the RTV before its cured it can leak, I've had the best luck with trans pans just using a flat gasket and spray tac if I use any sealant at all with it.

Anaerobic sealant is for flanges, basically 2 machined precision flat hard surfaces that will NOT bend/flex, i.e. it doesn't really need a gasket to begin with. When you bolt the surfaces together, the anaerobic sealant is deprived of air, which causes it to cure and it forms a almost shellac stain inbetween to prevent leaks. I haven't done a transfer case, but it seems from the outside, that this is the kind of surface anaerobic sealant is designed for. Like mentioned, it looks like red jelly, once you've bolted the flanges together and its cured and you pull it apart, it looks like shellac has been painted on the surface, you have to carefully shave it off with a razor blade (razor blades can really mess up aluminum if you're not careful) anaerobic sealant is tough to rub off with a scotch bright pad, but easily shaves off.

I haven't seen ATF RTV on the store shelf, if your going to use RTV for this seal, I'd go to the Chrysler dealer and get the Mopar ATF RTV. A good dealer will only charge you $4-$5 for a tube. Really clean off all the ATF, including the entire area where atf will drip down into the RTV, every time I've had ATF drip into the curing RTV, the RTV doesn't seal. Best I can tell, it causes the RTV to cure to itself and NOT adhere to the sealing surface and then ATF can continue to leak past it.

 

[wolfpackjeeper]

fwiw, on the Tcase whatever works for you is the way to go. but I would avoid using anything on the transmission pan. If it has a rubber gasket then put it on dry and torque to spec. The idea being that when you torque down a pan with permatex on it some will squish to either side and end up in the tranny oil where it will do the internals no good. Now I do not know if there is truth to that or not, but When I worked parts for a few years we were always told to tell people that, boss says they had a string of people come in with tranny problems they could trace back to a filter install where they were told to use black RTV.

I put my pan on dry and it does not leak

 

[KingOfTheHill]

If you've had trouble before, try this:
Make the layer as smooth and even as you can with your finger.
Let it set up for about a half-hour (soda and sandwich time.)
Install the case halves loosely - just set them together, and tighten the screws finger tight only. Go do something else for a half-hour or so.
Come back, and gently torque the screws to spec (probably somewhere around 19-21 pound-feet. If it's listed, it's on my site - all of my specs are culled from FSMs.)

That should give the RTV more time to cure, which should help. I've used this on difficult seals before.


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YUP... perfect execution

 

[Rick Anderson]

fwiw, on the Tcase whatever works for you is the way to go. but I would avoid using anything on the transmission pan. If it has a rubber gasket then put it on dry and torque to spec. The idea being that when you torque down a pan with permatex on it some will squish to either side and end up in the tranny oil where it will do the internals no good. Now I do not know if there is truth to that or not, but When I worked parts for a few years we were always told to tell people that, boss says they had a string of people come in with tranny problems they could trace back to a filter install where they were told to use black RTV.

I put my pan on dry and it does not leak

Totally agree, uncured RTV acts like a lubricant that lets the pan gasket (long thin strips between bolts holes) to squish out and forms leaks.

I have done dry flat gaskets and never had a problem. Lately I have been using Spray Tac on the gasket, which works well and is convenient. Spray Tac is just a sealant that also acts like spray adhesive. How much it helps seals, probably only slight at best, but it does act like a glue to hold the pan gasket on the pan and when tightening it down, it helps resist the gasket from squishing out in between the bolts.

Remember we are talking the trans PAN gasket here, NOT the flanges of the trans-engine or xfer case-trans.

 

[Talyn]

I used "The Right Stuff" several times on both oil and tranny fluid. I used it on my transfer case for a SYE install 5 years ago and still no leak. Just another option.

 

[fyrfytr1717]

I haven't seen ATF RTV on the store shelf, if your going to use RTV for this seal, I'd go to the Chrysler dealer and get the Mopar ATF RTV. A good dealer will only charge you $4-$5 for a tube.

My local Mopar dealers don't seem to be big on stocking sealants for retail sale. They didn't have the Mopar ATF RTV either. Wonder what they use in the shop? I managed to find the Permatex ATF RTV on the store shelf at one parts store, I think it was Pep Boys. I had already decided to go anaerobic at that point though.