^ lol X5SND, I was just clarifying my reasoning for suggesting the transmission fluid.

The problem is the transmission slips on every gear. If it has a problem of shifting gear, I think it will be less serious. The car is not even drivable. I need to get it tow from place to place to get it check.

No, he said broken component. The transmission.

Where to start?

Reduced viscosity doesn't suddenly prevent it from driving. Fluidity? The state of being a fluid? It it didn't have fluidity it would be a solid. The opposite of reduced viscosity. You appear to be suggesting that it has both properties.

Anti foaming is a fair comment. Doesn't just happen in one day though. Yes, that can affect shifting. But to suggest that it suddenly ran out of the additive package and then wouldn't drive at all is a stretch. Don't you think those shops that looked at it saw the fluid? And if it was suddenly foamy that they ignored that?

If the fluid stopped lubricating (very unlikely, since oils never stop being slippery, and the lubrication requirements for a transmission are very low) then internal components would wear to the point of failure. New fluid wouldn't help at all, until after the transmission was rebuilt. Needless expense.

Why would the gears need to catch? They are permanently engaged planetary sets.

In short, the suggestion to change the fluid after the transmission has stopped functioning is misguided at best. Adding in a recommendation to use a specific fluid is the definition of blowing smoke.

I am glad that you have become a supporter of the site. But in your zeal to promote your products, let's not suggest that posters waste money.

Planetary gears still need to catch in order to function bud, you think they just spin and magically everything else joins in. Ive done numerous transmission rebuilds, im actually completely building the 3 speed for our baja as well a 4 speed sequential for the formula. Oil doesnt being slippery but it does lose its lubricating abilities due to thermal breakdown of the molecules, additives can in fact wear out. The conjuction of all these factors can hinder driveability, basically from what your saying you dont need to change your oil? JCL you may think im blowing smoke, but i grew up around cars and automotive engineerings my major. Ive studied synthetic lubricants and have done tests in a lab using equipment dedicated for the testing and development of chemicals, ie a mass spectrometer. What many people fail to understand is lubrication is a HUGE factor in any components that utilizes the fundamentals of mechanics, or moving parts. And there is ABSOLUTELY no such thing as a magic oil that will last forever, thermal dynamics as well fluid dynamics in Automotive Engineering will teach you just that. I was making a suggestion that, in my professional career, i have seen help if not cure driveability and funtionality. Dont take offense, im merely stating that you should not be so quick to judge and jump to conclusions.

I'll go and think about how to get a permanently engaged gear set to 'catch'. I had always worked to the understanding that clutches engaged the gear sets, not that the gears themselves somehow disengaged.

Oil remaining slippery is another way of saying that it never loses its lubricating abilities. It can change viscosity, it can get dirty, but it doesn't stop lubricating. It especially doesn't stop doing so suddenly, ie in one day. And the transmission fluid is much more of a hydraulic fluid than it is an oil.

I never said you should never change your oil, you made that up. The OP doesn't have a drivability problem. He has no drivability, ie it doesn't move. Never seen an oil cause that, at least not without causing other problems that would then require repair. That means that changing the fluid can't fix it by itself, the resulting broken part would still be there.

Go back to the transmission not driving, a sudden failure in this particular case. The only thing the fluid needs to do is be non compressible, and for there to be enough of it. Other characteristics will impact the life of the transmission, but a sudden lack of drive suggests a mechanical, hydraulic, or control problem, not a fluid problem.

Good luck with your Formula SAE and Baja competitions. I once ran a collegiate automotive design competition. Went to work for one of the sponsors almost 30 years ago.

It can gradually degrade leading to further issues down the road. Mind you i did also say if the whole trans does need to be replaced he can get them from a pick n pull. I love pickin up stuff from those places, shoot my chevelle has a beefed up turbo 400 trans i found out there. I may pick up an ecoboost motor soon to swap into my Raptor once its delivered.