to start car is a 03 cavy with a 4t40e and i had the tranny fluid change at 54,000. the car has almost 100,000 miles and planning on changing the fluid again but was just wondering if it would be worth it to go synthedic or stay with the regular......if it is worth it was curious what everyone else is using in theirs



thanks in advance







RIP JESSE GERARD.....Youll always be in my thoughts and prayers...

Basically, I'll tell you the same thing we tell customers at work, that being, synthetic transmission fluid is recommended, though still not an absolute necessity, for vehicles that will be placing an excessive amount of stress on their transmissions. The primary candidates for this type of driving are those people who tow often, or tow large loads. Obviously, other scenarios occur in which a transmission is placed under greater than normal stress, and we try to determine this by asking customers about their driving habits/conditions, and also taking into consideration their current drivetrain setup.

The bottom line being, yes, synthetic is better. If you're simply driving around town or to and from Grandma's house, do you need it, no. However, if you have the extra money and want to be overly cautious while showing your car some love, go for it.

It is the same as motor oil. I see countless customers use synthetic motor oil but their vehicles, in combination with their usual driving conditions, will never reach the threshold at which they will gain any noticeable benefit over conventional oil. But as in the above, they don't mind paying the premium for that extra little piece of mind.

On a side note, we use Mobil 1 Synthetic ATF for the majority of synthetic-based transmissions. Mobil 1 Synthetic ATF

id say def. do it, but this time get the fluid flushed out professionally and have the filter changed as well.

i wouldnt recommend putting synthetic in either, everything has been worn and clearanced to regular fluid, you put synth in and things wont be the same. you may even end up buying a new tranny. if your car was still basically new, i would say sure though. but not now because of the higher mileage.

The only way I would run synth is if you get the fluid flushed out and put the synth in. This can be very costly to do. Probably a easy $200.



FU Tuning

z yaaaa wrote:i wouldnt recommend putting synthetic in either, everything has been worn and clearanced to regular fluid, you put synth in and things wont be the same. you may even end up buying a new tranny. if your car was still basically new, i would say sure though. but not now because of the higher mileage.

I'm not saying that I disagree with this statement, but at the same time, I don't fully agree. I would be much more concerned about viscosity compatibility. A recent example involved a guy at the shop not paying attention as he flushed an 06 Chev with Dexron III. It just so happened that this truck had one of Chevy's newer Hydra-Matic trannys that requires the new Dexron IV. The vehicle returned to our shop about 10 minutes after he picked it up. It was generating DTCs and wouldn't shift out of 2nd. The pan had to be dropped, filter changed, and the entire system needed to be reflushed with the Dexron IV.

Also, we "upgrade" transmission fluids on a fairly regular basis and have yet to have a transmission fail, or even throw codes for that matter (this is not to say that it absolutely can not happen, though I personally have yet to witness it first hand). I have however, seen instances where people have never maintained their fluids, or, have purchased a used vehicle which has been neglected. Their fluid is then severely burnt and brown in color (resembles motor oil) and gear filings are present on the dipstick. We disqualify service on such vehicles on the basis that whatever damage has occurred, it has occurred, and can not be reversed, furthermore, in many of these instances, filings have collected internally, and when flushed may become dislodged. As per usual, select customers know more than us, who do this on a daily basis for a living, and insist that we do it. Ultimately, numerous transmission failures have occurred in these situations. The "best" instance of this is the guy that made it approximately half a block from our shop and had his transmission die. Apparently we did know what we were talking about after all...

John Higgins wrote:The only way I would run synth is if you get the fluid flushed out and put the synth in. This can be very costly to do. Probably a easy $200.

I guess I just assumed that you would be flushing it, but like John said, that is the only way to go. Simply doing a pan service only removes approximately 1/3 of the fluid on most vehicles. Try to find a shop that utilizes a natural flushing system, in that it uses your vehicle's transmission as the driving force, and not the machine's power. One of the simplest ways to spot this is, when the flush is occurring, your vehicle should be running, and the machine should not be plugged into any air lines or power sources (may possibly be plugged in for a light or powered gauge however). The only connections should be two lines, one for the out (waste) and one for the in (new). Yeah, it's more expensive than pretty much every other "routine maintenance" procedure, but then again, it's a lot less than a new transmission.