Synthetic ATF or no Synthetic

[drifter420]

Hey Guys and Gals..

Will be lookin into doing a full flush ( via tranny pump method fill/run/fill etc. )

My car is a 97 SSEI with 4T65E-HD and was told not to run synthetic cause there's too much slippage and shorten the life more then regular tranny fluid.

I was also thinkin of adding in Lucas tranny fix as precaution but apparently it's not the best and the other option ( can't remember the name of that brand now ) I have never seen in Canada..

My question is.. if my mechanic and other bonneville owners are sayin not to run synthetic. Should I not?

It also calls for ATF IIE. Is there a better kind I can use without going synthetic?

 

[JAYCEE]

If other owners are reporting problems with synth, don't use it.

Auto-RX is good in automatics, especially neglected ones.

 

[unDummy]

Do not use ANY additives as a precaution.

Synthetic will not cause it to slip or shorten its life at all.

Mechanics mostly talk out of their ......

Have no fear in using Mobil1/Torco/Neo/RoyalPurple/SpecialtyFormulations/Amsoil/Redline/.... ATF.

Also, one of the best synthetics out there for long life transmissions is at YOUR GM dealer and called Transynd(which is a synthetic).

An aftermarket ATF cooler and aftermarket filtration will go a long way in preventing future mechanical failures.

Shift kits/VB mods can also tighten up a soft shift.

http://thrashercharged.com/l67_htm/shiftkit.shtm
http://www.transgo.com/sk_generalmtrs.php
http://www.perma-cool.com/Catalog/Cat_page25.html
http://www.magnefine.com/html/filtration.html

 

[oilboy123]

Sounds like a very knowledgeable mechanic to be.....not! A non syn oil will have more of a chance for shorter trans life, especially if it is not changed fairly often.

Run it with confidence. Depending on the mileage run RX then a good syn fluid. I have been running syn for years in vehicles. Two vans that I bought with bad transmissions I put syn in from the start.

My Dad has one and he drives the heck out of it and it still shifts perfect.

 

[ConfederateTyrant]

Go with a synthetic ATF, it'll last longer (if cost does not matter then change it as often as you wish), it can handle heat transfer better than non-synthetic, and you may be able to get some additional mpg. I've had great results with Amsoil Universal ATF, as have many others.

Ask this mechanic his opinion on synthetic oils, whether it's motor oil, gear oil, or ATF. Some mechanics are quick to say such things to deter people from using certain products because mechanics want their customers to believe them, and if the customer listens to everything the mechanic has to say, it opens a window of opportunity for mechanics to take advantage of their customers. This does not always happen and I do not mean to imply that all mechanics are liars, I've known some trusted mechanics who know their stuff. Do your homework! You came to the right place to research the suggestion that your mechanic has stated.

I agree with the suggestions of running Auto-RX first, then switching over to a high quality synthetic.

 

[wileyE]

The smart mechanic would recommend the EXACT specification fluid that the tranny calls for and NO additives. Some of these new tranny are real sensitive to fluids. Most the modern spec fluids are group3 or better, so by definition they all could be marketed as synthetic (but aren't).

 

[mechtech]

I'm not sure the synth ATF will slip more than the dino. They are friction modified to be the same. But if it did slip more, it wouldn't cause wear. It would be the fluid's less internal friction.
I'd use the synth ATF - it won't break down in an auto trany nearly as fast as a dino.

 

[mcrn]

i agree to use synthetic i think it is more important in an auto tranny than anywhere else. but if it does cause more slipping wouldnt that increase the heat? but then just get a shift kit like mentioned above but i think as long as its the same spec then there should be no problems.

 

[oilboy123]

Just because it is synthetic does not mean it will slip more.
Even though it does not seem so it would probably clean the clutch plates and slip less than a dino fluid.

 

[vizvo]

wileyE has it right. Go by the book. Don't forget to check for any relevant TSBs. To buck the knowledge of an experienced tech, and the findings of fellow Bonneville owners would seem to be betting against the house. How lucky do you feel?

Synthetic is good for temperature extremes. But Ontario isn't exactly the arctic circle. A quality name brand non-synthetic which meets spec will work fine.

 

[The Critic]

In Canada, the Petro-Canada Dexron-VI fluid would be the best choice for your transmission. It would offer the best long-term fluid durability, cold weather performance, and fuel efficiency over Dexron-IIIH. Depending on the cost, it would be the next best choice to a full-synthetic ATF.

If the cost of the Petro-Canada Dexron-VI is too high, Petro-Canada also produces a synthetic blend Multi-Vehicle ATF that has very impression specifications.

Either way, do a pan drop and filter change prior to performing a complete system flush. It is better to do a pan drop and filter change versus doing a complete fluid change without a filter change. Using either of those fluids, and even if you only perform a pan drop/filter change, I don't see why you cannot run the fluid for 50,000 miles until the next service.

 

[oilboy123]

You don't have to go synthetic. I myself like to, but to each their own.
If you run a dino fluid just change it fairly often. Good luck

 

[Greaser]

Been using Mobil 1 ATF (synthetic)for drain & fills in my 99 Jeep Cherokee's AW4 tranny since new.Do moderate towing and off-roading with it and at 192,000km it's shifts like new.

 

[Gary Allan]

quote:

---

Originally posted by wileyE:
Some of these new tranny are real sensitive to fluids.

---

Well, as you can see, this is a decade old trans. Besides the infamous Chrysler Ultraglide with its flawless design that could only be corrupted by stupid consumers using the wrong fluid (cough-cough) ..fluids haven't seem to plague the GM lineup. Nor were Ford failures attributed to improper fluid usage. All the Ford failures were allegedly due to poor design. Something unique to Fords, I guess. GM appeared to miss that fluid problem all together and design issues too.

Just lucky, I guess.

Use a synth if you want to. All that it will do is withstand heat better and flow better when its cold. No more delayed engagements @ -30