Im having the trans rebuilt and installing a yank 3500 , 373 gear. Whats the best auto trans fluid to use, amsoil ? :steering:

 

 

I've heard good things about GM synchromesh as well. Less hype than the other TL's out there, but just as effective without the worries about swelling seals, etc....

 

Amsoil claims three times the oxidation resistance as OEM stuff. Works good for me. :smash: :)

 

:iagree: :iagree: :iagree: ...The BEST!!

 

My suggestion is ask your rebuilder, you trusted his abilities and I'm sure he won't steer you wrong. Ron B.

 

DexronIII is all you need. Most rebuilders recommend this fluid, only $6 bucks a gallon at Pep Boys. If you change it every 10k miles (normal driving) your tranny will last a long time.

 

Right BHP :crazy:

This guy is installing a Yank3500 and has 3.73 gears, and he's hoing to drive this thing "NORMALLY" ???

Jim

 

Hope he has a cooler. So he will change sooner. :p:

 

Another option: Redline Racing ATF, with a shot of D4 ATF (about a 3:1 ratio Racing to D4).

I use that in my transmission now. I spoke with the engineer at Redline about it, the Redline Racing ATF is basically Type F fluid, but better.

Here's what I got for info between him (fluid info) and my tranny builder (mechanical info):

Redline Racing ATF: Type F, has better lubricating properties and higher temperature tolerances than Dexron III (Redline D4) ATF. Also, has no friction modifiers, so it doesn't allow the frictions to slip before locking-up.
The Racing ATF is also higher viscosity (putting some on one finger, with D4 ATF on another finger, the Racing ATF is noticable thicker, and has a different feel to it). The higher viscosity will drop your stall speed a bit, and it will thicken a bit more in cold weather until it warms up.
The only possible concern that the Redline engineer had was possible torque converter clutch shudder due to the lack of friction modifiers, but he wasn't certain it would cause the shudder, as they never tested it in a 4L60E. Other than that, he said it would not only be safe, but possibly be better than the D4 (of course, for obvious legal reasons, he didn't say "Sure, use it").

Redline D4 ATF: Equivalent to Dexron III+, but better than non-synthetic ATF, i.e., higher temperature tolerances, lasts longer, etc. However, the D4 has friction modifiers in it. The 4L60Es are designed to slip as each gear is applied, to make nice, soft shifts for Joe Public. The friction modifiers allow this slip without burning up the friction material (as fast).

Now, from talking to my tranny builder, we agreed that the Racing ATF would be the better way to go with the shift kit in, since it wouldn't allow the slippage. However, just to be safe concerning the possibility of the TCC shudder, and to thin out the Racing ATF a bit for cold weather (the Racing ATF even now acts noticeably different after it warms up), I add a bit of D4 ATF (as I said above, about a 3:1 ratio).

Hope that helps, let me know if you have any questions.


[Modified by Guardsman, 9:04 AM 1/14/2004]


[Modified by Guardsman, 9:05 AM 1/14/2004]

 

Thanks for all the help,im thinking of going with the Amsoil ATF, i flushed the lines and installed a cooler and just waiting on the parts to get here. :seeya :party:

 

fookydo,

I'm curious (because I'm local to you) who is rebuilding your transmission?

 

I went with the redline that has friction modifier, and am not too happy. the tranny just shifts too heavy now. Not awful, but not an improvement.

On the other hand, Redline diff oil did a great job removing the "can of worms" problem.

 

Do you mean you went with racing ATF which DOESN'T have friction modifiers?


[Modified by Richin Chicago, 11:53 AM 1/26/2004]

 

Wow, this concerns me. I am going to put Redline D4ATF into my new tranny and have heard good things about it. I am not using the "race" version just the standard Redline tranny fluid.

 

I used the synthetic high-temp ATF http://www.redlineoil.com/products.htm

It looks like the fluid isn't designed for sub 70 degree temps, and it certainly feels VERY heavy when cold. At least for my climate, I'd recommend stock fluid over the redline.

On the other hand, the Redline diff oil did miracles for the rear diff noise. :steering:

 

"My car shifts easier in the cold with Redline D4 ATF. In fact it was one of the reasons I installed it. From the Redline site:
Also provides tremendously improved shifting in cold weather. The best low-temperature shiftability for manual transmissions and transaxles which require ATFs."

 

I have Amsoil ATF in my mn12 and it's fantastic, but I hear it's not for a-4s. Some "experts" say the syn trans fluid is too sloppery for the automatic to work properly. I've also heard Redline can mess with seals over time, but I'm no expert. :cheers:

 

Rich, I can only report what I've felt. I can also say that the tranny became heavier as soon as i replaced the fluids this past fall, and that I'm not just blaming the cold weather effects on my fluid change.

 

I have gone the Amsoil, Redline, M1 ATF route, but I'm back to genuine GM Dexron III ATF from the Chevy dealer ($2.60/qt.)
Why?

First, you should run the biggest ATF cooler you can fit anyway to keep the ATF temps below 200F. Synthetics really shine in high temp resistance, but I'd like to avoid these high temps in the first place.

Second, I'd rather change my ATF more often (every two years) and use genuine GM Goodwrench Dexron III instead of using ultra-expensive synthetic ATF and leave it in there for more years.

Lastly, some, not many, but some 4L60Es do not like synthetic ATF and start to slip. Many posts in regards to this slipping of 4L60Es in trucks with synth ATF on the LS1 f-body forums, full size chevy forum and on the Pontiac GTP (4T65E) forum. Many went back to GM Dexron III.

When I switched my OEM Dexron out for M1 ATF in my 96 LT1 Vette, part throttle shifts became very soft. Didn't like that at all.

If you have to go the synth route, I would go with Redline as my first choice and Amsoil as my second choice.