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synthetic transmission fluid...........

Discussion in 'The Garage' started by funkycold, Oct 6, 2004.

  1. funkycold

    funkycold 1/2 ton status

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    synthetic transmission, like Redline, Amsoil, Lucas, and all the others.... are they worth the cost of them, or should regular transmission fluid be used?
     
  2. hi pinion

    hi pinion 3/4 ton status

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    i run mobil 1 in my 700....and in the eng, i dunno but when i switched to synthetic in my work van with 70k on it i felt a world of difference, in all aspects, fuel mileage, performance, etc,i think the same may apply with the trans but i could be wrong......ill never go back, the miles on gas saved with this stuff is worth it alone,i think its a great idea. /forums/images/graemlins/thumb.gif
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Yes, absolutely worth it. Fluid is the meat and potatoes of an automatic transmission. Once heat breaks it down, the fluid is no good, and eventually, neither is your transmission.

    If I ever buy another auto (Doubtful) I'll definitely use synthetic.
     
  4. CR

    CR Registered Member

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    You hear all kinds of things about syn. oils and fluids, both good and bad. I have runs syn. Mobil 1 motor oil and trans fluid in every vehicle I own for close to ten years. Both are good products and IMO can help get more miles out of a vehicle, but they dont make up for poor maint. practices.
     
  5. fad2blk99

    fad2blk99 1/2 ton status

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    *Hijack*
    I've been mulling over this myself...
    Between the four brands of ATF mentioned, who's is reccomended the most--Amsoil, Lucas, Mobil 1, or Redline?

    When changing to a synthetic, what about all the old oil left behind in the torque converer? Should I do a couple fluid changes over a few weeks to get most of it out-- or would that be just a waste of time and money?
     
  6. SUBFAN

    SUBFAN 1/2 ton status

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    Change once a year, and it will get worked out. There are ways and places that will completely flush out the old fluid.
     
  7. 88Silverado

    88Silverado 1/2 ton status

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    I guess I differ in opinions here.
    Its true a syn fluid may take higher heat and help the trans run a few degrees cooler in temp but if your running the temps needed for a syn fluid your starting to destroy seals and melt parts. Most standard trans fluids are good into the 300+ temps before they start to "Burn" or turn to varnish. Until the last few years with all the syn hype, standard fluids were fine. In fact, Allison, etc run/ran standard trans fluid in all their big transmissions like trash trucks and busses.

    When I was talking to the guys at Bowtie Overdrives about fluid type when I bought one of their Stage-2 transmissions the basically had the same philosophy I have. Buy whats cheapest and change it once a year or 20K miles so and you'll be fine. If you burn the fluid from getting it too hot, change it immeadiatly and hope you didnt do damage to the seals in the process. Theres links of fluid temp versus change intervals that have been posted before.

    Theres a couple different ways to flush the whole system. I buy a case of Chevron fluid at Costco for ~$13 and completly flush mine about every 1-2 years. Cheap and easy and ALOT cheaper than Syn. Lack of Transmission maint. is the main thing that kills an automatic trans IMO.
     
  8. hi pinion

    hi pinion 3/4 ton status

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    Ive heard this before too, (about the tranny fluid,Not the oil) that its not good for tranneis, but ok in motors...........i wonder how can that be though???? If you can feel it working tremendously well in the motor,compared to crude oil,why wouldnt it be the same for the TRANS??? I dont get it. /forums/images/graemlins/confused.gif /forums/images/graemlins/thumb.gif
     
  9. 88Silverado

    88Silverado 1/2 ton status

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    From what I have been able to determine is if the trans has some miles on it or hasnt been "Freshened up" in quite awhile the seals, clutches, etc are use to the properties of the mineral based oils. Changing over to Syn, which has different lube properties can cause shifting problems cuz the old parts have been use to the other stuff for so long. If the trans is relatively new or rebuilt, switching to a Syn fluid may be a good idea, especially if you go to the longer change intervals like 100K miles. When I changed to Syn on one of my old transmissions it never shifted right until I went back to mineral based fluid.

    Like I said, I just like to flush the fluid out of mine every 1-2 years. I can get a feel for what the pan looks like and what kinda wear material is being collected. The pan holds about 3 quarts of fluid where the converter and valve body hold around 10-12 quarts. When you do the standard change, you are just diluting the old fluid with a couple quarts of new. 12 quarts of Chevron ATF is $12. I do a complete flush and know I got good fluid. Figure at $3-4/quart for Syn, that becomes an expensive change. But if you do it once or twice over the life of the vehicle, its probably a wash.

    Doing a full flush is pretty easy. Just disconnect the return line at the radiator (upper line) and connect a hose to it and drop it into a 5 gal bucket. Start the truck and run for about 3-4 seconds. Shut off and add 3-4 quarts of fluid. Do this 3-4 times and youll be flushed. If you dont want to break the line you can use a syphon pump and stick the tube down the filler neck, suck 3-4 quarts out, add 3-4 quarts, start and run for 3-4 seconds and repeat until the new fluid appears.

    Of course, do this AFTER you have the trans warmed up and have changed the fluid and filter in the pan /forums/images/graemlins/thumb.gif
     
  10. funkycold

    funkycold 1/2 ton status

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    I am putting a new transmission, convertor, new cooler lines, and a new cooler. Is there any advantage to using the synthetic over reguler transmission oil for a new transmission?
     
  11. Diesel Dan

    Diesel Dan 1/2 ton status

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    I switched over to mobil 1 on my '00 crewcab when I had to replace the converter. It had about 90K on it, installed new converter and trans-go VB upgrade. Shifts just fine, I went with synthetic for towing. Better lube properties for the planetaries and hard parts. Towed 11K and TC locked up great, have 98K on truck now so still a little early to tell. Figure that was the perfect time to change over since entire trans was drained.
     
  12. jarheadk5

    jarheadk5 1/2 ton status

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    [ QUOTE ]
    In fact, Allison, etc run/ran standard trans fluid in all their big transmissions like trash trucks and busses.


    [/ QUOTE ]

    Not sure where you got that info from, but our Allison shop uses a certain spec of hydraulic oil (petroleum-based, not synth.) in the heavy Alli's. I asked the Alli shop foreman about it the other day (before this thread came up) and he says it's similar to ATF (which is a type of hydraulic fluid), but not the same stuff we're talking about.
     
  13. 88Silverado

    88Silverado 1/2 ton status

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    Allisons use standard Dextron ATF fluid (non synth) or C4 rated fluid. The ONLY Synth fluid Allison will warranty use with is the new Transynd which they have the market on. Otherwise the ol AT-545 Bus trans and the MT-643 trash truck trans etc. use plain ol Dextron ATF fluid or C4 fluid, which the Chevron Delo-400 15-40W Motor Oil meets.

    What I was trying to say is basically its up to the user to determine if the cost of going to Synthetic ATF fluid is going to give them any advantage over Dextron-III. /forums/images/graemlins/dunno.gif
     

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