Transmission Fluid

[disallow]

I have been tossing around switching to a synthetic trans fluid for a while now, as I run bypassed and do a lot of towing. The fluid I drained from my trans is pretty dark, though I expected worse.

We use a lot of Mobil Delvac Synthetic transmission fluid in vehicles at work. It is TES-295 certified for Allison Transmissions. I compared the specs on the websites of each respective company of what I use today (Valvoline maxlife, claims to be compatible with Matic J, S, K, and D) and this Mobil stuff, and the numbers are pretty similar from what I can tell. Viscosity is higher, which I would expect from a synthetic anyways.

I can buy a 5 gallon pail of this stuff for $100, or by the gallon for $20. Cost is the primary factor here, buying synthetic (if I can find it) would be about $50-75 a gallon for other synthetics or specialty oils.

Thoughts? Could I get away with the Mobil 1 Delvac?

t

[Tzvier]

not really sure it would be worth the risk. The compatibility it lists is for "Heavy Duty Trans", not sure ours qualify.

This was a good read and maybe you can pull something out of it I didn't
http://www.clubfrontier.org/forums/f8/t ... c-j-55979/

[smj999smj]

I've been using Valvoline Maxlife ATF in my 06 LE and 08 SE and it's been just fine. I'm going to stick with it!

[cgray]

Same here, I dont see a reason to switch. I tow a camper and boat and have not had any issues. I have also done the bypass as well.

[dawgn86]

Cgray

do you use the Valvoline ATF as well?

105k miles on my 06..never have had the ATF fluid changed. Have done the bypass too

[cgray]

Yes I do, I use maxlife for the tranny and transfer case. I changed both around 90k.

dawgn86: You probably want to get that changed/flushed if you are over 100k on original oil.

[dawgn86]

Cgray...you are correct on that..need it done asap

I was curious about doing what I have heard referred to as a "poor man's flush" hook the trans lines to 2 five gallon buckets...one for the old and one filled with new ATF. should be able to exchange the 12 quarts?

have you heard of this?

[disallow]

I've thought about doing this, but I'm not sure how much more effective it would be than drain and fill because your only diluting your 12qts of fluid with 4qts of new fluid each time. With the drain and fill, my math works out to the following, assuming a 4qt drain each time, the following is the concentration of the 'old fluid' at each drain interval:

#1 - 66%
#2 - 43%
#3 - 29%
#4 - 19%
#5 - 13%

I stopped at #3.

Doing it using the bucket would probably still only accomplish a partial flush, unless you run until its clear, as the new fluid would get mixed with the old as soon as it runs into the transmission. Based on the numbers above, you would need at least your 5 gallon bucket full of new fluid to get a full change, if not more. Based on my cost of $25 for 5L, that means its $100 to get a full change.

Not sure I was really clear on this, if the above seems to be gibberish, let me know and I'll take another run at it.

[smj999smj]

Trans flushing...even if using a fluid exchanger like dealers use...will never get all of the old fluid out of the transmission, but it does do a lot better job of getting more of the old fluid replaced during a service. Five gallons is a bit much; most fluid exchangers are usually filled with 10-12 quarts of ATF. One can essentially do the same thing as the exchanger by simply finding the return line on the radiator (or cooler, if you bypassed the radiator). Route the return line into a container (5 gallon bucket will work or several 1 gallon containers) and plug off the line going back to the trans. Install a trans funnel in the dipstick tube and start the engine. As the fluid exits into the waste containers, gradually replace it with new fluid. When done, reassemble the cooler line and dispose of the old oil appropriately. Hint: it's better to drain a little more than you fill because it's a lot easier to top off the fluid when you're done putting it all back together than to have to drain some off if you're overfilled!

[dawgn86]

Sorry..didnt mean to imply 5 gallons of ATF...only meant using 5 gallon buckets to drain old fluid into and one bucket for holding fresh ATF and let the other line suck it back into the transmission.

Think I will just drain out as much as I can through the pan and refill with new ATF. ...

[disallow]

My fluid was pretty dark, so I did 3 drain and fills. The fluid is nice and clear on the dipstick now, but to be honest, came out pretty dark out of the transmission.

I won't be neglecting my yearly trans fluid change anymore...

t

[dawgn86]

Terry

you went with the Valvolline Maxlife ATF correct?

[disallow]

I had 4qts of matic J kickin around, so used that for flush #1. After that I used the Valvoline Maxlife high mileage I found at Walmart for $25 for 5qts. Still have almost enough to do one more drain and fill.

Fluid came out dark, but transmission is acting totally normal. So far anyways.

[dawgn86]

My fluid on the stick still shows reddish, although somewhat darker than I would want. How many miles did you go between drain and fills?

[disallow]

Probably around 30-40k miles. And you have seen what I tow. Its been 2 years, and I've probably done about 1000 miles of towing my behemoth camper, with a bypassed trans cooler.