Amsoil ATF in Transmission?

Timothy60 · #1 (**permalink**) 10-23-06, 10:49 AM

Hello, My 93 Fleetwood has 161,000 miles on it and the transmission still works fine. I last had the transmission drained and the filter replaced at 150,000 miles. My mechanic suggested that I might consider draining the Mobil ATF that is in there now and replacing it with something called "Amsoil ATF". He said there is a special way of pumping out the old ATF until the new Amsoil comes out of the lines clean. He said the Amsoil will help me get the maximum life out of the transmission. OK, here are my questions:1. Is this a good idea if the tranny is working totally fine?2. Could a product like "Amsoil" actually be better than GM specified ATF?I'm taking the Caddie in for NYS inspection Wednesday, so I could have it done then. What do you gentlemen think?Thank you.

Wheelman322 · #2 (**permalink**) 10-23-06, 11:18 AM

I never tried thier ATF, so IDK, but what I do know, is that I am highly facinated with AMSOIL motor oil. I used to turn wrench for a living and have actual customer testimony that these oils have extended the life of there vehicles. Customers would come in raving about how thier gas mileage improved and thier cars actually felt smoother. It got to the point where all of the guys I worked with switched over to AMSOIL in there vehicles. I use nothing but AMSOIL motor oil, but was considering swapping out the ATF in my cars, and giving it a shot. I figure if thier MO's are this good, the ATF can't be too far off.

N0DIH · #3 (**permalink**) 10-23-06, 05:24 PM

FWIW, I ran amsoil ATF in my 91 Bonneville when we got it in 1994 @ 58K miles, and the car just went the boneyard (we gave it away 2 years ago) and at 275K, the trans still ran well and did not slip, shifting nice as always. I have never noticed a significant degradation in performance in the 200K we had it. I did NOT religiously run Amsoil ATF, it leaked a little on the pan, so I would have to add a pint or so every 20K miles, so I often didn't have Amsoil on hand, so I ran Mobil 1 10W30 engine oil. So it stayed synthetic most of its life until the new owners who had it (who didn't care for it well at all, why not, free, duh, run it into the ground and junk it.... last time I do that to help out...) only ran ATF, and whatever is dirt cheap...

So, yes, synthetics are often cheap investment. You can't prove easily if you ran petroleum based if it would have lasted as long or not, but likely knowing the antioxidation and higher base number of synthetics, very likely it would last longer. The cost of a drain and refil of Amsoil (just do it GM way, drop pan, R&R filter, and resinstall and add fluid is all you need to do. Don't waste $$ on flushing or trying to do more than GM recommends. Not worth it.

C66 Racing · #4 (**permalink**) 10-23-06, 09:56 PM

Quote:

Originally Posted by Timothy60

OK, here are my questions:1. Is this a good idea if the tranny is working totally fine?2. Could a product like "Amsoil" actually be better than GM specified ATF?I'm taking the Caddie in for NYS inspection Wednesday, so I could have it done then. What do you gentlemen think?Thank you.

I'm obviously biased, so please feel free to take this with a grain of salt.

1. In my opinion, yes. The reasons for this are in my answer to #2.
2. The GM Dexron II/III fluid is not synthetic. AMSOIL ATF, which incidently is the same fluid I use in my 2002 Corvette Z06 manual six speed gearbox which sees only track use, is a Group IV PAO based synthetic. This provides numerous benefits which can be seen on the link to my dealer website. In short, they are:
- Resists Oxidation and Thermal Degradation
- Provides Low Temperature Protection
- Antiwear Protection
- Extends Drain Intervals

Timothy60 · #5 (**permalink**) 10-23-06, 11:00 PM

Thanks for the input. I'm going to go ahead and have the Amsoil ATF put into the tranny on Wednesday. From what you've said, there doesn't seem to be any negatives to this choice. I'm also having new AC air shocks installed on the back axle. There goes this week's pay check! Thanks again for your advice, gentlemen.

N0DIH · #6 (**permalink**) 10-24-06, 09:28 AM

Only negative is the cost, but when you factor in a rebuild later, and the possibility that it will push that out a lot more, it is well worth the cost.

While you are at it, get an extra quart and drain as much power steering fluid out too, it works well in power steering too.

Timothy60 · #7 (**permalink**) 10-26-06, 11:04 AM

Picked up my Fleetwood yesterday after work. I'm really impressed with the new AC Delco air shocks in the back. What an improvement they make! But I'm even more impressed with the Amsoil in the transmission. The difference was immediate and dramatic. The shifts are crisp! I didn't have the flush done; just the pan dropped, new filter kit, and Amsoil. Thanks for your advice because it was money well-spent.

Timothy60 · #8 (**permalink**) 10-26-06, 11:12 AM

Picked up my Fleetwood yesterday after work. I'm really impressed with the new AC Delco air shocks in the back. What an improvement they make! But I'm even more impressed with the Amsoil in the transmission. The difference was immediate and dramatic. The shifts are crisp! I didn't have the flush done; just the pan dropped, new filter kit, and Amsoil. Thanks for your advice because it was money well-spent.

C66 Racing · #9 (**permalink**) 10-29-06, 01:55 PM

Quote:

Originally Posted by Timothy60

... But I'm even more impressed with the Amsoil in the transmission. The difference was immediate and dramatic. The shifts are crisp! I didn't have the flush done; just the pan dropped, new filter kit, and Amsoil. Thanks for your advice because it was money well-spent.

Glad to hear the change worked out well for you. Thanks for the feedback!

creeker · #10 (**permalink**) 10-29-06, 05:41 PM

Is it safe to mix amsoil synthetic ATF with ordinary ATF?. tnx,if you replace
filter you only drain about half of the fluid. tnx

C66 Racing · #11 (**permalink**) 10-29-06, 06:02 PM

Quote:

Originally Posted by creeker

Is it safe to mix amsoil synthetic ATF with ordinary ATF?. tnx,if you replace
filter you only drain about half of the fluid. tnx

Yes. AMSOIL lubricants are compatible with both synthetic and conventional lubricants from other companies.

Hammondsix · #12 (**permalink**) 10-29-06, 07:02 PM

well i poured fluid in the tube while the cooler line was disconnected so it spat the olds stuff out. managed to change all 15 quarts. Is it bad for the tranny to be deprived of fluid for short moments while in park?

N0DIH · #13 (**permalink**) 10-29-06, 07:09 PM

Talk to Shane at CPT (he just had a baby or wife is in the hospital, so he isn't very responsive at the moment).

I would say it damaging, but how long is how bad, I have no idea.

C66 Racing · #14 (**permalink**) 10-29-06, 07:52 PM

Quote:

Originally Posted by Hammondsix

well i poured fluid in the tube while the cooler line was disconnected so it spat the olds stuff out. managed to change all 15 quarts. Is it bad for the tranny to be deprived of fluid for short moments while in park?

I'm not an automatic transmission expert, but I suspect that even with the tranny in park, the engine's driveshaft is spinning some components in the tranny implying that it isn't good to have it running without fluid. As for how bad it really is, I have no clue. Hopefully, since it was for a short time and there was no load on the tranny, you may be okay.

creeker · #15 (**permalink**) 10-29-06, 10:14 PM

Hammond six,just curious,you said you used 16 qts. of a.t.f., my 80 cdv only calls for 4 u.s. qts. after a complete drain.