Fluid brands?

[RyanbabZ71]

Ok I am getting things together to start changing fluids and filters. My question is what brand of coolant and transmission fluid should I go with? The GM stuff isnt to expensive except the decool is $12.07 a gallon and I need 4.

 

So any suggestions?

 

Thanks

[JayMan]

As far as DexCool, GM got Texaco/Halvoline to develop DexCool. So why not just pop down to the local parts store and use the Texaco/Halvoline brand? That's what I use and it states "GM approved."

 

My fluid list:

 

Front Axle: Mobil MobilLube SHC 75W-90. I have pails of this stuff around for my commercial trucks. It works well in extreme cold and in hot temps. Do NOT use in a G80 rear axle!

 

4L60E: Mobil 1 ATF. I can get it for $5.25 a quart at my local Mobil distributor.

 

Transfer: I have AutoTrak so use the dealer AC Delco AutoTrak II fluid: it's blue, like a Smurf.

 

Rear Axle: Mobil 1 Gear Oil 75W-90 (Approved for limited slip use), $4.25 a quart at my local Mobil commercial distributor. Some folks report lower noise using the new Mobil 1 Gear Oil 75W-140, also approved for limited slip.

[99silveradoz71]

Used the Prestone Dexcool if I recall.

 

Question, I've seen a few of you mention mobil 1 distributors...how do you locate them? Only way I've been able to get it here is from the parts stores...I'd like to flush my ATF, and it'd probably be easier and/or cheaper to purchase the fluid in a bulk quantity instead of the quarts. I checked their site, but I believe it just had retail listings for Ohio.

[RyanbabZ71]

Jay

 

My front and rear diffs are good to go. I already have the autotrac fluid dont need any of that. As far as the trans I plan on dropping the pan and replacing the filter. Did you only replace 5 qts of synthetic?

[carguru]

Jay,

 

Any problems running Mobil 1 ATF? I know that shift quality was pretty crappy when I switched my '99 over to Mobil 1 ATF (full flush). For some strange reason it caused the tranny to shift erratically. I flushed it out after 5k and went back to regular Mobil Dexron III and the shifts did fine. Another friend of mine with a '96 Impala SS had the same experience. Just curious.

[RyanbabZ71]

whered you guys get the regular mobil ATF?

[JayMan]

Used the Prestone Dexcool if I recall.

 

Question, I've seen a few of you mention mobil 1 distributors...how do you locate them? Only way I've been able to get it here is from the parts stores...I'd like to flush my ATF, and it'd probably be easier and/or cheaper to purchase the fluid in a bulk quantity instead of the quarts. I checked their site, but I believe it just had retail listings for Ohio.

The Mobil techline voice prompts have all changed, so I don't know what the exact number is after you get through.

 

Call 1-800-662-4525

 

Or check out the following URL:

 

http://www.prod.exxonmobil.com/channelpart...r_directory.jsp

 

I have noticed that Mobil 1 ATF in 5 g pails (20 quarts) saves you at least $10 over buying quarts.

 

Hope this helps!

[JayMan]

Jay

 

My front and rear diffs are good to go. I already have the autotrac fluid dont need any of that. As far as the trans I plan on dropping the pan and replacing the filter. Did you only replace 5 qts of synthetic?

I did my 4L60E last a couple of years ago, and if I recall the pan drain took 6 qts.

 

Remember to be careful with the shift cable bracket on the driver side of the pan.

[RyanbabZ71]

Remember to be careful with the shift cable bracket on the driver side of the pan.

 

yea I know that looks fun

 

any helpful suggestions?

[JayMan]

Jay,

 

Any problems running Mobil 1 ATF? I know that shift quality was pretty crappy when I switched my '99 over to Mobil 1 ATF (full flush). For some strange reason it caused the tranny to shift erratically. I flushed it out after 5k and went back to regular Mobil Dexron III and the shifts did fine. Another friend of mine with a '96 Impala SS had the same experience. Just curious.

I think you really should switch to a synthetic ATF when new, certainly with less than 5,000 miles on it.

 

With use, you build up crud in the valve body, shift solenoids, the band and clutches wear, etc etc. The synthetic ATF has higher detergents and is a bit thinner, so if there is an underlying mechanical condition, you'll notice it once you change over.

 

Note this applies to using any synthetic ATF.

 

Regular Dex III is a bit thicker so probably cushions everything better, thus the shift quality improves. I suppose as long as you change/flush frequently and use an external trans cooler, you probably don't need synthetic ATF.

 

Here are two conditions where I would insist on using a synthetic ATF;

 

1. Heavy towing near the rated limit, especially in mountain grades and hot temps

 

2. Extreme cold especially -35 F or colder.

 

Remember that for extreme cold, an ATF can't exceed a Brookfield viscosity of 100 Poise or the torque convertor will fail to work and the shift solenoids will be very sluggish.

 

Most regular Dex III ATF fluids reach this limit at -35 F. Mobil 1 ATF is rated at 51.5 Poise at -40 F.

 

I did my first ATF change at 600 miles (Pan drain and filter) then again at 1,200 miles after 600 miles of heavy towing for the first time. Used Mobil 1 ATF both times. Did another pan drain and filter in 2002, pan was spotless.

 

My 4L60E shifts very smoothly in normal use, nice and firm in Tow/Haul mode. At -40 or colder, there is no delay when I shift out of Park.

[JayMan]

Remember to be careful with the shift cable bracket on the driver side of the pan.

 

yea I know that looks fun

 

any helpful suggestions?

Well, I'm sure you've noticed the cable bracket is metal and the shift cable has a plastic collar that slides/locks into it.

 

The first time I prepared for the pan drain/drop, I also noticed the shift cable assembly would interfere with getting a couple of the pan bolts off.

 

I went back to the dealer and they suggested a special tool: it looks like a trim removal tool, with two fingers that fit the retainer clip around the plastic collar.

 

With that special tool, you hook the two fingers behind the collar and gently pry, the retainer clip for the shift cable collar should slowly pop out.

 

You can see the problem here if you go to an independent shop, especially God Help You a Qwicke Lube While U Wait place, and the loser working on it thinks he can "gently" bend the bracket/collar aside.

 

SNAP!

 

With the shift cable, there is enough slack you can carefully move it aside to get those two bolts that are otherwise impossible.

 

Once you have the pan off and cleaned, and the filter changed, just reverse the procedure. My shift cable collar and retainer clip just snaps back into the bracket no problems at all.

 

Note: whatever you do, do NOT grasp the two tangs next to the spring on the shift cable assembly! The Helm warns of this: you will disengage the two ends of the shift cable!

 

Then it's a VERY long and complicated procedure to realign the two pieces so you will have proper shift detent.

[RossT]

do you have a part# for the tool?

[JayMan]

I looked at the tool and it has no part numbers stamped on it. Will have to ask the dealer. I bought it 4 years ago and can't find the receipt.

 

I suppose if you're careful, you could use a small screwdriver with a thin wide blade: gently pry behind the retainer and it should pop off the bracket. Don't pry against the plastic collar though.

[RossT]

Thanks Jay!

[RyanbabZ71]

anyone know where to get plain mobil ATF?

 

I found the havoline coolant at walmart