Fluid changes

[jseabolt]

My 96 AWD has 100,000 miles on it now. I thought I'd change some fluids and new spark plugs. I think the lady who had it before me had proper maintence done on it but you can never be sure.

It had 82K miles on it when I bought it a year ago and I've put 20K miles on it since. It's been a damn good vehicle so far.

Got a few questions. Mainly just to make sure I'm putting the correct stuff in it.

Automatic transmission: I've "heard" that changing the filter will crap the transmission out. Surely not? I've done this on other vehicles with no issues. Or is this if you change the entire fluid in the transmission? Like do a power flush?

They say the new fluid changes the PH inside the transmission and will eat up the bands and clutches. I've never actually read this in any shop manuals, just word of mouth.

I was just going to replace the filter, add three quarts of new fluid and top off as needed.

Transfer case: Any harm in replacing the fluid in the transfer case while I'm at it? Will new fluid crap the transfer case out or is changing it every 60K miles as the owner's manual says a good idea?

Is Costal DexMerc OK to use in the transmission and tranfer case? The jug says for 1988 and newer Ford vehicles. Just wondering if this stuff is compatible with what's already in the transmission.

Front and rear differentials: The Chilton's manual says to use some special fluid if it has locking differentials. Mine is all wheel drive. I wasn't planning on draining the fluid. Just topping off with gear oil if needed. So what's in these differentials? SAE 80 weight or this special oil that Ford sells. That special oil maybe for the V6 models with Traction lock.

I thought about just taking it to the Ford dealer (not those DAs at Jiffy Lube or Wal-Mart) and tell them to do the above stuff since it would be much easier if I had a lift. I'm not as young as I used to be...

 

[SoNic67]

Looks like you are willing to put anything in your truck.
My AWD requires "MERCON V ATF" in the transmission and "MERCON ATF" in the transfer case. In mine I used Castrol brand, originally should be Motorcraft. Dex/Merc should be OK for transfer case (Mercon), but I wouldn't mix it with what you have there now. MERCON V can be used instead of MERCON, but not mixed.
I wouldn't do a transmission "flush" (power flush in a shop), but I would change the filter. Actually, I did install a supplementary transmission oil filter - there is a thread somewere about that.
Front Axle lubricant "SAE 80W-90 Premium Rear Axle Lubricant" and back axle "SAE 75W-140 High Performance Synthetic Rear Axle Lubricant" - last one it should be "lubricated for life" if you don't submerge the axle in water. Actually on my axles there is a tag that says what it needs, something like this on the rear:

 

[asasial]

i flushed my trans. pulled the top line off going into the radiator had someone start truck had another person adding trans fluid as i was watching it come out of the tube did this until it i got clean fluid coming out. shut truck off hooked back up line, and topped off the fluid.

 

[ahodges]

Automatic transmission: I've "heard" that changing the filter will crap the transmission out. Surely not? I've done this on other vehicles with no issues. Or is this if you change the entire fluid in the transmission? Like do a power flush?
They say the new fluid changes the PH inside the transmission and will eat up the bands and clutches. I've never actually read this in any shop manuals, just word of mouth.
I was just going to replace the filter, add three quarts of new fluid and top off as needed.

I've done it both ways with 122,000 on my 1996 V6 tranny with no ill effects so far. This statement is very controversial, but the dealer said that when they do a tranny flush, they don't change the filter. He said that the filter should be good for the life of the tranny.
By doing a flush and not adding any cleaning chemicals you would be safe and is the best way to go.
Either way, I hear the fastest way to destroy and Ford tranny is to use anything other than MERCRON V. Only use MERCRON V in it and you shouldn't have any problems.

Transfer case: Any harm in replacing the fluid in the transfer case while I'm at it? Will new fluid crap the transfer case out or is changing it every 60K miles as the owner's manual says a good idea?

Really any MERCRON V would be ok for the transfercase. Of coarse the dealer recommends Motorcraft which is what I use since it isn't too expensive, but any high quality Mercron V would be ok.

Is Costal DexMerc OK to use in the transmission and tranfer case? The jug says for 1988 and newer Ford vehicles. Just wondering if this stuff is compatible with what's already in the transmission.

I deffinately wouldn't use it in the tranny, but it should be ok for the transfercase.

Front and rear differentials: The Chilton's manual says to use some special fluid if it has locking differentials. Mine is all wheel drive. I wasn't planning on draining the fluid. Just topping off with gear oil if needed. So what's in these differentials? SAE 80 weight or this special oil that Ford sells. That special oil maybe for the V6 models with Traction lock.

The front differential oil can't be changed without taking the axle out, so as long as it isn't leaking any oil then it should be fine. It takes 80W-90.
The rear differential can be changed but really shouldn't need it unless an axle seal or differential cover is leaking. As SoNic67 said, It takes fully synthetic 75W-140. The special oil you are talking about is a friction modifier for a limited slip rear end. You can find out if you have one by checking the axle code on the inside of the drivers door and cross referencing the code. They are online if you search it. You can get the friction modifier if you need it from the dealer. Its only like 4 bucks at the most.

 

[jseabolt]

Looks like you are willing to put anything in your truck.
My AWD requires "MERCON V ATF" in the transmission and "MERCON ATF" in the transfer case. In mine I used Castrol brand, originally should be Motorcraft. Dex/Merc should be OK for transfer case (Mercon), but I wouldn't mix it with what you have there now. MERCON V can be used instead of MERCON, but not mixed.
I wouldn't do a transmission "flush" (power flush in a shop), but I would change the filter. Actually, I did install a supplementary transmission oil filter - there is a thread somewere about that.
Front Axle lubricant "SAE 80W-90 Premium Rear Axle Lubricant" and back axle "SAE 75W-140 High Performance Synthetic Rear Axle Lubricant" - last one it should be "lubricated for life" if you don't submerge the axle in water. Actually on my axles there is a tag that says what it needs, something like this on the rear:

On the contrary. The reason I asked was to be sure I used the correct type of fluids.

I'm having to go by the Chilton's manual because the owner's manual does not list what types of fluids go in the differentials or the transfer case.

The Chilton's manual also contracts what your saying about the rear differential however mine does have the same tag indicating synthetic oil to be used.

Just wanted to be on the safe side and not mix incompatible fluids or use the incorrect and damage something.

The rear differential is leaking so I plan on chaning the gasket so I'll need to add all new fluid. So I suppose I'll need that friction additive as well?

 

[jseabolt]

The front differential oil can't be changed without taking the axle out, so as long as it isn't leaking any oil then it should be fine. It takes 80W-90.
The rear differential can be changed but really shouldn't need it unless an axle seal or differential cover is leaking. As SoNic67 said, It takes fully synthetic 75W-140. The special oil you are talking about is a friction modifier for a limited slip rear end. You can find out if you have one by checking the axle code on the inside of the drivers door and cross referencing the code. They are online if you search it. You can get the friction modifier if you need it from the dealer. Its only like 4 bucks at the most.

The front differential appears to be OK (not leaking).

The rear differential cover gasket is leaking so I plan on changing the gasket so I'll need to add all new fluid. So I suppose I'll need that friction additive as well? As far as the axle code on the driver's side door sticker all it says is D4. Any idea on that one?

So as far as the transmission and transfer case are concerned, I can use the same stuff? Motorcraft Mercon V? According to the Chilton's manual a gallon of Mercon V will do it for the transmission and transfer case (2.5 pints and 3 quarts).

Changing the fluids is not the problem. It's determining what's supposed to go in each component. It would make more sense that there wasn't 10 types of Motorcraft ATF fluid.
My old 68 Ford uses Type F in the C4 transmission.

And two different types of differential oils. And what oil is required for whatever type of differential you do have. And what differential requires the friction additive.

That's why I'm thinking I should just take it to the dealership so they will know what's supposed to actually go in this thing!

 

[ahodges]

Well the D4 axle code stands for a 3.73 gear ratio with the limited slip so you will need the additive. its like a 3 oz bottle you put in before the oil.
Those figures are probably right if you're doing it yourself. The tranny will only take about 3 quarts if you just change the filter and 2.5 sound right for the transfercase too. If you take it to the dealer for the tranny see if they will leave out the cleaner and conditioner additives. It should be about $20 cheaper that way too.

 

[SoNic67]

You can download your owner manual for free here: Dead Link Removed

 

[gavin]

use only Mercon V ATF in the transmission.
It was around 1997 or 1998 when Ford released a TSB stating to not use Mercon, but to use Mercon V instead. This is why the ATF dipstick may say Mercon on it.

If you want to flush out all the fluid, you can actually access a drain plug in the torque converter; the bottom of the bellhousing will have a rubber plug; you remove that, then manually rotate the engine crank until you see the plug through the access hole. It does take forever to drain this way, though, since it's such a tiny hole.
This would also require ~17 (iirc) quarts of ATF, and a lot of time getting it refilled (it took me ~1.5hrs to refill).

Transfercase doesn't really matter. Mercon or Mercon V. The difference between the 2 fluids will not affect the lubrication of a t-case. Since the t-case uses so little, buy a case of Mercon V for both the transmission and t-case.

Rear axle; a lot of full synthetic gear oils do NOT require the friction modifer additive for clutch-driven limited slips. I have used Mobil 1 and Royal Purple gear lube in my rear diff, without friction modifier, and have had no issues.

The front axle; you can suck out a lot of the old oil from the fill hole if you have a hand pump.

The manual calls for 75W-140 for the rear and 80W-90 for the front, I believe. Although depending on your climate and driving habits, you could probably get away with 80W-90 front and rear.

 

[Fifty150]

i flushed my trans. pulled the top line off going into the radiator had someone start truck had another person adding trans fluid as i was watching it come out of the tube did this until it i got clean fluid coming out. shut truck off hooked back up line, and topped off the fluid.

If you get a piece of transmission hose, about 5 feet in length, then attach it to the end of your transmission cooling line going to the radiator, you can drain right into a 5 gallon bucket.

Or if you have a trans-cooler, it is a lot easier to grab one of those lines that is going to the cooler from the radiator, or from the cooler back to the transmission. Remove the return line from the cooler to the transmission, hook up a 2 foot length of transmission hose to the cooler, then just direct the other end into a drain pan.

 

[OutofDate1980]

use only Mercon V ATF in the transmission.
It was around 1997 or 1998 when Ford released a TSB stating to not use Mercon, but to use Mercon V instead. This is why the ATF dipstick may say Mercon on it.

If you want to flush out all the fluid, you can actually access a drain plug in the torque converter; the bottom of the bellhousing will have a rubber plug; you remove that, then manually rotate the engine crank until you see the plug through the access hole. It does take forever to drain this way, though, since it's such a tiny hole.
This would also require ~17 (iirc) quarts of ATF, and a lot of time getting it refilled (it took me ~1.5hrs to refill).

Transfercase doesn't really matter. Mercon or Mercon V. The difference between the 2 fluids will not affect the lubrication of a t-case. Since the t-case uses so little, buy a case of Mercon V for both the transmission and t-case.

Rear axle; a lot of full synthetic gear oils do NOT require the friction modifer additive for clutch-driven limited slips. I have used Mobil 1 and Royal Purple gear lube in my rear diff, without friction modifier, and have had no issues.

The front axle; you can suck out a lot of the old oil from the fill hole if you have a hand pump.

The manual calls for 75W-140 for the rear and 80W-90 for the front, I believe. Although depending on your climate and driving habits, you could probably get away with 80W-90 front and rear.

I have a D4 code for rear axle (Limited Slip ratio 3.73) and used Mobil 1 Synthetic Gear Lubicant 75w-140, I didn't add the friction modifier, so I should be OK ?

The owners manual states that 4oz of friction modifier needs to be added for Traction-loc rear axles, which I gather is different from Limited Slip.

 

[gavin]

I have a D4 code for rear axle (Limited Slip ratio 3.73) and used Mobil 1 Synthetic Gear Lubicant 75w-140, I didn't add the friction modifier, so I should be OK ?

The owners manual states that 4oz of friction modifier needs to be added for Traction-loc rear axles, which I gather is different from Limited Slip.

I used Mobil1 full synthetic without adding friction modifier and had no issues

 

[bobflood]

I have a D4 code for rear axle (Limited Slip ratio 3.73) and used Mobil 1 Synthetic Gear Lubicant 75w-140, I didn't add the friction modifier, so I should be OK ?

The owners manual states that 4oz of friction modifier needs to be added for Traction-loc rear axles, which I gather is different from Limited Slip.

Traction-Loc was Ford's name that year for limited slip - they are the same thing. If you have a D type axle you should be using the friction modifier, or an oil that already includes it (many synthetics do).

There is no gasket; you will use RTV to seal the cover. Forget the BS about it being "permanent" and go ahead and change it out.

 

[OutofDate1980]

Traction-Loc was Ford's name that year for limited slip - they are the same thing. If you have a D type axle you should be using the friction modifier, or an oil that already includes it (many synthetics do).

There is no gasket; you will use RTV to seal the cover. Forget the BS about it being "permanent" and go ahead and change it out.

I previously changed out rear axle lubricant and used Mobil 1 75W-140 synthetic with SuperSyn. Anyone know if Mobile 1 includes the friction modifier ?

 

[OutofDate1980]

ATF change

If you get a piece of transmission hose, about 5 feet in length, then attach it to the end of your transmission cooling line going to the radiator, you can drain right into a 5 gallon bucket.

Or if you have a trans-cooler, it is a lot easier to grab one of those lines that is going to the cooler from the radiator, or from the cooler back to the transmission. Remove the return line from the cooler to the transmission, hook up a 2 foot length of transmission hose to the cooler, then just direct the other end into a drain pan.

Reading these threads I've learned that I should be using Mercon V rather that Mercon in transmission. Wondering if I drain the pan, change filter, and drain converter then add Mercon V would be OK, or should I flush the transmission ?

 

[gavin]

I previously changed out rear axle lubricant and used Mobil 1 75W-140 synthetic with SuperSyn. Anyone know if Mobile 1 includes the friction modifier ?

as I stated previously, I had no issues.

I used Mobil1 full synthetic without adding friction modifier and had no issues

Reading these threads I've learned that I should be using Mercon V rather that Mercon in transmission. Wondering if I drain the pan, change filter, and drain converter then add Mercon V would be OK, or should I flush the transmission ?

that would work just as well, assuming you can drain the converter. I can't remember what year, but I believe they did get rid of the converter drain plug; or atleast accessibility to it.
"Flushing" just means removing old fluid at the same time as adding new fluid. Both ways accomplish the same thing.
And yes, Mercon V.

edit: err, you should be able to drain the converter. I could on mine, and I have a later build 97 model year.

 

[Big Z]

Add the friction modifier to the rear axle. And I'd flush a dozen quarts of mercon v, which is a cinch off the trans cooler.

 

[OutofDate1980]

Gavin; Rear axle: would it hurt to pump out 4oz of the Mobil 1 and replace with friction modifier (I have the modifier) ? Sorry to keep on going over this, but get a little nervous when I read to use the modifier, and don't know if Mobil 1 already has this modifier included.

Transmission: I have the torque converter with plug. If I have read correctly, even draining the torque converter only about half the transmission fluid can drained completely, so IMO I would have a 50% mixture of Mercon & Mercon V. Any draw backs to this mixing of Mercon / Mercon V ? The Mercon portion would decrease with subsequent fluid changes.

 

[SoNic67]

...converter only about half the transmission fluid can drained completely, so IMO I would have a 50% mixture of Mercon & Mercon V. Any draw backs to this mixing of Mercon / Mercon V ? The Mercon portion would decrease with subsequent fluid changes.

That's my worry to on another Ford car. In the original manual of my 96 Sable is a warning "do not mix Mercon with Mercon V". But I have read a latter date TSB that says that Mercon is phased out and all the transmissiond that use it can be switched to Mercon V. Even their replacement procedure will have some mixing involved. Looks like at some point the formulation of Ford/Motorcraft Mercon V changed to allow mixing with old Mercon (they changed the colour of the bottles too). Now, I don't know if the Mercon V formula licensed to other manufactures (Castrol, Mobil) is the first one or second one. Maybe an email to those manufacturers will answer to that, maybe not... I couldn't find nothing on net about that.

 

[gavin]

Gavin; Rear axle: would it hurt to pump out 4oz of the Mobil 1 and replace with friction modifier (I have the modifier) ? Sorry to keep on going over this, but get a little nervous when I read to use the modifier, and don't know if Mobil 1 already has this modifier included.

I, personally, don't think there would be any issues but I really do not know.

Transmission: I have the torque converter with plug. If I have read correctly, even draining the torque converter only about half the transmission fluid can drained completely, so IMO I would have a 50% mixture of Mercon & Mercon V. Any draw backs to this mixing of Mercon / Mercon V ? The Mercon portion would decrease with subsequent fluid changes.

it took me.... 17 quarts? to fill my transmission after draining the pan and torque converter.