While most of the pro/con opinions here about the value of synthetics has been about engine oils, I think there's no question that synthetics should be used in automatic transmissions and power steering units, and to a lesser extent in axles and transfer cases.

Almost every auto trans I've ever serviced that's been driven for a while has degraded, off-odor, off-color, oxidized or burnt ATF, especially if the vehicle has been used for towing and even where there might be an oil cooler. And EVERY power steering unit I've ever seen has had burnt, degraded ATF in it and usually making noise. Sometimes it doesn't take very many hard miles at all. It can't be lubing efficiently.

Obviously, standard dino ATF is being pushed to it's technical limits in many vehicles. It's burning up and degrading, usually well before the recommended change intervals. Sure, you can change it more frequently, but it's still being stressed to the max, and there's nothing I can think of that's more fun on a weekend than dropping the tranny oil pan to do an oil change.
There's nothing I'd like more than to spend $2,000+ on replacing an E4OD transmission.

Ford either is, or has gone to synthetic ATFs in their newest vehicles like the Focus. Since switching to (brand X) synthetic ATF in a truck frequently used for heavy towing, I've noticed no degradation, no 'off-color' or smells. It's still clean and red. The trans shifts deciseively instead of mushy, something I immediately noticed after making the switch.

If use in an engine is debatable, there shouldn't be any question that synthetic ATF is to be greatly preferred in power steering units and automatic transmissions. Did it cost a lot for 15 quarts of the stuff? (including draining the torque converter)
Yup. About what taking the truck to a dealer and having them do a change would have cost.

 

I just had one of those expensive E4OD rebuilds and added an aux. cooler. The trans guy says use the cheap stuff and change it more often. I think I'll spring for the Valvoline blend (Mercon V) ATF for the slight extra cost, but 15 quarts of Mobil One ATF? How long do you want to extend the drain interval to justify that price? $6 is the cheapest i've seen it.

Axle lubes are a different story. You don't need very much, so cost is not a big issue. I think the factory fill for many drive axles is now synthetic anyway. Two warnings from personal experience. 1) It will leak out of an older pinion seal that does not leak on dino. 2) Even if the label says that it is good for limited-slip units, you must use the friction-modifer additive. The synthetic reduces friction to the point of causing chatter in the track-lok unit. The Valvoline blend seems to work ok on my older vehicles.

 

Have you read your owner's manual? There is a warning there to not use MERCON V in an E4OD. E4ODs do not like MERCON V, and they will have a shorter life if you use that fluid.

A good MERCON fluid is what E4ODs should run. Mobil 1 is the best MERCON fluid (In my not so humble opinion), but any MERCON is better in an E4OD than any MERCON V.

Mark

 

How about ATF fluids with the ratings of both Merc 4 and 5?

 

The manual also states to not use a dual MERCON and MERCON V rated fluid. There is no such fluid as MERCON 4.

Mark

 

My truck is a 1994, so my owners manual is silent about Mercon V. The Valvoline bottle says Dexron, Dexron-II, Dexron-III, Mercon and Mercon V.

An interesting side note from my owners manual. The power steering fluid called out is type F ATF, not Mercon.

Also, synthetic axle fluid is required for the 4.10 ratio 8.8 and optional for the others.

 

I have a friend who just had his tranny rebuilt by a reputable racing transmission shop here in Denver, and when asked about running synthetic fluid in the tranny, they said "Don't put that crap in there." They will void any of their warranties on new or rebuilt trannies if any additives or synthetic fluids are used. Now I am not sure why, but they seem to know there stuff about trannies, so I value their opinion a little more.

My question to you: does anyone here know why the shop would say this? I don't have enough knowledge of transmissions to justify not using synthetics. My first guess would be that the synthetic fluids are better, especially when using the truck for towing.

Also, has anyone run synthetics in the tranny, and what were your findings?

Aaron

 

[updated:LAST EDITED ON 26-Apr-02 AT 12:40 PM (EST)]I run Mobil 1 synthetic ATF in both my '89 Lincoln with an AOD and my '82 GMC diesel with the 700R4 - I have over 250K miles on the 700R4 and about 173K miles on the AOD, and neither has ever been worked on. However, I also installed huge tranny coolers - rated for a Class A motorhome pulling a 10,000 pound trailer. The diesel has towed a lot, and the tranny is starting to show it - sometimes the lockup torque converter gets confused and doesn't seem to know what to do. On the other hand, the AOD in the Lincoln is perfectly sound and I've never had a single problem with it...though I did drive it through a pond once (about 2 feet of water) and had to change both the tranny and rear axle lube because they were contaminated with water. I learned my lesson - don't drive through ponds with Lincolns!

The long life of my trannys might be more because of the cooler than it is because of the fluid - I really have no idea. I change ATF every 50,000 miles on average, unless I do something stupid and have to change it before then. Since I do stupid things on a regular basis, the true change interval is probably closer to 40,000 miles.

As far as problems running synthetic, I haven't had any (yet?) - but if I had a new truck with an auto tranny I'd probably do a lot of research before switching it over. However, I put oversized tranny coolers on everything - the synthetic ATF might be questionable, but I think most tranny shops will agree that "cooler is better".

LK

 

>My question to you: does anyone here know why the shop would
>say this?

Because of the myth that synthetics are "slipperier" than conventional fluids. That isn't true.

>Also, has anyone run synthetics in the tranny, and what were
>your findings?

I was involved with the transmission for a 650 HP off road racer a couple years ago. They used an E4OD and Mobil 1 synthetic. The fluid saved the transmission from destruction a few times and saved a win. I think it is the best fluid that you can run in an E4OD.

Mark

 

Aaron:

I'm currently using Red Line D4 ATF in my '96 F-260's E4OD tranny. It's an approved replacement for Mercon ATF. I put it in when the tranny had more than 100K miles on it.

Immediately after putting it in I noticed that shifting turned from mush to very firm. It became very decisive, at less then full throttle it really bangs the gears as I think an auto trans should, even at full throttle or when tugging a big horse trailer it shifts much more firmly. The difference was like night and day, like installing a shift kit. No kidding, no exaggeration. Huge difference that I didn't expect.
As for the long term benefits, I can't say, other than I used Mobil 1 ATF in the transfer case of my old '87 Ranger since almost new and after well over 150,000 miles of use, no noise, no leaks, no problems with it, either. But that's an apples-n-oranges comparison.

The downside is the cost, at $7 bucks a quart for 15 quarts the Red Line ATF made for a pricey tranny oil change. I'm hoping I can keep it in there longer than the other ATF before it starts to go brown or degrade- that recovers some of the cost, too. So to answer your question, yes, I use it, and yes, so far, so good.

(Disclaimer: I have no financial interest whatsoever in Red Line or Mobil Oil}

 

Well, since there are people like Parrothead and Mark that have used the synthetic ATF with good results, I think I will go ahead and try it. Both of my vehicles need a tranny fluid change this summer, so I was thinking of synthetic, as everything else is synthetic in the vehicles. I guess it could be a biased opion from this particular tranny shop, but they do have a good reputation. I know that synthetics don't harm clutches, as I run Mobil 1 15W-50 in my YZF600R, and it runs great. Thanks for the advice everyone.

 

I can't believe I'm typing in the Oil and Lubrication board again... :P

Oh well - to avoid getting in trouble I will stay away from the pro-synthetic commentary and focus on the misinformation jimandmandy was handed.

My proposed question (to anyone - I don't mean to pick on jimandmandy because that wasn't his/her (?) claim): Have you ever changed out an auto-tranny's ATF and filter and actually put the 'cheap' stuff in there? I have, and I noticed the degradation of the performance of the tranny immediately. I think it was Amoco ATF that we put in there - what utter crappola.

I feel this Amoco ATF is very representitive of the cheap (and perhaps even better than the no-name very cheap) ATF's out there, and I would never advise someone who cared about their vehicle enough to get the ATF changed to use anything like it.

"Cheap stuff & change it more often"?? not in my +$1000 transmission, buddy.

Now for rebuilts.... you may be facing the dilemma that new engines face - the less protective (yes, I believe synthetic ATF is more slippery) regular ATF may allow the new parts to wear their surfaces together much like newly rebuilt engines stil use regular dinosaur oil to allow the piston rings to seat. After a break-in period of about 3000 to 7000 miles the change to synthetic (in engines) is alright, so I imagine the call to not use syn-ATF in rebuilt trannies is for the same reason. Give the parts time to mesh to each other, then protect them from further wear with synthetics.

 

This my first automatic Ford. The others were manual. We have had many Hydramatics, Powerglides and Torquflites over the years and never had so much confusion over ATF. You could put in any brand of type A, and later, Dexron, and there was no difference in performance.

Since Valvoline is a commonly available and generally respected name brand, I thought it would be a safe choice. Since Mercon V did not even exist in 1994, the owner's manual just says Mercon. Can someone please point me to a Ford site or TSB that prohibits Mercon V in an E4OD, or a direct quote from an owner's manual giving the model year.

It will be a while before my first change since the rebuild, but I don't want to make a mistake with it. Thanks for your input.

-Jim

 

I have a copy of Ford TSB 1-15-7, titled Fluid-Transmission Fluid Usage Charts.

It calls for MERCON in all E4OD and 4R100 transmissions. It also states that using MERCON V or a dual rated MERCON/MERCON V may cause transmission damage in a transmission that requires MERCON fluid.

Mark

 

I'm not going to agree or disagree with the TSB, I'm not an engineer with Ford. But I will point out that that Ford is also implying that use of any grade of motor oil other than the approved 5W-20 in the newer 4.6/5.4/6.8L truck engines may cause engine damage and might void the warranty. (I also drive a 2000 F-150 5.4)

Here's a quote from an email from Ford: "..5W-20 oil provides optimum fuel economy and durability performance meeting all requirements for your vehicle's engine. If you choose to use 5W-30 engine oil (the grade of oil I asked about), and a defect should occur as a result of the oil, then the cost for that particular repair will not be covered under your manufacturer's warranty..."

There has got to be some common sense applied here. I have a feeling there is no technical reason whatsoever for many of the stipulations being made by Ford other than those written by their attorneys and other corporate weasels, not their engineers. To each his own, but as long as my vehicles are out of warranty, I'm going to continue using my best judgement and the best quality lubricants in them until someone can point out *exactly* how using a premium synthetic or dino ATF or 10W-30, 10W-40 grades of engine oil with the latest API reatings can harm my vehicles.