I work for the NC Highway Patrol. They have over 2000 troopers who put their cars through some very hard use with wide open throttle shifts a common scene. They are running ford V8 engines in Crowns and some Explorers. I have talked to our vehicle repair techs throughout the state about this exact subject.
With several thousand hard driven cars, they rarely ever see any transmission failures in the life of the car (usually retired at 160-200k) even with this harsh driving environment. They are then sold to Taxi companies who keep on driving them.
This is what they said they do:
They never remove the pans or change filters
They flush every 30 K miles
They only use synthetic transmission fluids
My personal state vehicle is over 100K miles and I drive it hard going up and down mountains to access radio tower sites. I think their success will show me what I am going to do with my Explorer.
FYI, this is exactly the case I just made. The 1980 new model Ford auto four speed was the AOD. It failed regularly in highway patrol cars. The police got tired of sending them back or rebuilding them themselves. The AOD was a very poor trans from 1980 to about 1988, they had a lot of built in deficiencies. The OD bands are too thin(not wide enough), the OD servos did not apply enough force to the OD band, thus 4th gear went out very fast in police cars. The early models had "C" OD servos in them, the V8 cars got "B" servos(Wow(sarcasm - still small)). If you rebuild an AOD, throw the "C" and "B" servos in the scrap pile, they're awful.
So, the AOD was improved by Ford in the late 80's, until the AODE came along in trucks, which had a wider OD band, and better OD servo. The Super Coupe got the best Ford OD servo, the "A" servo.
The 4R70W is exactly like an AODE but with a wide gear ratio 1st/2nd gear set. The 4.6 version got a different bell housing pattern, and is otherwise identical to the 302 4R70W we have in the Explorer. Ford made the last big upgrade in 1998 with a far better mechanical diode. Each Ford upgrade made them better, and better, until they are now considered to be dead reliable.
Go back to the early 80's, that was Ford's worst trans every made, by police dept. opinions. The AOD developed into the AODE and the 4R70W/4R75W, many many parts interchange.
My point is made, Ford put out that trans without fully developing it. The aftermarket made improvements first, TransGo had VB correction kits in 1986, and Art Carr sold them also. I bought those, and installed them, I had an 86 police Crown Vic, an 85 Crown Vic, later two 95 Crown Vics. I know the cars, I know the transmissions in them.
The current 1998 and newer Ford four speed is great, but it's because of the continuous upgrades and development by Ford and the aftermarket. It's not great because of good maintenance or flushing the fluid, nor from neglecting it as some people advocate.
That is the four speed Ford auto, not the five speeds or anything past 1990. Ford's five speeds are all derived from the A4LD, a POS four cylinder based trans. It began in might weight cars of the mid 80's, and Ford revised it for the Explorer, and then designed the 4R/5R55E from it. The guts of those are all similar, not up to heavy duty use, not adequate for a 4500lbs truck, towing, or high power. These are a whole different animal, all the wishful thinking and aftermarket parts will not make it strong like the four speed 4R70W. They aren't capable of 1000hp, and 500hp is really too much, so stock vehicles are okay with them, but not much more.
All that said, the VB is still the weak point of all of them, every last one, stock, old, new, anything without a VB kit. The stock shifting is not very good for long life, police car or not.
Any Ford vehicle will benefit from a VB kit, the weaker models and newest versions need it more. Ford makes improvements, but it takes them years and your failures to figure it out. The aftermarket is ahead of Ford in developing those VB upgrades, they always have been. I doubt Ford is going to change their ways and put TransGo/Superior/Sonnax/etc, out of business soon.
No matter how good you think your vehicle is, it will be much better if you get a VB kit installed. Any firming of the shifts increases longevity, slippage whether you can feel it or not is bad, that's what eats the frictions and steels.
It's just like politics, my state has good Senators and Representatives, it's the other states who need to change theirs. No, it's all of them, every Ford auto trans needs a VB kit, not just all of them except yours. That's my not humble opinion. Regards,
