transmission shifting question.......mr warman

94 explorer eb....4 liter/od......i drive 18 wheeler and this will make sense with the question......i bought the vehicle and it is in extremely good condition....133000 miles....the question is the auto tranny with o/d.....when i let the fuel off coming down a hill on the interstate or a fast 2 lane the tranny comes out of o/d to drive.....and stays there till level ground.....i liken this to what i call " the jake brake effect".....or compression brake......is this a normal act or just a prelude of bad things to come?.....any answer will be appreciated
Reply to
THE BIG GUY
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I can't think of any condition that would cause a downshift under the conditions you describe. What would normally happen is that the torque converter clutch would unlock to prevent driveline "boom". It could be that the TCC sn't unlocking but I would expect the car to stall if you pull over to the side of the road if this were the case. I can't recall if my own '92 (or any of the other A4LD equipped vehicles that I've driven) does what you describe.... at least I haven't noticed anything that seems odd in this respect. Even with the TCC unlocked, you'll get some engine braking....

The A4LD isn't a really bad transmission but the overdrive section is quite fragile. Many operators select the OD position on the shift quadrant no matter what driving conditions are present. I only select OD when I enter higher speed areas - at lower speeds, the transmission can hunt causing the OD band to overheat and self-destruct. I'm at 175,000 km (not quite 110,000 miles) including our gnarly Alberta winters - I'm a volunteer firefighter so my poor car has been subject to some pretty cruel sub -30 degree shenanigans....

Your transmission is right around the "golden" mileage but, in the abscence of other concerns regarding shifting or cold operation, you may want to perform a fluid exchange, replace the filter and perform a band adjustment. Avoid using OD unless you are going to be at speed for a sustained period (also avoid using OD when towing or heavily loaded). If you have a shop perform the fluid exchange, do NOT allow them to use a chemical flushing agent. Expect 18 to 24 liters of fluid to be used (sometimes more). Change the filter AFTER the fluid exchange. Hope this helps.....

BTW - Mr. Warman was my Dad... I'm Jim 8^)

Reply to
Jim Warman

I would bet odds that this doesn't happen if he takes his EB out of cruise control. I've noticed that vehicles with cruise control engaged descending a grade will try to maintain speed by throttling back and dragging on the engine to accomplish this. It's not just his EB that does this. Turn off the cruise control and this phenom doesn't happen. The vehicle will accelerate downhill, as would be expected. Now, being a skeptic, the big guy didn't mention whether it was or was not turned on.

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Reply to
John Riggs

Oh, great! My '02 XLT V-8 5R55W is approaching 80,000 miles - about 15K of that towing a 3400-lb trailer (the Explorer has the factory tow package with 7000-7300 pound tow rating, so the trailer is reasonably light weight). I'm about to start another 3000-mile trip with trailer. In the absence of any meaningful guidance from the Ford web site or owner's manual, I took it to the dealer where I bought it, explained the above, and said "Should anything be done to the transmission?" The response - "Yes, we recommend flushing it." And they did. According to the invoice, they power-flushed it with a BG flush kit, BG conditioner, and 16 units (pints? liters? at $3 each) of Mercon V fluid. Cost = $130. No mention of a filter, no mention of adjusting anything - and for that price, it almost certainly was not done.

So where does that leave me, Jim?

Bill Jeffrey

Reply to
Bill Jeffrey

Where do you wonder if that leave you?

-- Lady Chatterly

"bahahahaaaaa ... gawd, i hope the phantom botrunner appreciated that one" -- Vampi Fangs

Reply to
Lady Chatterly

I used to be a big proponent of chemical flushing. My own experience is of

*most* customers gushing over how nice things are after the flush. As a service operation (not a stop-gap repair), a chemical flush is probably not a bad thing..... my big fear is that the chemical may not be totally evacuated from the system - and at the price of modern transmissions, I don't think a shake of the dice is a good thing. Like motor flushing, chemical transmission flushing may also free up deposits that will be trapped within the system with nowhere to go.

I don't believe that using the flush chemical is going to kill your transmission (though I have yet to see any definitive studies) but you might show this cut and paste from the 02 Explorer shop manual to your dealer.... "CAUTION: Use only clean automatic transmission fluid. Do not use any supplemental transmission fluid additives, treatments or cleaning agents. The use of these materials can effect the operation of the transmission, resulting in internal component failure. "

Naturally, Ford is covering their backside with this kind of statement but, in a properly serviced assembly of any kind, the fluid in question would be replaced before there is any need of chemical assistance.

Reply to
Jim Warman

I think you're reading more into the cruise control that is warranted.

If the vehicle speed rises above the set speed, it closes the throttle. Period. Because it knows it doesn't need to add any to maintain the speed.

Most of its "smarts" have to do with how much to accelerate when the speed is below the setting, depending on how much below the setting the speed is, and, maybe, the rate of acceleration it's getting when it tries to bring the vehicle up to the speed setting. For example, level pavement vs. going up hill.

However, I don't give it much credit for smarts in this regard, either, since the engine management system will downshift, or whatever is necessary, based on the various parameters it monitors. No thanks to the cruise control!

Reply to
Alan Moorman

I believe I am correct. Yes, it will throttle back. I know it works with newer vehicles, but I don't believe it has much to do with my '92....it rolls way too easy.

Reply to
John Riggs

Kinda think that's what I said.......

Yeah, the OD seems to really almost free-wheel instead of providing any engine braking. I know the gear ratio will do that, to an extent, but, gee!

Reply to
Alan Moorman

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