Tranny advice! Auto slips in Drive SOMETIMES.

[99fordexploder]

Thanks in advance for ANY advice.

I just got a 99 explorer sport, 4.0 ohv, 2wd.

It runs and shifts great MOST of the time. In the past week, the tranny slipped in the first gear.(AUTO TRANNY)

It ONLY did it after the car was already warm, and then turned off. After about ten minutes of waiting(store run) i would get back in the car and start it. After backing out of my parking spot, i would put it into drive, and when i give it gas, it would just rev to about 3k. rpms, and then start to grab. It startled me, so i let off the gas and tried again.

It did the same thing. After doing that twice, the car shifted and drove PERFECT. The tranny doesn't slip AT ALL between gears or when flooring it. It doesn't even slip when flooring it off the line.

ONLY did it twice, after already warm, and starting to drive in Drive.


Is my tranny going bad, or is it a smaller problem? Usually tranny's seem to start slipping BETWEEN gears when going bad, thats why this is confusing to me!

thanks for ANY advice

 

[jasonb]

please do not double post the same thing in two different forums. Since this doesn't appear to be an emergency, the 911 thread has been removed.

When is the last time you've had the fluid changed?

 

[99fordexploder]

What kinda fluid do you recomend for my 4.0 ohv AUTO tranny?

I just got the explorer, and it has 80 thousand miles.

The fluid is to the full mark, and smells just fine. I already bought a bottle of lucas tranny slip stop, but i am now thinking i'll change the fluid at the same time as putting that in.

Do you guys recomend the dealership stuff or something else?


This doesn't really sound like a BAD TRANNY.... Does it????? Maybe tranny ecu? Do these tranny's have a cable that can be adjuste(like tcm controlled honda tranny's)??? The only other prob. i noticed is that my tranny is slow to shift into drive when i go from reverse or park to drive.

THANKS FOR ANYTHING YOU CAN RECOMEND!

 

[Glacier991]

relax.... what it sounds like is the leaking low/reverse servo, which is fixable from under the car.... While there could be a myriad of other things..... the a4LD and 4R55 and 5R55 all share a comon feature, a low reverse servo. FORD used an O ring seal.....in time it would leak... causing a delay in R and or !st engagement. Do you notice any delay in R ? If not that's ok... R has higher pressures working it. Most of us learned to live with it... engage gear, wait a minute for the clunk and then add the gas.... there is an aftermarket double lip seal to replace it... and yes it IS something you can do yourself, and from underneath the car... or buy the seal and take it to a shop and ask them to quote you a price to replace it (should be under $120 in labor). I cannot be absolytely sure, but this IS a common Explorer problem, and your description sounds pretty much like that might be it. Don't add that tranny slip at this point, I don't think this is a slip, just a delayed engagement..

 

[99fordexploder]

cool. So when i go to the parts store, what exactly do i ask for?

What worry's me is that it slips a couple times before it goes.

It will slip, start to slowly grab at 3k rpm. I'll let off the gas and then give it more gas. It will do the same thing again, and on the third try it goes just fine. Could it just be Partially grabbing???

And what fluid should i use? I think i'll change it anyways.
THANKS A BUNCH!

 

[Glacier991]

the seal is on the servo that powers the low/reverse band, so yes it IS slipping, because inadequate pressure is being applied to the band. 99 was Mercon V. There should be a Transtar distributor in San Diego... tell them you need the low reverse servo double lip seal for a 5R55E transmission. Let us know how you make out.

 

[99fordexploder]

YOu are AWESOME.

Thanks a LOT. I'll get that replaced a.s.a.p.

I try to do all my own work. Is this a fairly easy process? Can you give any tips? Thanks!

 

[Glacier991]

I guess I should ask... is this in R or OD? I've been assuming we were talking reverse and now I see you may be talking ONLY delayed forward engagement... that raises a few other issues.... lets talk BAD ones first.... leaky forward clutch seals... bad because that's only fixable by teardown. Other possibles: partially plugged filter (high on the list) loose valve body bolts (an easy thing to check while you are changing the filter) or a misadjusted linkage (I think this is unlikely in your case).... so... before you run off for that seal... change the filter and check the valve body bolts for tight... let us know how THAT goes... sorry... I just had focused on a reverse problem and that servo.... you clearly said you had put it in drive. My mind ran away with me. The low reverse servo can be a candidate but check these easier things first.

 

[99fordexploder]

It's having a fully tranny flush right now.

 

[Glacier991]

Once that is done,drop the pan and change the filter (see part 4 of the rebuild diary if you want to see info on that and what kind of filter to buy) and check the tightness of the valve body bolts at the same time.... goodhand tight is all that is required.