99 Explorer Transmission

[fraxinusalba]

I was pulling a loaded trailer down a winding gravel mountain road and when I shifted the auto transmission to 1st, it was like putting it in neutral. There was no holdback at all with engine idling. If I gave it some gas and got the RPM up to about 1500-2000, could feel it go in gear but when I let off the gas, it coasted like it was in neutral. Put it in 4WD low and did same thing.

Any ideas what problem is?

Transmission seems to run fine otherwise.

 

[Glacier991]

Help me... is your tranny behind a 4.0 or a 5.0?

There are a range of possibles... some benign and some ugly. If everything else is ok, yours may be simple as a Digital Transmission Range Sensor adjustment. Let's start with some info to allow us to help - like WHAT tranny?

 

[fraxinusalba]

additional info

Here's the additional info

1999 Explorer XLT
4.0 SOHC
5R55E transmission
150K miles

No trans repair I am aware of - owned since 80K miles. Regular change of fluid and filter. No slippage and shifts fine on acceleration.

Thanks for your help. Have spent hours searching this site and others for info but have found nothing regarding this type of problem.

 

[IZwack]

I think the transmission is acting as it should. At idle RPMs and in 1st gear with the vehicle moving, the torque converter should have stalled which means the vehicle is mechanically in neutral. An automatic transmission can only "engine brake" above the torque converter's stall RPM. And when you stepped on the gas a little to bring the RPMs up, the torque converter kicked back in as the RPMs went above the stall speed and the vehicle felt like it was back in gear.

BTW, If you think you need to be in 4LO in order to control the vehicle plus trailer, then maybe you need a larger vehicle for towing .. and brakes on the trailer .

 

[manaen]

BTW, If you think you need to be in 4LO in order to control the vehicle plus trailer, then maybe you need a larger vehicle for towing .. and brakes on the trailer .

I'll second that, anything 1500 and up should have brakes especially when working on mountains.

 

[gijoecam]

There's a definite problem there though... it sounds to me like the transmission is malfunctioning. IIRC, from these boards and the service manual, any time the throttle position goes to closed (i.e. ratch voltage) the torque converter unlocks, and the coast clutch is activated in the transmission providing some level of engine braking. Then manually downshifting to 2nd or 1st should provide additional engine braking. If it's not, shifting to 4 low on the fly isn't going to do anything anyways (and if it does shift to 4low, you're going to have a blown transfer case).

-Joe

 

[fraxinusalba]

Thanks for the towing tips guys but sounds like you have never towed much off the pavement. Go find a mountain gravel road about 3 miles long with 10%+ grade from top to bottom, washboarded, hairpin turns, and potholes. Hook a trailer to your vehicle weighing about 800-1000 lb and see how fast you want to go down it. I don't care if I had a F350 Super Duty, I'd still only want to go 10-15 MPH max. So you got two choices, ride the brake for 3 miles and hope they don't get so hot that you can't stop or use the engine/trans for braking to keep the speed down. I prefer a little help from the engine/trans so when I get to that last hairpin turn at the bottom, I know the brakes will still work so I can slow down enough to go around it instead of taking the short cut over the bank and through the woods. With auto trans, high range 1st gear still lets the vehicle get up to 25-30 MPH. In low range, you can slow the vehicle to what I consider a safe speed without constantly riding the brakes. Or at least you should be able to if the trans/PCM is working properly.

My 97 Explorer "locks" in 1st if I shift it to 1st so I figured something isn't working right on the 99.

I never shift to 4WD low on the fly. Actually, I don't think the PCM will let the vehicle shift to low range unless it is in neutral and stopped. I've tried shifting to low range when just barely moving before (less than 1 MPH) and it won't shift until I come to complete stop.

 

[gijoecam]

I was agreeing with you... I had an erant 'not' in there, but it's gone now. I would agree that there's a problem. As for what specifically, I don;t know.

 

[manaen]

Thanks for the towing tips guys but sounds like you have never towed much off the pavement.

Actually I do quite a bit in Northern PA, but for some reason I must have been smoking crack when I read your post the first time.

In fact this type of situation is the reason I like hydraulic surge brakes on my camper. They will operate independently of the truck brakes while using the engine braking in 1st or 2nd down mountains. But there are many other advantages to electric brakes too.

Somehow I thought you were saying that you had to shift to first to get engine breaking, and you wouldn't get breaking in drive. after re-reading your posts, I'm not sure how I came to that conclusion I'll blame it on my ADD

I'm not an expert on tranny's but there are plenty of people here who are, I'll just throw out a few random thoughts..
is it possible the coast clutch solenoid is either bad, or maybe it is a case of the OEM bracket failure, allowing the solenoid to slide out and release pressure. Now that I think about it, I think that is the area where my solenoid bracket was bent when I installed my tranny upgrades which upgraded the OEM bracket.

Also, when was the last time you changed fluids and added a new filter, maybe it is just a debris problem in the valve body

 

[fraxinusalba]

Well, I just came back from a trip to a lake towing my boat and had to cross 3 or 4 mountains getting there. I have engine breaking with OD off and in 2nd gear. I also get engine breaking in 1st if the speed is high enough to start with (around 30 MPH) when I down shift to 1st. But when I slowed to less than 10 MPH to go around a sharp curve and engine dropped to idle speed, no engine breaking in 1st afterward - started coasting like trans was in neutral.

So after playing with it some, I discovered that I get engine braking as long as RPM's don't drop below about 1200. Below that however, it goes to coasting and won't pick up again unless engine is revved. I got up to 50 MPH while trans was in 1st and coast clutch never did engage. Up shifted to 2nd and immediately got engine braking.

So if anybody knows why the coast clutch won't engage when engine goes to low RPMs, would appreciate the help.

 

[manaen]

almost sounds like a tourqe converter problem, but I'm not entirely sure how the solenoids and the TC interact on these newer trannies.

Also sounds like your truck has an aftermarket stall converter. Has the truck always done this?

 

[fraxinusalba]

Not sure if the truck has always had the problem. Bought it used and had been using my 97 most times when towing boat or trailer. Never had a call to use the engine braking on the 99 to such an extent until recently. Had previously only downshifted to 2nd a few times and always got engine braking when doing that. Also always got engine braking when turning OD off.

 

[bluestream1]

Check out TSB 03-22-10
Issue: No engine braking in Manual 1st
Action: Check for blown separator plate gasket in your transmission valve body. A simple fix, and lots of info on this site.

I had the same symptoms you had, and and installed Kit 3L5Z-7M203-JA to restore engine braking

 

[himalophile]

I'm sure a have the same trans you have. Based on my experience yours is behaving normally for that unit. Dealer found "nothing wrong" but this was some years back. It brakes in 2nd but NOT in 1st. Might brake in 1st while cold for a while. Seems to be way this unit was designed. bluestream1 indicates a TSB exists and a kit to make it brake in 1st. In fact I just checked and found that the TSB 03-22-10 was issued Nov. '03 and it does have somthing to do with tranny braking. So looks like I'll need to look into this too. Thank you bluestream1.

 

[manaen]

yeah I checked mine today, it has engine braking at any rpm/ speed in 1st gear, although I do have the VB upgrades and shift kit installed but that shouldnt make much difference on the engine braking.

Sounds like bluestream is onto something there...

good luck, keep us informed.

 

[Glacier991]

Lack of enginebarking AT ALL in Manual 1st gear has a range of possible problems, somenot good. The fact that you have it "to a point" rules out the Baddies (mechanical things like srpags, reverse clutch, coast clutch etc) and brings us down pretty much to just one thing - the Valve Body. (Main control as FORD now calls it).

You can try something as simple as the FORD MOD described in the 5R55E VB Rebuild Diary (parts cost under $30), or go for a VB rebuild. Good chance you have a separator plate issue, and the FORD mod has a bonded separator plate that assists repeat problems.

My buck says it's VB related.

 

[fraxinusalba]

Thanks for the info guys. I'll check out your suggestions as soon as I have a chance and post back.

One more question - Are the parts mentioned above only available from Ford Dealer or is what I need available elsewhere? Nearest Ford dealer is about 50 miles away.

 

[bluestream1]

I bought my Ford parts here: http://www.trademotion.com/partlocator/index.cfm?siteid=213787
Good people; they won't let you down...