Help diagnose transmission problem

[cookiedoh]

Having trouble with 1998 Explorer Sport 4.0L 4x4 transmission. It's real sluggish in 1st gear. There's some wierd shifting near 2-3 or 3-4, not rough just back and forth a few times. Check engine light is on, giving the following codes:
750 Shift Solenoid A Malfunction
1762 Transmission system problems
1405 DPFE Upstream Hose Off Or Plugged

My mechanic said it has no first gear, hence the sluggish. Ths sluggish first (or 2nd?) was intermittent and seemed to be more often when it was warmed up. Now it's alwasy sluggish. Changed the fluid and filter 6 months ago when it first started. To clarify, I just drained the pan not cooler, etc.

Could it be something simple like a control module or is it time for an overhaul?

Thanks

Vin 1FMYU24X7WUB81590 incase that helps.

 

[BrooklynBay]

Welcome to this forum! Did you check the solenoid, valve body gasket, valve body bolts, and the electrical harness connector? Did you check the DPFE sensor, and the vacuum line?

 

[cookiedoh]

No I didn't check any of those. I will have to get out my repair manual to try and find all the things you suggested. I think I'll bring it in to a tranny shop, they say they will diagnose for free... We shall see.

 

[cookiedoh]

Alright, they tell me "it's slipping all over the place and the valve body is junk" They can put in a new valve body for $500 which may fix it and may not. Or put in a reman transmission for 2k. I'd like to rebuild this transmission myself for the knowledge. Time isn't a huge factor. I replaced head gaskets and radiator in my last car. But I'm nervous about some of the specialized tools like the alignment tools I read about. Obviously I'll need a pretty good guide, I haven't determined which transmission it is yet(door post right?) Maybe it will be one of the ones that has a diary on here. My Chilton manual doesn't really seem to cover overhaul, just removal and installation. So, is this a project I should do? If so, any good sources for parts? Anyone want to buy a project car?

Thanks

 

[daffy]

It takes a pretty specialized person to do a tranny rebuild.

Do you have a local college that has an auto program?

My dad called the local community college, and found the instructor would take it as a class project. Did the rebuild for the cost of parts. Took 8 weeks to get it back, but the rebuild only cost about $120 (IIRC).

Thing shifted like a champ until he sold it.

 

[hworksinc]

There are a few threads in the Transmission/T-case section that give an overview of transmission disassembly and reassembly, depending on what model you have (model is on the door post - in code). Just do a search for your model once you figure it out.

I'm considering rebuilding/upgrading mine this summer - nothing wrong with it, just want the experience. It's definitely not a job for the faint of heart, but decent mechanical knowledge and the right manuals/data sheets should be sufficient. Of course, there is always the chance of breaking something major - always a risk with big projects like this. As long as you can take your time to do it carefully and do it right, I don't see any reason not to do it yourself.

 

[cookiedoh]

Alright so it is a 5R55E (code D on door) I'm leaning towards buying a reman or used and just swaping instead of rebuilding. It looks like I can pick up a reman for 500-700 plus shipping on ebay...

 

[BrooklynBay]

Start with rebuilding the valve body. Check the 5R55E valve body rebuild diary for more information.

 

[cookiedoh]

Got another symptom I forgot to mention. When pulling a trailer with heavy load (snowmobile trailer out of hole where it is stored) I pretty much had to floor it to get it to crawl forward. Does this still sound like it might just be a valve body problem?

If I do the valve body rebuild and it ends up not fixing it, am I out anything? Would I need to replace any gaskets or other parts if I had to remove the tranny and really overhaul? I would be able to save and re-use new fluid correct?

Thanks.

 

[BrooklynBay]

It's not a waste to rebuild the valve body even if you have to rebuild everything in the end. A VB rebuild is necessary along with an entire rebuild anyway. You might be able to reuse the fluid if it looks clean.

 

[cookiedoh]

If it's not much trouble, could somebody double check my parts list? This is all from www.bulkpart.com. The transgo kit description says it "Valve body gaskets not included" Do I need the bracket for the EPC or does the kit include one?

56010G Filter, A4LD, 4R44E, 5R55E 4wd 1986-UP
56300EF Pan Gasket: A4LD / 4R44E series
D56431A Solenoid,4R44E / 4R55E / 5R55E, EPC (56431A)
T56165H TransGo Shift Kits 4R44E / 55 Valve body & separator plate calibration & Clutch seal parts
56320H Gasket, 4R44E / 5R55E, valve body, upper
56321H Gasket, 4R44E / 5R55E, valve body, lower
S56741F Boost Valve Kit, 4R44E / 4R55E

 

[BrooklynBay]

You could get the bonded separator plates which have the gaskets already bonded to them. Does this boost valve come with the O ring design or the OEM design? The 4.0L uses the high ratio boost valve.

 

[cookiedoh]

How do you guys feel about the Ebay remanufactered transmissions? I'm looking at a 5r55e that comes with a torque converter and a 30 day warranty (parts) for $699 shipped. I have no real way of knowing how thoroughly they remanufactored the unit.

The parts for the valve body came out to a little over $200. For not much more I can get one from central valve bodies. But I'm worried with my slipping issues that a valve body wouldn't be enough. I'm wondering if $700 for a whole new transmission would be a better buy.

Are the symptoms I described enough to hazard a guess about wether a valve body is enough? If it isn't it means a full tear down, inspection, replace parts, new seals, gaskets, etc correct?

 

[BrooklynBay]

It's hard to say how they are unless more people buy them, and leave feedback on this forum about a specific seller. Central Valve Bodies is another EBay seller. He has a good reputation on this site, and gives EF members a discount.

 

[cookiedoh]

What do you think about valve body fixing slipping? No real way to tell?

 

[BrooklynBay]

You could start with the valve body.

 

[cookiedoh]

Good news! The new valve body fixed my problems. Aside from breaking off and replacing a valve body bolt, it went fine.

Except, after about 20 mins of city driving it stopped shifting from 1 to 2 as it was supposed to. From a stop as I accelerate the RPM's get up to about 3500 and it the car just drags along in first gear. If I take my foot of the pedal it shifts to second and then I can proceed. It's like it's too high RPM's to shift. I can't get it into second by letting off the gas until I get going fast enough, which in first gear requires the high RPMS. I let the car cool down and drove an hour later and it works fine. I sent an email to Central Valve Bodies, but I thought I'd post here too.

Thanks for the help

 

[skoal_mint]

I'm having the same problem with a customers truck, replaced the tranny and is doesnt want to upshift at high rpm

we were told to change the speed sensor but that wasnt the porblem

 

[cookiedoh]

I read that it might be the throttle position sensor. Not sure if that fits since it only seems to be a problem once it gets hot. TPS might help you out though.

 

[skoal_mint]

does the explorers have a kickdown cable, or is it electronic