98 V8 Explorer, 4R70W tranny hesitation when put in drive

[crazyflights]

I have a 98 Ford Explorer V8 with auto tranny, has 127xxx miles on it and I got it around 120,000 and was suppose to have rebuilt tranny in it, but what all was done to it and why it needed repaired -Im unsure? but did look clean so was out forsure, has drove fine

1st issue
-since I got it if your cruising in 4th/od maybe on slight incline at lower rpms, but want to accelerate hard to maybe pass somebody, when you smash throttle down, would sound like engine was reving rpms but tranny not responding, but then making almost a clunking sound when down shifted, heck maybe it didnt even down shift? I just avoid driving it like that, if you drive it easy never does that, or accelerate hard from lower gear all the way thru upper gears doesnt do it. -wasnt to worried rarely acted up,

But now 2nd issue maybe relate prolly not?

When your parked, in park, go to reverse has immediate response your in reverse, but go down to drive and has couple second hesitation before you feel it engage, even slighty have to rev it then feel engage and drives fine, but every so often if coasting and no load on it, when you put power back to it it feels like its not engaged, then kicks back in and drives fine.

Has clean fluid, proper level.

No codes?

Been reading alot, and will keep reading thread but wanted some help from anyone with thoughts,

So far from what I read maybe the Main pressure regulator Valve? Which Sonnax part # 76948-09 might help engagement?

thanks for all the help.

 

[crazyflights]

Here is description of problem with Main pressure regulator Valve, for the replacement part.

A common complaint in vehicles with an AOD-E/4R7OW transmissions is low line pressure or throttle sensitive buzz, especially when hot. This is often caused by a worn main regulator valve. The valve frequently wears on the boost spool diameter and allows EPC (electronic pressure control) oil to leak to exhaust. This leakage results in poor line rise. When the oil temperature increases, the oil becomes less viscous and more leakage occurs.
Another common complaint with these transmissions is poor reverse boost, often the result of a worn pressure regulator boost sleeve. The sleeve should be checked while replacing the main pressure regulator valve. Sonnax offers a replacement pressure regulator boost valve and sleeve kit.

I dont think this best describes my problem? Can anyone advise me if the DTR sensor may have something to do with this?

 

[crazyflights]

Anyone have any idea

 

[ragajungle]

not to over simplify, but have you had the pan off? "Rebuilt" transmission can mean a whole bunch of things: being power washed, having a "soft" rebuild VB, T/C, Etc), or having it truly rebuilt.

Some things to think about:

Depending on WHAT happened to the trans prior to its rebuild and WHO serviced it can impact the length and quality of service it will provide. If say someone DID do an entire rebuild, bands, clutch pacs etc, but failed to flush the Torque Converter, and trans cooler adequately all the remenant problems from the initial issue will find them selves back in the valve body, the EPC, and Torque Converter.


It would pay to drop the pan and have a look. It would also be a good idea to get a pressure guage on her and see if low line pressure is causing the issue or if you have other issues going on.

If she slips in passing gear it could be a band, or it could also be a sticking/leaking valve (as your above post suggests)

I do it all the time too at work. I jump to worst case scenario mode, and sometimes it's just a clogged filter.

 

[crazyflights]

It doesnt slip while ingear, sometime just feels like it goes to neutral when coasting and then getting back into it, but not always, I think dropping pan will be in order and also checking line pressure before that.

hard to say what they dropped it for. Its had all easy miles. was 1 owner


is there some kinda of sylenoid for when it goes into drive.

 

[ragajungle]

b2guy,
Somewhere on here there is a 4r70w thread covering it's vb. Yes it does utilize a EPC solenoid for pressure to the vb for forward gears, but before you spring for a $110 EPC pressure test it. If pressures read in spec you are having a possible internal soft/hard part failure. Sounds like a torque converter issue maybe? Someone else maybe chime in?

 

[crazyflights]

Hmm, I hope its not Torque Converter, I will see what I can figure out.

 

[crazyflights]

New Epc sensor, filter and oil still doesnt work right, also has gotten worse the delay take quite awhile before it goes. Now what.

 

[swetrid]

Sounds like seal problem to me.

 

[crazyflights]

Swetrid-- which seal? like valve body seal? something I can do with it in truck? or need to remove- any other thoughts, but thats what Im starting to think also.

 

[swetrid]

Ford use to have a tsb for forward clutch sealing rings back in the day. You would have to remove the transmission though to inspect them.

 

[mayeskeith]

hello , I have a 2001 explorer with a 4R70oW it seems to slip around 3rd gear, it reves up but hardly any movement. any ideas? I'm planning on doing a rebuild on sat.