My tranny is weird in my '94 automatic....

When I drive my (automatic) '94SC fast my tranny hesitates to switch gears from second to third. When I drive the car normal everything seems to be fine and dandy, but I drag-raced my brothers '91 5speed from a dead stop today and I was pulling on him hard until time came for the tranny to switch from 2nd to 3rd.:( My car took a nose dive because the tranny hesitates and will not change at a reasonable time unless I let off the throttle for a second.

I just had the tranny serviced with a brand new filter to solve this problem, but it did not help one bit. Does anybody know what's going on?:confused: :confused: :confused:

Dirtybird91
 
a tranny service usually won't solve a problem like that. the trans service is maintenance, if you have a transmission problem due to not servicing it, it's too late. Having said that, you may have a minor problem, not a major one. If i'm not mistaken the 94 is the 4r70w / AODE type transmission....electronically controlled..... take it to a reputable transmission shop where they can attatch their scan tool to it and see if it's an electronic problem rather than an internal trans problem. Another possibility is that whey you get to higher RPM's you have an engine missfire or something......... many people confuse that for a transmission problem. My best friend own's a transmission shop and you'd be surprised how many times he test drives a car that comes to him with a 'bad' tranny, and ends up fixing it by putting new plug wires on.........
 
MLPS = Manual Lever Position Sensor, also known as the Nuetural Safety Switch. It is fairly common for them to crap out on the earlier 4r70w's. I need to replace the on in my Mark VIII actaully. A common symptom is the tranny seems to be hunting for gears, kinda like it is confused, or will actually come out of gear while driving. It's located on the side of the tranny and is fairly easy to replace. What you might want to do is pull codes on your car and see if it throws one for the MLPS. I had a code for it in my stored codes with no CEL, so it might be in there.

Thomas
 
Thomas...

That is exactly what my symptom is. I usually ignore this issue being that it's never a issue unless I drive it hard. I took it to the track to test some quarter mile times and this issue had the car running mid 16's.
I will be having the codes pulled first thing in the morning.
I think I liked the tranny better in my '91 AOD.:(

Frank
 
Having both and AOD and an 4r70w, I know the feeling. With a little work, they can both be pretty good trannies. My track times are pretty crappy also and feel that this has something to do with it also. Let me know how it turns out.

Thomas
 
Hmmmm..........

Yesterday my twin brother and I decided to test his '91 5speed against my automatic '94. I was pulling on him until the shift from 3rd to 4th, and then the car studdered to go into gear and nose dived.:( He pulled away after that with much zeal!:mad:

Frank
 
Old Thread, but info looks about right?!

I have read this, and if i assume right, the 4r70w is a version of the AODE. So, if that's right, and this MPLS sensor thing. My mom's 96 LX V8 just started acting up a little. The trans. would randomly decide it wanted to change gears, nothing JURASTIC like shifting to 1st from 3rd, but you could easily tell. Sometimes it would shift into neutral. Anyways, could this just be the MLPS? How else can you tell that it would be this sensor? About how much is this sensor and where to buy it? And lastly, how hard it is to get to this to replace it?

Thanks,
Nick
 
The trans. would randomly decide it wanted to change gears, nothing JURASTIC like shifting to 1st from 3rd, but you could easily tell. Sometimes it would shift into neutral. Anyways, could this just be the MLPS? How else can you tell that it would be this sensor? About how much is this sensor and where to buy it? And lastly, how hard it is to get to this to replace it?

Your mom's car has a 4r70w transmission. From what you have described, that sounds exactly like a MLP Sensor problem. It should throw a code for it, but the check engine light may not come on. You need to buy it from Ford and they are about $65 or so. Unplug it and two bolts to change it. It's right on the side of the tranny just above the pan on the driver's side. Not too difficult, just a tight work space.

Thomas
 
I'd definitely review that article on the 4R70W trans on the TCCOA site. When my '94 started hesitating & shuddering between shifts, some years back (only had about 20k on the car, still under warranty; but Ford's latest TSB only recommend flushing the fluid & they even charged me for it !!) I went thru that article and bit the bullit. Had the MLPS, accumulator pistons, etc, etc replaced. Changed over to Mercon 5, installed a Transgo kit (better to follow the valve body mods in the article or install a '96 body,I believe), put on the bigger pan & filter. Now I have 110k, some 5 or so years later with no problems.
 
No mn12 came with AODE. Mustang trans. 89-93 had the AOD and 94 -95 had the 4R70W. As far as these tranies go I have had very good luck with the 4R70w and the valve body mod on tccoa. Once you discover how these work you can mod these to your likeing in every way, like how hard you want it to shift and how fast you want it down shift. Just doing the mod changes it from a sliding gear change to snap your neck and break the tires loose kind of shift. My MLPH went south on me also. If it has a orange gasket on the little black cover, it has been changed. The TBS said that water would get in and cause it to shift in to wrong gears at the most unfaverable time. Mine liked to down shift to second at 50mph for no reason.
 
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