Something I recently discovered with my '93 E4OD that caused harsh shifts was the neutral safety switch.

When I pulled the codes, they indicated the switch.

It is exposed to the weather (deep water) and had a LITTLE green corrosion on the contacts.

Talked to a Ford tech. friend and he chuckled and said he's seen this before. Seems when the switch loses contact the computer thinks something could be really bad with trans. so it applies full hyd. line pressure to the clutches to minimize slippage. This results in harsh shifts. Also, intermittent contact = intermittent problem.

I call it a neutral safety switch but it is more than that since it has about 10 wires going to it. Located on side of trans. on gear selector shaft.

They are available at parts stores as well as dealer.

 

My truck has god awful hard shifts, but only when its warmed up. Did yours do the same or all the time?

 

No.....this truly started as an intermittent problem, maybe once or twice a week. Sometimes first shift of the morning, sometimes last shift of the evening. The shifts would bang the whole truck.

Became more regular late in the summer. It's been so wet this summer I think it triggered some corrosion on the connector teminals or internally.

Scanning the computer codes keyed me in on the gear selector switch.

 

How do you scan codes for the transmission? I've never had any type of indicator light either, did you? My shifts are just as hard. They feel like the rear end is going to rip out sometimes.

 

The codes are stored in the EEC-IV, so the regular engine scan picked up my trans problem.

I had no indicator light for the shift problem as well.

I know what you mean about the rear end...I was checking u-joints, motor mounts, trans mounts, etc. It sure seemed like something was going to break with the way it would shift sometimes .

 

I've been troubleshooting a hard shift in mine ('01 5.4 SCrew). I've changed the fluid/filter, and still have a quick/hard shift (though it doesn't slam into gear unless I really get on it). I need to check the accumulator springs as well, but am interested in looking at this switch at some point too....just in case.

Thanks

BTW, my tranny is the 4R70W, so don't know if this would even apply.

 

The 1-2 accumulator lower spring is one of the weak links on the 4R70W. Prior to changing my 1-2 sping, it felt like I had a shift kit in my tranny. I would even chirp the tires when it would shift from 1st to 2nd on dry pavement. The spring was broken in about 4 pieces! I'm just glad it did not ruin the accumulator cylinder walls.

Check it out and good luck.

Jeff

 

Just the other day my overdrive light started flashing, I haven't been driving the truck much but it's a 98 F-250 light Duty with 127K miles. The last time I drove the truck I was hauling a heavy load of dirt up a steep driveway. Wondering if I may of damage the tranny. The tranny has been giving me a whinning noise since a 100K miles, it seems to happen in the early mornings between the 1st and 2nd shift. Any ideas what this may be.