Ok, so I've been hanging my head against the wall on this one.

It's a 95 f150, 302 with 4r70w auto trans. Thing runs great when it's cold. But once it's hot, I lose first gear. It starts in second gear, no matter what I do. Manually shifting it doesn't help. It actually feels like 1st is gone even in manual. But cold, auto and manual both give me 1st. Trans fluid doesn't smell burnt either. When I got the truck a couple months ago, I noticed it was a little overfilled. So I just did a filter change, no luck. Even more unusual is that if I turn off the truck, like running in the shop for a coffee(3-5 minutes tops), it gets first gear back until the first stop. Then it's starting in 2nd again.

I've also noticed my temp gauge hanging around near the m/a of "normal". It periodically comes down to mid gauge but couldn't put my finger on the cause. Seller told me he did pump and t-stat. Pump looks new, so I'm believing him..for now.

The trans problem seems to happen when the temp gauge gets to the high side.

Trans filter changed. All other gears function perfectly. OD works. TC lock up works(verified by lightly tapping brake when cruising and can hear the slight kickdown). Replaced shift tube bushings, thinking it was a position issue with the shifter. No blinking OD Light, no check engine light. With 135k, the thing runs and drives buttery smooth when it's cold. Just because it's got 35s, I turn off OD unless I'm on the highway (55 speed limit or more). It still acts up even if I leave OD on though.

Now, just earlier today, I wiggled the fan blades at 9&3, and detect a slight amount of play in the fan clutch. I'm leaning towards my fan clutch being the culprit for both the hotter than normal running temp, which in turn is somehow causing the 1st gear problem. My question is, could the hotter temps be causing my trans to start in 2nd and not have 1st at all?

I'm leaning towards replacing the fan clutch, which should definitely fix my hot running issue. I'm basically hoping that will fix my shifting issue..

Any input is appreciated. I searched all over the forum and can't find anything similar enough to my problem. So, I apologize if I just missed it.

Thanks all.

 

Is it going into neutral when it's supposed to be in 1st? I have had an issue with a speed sensor with an old F250 and an e4od. The speed sensor was reading sporadic which caused the trans to not know what gear to be in. The truck would either go neutral or just stay in 2nd gear. The speedo would read correctly the whole time btw.

 

It starts in 2nd gear. That fun little feature Ford used for decades, where you could put the shifter in 2 and it would make a nice no-slip start for slick conditions. It goes, it's just slow and winds out until 2-3 shift. But this only happens when it's hot. When the truck is cold, and until it hits the (over)hot side of things, it shifts great. It doesn't miss a beat, no slips no slams, nothing!

Which of the sensors controls this? I believe there's 2 or 3 on the 4x4s right? 1 on the t-case for 4wd shifting only, one on the trans and one on the rear axle? Again, it's got the 4r70w, or AOD I suppose.

To add to this.. and what should have been an update...
I've come to the conclusion that it's definitely running too hot, damn near overheating. The fan clutch is definitely bad.. no engagement at all. Not during start up, not at any point when it gets hot. The system holds pressure for sure. I've gone out nearly 6 hrs later(at the longest so far) and still gotten a little pressure to release from the lever rad cap. The previous owner did the water pump, but it does not appear he did the thermostat. And the fan clutch looks original, or minimally not replaced in many years. (135k on truck)

So, I'm going to start with replacing the t-stat and fan clutch. And while it's drained I'm going to make sure that he didn't use straight antifreeze and take it upon myself to make sure it's mixed. Hate to dump good AF, but I have to be sure. Or minimally, I'll test it and add some water as necessary.

I can't help but wonder if Ford incorporated some kind of overheat protection into the 4r70w transmission, or some kind of tow/haul sense? I know... I sound crazy.. but considering this only happens once it's past mid range into the hot side of things.

The sensor bit makes sense though. Even when this is happening, I can turn the truck off and start it again, immediately getting 1st gear back. But this only lasts until the first 1-2 shift (which is still normal). So if I fix my hot running/overheat issue and it does not fix the trans problem, I will move to sensor testing. But I can't ignore the temp issue.. It's the great white elephant.. so I have to address that first.

The other thing I'll probably do is stop and talk to an old friend. I recently discovered he works at a local transmission shop and is a bit of a FTE himself.. not sure if he's found this site or not though.

 

It could be heat, I'm honestly not sure but I have had speed sensor issues. On my truck it was on the rear axle. Also check for wiring rubbed thru at the drivers door under the rocker, I have had rusty rockers actually rub thru the wires controlling the trans. Owning old trucks turns into a lot of fun stuff! Lol.

As for the clutch fan being bad: if you replace it I would get a junk yard electric fan setup off of a car and wire it in. Save some mpg's and free up some hp all while taking control of the heat situation. A new thermostat never hurts along with a coolant flush too. These trucks will take some extra maintenance and repair after all they are old enough to drink now. Lol

 

Also now that I think of it check your fuses... there is a trans control fuse that will die every once in a while causing shift troubles. Think it's a 15a on the inside fuse panel

 

I will check, but wouldn't that cause a permanent problem, like not temperature related?

I will also check on the wiring and consider an electric fan. Problem I have is junkyards around me usually charge an arm and a leg for that stuff. There is aftermarket stuff, but I want to do it correctly, so I won't put a 14in fan on.. lol. I'd sooner spend money on one that will cover the whole rad, or minimally has a shroud to help with airflow.

 

Yes and no. If you just start the truck the speed sensor isn't much of a factor because the truck hasn't moved but it would typically screw up consistently from then on out. There are about a thousand things that can screw these things up, I'm just trying to eliminate the cheap easy fixes first. It could be a heat issue as well but I would expect the fluid to be burnt if it was that much of a factor.

 

Ok, thanks. You're right, can't hurt to check the obvious cheap stuff. I have a multimeter, would you happen to know what the resistance range for the speed sensor is? Just in case it's not obviously broken. I don't even have a Chilton manual yet. Can't find them locally, so will probably have to order one.

As to the burnt fluid, I don't know if the guy changed it right before I got it. It wouldn't surprise me, as from what I can remember from my grease monkey days, it should have seemed less... red.. than it was. I just did it as it was the most obvious thing to do for many trans problems.(and not knowing when it was last done). But it definitely seemed too clean for such an old truck.

For all I know, this guy has a problem as well and just neglected to tell me.

 

I don't know what the resistance should be on the sensor. Google may be able to help with that question.
It sounds like whoever you bought it off of may have been trying to fix this issue before selling the truck (or was trying to hide it).

 

Ok, thanks. I'll see if I can hunt it down.

^ wouldn't surprise me in the least. Although it wouldn't have been a deal breaker. At least he could have saved me some work by telling me what he tried already. Lol

 

Most Fords temp gauges set at about NO on normal so I would say you are running pretty hot. If the clutch fan is bad you would see the temps rise at idle or in slow traffic above 35 mph you don't need a fan. So if it that hot running down the road then you still have a cooling issue. Either the rad is plugged on the inside or the outside. Or tstat is have issues. I believe these have a flat plate aux cooler need to check it for flow. You also need to make sure the right water pump was put on. I.e. It's turning the right direction and the metal plate is between the pump and timing chain cover.

 

Thanks. I kind of figured. Which is why I want to do both the fan and t-stat. It's funny you mention the right water pump bit. I would hoped he would have given all the right info to get the correct one. Being that it's not completely boiling over and the top rad hose is way hotter than the bottom rad hose, I would have to think that the pump is correct. But I'll dive into that if the fan and t-stat done solve the overheat issue.

​​​​​​I've had ONE vehicle in the past where the t-stat only partially opened. I know they usually stick part open or completely closed. But I have to wonder on this, because it normally runs around AL but does occasionally drop to dead middle sometimes. So I feel like it's just hanging up.

 

Ok, so I was doing some digging on electric fan conversion for my truck. Using a flex-a-lite will work but obviously I'd need to get a shroud made, since half of mine seems to be missing.

But I found many forum posts in other Ford forums where users are just using other Ford efans for our trucks. One, in particular, grabbed my attention.

A guy said he used efans and shrouds from a 96 crown Vic for his 88 f250 with a 460 and his 94 bronco with the 351. And apparently the only trimming he had to to was the bottom where the shroud slips in to the rad.

So off to rockauto I went.. they have a motorcraft fan assembly(with shroud) for about 120. Now obviously I would then need a fan controller, which is easy. I also check on JC Whitney and it would seem the core dimensions are the same for the radiator on my truck and the crown vic. The in/out pipes are different, but I'm not concerned about that obviously.

 

double post.. stupid phone. Sorry.. and I can't find an option to delete.

 

If you decide not to go electric fan, I have a fan and clutch off my '89 5.0L that you can have for cost of shipping. Just let me know.