Can somebody please provide me with information on how to locate the speed sensor and differential sensor in a 1993 F350 Diesel (Crew Cab with an automatic transmission)?

I can back my truck up, put it in gear and drive; but, at 20 mphs, when it should be shifting, it isn't. We changed out the TSP/Filp but it didn't resolve the problem. Interestingly, the OD is not flashing and the truck when put on the "computer" did not give any codes.

Any assistance would be greatly appreciated.

 

The speed/abs sensor is on the top center of rear differential. It has one bolt holding it on with wires coming out the top.

 

It's about the size of a walnut. I don't think there is anything else on the differential that has wires coming out of it either.

Easy to remove and replace.

Usually when the sensor fails it will several things depending on how bad it is. It will usually turn on the ABS light. It will occasionally to frequently cause the speedo to jump. If the speedo jumps frequently, then your cruise control will shut off.

Sometimes when it fails it might leave junk in the differential, so it might be worth changing the fluid sometime soon. If the sensor is chewed up when you remove it, then it probably did leave debris.

Good Luck, easy job to do it yourself, dealer will charge about $60 plus $15 for the part.

Jim Henderson

 

It's located on top of the tailstock on the drivers side. You need a 10mm socket to remove the retaining nut. Pull the sensor out and remove the wiring plug. Then remove the clip retaining the gear on the end of the sensor assembly. Install the gear onto the new sensor and insert it into the case. Use care so as not to damage the O-ring on the sensor. Replace the retaining nut and plug the wiring back in. All in all about 3 minutes. However if the sensor is faulty you should get a 503(?) code.

 

Thank you for your information. I finally sent the truck to "Lee Myles" Transmission. They ran the codes and came up with codes:

23 - Throttle Position Sensore out of range
26 - Transmission oil temperature fault
91 - Shift Solenoid 1 (SS1) Circuit Failure
93 - Coast Clutch Circuit Failure

They told me after setting the TPS and installing a solinoid pack that the transmission was "bad" and had to be rebuilt. I read somewhere that this transmission (automatic) has a life expectancy of 135,000 to 175,000 miles and we are at 136,000 ...

Are they trying to give me pain in my butt again?

 

Assuming your 93 diesel has an E4OD, you probably do need a rebuild. The E4ODs prior to 95 were notorious for problems especially with a diesel. The Torque Converter would often fail and overheat the tranny and also send bits thoughout the tranny which caused failure.

When they rebuild it, they should use new specification components. Ford revised the specs on many things in the tranny because of known problems.

When I had my gas 94 E4OD rebuilt, because of my stupidity, oops forgot to check fluid before a tow, it cost me about $2,500 for all new spec and built for heavy duty towing. The uprated components used on mine included, heavy duty pump, clutches, new spec torque converter, and a few other bits and pieces that I forgot. I have towed 8,000#+ for about 30,000 miles since the rebuild and so far so good.

So yeah with an E4OD and especially with diesel, you probably do have a problem. Torque shudder is a classic symptom, The car will feel like you are driving oin grooved pavement when you do a gentle acceleration at about 50mpg. You may also get intermittent harsh shifting.

Your diagnotics... 26 - Transmission oil temperature fault and 93 - Coast Clutch Circuit Failure may be a symptom of the TC failing. The 91 - Shift Solenoid 1 (SS1) Circuit Failure may be a symptom of th bits floating around.

Keep in mind, I am no tranny expert, I just get to pay the experts to teach me the error of my ways.

Good Luck,

Jim Henderson

 

Thank you so much for taking the time to respond. Prior to my friend using the truck and blowing the engine, it ran beautifully. It never overheated, no shuddering, no bad shifting.

You are correct in the type of transmission my truck has. Is it true that these transmissions are only expected to last 135,000 to 175,000 miles? If so, why in the world did they use this type of a tranny when the diesels are built to run in excess of 200,000 miles? My friends has over 500,000 miles on her (it is older and doesnt' have the turbo).

 

> when the diesels are built to run in excess of 200,000 miles

You have to replace clutches in any tranmission after a while, no matter what you drive. It is just much more expensive to replace them in an automatic then a standard transmission. The more you use it, the more you replace it. My boss's Dodge 4x4 dually goes through a transmission every 60k-75K, he is still on the same diesel motor with the 3rd transmission.

On the other hand I got 189K out of my Aerostar AT (A4LD - even run dry once by my wife) and they are known for being weak. Though I changed the fluid and filter every 30k.

Even on tractors and med. sized trucks, automatics are usually only good for 70-100k before something has to be rebuilt. Some makes only last about 50k with in the city use. I have never even seen an automatic in a class 8 truck.

With an automatic, no matter what they tell you, used for towing or business, if you do not want to rebuild it every 70-100k you have to change the fluid every 20k-30k. Plus, add the best trans. cooler possible. Then you might make 150K+ miles to a rebuild. After 150K you start crossing your fingers at the beginning of every trip

If you do a across the country haul with a heavy load, when you get back change the fluid and filter. You have to go through a lot of $30 filter and fluid changes to equal one $2000+ rebuild that you have to pay someone else to do.

People change clutches in manuals all the time. But, $100-$200 worth of parts and a few hours of shop time, and you are gone. So, its easy to forget what exact mileage you had it done. Replace an automatic transmission and it is $omething you remember for a while.

When you hit a 100K you have to start thinking "what is next". It is usually the automatic transmission. Just the way it is. imo

 

Trannies are just like all other mechanical devices, full of compromises and with an "expected" life expectancy under "normal" conditions.

Some models will last longer than others overall and within the same model group some will last longer than others of the same type and build. Just the way things are, plus... people have very different driving, maintenance, and abuse styles. If you don't maintain or you abuse, or you tow a lot or drive like a nut, your tranny on "Average" will fail sooner.

Some of us just get lucky too.

Ford and every other maker designs their product based upon an expected failure rate. Usually this is calculated to provide the least amount of warranty claims and reasonable service life for the customer. When Ford designed the E4OD, I was told they did not take into account the torque and the "harsher" power pulses thru the transmission. So the tranny was more prone to failure "On Average" than Ford expected.

Ask anyone with an early year SHO about tranny life and they can tell you Ford does make mistakes, as does every maker.

I would expect a decent E4OD to get well over 100K in easy "commuter" style driving. You will probably get less if you tow or your drive a lot of hard stop and go with Jackrabbit starts etc, least on "average". An E4OD would probably last longer in a shortbed 2WD F150 with a small engine than it will in a Crewcab F350 long bed dually with 4WD. One has lots of weight and is expected to see harsher conditions as a work truck, the other is usually a "commuter".

100K isn't bad, I know several owners of Mercedes big $$ cars who would be delighted with that kind of life expectancy on the tranny.

Jim Henderson