Hi Gang, I need some direction on my trans problem. The vehicle is my plow truck, a '95 F250 with 460/E40D and 90k on the odometer. I got stuck while plowing in the last snow fall of the winter. It didn't want to go into low range so I just hammered it in reverse and ending up overheating the trans and puked about 1.5 qts out the front seal. I only drove it 150 feet or so before I noticed the front seal leaking. The fluid looked and smelled good so I topped it off. It didn't leak so I drove it about 20 miles with no problems but then I noticed it slipped in 3 rd gear so I parked it. Last week I changed the filter and 17 qts of Mercon.
On the test drive I found it is not leaking, 1st and 2nd gear seem fine, but it slips then catches repeatedly in 3rd. The speedometer is erratic, but it has been intermittently erratic in the 5000 miles I have owned the truck. The old fluid was a little dark, but not bad. The magnet in the pan had a little sludge, but otherwise the pan was clean.
I have a hard time believing I fried 3rd gear by driving it 150' in 1st gear with the front seal leaking.
Any suggestions? Thanks!

 

The E4OD transmission is 100% electronic controlled. The signal path for the speedometer is exactly the same for the transmission. Check for codes as a first step to see what is going on. You can have codes without a Check Engine Light on.

 

OK, I've been meaning to get a code scanner anyways. Anything special I should look for in a scanner?

 

If you are OBDII and I think you are this is a good one, Equus 3145 Amazon.com: equus 3145

Or if you want to count flashes for free try this: Fuel Injection Technical Library » How To Run a Self-Test

 

OBD-I = Equus 3145

A paper clip is much cheaper but counting flashes gets a little tedious.

Your truck will display three digit codes.

 

Hell, I meant OBDI and typed OBDII.... Thanks for catching that boo boo....



You're suppose to read what I mean, NOT what I type!!!!

 

It's all good

 

OK, I got the codes. If they are 3 digit codes then it gave me:

KOEO 565 565 Canister purge circuit failure
CM 332 332 EGR valve opening not detected

These don't seem to be relevant to my situation. Are you sure they aren't 2 digit codes?

Thanks!

 

Check the connections at the speed sensor or for the $20.00 it costs just replace it.The pcm gets the same signal the speedo does and if not correct can cause all kinds of issues.

 

100% positive you should have three digit codes.

 

Now that we know the PCM is happy, as it relates to the transmission, you can move forward with diagnosing the problem.

If the speedometer is erratic as you stated previously, you need to look into the root cause. It may have been doing it before, but you do not know what the drive signal looks like. The VSS signal from the rear axle is sent to the RABS module then onto the PSOM located behind the instrument cluster.

This device divides the VSS signal down to a useable signal for the speedometer then onto the PCM. If the speedometer is wonky you can bet the signal to the PCM is probably compromised as well. If the VSS signal was dropping out there is usually a code for it. If the signal is varying, but never dropping out then there will be no code. Until you check for said codes, it's speculation on the cause.

Replacing the VSS does not typically resolve the issue. It is advisable to pull the VSS then inspect it for signs of excessive build up from the rear axle lube. If it is covered in sludge it may be a sign of a bigger problem. If it is a light coating, wipe it off then re-install it.

You can check the VSS signal using a DVM:

1983 Ford Bronco PSOM picture | SuperMotors.net

If the input signal is good then you may have a PSOM going bad. You can pull the instrument cluster then inspect the PSOM. It is known to have bad capacitors and/or loose/corroded connectors. It's a worth a shot to clean the connectors regardless if they look bad or not.

 

Interesting development on my problem. I have a dump bed kit on the the truck. I don't really use it much as I have a 1 ton Dodge dump truck, but it is nice to lift the bed to work underneath. I found that the support cable that holds the scissor up when the bed is down had broken. So, the scissor and hydraulic ram were resting right on the top of the differential. The wires to the VSS were mashed flat but not broken. My new parking brake cable is damaged too. Anyhow, I replaced the supprt cable with a chain and I cut out the bad wires and soldered the good ends together. I also checked the VSS and reseated the connector on the shift lever sensor. There are now no warning lights and the trans seems to work just fine. Even my front seal is not leaking. Thanks so much for all your help!

 

Glad to see you got it resolved!

 

By the way when the transmission over heats the oil you seen came out of the vent on top of the transmission and not the front seal.
If it had came out of the front seal it would still be leaking.