Hotrodfordaj

hello, I have a 1991 f150, 5.0 AOD that I am fixing up with my kids and using a daily driver. I had to replace the abs speed sensor on the rear diff, and TPS as both sensors were producing trouble codes. I replaced both sensors, engine is running perfect, but now the abs light comes on, and the truck shifts in and out of over drive very hard, and downshifts from overdrive late. shifts thought the other gears perfectly. also the cruise control stopped working at the same time the abs light started coming on. the trouble codes on the check engine side are gone now, but ABS light is on and rough shifting in OD. when we move the selector to D and shift to OD manually it shifts fine..... I did replace the bad abs speed sensor with a BWD brand from Oreilly autoparts. I have since ordered the original motorcraft sensor, but would this actually cause my issues? being a 91, it has a cable speedodometer. ANY help would be appreciated... I prefer not to pay $100 just to have our nearest Ford dealer to pull the ABS codes..... thank you in advance.

Hotrodfordaj

further note, I have been coming these forums and others for 2 weeks, also searching Google.... everything I find either is for an E4OD, or 92 later. thanks

Chris_1

iTrader: (1)

Well as far as that speed sensor goes, everybody says "motorcraft only" for good reason.
Being that they are basically a magnet, what usually goes wrong is that they get a buildup of tiny iron filings; just from the gears wearing, they do do that:
The iron filings build up to the point that the sensor reads metal all the time instead of reading the teeth and spaces on the tone ring.
Usually you can just wipe them off and they work again...usually.
But if that cures the problem, it will come back - you'd need to pull the cover, wipe down everything you can reach and put in fresh fluid.
I'm not as conversant on pre 92 (electronic speedo) E4Od's control sensors so I'm not sure if the diff sensor is tied in to the tranny, but it well could be and with your abs light on and your tranny shifting funny... especially after putting in an aftermarket diff sensor, I'd be looking at that first.
I have seen some of the earlier E4Od's with a sensor of sorts right where the speedo cable goes int the tailshaft (or transfer case). Something else to maybe check on.
Yours being an AOD I'm not sure just what, if anything is controlled electronically. You're sure it's an AOD ?

Chris_1

iTrader: (1)

No electronics maybe. Here's an excerpt from Hemmings on the TV cable.

The throttle valve linkage or cable adjustment is very important to allow the AOD to shift properly. Start with a good bushing on your throttle linkage and check this bushing often after installation. Many complaints of improper shifting can be traced to this bushing. New bushings are less than $3 and can be obtained from your dealer or you can purchase aftermarket aluminum replacement bushings, which will last much longer. To correctly adjust the TV cable assembly, release the locking tab on the TV cable and have someone hold the throttle full to the floor. Lock the tab down and mark this setting on the cable casing. This will be your maximum TV setting. Measure 5/16 in. back from that mark (with throttle still wide open) and scribe another mark as your minimum throttle valve setting. Then make a third mark halfway between both scribe marks (5/32 in. from either mark). Unlock the locking tab again and set the adjustment at this halfway mark to have a properly adjusted TV cable.

Hotrodfordaj

thank you for your response, the cable adjustment idea is a good thing to check. I have a new motorcraft abs sensor on its way.... will update as soon as I have time to do the adjustment.

Hotrodfordaj

I replaced speed sensor, and also found that my led tail lights were causing the rabs tp come on. All that fixed, the truck still shifts way to early. Going into OD at 35 mph. Could TV cable be the culprit for this issue? I'm gonna do the adjustment procedure later

Hotrodfordaj

UPDATE: I have replaced the abs sensor on the rear diff, but the transmission still is shifting very early, and downshifts very late. shifts are smooth, but I'm in 3rd gear by 30mph, and OD by 35mph. this transmission is definitely a ford AOD. ive been told the governor on the tailshaft needs cleaned, as it controls shifting by pressure and output speed. my speedo is cable, and I already done the factory adjustment on the TV cable. any help or thoughts? it is my daily driver, id prefer not to use a transmission shop, as I don't have the extra money. thanks for any help.

Chris_1

iTrader: (1)

I think the governor on the tailshaft would be for the 1-2 upshift (it is on the A4LD anyway).
Normal driving, my 4R70W will be in overdrive by the end of the block, or sooner. Unless you've got your foot into it hard, most automatics will be in top gear by 30 mph if not sooner.

wde3477

FWIW, I had the AOD and experienced the perceived quick upshifts and slow downshifts from the get-go, along with going into OD with a bump considered harsh by today's standards around 35-38mph on easy acceleration. On deceleration, didn't appear to kick out of OD until around 25. Even after the rebuild at 207K miles, behaved pretty much the same way. Can't say whether it was right or wrong, but it was consistent throughout the twenty-something years. Suspect it may have been one of Ford's better ideas towards bumping up their fuel economy and lowering their emissions numbers...?

jrfiol

Hello! I just got a truck with the AOD transmission. I do have some shifty shifting going on. It'll start jerking when i pull of the gas or am cruising at certain low speeds. I wish to change the sensors,and any transmission components prior to undertaking a rebuild. From your experience, could you list the components I should replace? If you can, I would really appreciate it.

Kindest regards,