1991 Ranger Automatic 3.0L 186,000 miles

Today the overdrive didn't work on my truck. It has been OK up until today! Two years ago the same thing happened but the cruise control wouldn't work either. The trans shop put in a used speedo sensor they had on the shelf. All was good until today.

Do you think the used speedo sensor failed? The cruise control does work this time but the trans won't shift into overdrive. This creates some rather high RPM's when driving on the highway. I'm hitting 3 grand at 60 mph.

The trans fluid could be pinker but it is not burned and does not smell. The trans does not leak any fluid either. I can buy a new speedo sensor for $25. Anyone with any ideas? Should i try the new speedo sensor? Will i mess up my engine by running without OD?

 

You'll be fine not running OD for a while. I wouldn't go much over 60mph for any extended period. With the short tires on 2WD and usually steep gearing in these trucks, the rpm does get on up there when not in OD.

As far as the actual problem, I'm not sure. Auto Trannies aren't my specialty! I'm sure someone else will post shortly.

Since it's just not going into OD, I would say it is an electrical problem rather than a mechanical one. It's not slipping, so we can eliminate that, and third is still fine, so I am thinking fourth should still be mechanically fine. I think when OD disappears with an internal mechanical failure third gear usually goes with it.

 

If it is an A4LD, it probably has two solenoids internal to the trans. One for the torque converter lockup, and one to apply the band for OD.
However, if it is not a solenoid on vacation, you have probable failure coming down the road. The input shaft can twist its splines, the planetary can go bad, the thrust washer can eat the bearings... i could go on.
If it was a gradual thing, one could suspect the band or servo getting tired. If it is an 'all at once', I'd be looking at the solenoid or hard parts failure. I would not let it go on for long without checking as it will not improve the operation of the rest of the parts...
tom

p.s. I would not expect the sensor to be faulty if the cruise failed last time the sensor failed, but works now. You can throw the $25 at it, but don't get your hopes up. My speed sensor died on a trip with an AXOD, no cruise, no torque converter lockup, but I did have overdrive. You can check by tapping the brake enough to turn on the brakelights while at cruising speed. The BOOB switch will tell the converter lockup to let go, and rpms will increase for 5 seconds or so and the tc will lock up again... That is with a good sensor, boob switch, solenoid, and lockup converter. tom

 

Bad news....The transmission shop said the trans needed to be rebuilt. He said it was not an electrical problem. He gave me a price of $800 for a rebuilt A4LD unit he had on the shelf. Price included the TC too. He told me that this is the same trans that is used in the aerostar.

He said if i decide not to rebuild, and still want to drive the truck, to put it into "D" instead of "OD". That way the trans is not trying to go into OD.

Whatcha all think about $800 for the rebuild? YES (good price) or NO (too much money)?
1991 - 187,000 miles - lots of rust - does not burn oil

 

Sounds like a really good price on the tans & tc and maybe you should go for it. You might check with them for a warranty too. In the mean time check around at a couple of other trans shops to see what they get for a rebuild with a tc and warranty. The rebuild for the A4LD in my 91 4.0 2wd supercab cost twice that when it had about 170k on it and I got a 12 month/12k mile warranty with it. Also check around to see what kind of reputation the shop has and if they have given anyone difficulty with warranty claims.