1991 Explorer Transmission Woes

[jurassicerik]

Hey everybody. New to the forum, new to the explorer world. I picked up a 1991 explorer xlt made up to look like a jurassic park tour vehicle. I've been quite enjoying driving it but the transmission definitely has something wrong and wondering if you guys have some insight.

Not sure if these issues are connected or separate, but first thing is it takes absolutely forever to shift from 1-2nd. From a stoplight it will wind out to about 4500-5000 rpm before shifting, and then the next few gears shift normally.

Next problem is highway cruising rpm. Around 70 mph is right around 3500 rpm. I will let off the gas, try to coast down hills and it will drop slightly, but anytime I'm back on the gas it wants to sit around 3500 rpm. 60 mph is around 2900 rpm for reference there. I'm getting around 12 mpg because of the high rpms and it's killing me haha. As far as I know my transmission is a A4LD? It says my axle code is a D4 which should work out to a 3.73.

I have researched this forum and saw someone talking about a torque converter lockup test. In the test you are crushing down the highway and just barely tap the brake pedal, if the rpms increase slightly then your torque converter lockup is typically working. I performed the test and the rpm did increase slightly with a tap to the brakes, making me think the torque converter lockup is working.

Do you all have any suggestions for me? Or does it sound like I'm in need of a transmission rebuild at this point?

Thanks for your time!

 

[jurassicerik]

Obligatory picture of said explorer haha

 

[RangerX]

Have you checked the trans fluid level and color?

 

[jurassicerik]

Have you checked the trans fluid level and color?

Yes fluid is full with no visible leaks underneath. Fluid color is acceptable. Not factory fresh pink but not brown either, sort of in an in between spot you'd expect an older explorer to have.

 

[Josh P]

You lost 3rd gear.

 

[jurassicerik]

You lost 3rd gear.

At a dead stop I will accelerate up to about 70 and it does click through all 4 gears on the way up to 70. What makes you think 3rd is lost? And how would that effect the cruising rpm when the trans should be in 4th gear at that time?

 

[Josh P]

2nd gear is 1.47 to 1. Overdrive is .75 to 1, so 25% which would give you a 1.09 to 1 ratio in 2nd with overdrive engaged. 2900 rpm would give you 61mph with a 3.73 axle.

 

[410Fortune]

The A4LD is an automatic four-speed transmission built off the three-speed C3 platform. Ford added an overdrive gear to the C3's build, plus integrated electronic controls into its design. Solenoids control both torque converter lockup and the third to fourth shift as a result.

How to: - Ford A4LD rebuild diary - How to rebuild Ford A4LD

Ok, if you go back far enough you will see where I was attempting some time ago to figure out a "near bullet proof" A4LD rebuild. Time, and other things got in my way, but now with 205K on my stock 92 A4LD, I figured it was time to get serious about rebuilding it. Then I hit on an idea.... why...

www.explorerforum.com

They can be rebuilt to be very strong
The knowledge is out there
Careful because the “rebuild”
Is often when the trouble starts. A full remanufacture is different then a soft rebuilds knowledge is power and can make the difference between a nightmare nd a lifetime truck project

Brownish fluid and issues. = this a4ld on borrowed time
If you do replace it upgrade the coolers get the larger plate and fin style cooler you can (Chevy trucks good source)

 

[Josh P]

Gears 1-3 are hydraulic shift, and as 410 stated 3-4 shift is electronic. The ecm does not check rpm vs mph to confirm it is in the correct gear at speed.