Question about swapping in an 8.8 Explorer rear & signal to my speedometer

[Bob Hatcher]

I am swapping in an 8.8 rear out of an Explorer or a Mountainer because of my project to swap in a 302 into my 2000 Ranger in place of a 3.0 - not noticing any unit on the original automatic transmission for getting a speed signal to my speedometer, I started reading up on this subject - her is what it said on this site: "The 1998-2000 Rangers are not equipped with a VSS (Vehicle Speed Sensor). The PCM (Powertrain Control Module) receives vehicle speed information from the antilock brake system rear wheel speed sensor. The raw signal from the ABS/VSS sensor on the rear axle goes directly to the Explorer 4WABS module where the signal is corrected for tire diameter. Then the corrected signal is sent to the PCM, speed control, cluster, etc. In this system, the PCM is an end user of the corrected VSS signal. " - that being said, does anyone know if my speedometer will still be able to get the proper information from the ABS wheel sensor on the 8.8 rear? Thanks

 

[JoshT]

Yes, the abs sensor setup is the same. The truck's wiring isn't going to care if you are running an Explorer or Ranger axle, as long as it is receiving a signal from the abs sensor.

That said, if you are changing gear ratio and/or tire size it will affect the accuracy of the speedo during to them not matching the conversion formula.

FWIW and IIRC, the '98-'00 Rangers (and maybe later) calculate speed to the same way that the '99-'01 Explorers do. Both use the rear ABS sensor signal, convert it in the ABS control module, and send to the speedometer. I'm thinking that all rangers with ABS used the same sensor setup until they added stability control in 2009 or 2010. Same for the Explorers until they went to IRS, and maybe even later than that.

 

[Bob Hatcher]

Yes, the abs sensor setup is the same. The truck's wiring isn't going to care if you are running an Explorer or Ranger axle, as long as it is receiving a signal from the abs sensor.

That said, if you are changing gear ratio and/or tire size it will affect the accuracy of the speedo during to them not matching the conversion formula.

FWIW and IIRC, the '98-'00 Rangers (and maybe later) calculate speed to the same way that the '99-'01 Explorers do. Both use the rear ABS sensor signal, convert it in the ABS control module, and send to the speedometer. I'm thinking that all rangers with ABS used the same sensor setup until they added stability control in 2009 or 2010. Same for the Explorers until they went to IRS, and maybe even later than that.

Thank you for the great information, Josh - on that same subject, I am being told that a lot of Rangers came with the 8.8 especially aiming at the ones that had the 4.0 engines installed from the factory - if this is true, I have to assume that they were all Rangers had drum brakes in 1998 - 2000 and, if I want to upgrade to a rear disc, I would definitely need to aim at the Explorer/Mountaineer? I will check the rear in my truck today but I believe it to be the small rear.

 

[JoshT]

Going off memory here. I think most Rangers in that year range came with 8.8 axle. All of the 4.0l Rangers came with one axle. The 4 cylinders were most likely to have the 7.5" axle. I'm not sure about the 3.0L.

Check the door warranty label, it has the axle code on it that can be matched to article in tech library. If the label matches the vin, but not the axle then someone swapped the axle in the past.

All Rangers from 1983- to 2009 or 2010 came with drum brakes.

Explorers started getting rear disc in 1995. The 2 doors might have been in 1996, they were delayed on the redesign I think.

Explorer 8.8 or Mustang rear disc swap would be your easiest routes to rear disc.

 

[Bob Hatcher]

Going off memory here. I think most Rangers in that year range came with 8.8 axle. All of the 4.0l Rangers came with one axle. The 4 cylinders were most likely to have the 7.5" axle. I'm not sure about the 3.0L.

Check the door warranty label, it has the axle code on it that can be matched to article in tech library. If the label matches the vin, but not the axle then someone swapped the axle in the past.

All Rangers from 1983- to 2009 or 2010 came with drum brakes.

Explorers started getting rear disc in 1995. The 2 doors might have been in 1996, they were delayed on the redesign I think.

Explorer 8.8 or Mustang rear disc swap would be your easiest routes to rear disc.

I took a couple of photos today of the center of the rear, the tag & the door frame sticker - matching them up with photos of a 7.5 & an 8.8, it looks like it might be a 7.5 and the rear is original

 

[Bob Hatcher]

I took a couple of photos today of the center of the rear, the tag & the door frame sticker - matching them up with photos of a 7.5 & an 8.8, it looks like it might be a 7.5 and the rear is original

Everywhere I read today states that my Ranger rear, with the code 86, is a 7.5 open rear with 3.73 gears so my plan will be to locate an 8.8 - thanks everyone

 

[Mechrick]

That said, if you are changing gear ratio and/or tire size it will affect the accuracy

The tone ring for the rear speed sensor is on the ring gear, so gear swaps won't change the speedo accuracy, but tire size will.

Ford has used the axle-mounted speed sensor since the late '80's, and will always have a reluctor in the rear axle (sine wave, which is why it's a twisted pair). The signal will go to a module for buffering into a square wave, which could be the speed control module, the GEM module, the cluster, or the ABS module depending on the vehicle. The PCM only works with a square wave signal.

 

[don4331]

The fact; all the fact

99% of the time a Ranger with an open axle will be traction limited, so a V8 will never be able to hurt the 7.5". OK, there are disadvantages to the open axle, but that is kind of a separate issue.

And we will note that a Ranger 8.8 only have the same 28 splines axles and 2.80" tubes, so Ford rated both at 2,700lbs GAWR.

One thing to note: The tone ring on all 7.5" axles has 102 teeth; all 8.8s have 108 teeth (9.75s have 120), so swapping in an 8.8 automatically results in your speedomter (and odometer) reading ~6% low!​

The advantages of the Explorer axle are: Larger diameter tubes & 31 spline axles. Together, they increase GAWR to 3,200lbs. (Doesn't change what truck is rated for, just the axle itself).

The biggest "issue" with installing the Explorer: It is set up spring under, while Rangers are spring over.

If you are lowering your Ranger, this is a positive. Otherwise, you probably want to change it to spring over (simplest way to do that is DJM rear axle lowering kit for F150...the same bracket that allows spring under on the F150 allows spring overwhen working with Explorer axle - both being the 3.25" tube 8.8s).​

​

There are a couple minor items, as you may have noticed:

The Explorer axle shocks mount to the spring plates, while the Ranger ones mount to the axle. The solution is to use 2 Explorers ?driver's? plates. (I'll need to double check that).​

The Explorer sway bar mounts toward back while Ranger mounts forward (I see in your picture that your Ranger doesn't have rear sway bar). Solution is to drill a couple holes in the back of your Ranger frame to mount the sway bar link (if you want the sway bar). It's not as effective as the mounting points are further back (and your truck apprears to be a SuperCab), but it helps.​

I believe the Explorer parking brake cables actually direct connect in place of the Ranger ones (something Mustang ones don't).

I'm not saying don't swap to a Ranger 8.8; just giving you all the information, so you can make an educated decision.

 

[JoshT]

The tone ring for the rear speed sensor is on the ring gear, so gear swaps won't change the speedo accuracy, but tire size will.

That's....

Well, that's a very good point. Not sure why I never really put 2 & 2 together to realize that.

I've changed tire size in the computer before, but never messed with gearing. Didn't notice a setting for it, but wasn't looking for one and kind of just assumed that it was buried there somewhere. I kind of assumed that it was in the PCM and asked a tuner about changing gear ratio as part of getting a tune, but they said that there isn't a setting for it. Did not really understand why, but it makes sense now.

 

[don4331]

There's a setting for gear ratio in the PCM - it 'tunes' the transmission shift points...