1988RedT2 MegaDork
1/15/22 6:46 p.m.

Okay, so when I bought the truck, a 2006 Dodge Ram 1500 SLT 4x4 with the 6-speed Getrag transmission, it came with the bed full of boxes of brand new suspension parts the PO never to the time to install.  With just 125k miles on it, the front wasn't terrible, but I figure heck we've got the parts, might as well install them.

It was pretty much the whole shebang--upper and lower control arms with ball joints installed, quick struts/springs, and tie rod ends.  My son and I did the install work this week.   I need to get it aligned, but it still drives at least as well as it did, gained maybe an inch in ride height, and all the squeaks are gone.

When we did the driver side, I noticed that the hub/bearing sounded a bit crunchy.  I also noticed that there is some sort of speed sensor on the front driver side, but not the front passenger side.  If the sensor is for ABS, how can it be only on one side?  This truck, I am certain, came with ABS on the rear only.  What's that sensor for?  On the Rockauto site, it looks like trucks with 4-wheel ABS get a sensor, and 2-wheel ABS don't.  The sensor I have is hooked up to wiring, and I assume I need the new part to have a sensor.  Anybody got some insight for me?  TIA!


93gsxturbo UltraDork
1/15/22 6:56 p.m.

Does your truck have 4 wheel abs?

1988RedT2 MegaDork
1/15/22 7:20 p.m.

In reply to 93gsxturbo :

No.  ABS on the rear wheels only.  One of the front wheels has a sensor, and it attaches to factory wiring.

Streetwiseguy MegaDork
1/15/22 7:21 p.m.

I'm thinking the rear has to have some speed number to compare.

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
1/16/22 8:54 a.m.

That RWAL is two generations newer than the system I worked on, but I'm people who knows people, so I asked around.

Bottom line is that none of my people could remember that far back. Front WSS could be used by RWAL for vehicle speed calculations, and/or for better rear proportioning when braking hard but not yet unstable.

if it was my truck, if it doesn't currently have an ABS fault lit up, i'd replace the wheel bearing assembly with what's on it, vs what RA lists.

93gsxturbo UltraDork
1/16/22 9:04 a.m.

Unplug the sensor and drive around.   Make your decision based on the outcome.

dculberson MegaDork
1/16/22 9:13 a.m.

A 2006 with rear wheel only antilock? God bless ye, dodge, it's amazing you've managed to stay in business. 

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
1/16/22 10:34 a.m.

What others have said is correct.  The RWABS can only work if it references what the front wheel(s) are doing.

and I agree, dculberson... who makes a 2-wheel abs in 2006?

cyow5 Reader
1/16/22 11:16 a.m.

I can actually see why a truck would have only RWAL. It probably has enough rear bias to lock when unloaded so that it doesn't overload the front when loaded in the rear. But sense it can't detect how much weight is in the bed, it needs to have a higher default rear bias. RWAL then bleeds off brake pressure when it is unloaded. The whole time, the front never has enough bias to realistically lock first. 


Does the truck have traction control? If so, that's probably another reason for a single front WSS. Otherwise, it won't know the difference between the rear tires slipping vs. the truck accelerating. 

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
1/16/22 12:58 p.m.
Curtis73 (Forum Supporter) said:

What others have said is correct.  The RWABS can only work if it references what the front wheel(s) are doing.

Perhaps true of this 2006 system, but the RWAL systems I calibrated in the 1990s had only one sensor, in the pumpkin.

1988RedT2 MegaDork
1/16/22 6:19 p.m.

Thanks for the replies, guys!  I guess my next move will be to call a local dealer and get him to quote the part and see how much information about the system he's willing to share.

I too was rather surprised to find that a truck that "new" only had RWAL.

Our Preferred Partners