Hey ya'll, I'm new to the forums. I've got a question for the experts. I've got a 99 Ranger 4x4 3.0L. When braking, right as it comes to a stop the truck VIOLENTLY jerks. Not a single lurch or jerk, but multiple, seriously hard jerks in a row until it stops jerking. Upon acceleration from a complete stop it doesn't really jerk but hesitates to take off, and takes a bit more gas than normal like it is being held back. After it gets moving it shifts normally, and seems to brake reasonably normally until coming to a stop. The other night it completely seized. Upon acceleration it squealed and wouldn't move. I had it towed home and it rolled right off the hauler? I'm not sure what is up exactly.

I used my dad's scanner and pulled codes C1230 Wheel Speed Sensor Rear Center Input Circuit Failure, C1102 Acceleration Switch Circuit Failure, C1095 Pump Motor Circuit Failure, and B1676 Battery Voltage Out of Range. I manually tested the battery with a multi meter and it read 13.6V.

I pulled the fuse to the ABS system and it is still occurring. I suspected a frozen caliper or collapsed brake line, maybe even the notorious Ranger slip yoke issue, but this doesn't seem to mimic anything I've read on the forums from those issues or anything I've ever encountered from a frozen caliper or malfunctioning ABS before.

ANY THOUGHTS? Lol...

 

You don't mention, manual or automatic?

 

It's an automatic.

 

Shift to Neutral when slowing down, see if it acts the same way

 

I'll give that a try and report back. Thanks for the direction, I sincerely appreciate it.

What does it mean if the issue stops when in neutral, and what does it mean if it continues doing it in neutral? What are the next steps I should take in either potentiality?

 

If problem stops in Neutral then it means the torque converter is not unlocking fully when stopping, which could be failing TCC solenoid valve or torque converter
If its the brakes then it would still have the problem

Torque converter is attached to engine so spins at engine RPMs, always
It is also connected to input shaft of transmission

As engine spins ATF inside the torque converter passes on this spinning to input shaft, this is called a Fluid Coupler
It is set up so at lower RPMs of the engine the transmission can stay "in gear" and not stall the engine, so like a Clutch on a manual trans

As engine RPMs increase the torque converter increases pressure to spin the input shaft to make you go forward
This is a very inefficient way to drive and why automatic's MPG is lower than manual trans, always
There is a way to "lock" torque converter so engine and input shaft spin at same RPMs for best MPG
TCC solenoid does this
And torque converters also have a "Stall speed" that locks it at certain RPM and above

But these "locks" must release when you stop or engine can stall, i.e. jerk violently until they relase

 

Wow, what incredibly insightful information. I'm certainly not a professional mechanic, or expert, but I am a science student and do enjoy tinkering, and cars (when I have time), and certainly learning how things work from people that both understand and are generous enough to share their wisdom.

Ok, I'm gonna test her out when I get home and try and bring some meaningful diagnostic data to my next response. Thank you again for your generosity helping me work through this. I am on a tight budget and I'm almost certain I couldn't afford someone with your expertise right now lol : )

 

Hey again, back after a while. Hope you've been well. Thank you again from before for all the information to get me started diagnosing this issue. I've been so busy with school and helping family I just now got back to my truck project.

I took the truck to a mechanic and was told the transmission is going out. They said it had a frozen caliper on the front left, which they freed, and an issue with the emergency brake which they fixed. Once they had all 4 wheels moving freely, they said it still shuddered. They found the auto trans fluid was not only low but dark and burnt, with metal debris in it (which I did not see when I checked it on the stick). They concluded it was likely a failing transmission and the clutch plates were wearing, and that it could be due to a failing transmission pump. They did mention they would not be able to work on the transmission for what that is worth, so they didn't have a vested interest to make it a transmission issue.

Does this sound plausible? Could the failing torque converter solenoid issue you described present this way?

* * * * * * * My fiance' drove the truck to the repair shop and did not test whether the shuddering stopped when braking in neutral