..............I had the output shaft seize in the rear support, had to wait 4 it 2 cool off some b 4 i could drive though........pulled tranny apart then i found the problem.........kim........
Rear Tires Suddenly Lock Up Going 65
- Thread starter T56MaxTorq
- Start date
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OwdKasd
Well-Known Member
I could see maybe rear end but why would brakes all of a sudden lock up without being applied? I still think while manually shifting reverse may have been engaged somehow. Eventually if it happens again something will brake and then it'll be easy to pinpoint.
Oklacarcollecto
Life is an experiment
Strut bar as I mentioned in the post.
This Bad Demon
Well-Known Member
Have you ever replaced the brake hose that bolts to the axle, where the rear metal brake lines attach? Maybe it's closing up and locking the rear brakes.....Like the front brake hose would lock up one wheel it's locking both because it's the only way in or out for the fluid to go.....
OwdKasd
Well-Known Member
So you're saying the parking brake strut came loose and locked up both rear wheels??? That doesn't sound even remotely possible. But you seem to really know alot about this stuff so who am I to argue. He can just pull the drums off and rule that one out.
Oklacarcollecto
Life is an experiment
That is a very very good idea. I had a front hose do that and lock a caliper down.
67Dart273
Well-Known Member
DO NOT drive this car until you get this "found" and fixed
Order of probability in my mind:
Rear axle: Something broken, loose pinion shaft, something loose floating around in there
Transmission.
Brakes. Unlikely, MIGHT indeed be a loose hardware problem. This is NOT going to be a hydraulic problem. The ONLY way that hydraulics could cause this is AFTER you have applied a LOT of pressure to the pedal, and that would be pretty rare.
Order of probability in my mind:
Rear axle: Something broken, loose pinion shaft, something loose floating around in there
Transmission.
Brakes. Unlikely, MIGHT indeed be a loose hardware problem. This is NOT going to be a hydraulic problem. The ONLY way that hydraulics could cause this is AFTER you have applied a LOT of pressure to the pedal, and that would be pretty rare.
T56MaxTorq
Well-Known Member
I'd love to throw in an overdrive. Road trips would be fun.
It's not a strut bar, there is nothing dragging or making noise, unless it ripped off but I didn't feel anything like that.
T56MaxTorq
Well-Known Member
Nah I'm not driving it, only for a little troubleshooting perhaps. It happened so close to work it made sense to just go there.
Oklacarcollecto
Life is an experiment
Dart_Doctor
Asa style
this is what i was trying to say thanks
dodge freak
Well-Known Member
X2 on the don't drive it.
You want to fine but if you wreck it, oh well. Maybe if you keep the speed around 35 mph max OK but at 60 you could lose control and even kill somebody--if not yourself. Unlikely but a maybe, it happen once and it could do it again unless you find and correct the problem.
Losing control at speed is no fun what so ever. If I never feel that sinking lost control feeling again it be a good thing.
I would lift the rear up and rev it in gear and listen for any odd noises.
You gotta find the problem--and DON'T sell the darn thing saying it works fine. lol
It could last a long time before happening again but you never know and it could easily happen the next time on the highway.
You want to fine but if you wreck it, oh well. Maybe if you keep the speed around 35 mph max OK but at 60 you could lose control and even kill somebody--if not yourself. Unlikely but a maybe, it happen once and it could do it again unless you find and correct the problem.
Losing control at speed is no fun what so ever. If I never feel that sinking lost control feeling again it be a good thing.
I would lift the rear up and rev it in gear and listen for any odd noises.
You gotta find the problem--and DON'T sell the darn thing saying it works fine. lol
It could last a long time before happening again but you never know and it could easily happen the next time on the highway.
Rear rubber brake hose is a good scenerio. Keep us posted on this one. My wifes VW beetle brakes would slowly apply (all 4) she kept coming home saying there was no power and by the time i would go check it would roll fine. then 1 day I was waiting when she pulled up and I jacked up all 4 corners and the brakes would be applied on all, but after a couple of minutes they would cool and release. Drove me nuts. found that the rod between the pedal and master cyl. was adjusted just a tad too long (she liked having pressure at the pedal all the way up) quick adj. of rod fixed it. I know this is a different car and system but brakes do some crazy things.
T56MaxTorq
Well-Known Member
I'm a little confused on what you mean..
I may have applied brake pressure after the "lack of power" feeling but I'm unsure. This may have really locked up the brakes and after the tires locked up I for sure applied the brakes and controlled the car to a stop. I don't have power brakes, or power steering so it was a rather terrifying experience.
I've never replaced any brake hoses. I'm a new owner to this duster, I bought it about 6 months ago. Had a cam go flat and I rebuilt the carb, added msd ignition and wires, interior work, etc etc. I've put maybe 1000 miles on it..if that.
Other people have agreed that it may be a brake problem so I wan't to cover everything and find the problem before I take it on a drive.
Will update and add pictures as I tear into it.
67Dart273
Well-Known Member
I find a situation involving brake pressure difficult to believe.
In order to cause this, you would have had to just about "dynamite" the brakes to cause that much pressure. Even a fairly hard stop would not cause this, and you would have remembered that at the time.
This SURELY has to be a mechanical problem in the axle or trans.
If you have a limited slip (sure grip) I could see where a brake mechanical hardware problem to be viable.
YOU NEED to tear into this and find the problem.
In order to cause this, you would have had to just about "dynamite" the brakes to cause that much pressure. Even a fairly hard stop would not cause this, and you would have remembered that at the time.
This SURELY has to be a mechanical problem in the axle or trans.
If you have a limited slip (sure grip) I could see where a brake mechanical hardware problem to be viable.
YOU NEED to tear into this and find the problem.
T56MaxTorq
Well-Known Member
Also, I adjusted the bands as follows:
Kickdown band: 72 inch lbs, back off 2 1/4 turns, tightened lock nut.
Low and Reverse band: 72 inch lbs, back off 2 turns, tightened lock nut.
I used a quality torque wrench and backed off the lock nut a lot so it wasn't torquing against the lock nut instead of the adjusting screw. Made sure that the adjusting screw wasn't binding or catching up in its home and causing an inaccurate torque.
There was a bit of friction material sludge in the pan but no giant chunks of metal, a few slivers but who knows when the pan was dropped last. I put in a tranny cooler and an external wix tranny filter a couple months ago.
Having such recent tranny work and the gear oil change really makes me think it's related, but I'm not doubting anything.
Kickdown band: 72 inch lbs, back off 2 1/4 turns, tightened lock nut.
Low and Reverse band: 72 inch lbs, back off 2 turns, tightened lock nut.
I used a quality torque wrench and backed off the lock nut a lot so it wasn't torquing against the lock nut instead of the adjusting screw. Made sure that the adjusting screw wasn't binding or catching up in its home and causing an inaccurate torque.
There was a bit of friction material sludge in the pan but no giant chunks of metal, a few slivers but who knows when the pan was dropped last. I put in a tranny cooler and an external wix tranny filter a couple months ago.
Having such recent tranny work and the gear oil change really makes me think it's related, but I'm not doubting anything.
T56MaxTorq
Well-Known Member
I do have a suregrip, unsure if it's a dana or borq-warner unit though.
Defiantly tearing into it to find the cause. I cannot drive on eggshells waiting for it to happen again. Luckily I had both hands on the wheel and there was no traffic around me, I would have been rear ended for sure.
440outlawdart
Well-Known Member
i had this problem in my drag car,727,would just lock up on the return road,come to find out something in the tranny let go,pull the tranny and have it inspected,on another note i had a bad rear brake hose on another dart.while foot braking,would act like the brakes was applied always,but the problem you discribed sounds like a problem i had,its only going to get worst,may be ok one time then not another,dont want this to happen in traffic
dusted72
Thanks Hemiroid!!!!
This may be a long shot but I had a turbo 400 break the sprag and it did the same thing at 65 mph. May not be related but it could be.
TrailBeast
AKA Mopars4us on Youtube
I like the brakes posts, especially the master cyl adjuster post.
Think about it.
The seal in the master cylinder could be past the point in it's bore to not let the fluid come back from the wheel cylinders.
It would just move the fluid back and forth to the brakes but not let new fluid in or out of the lines.
At a good road speed the lines got heated by the engine and exhaust causing a hydraulic lock.
If this happened it was probably all four wheels but the backs lock up sooner and there ya go.
Hmmm
Think about it.
The seal in the master cylinder could be past the point in it's bore to not let the fluid come back from the wheel cylinders.
It would just move the fluid back and forth to the brakes but not let new fluid in or out of the lines.
At a good road speed the lines got heated by the engine and exhaust causing a hydraulic lock.
If this happened it was probably all four wheels but the backs lock up sooner and there ya go.
Hmmm
cudamark
Well-Known Member
I'm thinking it's a valve body problem or temporarily plugged oil passage. In a race car, a transmission brake applies reverse and forward at the same time to keep the output shaft from turning. Maybe something went haywire to cause the same sort of thing. It would also explain the "loss of power" as the engine would be working against the converter like you were bringing the RPM up to stall speed. I can't see the brakes or rear axle doing that, and then just as suddenly, curing themselves, although the loose pinion nut/shaft may have some legs. You'd think there would be a bad leak if that was the case though....
This Bad Demon
Well-Known Member
When you raise the rear of the vehicle and look at the back of the axle, like you looking to the front of vehicle.....You will see where the two metal lines for the rear brakes going to a rubber hose with a brass end to it......I kno/heard of people having the front brake hose collapse an lock up the wheel.....When they get it stopped, after a few minutes they can usually drive it until it happens again....Now with the rubber hose for the rear brakes, if it collapse then both rear wheels will lock, because it's the only way for the fluid to pass to rear brakes.....
I know where a 69 GTX sits today with the same problem. Last time it hit the 1/4 mile track it got into 3rd gear and locked up both rear wheels and slid to a stop. Driver backed it off the track and drove it up on the trailer.
That was years ago and the car hasn't been driven since. Owner has a Dana 60 rear to put under it but really doesn't know if the rear is the problem.
I've heard of times when a floor shifter combined with a broken left ( bisquit type ) motor support changed gears. From drive to reverse is a stretch though.
Bottom line, I've tagged this thread so when yall figure out where the problem is I can call ronnie and tell him. Good luck
That was years ago and the car hasn't been driven since. Owner has a Dana 60 rear to put under it but really doesn't know if the rear is the problem.
I've heard of times when a floor shifter combined with a broken left ( bisquit type ) motor support changed gears. From drive to reverse is a stretch though.
Bottom line, I've tagged this thread so when yall figure out where the problem is I can call ronnie and tell him. Good luck
T56MaxTorq
Well-Known Member
Wow! This seem to be more common than I had thought. I see how it could be a motor mount jumping gears, and you're right, that is a long stretch.
This is what I think happened.
Whatever it was, it had to of initially absorbed a LOT of energy to lock up both tires as violently as it did on a 3200ish lb vehicle going 65 mph while a strong 360 is also applying torque at 3000rpm in the same direction.
Brakes seem to be the only logical thing that could malfunction and absorb this amount of energy and could possibly show little/no signs of damage. But I just can't see brakes as the problem (although they will certainly be checked), to instantly lock both tires due to a collapsed or damaged hose or master cylinder. Where would the energy come from to apply that much brake pressure?
You'd think the ring and pinion or anything in the transmission would just explode if told to put up with that much stress. Or like mentioned, leak, vibrate, make noise. Anything besides magically fixing itself. Haha
If the tranny somehow went into "trans brake mode" I may have felt it as the loss of power (the friction of the forward and reverse band slipping), then as soon as I let off the gas there wasn't anymore torque (probably negative torque) from the engine and it could actually lock up the output shaft now and that would have locked the tires.
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