Rear Tires Suddenly Lock Up Going 65

-
T56MaxTorq

T56MaxTorq

Well-Known Member
Joined
Dec 21, 2010
Messages
1,023
Reaction score
376
Location
CO
Well this was an interesting experience.. I pull the duster out onto a rural highway, manually shifting, 1-2, 2-3. Going about 65mph and I feel something funny, like a lack of power, I think it's a fuel problem, maybe I bumped the fuel pump switch by accident, nope. I hear sqealing tires and the rear tires (both) are compeletly locked up. After fighting with it from going into the ditch I come to a stop with a ton of tire smoke and huge skid marks behind me. WTF just happened I thought to myself. Engine is still alive. Brakes are good. I shift through every gear and they're working as advertised. I then drive to work normally, no issues. Hopefully you guys can shed some light onto this.

Specs and what I've done recently since the past 5 or so cruises:

73 Duster, 360, 904 tranny, 3000 stall, 3.55 gears w/ suregrip

Just changed the tranny fluid and filter and adjusted bands (72 inch lbs, back off 2 1/2 turns). I did find some orange rtv in the pan, 2 small chunks. Also drained the converter and refilled with dexron atf.

Added a little brake fluid, peddle was a little soft. Good now.

Topped off the radiator.

I'm guessing a major transmission malfunction, any ideas?
 
I don't know but it sounds like a brake issue. If the brakes are adjusted to tight they can expand and act like they're on. Did you use the brakes previous to this happening?
 
When it locked up did the engine RPM drop or stay up till you took foot off pedal? Maybe the rear spider gears stuck. and when it stoped loosened up again.
 
I havn't touched the brakes for a while. I used the brakes leading up to the on ramp but while accelerating, everything seemed fine, til I hit about 60 or so and the "lack of power" came about. I do use the E-brake a lot when I park in the driveway. But today, the e-brake wasn't used.

I don't recall engine speed. It all happened quick, at that speed I'm at about 3000 rpm and I think the engine speed went to idle as soon as I let off but I'm not sure.

Oh and I did change the diff fluid and added a friction modifier for the suregrip when I changed the tranny fluid.
 
Right after I came to a complete stop I put it in park, caught my breath, then shifted through every gear, 1st, 2nd, Drive, Reverse, all worked just fine. I was even thinking I somehow pushed the brake by accident but there wasn't any nose dive, and my brakes arn't good enough to stop as fast as I just did.
 
Did you have it in a shop recently?
New thing the law is using to hold down speeding at
65 MPH triggers a hidden sensor and locks up the
drivetrain they are paying shops to install it
 
dodge71demon said:
Did you have it in a shop recently?
New thing the law is using to hold down speeding at
65 MPH triggers a hidden sensor and locks up the
drivetrain they are paying shops to install it
Click to expand...


what?????????????????????? without the cars' owners permmission. please, enlighten me!
 
My guess is maybe you have a broken tooth in your rear gears.It might,ve got caught up and when you stopped it fell,letting the gears spin freely.Now this is just my hypothisis LOL
 
i also think it is in the rearend, if you were able to drive it home after the lock-up. i cannot see a tranny taking that kind of jam, and still shift fine afterwards.
 
magnumdart said:
Cat got caught in the driveshaft. You must have shifted it into reverse.
Click to expand...

:eek:ops::eek:ops:

Originally Posted by dodge71demon View Post
Did you have it in a shop recently?
New thing the law is using to hold down speeding at
65 MPH triggers a hidden sensor and locks up the
drivetrain they are paying shops to install it

what?????????????????????? without the cars' owners permmission. please, enlighten me!

Baahaaa!! And Elvis is still alive singing in Vegas.... :cheers:
 
Seems strange that if something mechanical is able to stop the rear tires like that (besides the brakes) going that fast, something should have snapped or broken.
 
mod5v said:
:eek:ops::eek:ops:

Originally Posted by dodge71demon View Post
Did you have it in a shop recently?
New thing the law is using to hold down speeding at
65 MPH triggers a hidden sensor and locks up the
drivetrain they are paying shops to install it

what?????????????????????? without the cars' owners permmission. please, enlighten me!

Baahaaa!! And Elvis is still alive singing in Vegas.... :cheers:
Click to expand...

Our worthless goverment at work
 
I think I may have to pull the third member out and take a look. I didn't pull it when I changed the oil, just sucked out all the bad and threw in new oil. But the way the car acted just before the tires locked up makes me think it's the tranny. It was maybe a few seconds of lack of power, then the tires locked up. Maybe some trash in the plumbing wouldn't let a band or clutch actuate/release and siezed all output movement. I don't know everything about the 904 and if this is even possible. But I also agree with the rear end thinking that the tranny couldn't take that kind of abuse and still shift fine/or even function. When I drive it home I will give an update on how she drives and shifts.
 
I had the same thing happen years ago with a 4 spd big block 67 Belvedere.

It turned out the big block made enough torque to, over time, loosen the pinion nut, which allowed the pinion to drive too deep into the ring gear.

It stopped me dead in my tracks. Put it in reverse, and it loosened pinion and allowed me to baby it home, but any hard accelleration caused the pinion to "over" engage, wedging the gears so tight they would stop the car...but, it didn't happen every time. Every 3-4 hard launches created the same result, and that's when I pulled the drive shaft and found the pinion nut was very loose.

Let us know what you find.

Southernman
 
I once incorrectly adjusted the fwd band and it drove fine til I got up around 45,50 mph then It's like I jammed on the brakes had control of the front but the rear was a.big anchor. I'll bet your band will show some level of distortion. It all just sounds.so familiar. Good luck.
 
brakes check the back lines this happened to me in my old 65 barracuda a line was clapcing and it would lock the back brakes up .. im not sure how it was doing it but it was lol
 
Well the drive home was uneventful, slow speed/high speed/hard acceleration/auto shift/manual shift/downshift..everything transmission wise works normally in that short drive. If it did go into reverse at high speed it was defiantly uncommanded.

I have experienced in the past when driving low speed like in a parking lot..it will not upshift normally until I rev it sometimes past 3k, usually it shifts at 1500-2000 for 2nd and 3rd when I'm just clunking around town.

Also..again this is a known condition, 1-2 upshift can be very harsh, sometimes even bark the tires if manually shifting around 4-6k rpm.

Even after the band adjustment and fluid change all these conditions still exist and has the same behavior.

Lost with this one but the rearend is coming apart shortly before the next long drive.

Thanks for all the advice guys! I'll look at the gears and pinion nut and brakes for sure.
 
T56MaxTorq said:
Well the drive home was uneventful, slow speed/high speed/hard acceleration/auto shift/manual shift/downshift..everything transmission wise works normally in that short drive. If it did go into reverse at high speed it was defiantly uncommanded.

I have experienced in the past when driving low speed like in a parking lot..it will not upshift normally until I rev it sometimes past 3k, usually it shifts at 1500-2000 for 2nd and 3rd when I'm just clunking around town.

Also..again this is a known condition, 1-2 upshift can be very harsh, sometimes even bark the tires if manually shifting around 4-6k rpm.

Even after the band adjustment and fluid change all these conditions still exist and has the same behavior.

Lost with this one but the rearend is coming apart shortly before the next long drive.

Thanks for all the advice guys! I'll look at the gears and pinion nut and brakes for sure.
Click to expand...

I would also think rearend and maybe brakes. If it had just been one wheel I would have thought about the strut bar coming out and getting between the shoes and drum.
 
You must log in or register to reply here.
-

Back
Top