1993 5.0 Mis Shifted- 1st Instead Of 3rd!

dz01

Member
Mar 31, 2005
274
10
19
Massachusetts
No idea how I did this, but I tach'ed out first and second and instead of grabbing third, I put it back in 1st! Rear wheels hopped and I'm sure I sent the tach into orbit. I'm pissed I did this and have been driving a standard for years without any instance of mis shifts.

Good news- I did throw the clutch back in immediately and shifted to the right gear. Car seems to drive fine without any noticeable issues (although hearing engine noises is hard when my exhaust is so loud (flows w/o cats). Car seems to shift and drive fine. Exhaust does seem louder, but that's probably just me.

I don't think I cannon-balled my rear end or tranny, but I'm questioning any damage to the motor. Like I said, it's really hard to discern any motor noise and of course mentally I'm assessing every little thing the card does now.

Questions:

1. I know lots of damage could be done, but what should I be looking out for?

2. Does the rev limiter (6250 I think) do anything in a case like this or is that just for progressive acceleration? I was told by a local mechanic that the rev limiter does not come into play for what I did. Only if you're tach'ing out gears?

Anyone else do this by accident (and willing to admit it?).
 
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Rev limiter just cuts fuel. If you have another means of spinning the engine (i.e., the forward momentum of the car working through the drivetrain to spin it), the engine can/will spin higher than any rev limiter.

If the engine still runs fine, it probably does not have any severe damage. One of the first things that might happen is valve float, which of course can lead to piston contact.

You probably just overstressed the drivetrain a little, but that's OK. Drive it 'til it falls apart, and then just put it back together and drive it some more. Maybe buy a better shifter with stronger centering springs before you try to bang on the gears again.
 
We all have done it before. Chances are everything is fine. You would know if you screwed something up, just don't make this a habit! You may need some sort of shifter to prevent this from happening in the future
 
Had a turbo 400 shift from second 70mph to park 0mph on the dyno once...a check ball was stuck in the valve body that caused this. It sheared a 35 spline axle off but the transmission and engine were othwise fine. It was a freak thing but the damage was noticeable right away. Like the others say if it is seemingly fine then it most likely is!
 
Thanks for the feedback! I did pop the hood and listen closely to the motor at idle and slightly raising the RMPs. Everything sounds normal, but hard to tell with my pipes so loud. Tranny seems to shift exactly the same. I'll run it a few more miles this week and see if anything is noticeable.
 
You would have known if damage was done, it would have run poorly after that.

I was full throttle one day, let off in it stayed wide open, just bouncing off the limiter. Turned the car off quickly. Popped the hood and the return spring was off the TB, stuck on a vacuum line. Put it back on, started the car and on the way home wasn't running on 8 cylinders.

Took the valve cover off and found broken valve spring. Steeda Hi-Rev valve springs my ass. Rev limiter was set to 6300RPM, not very hi revving.
 
You would have known if damage was done, it would have run poorly after that.

I was full throttle one day, let off in it stayed wide open, just bouncing off the limiter. Turned the car off quickly. Popped the hood and the return spring was off the TB, stuck on a vacuum line. Put it back on, started the car and on the way home wasn't running on 8 cylinders.

Took the valve cover off and found broken valve spring. Steeda Hi-Rev valve springs my ass. Rev limiter was set to 6300RPM, not very hi revving.

Had that happen to me one time with a cheap set of floor mats that caught my accelerator pedal and wouldn't' let it up off the floor. As far as I know, they're still laying in the ditch next to the road where I pulled off to scrape the poop out of my shorts?
 
Put some more miles on the car. Honestly, the only thing I really notice which is probably more of me reaching, is the exhaust seems to stink more than I remember. Although I didn't put many miles on the car last year when I pulled the cats off. It's nothing crazy, just smells like an old 65 mustang. Other than that, seems to shift fine, idle normal, clutch feels the same. I was able to estimate this morning I was probably doing about 40mph when I dumped it back in 1st. In my head, it felt a lot faster than that.

Also- what is "valve float" and does is that a temporary thing? Does it always result in piston contact?
 
  • Valve float is when the valve or valve train momentum overcomes the tension of the valve springs and the valve's closing does not follow the closing ramp of the camshaft. The first problem it causes is duration increases to the point where compression and power drop off. Then the valve train parts have enough clearance to clatter against each other. If you are lucky and this is a one time occurance, little or no damage is done. As the 302 is supposed to have some valve to piston clearance, a collision of parts is not going to happen in mild cases. But if the valves pop open way too far for long enough, say from a overstressed or broken spring, contact can occur. Was that TMI?
 
  • Valve float is when the valve or valve train momentum overcomes the tension of the valve springs and the valve's closing does not follow the closing ramp of the camshaft. The first problem it causes is duration increases to the point where compression and power drop off. Then the valve train parts have enough clearance to clatter against each other. If you are lucky and this is a one time occurance, little or no damage is done. As the 302 is supposed to have some valve to piston clearance, a collision of parts is not going to happen in mild cases. But if the valves pop open way too far for long enough, say from a overstressed or broken spring, contact can occur. Was that TMI?
Good info! Thanks! I'm assuming I would know if damage occurred by listening to the engine at idle?
 
Weakened springs would show every time you tried to pull RPM's near the red line. Damaged lifters or minor valve train damage would be audible at idle and would be locatable with a long screwdriver or stethascope. Major damage would just plain run badly if at all. That's why they are mostly saying just drive it, you would know if you broke it.