Silly question regarding manual tranny

Hello,

A coworker had a weird accident where he was driving his oldish Toyota
Sienna and tried to apply some engine brake with his automatic
transmission.

He was able to push the shaft up into Reverse; neddless to say, he
lost control and the car swerved hard and rolled over a few times. The
van was totalled, of course, but fortunately the driver walked away,
shakingly.

Now, the question is: is it possible to push the stick from the fifth
into reverse on my 2000 Civic manual tranny while having forward
movement? Or is there some mechanical stop that prevents me from doing
such a stupid thing? Not that I would ever want to do this, just for
my general knowledge regarding transmission design.

Thanks,

Serban

 

There's a mechanical block. From 5th, you have to move the lever into the
center of the neutral pattern, then into Reverse. Try it (with the car
stopped) and you'll see.

 

Yep - it's possible (not at all easy) with any manual transmission. However,
as anybody who has accidentally hit the reverse slot while trying to
downshift will attest, it is accompanied by a horrible grinding of gears and
lots of resistance. What the driver is trying to do is to get the gears in
the transmission to stop spinning forward at high speed and start spinning
backward. The tranny won't actually go into reverse until the gears mesh,
and that isn't going to happen without a fight. Reverse gear is not
"synchro'd" - provided with a synchronizer to quietly coerce the gear speeds
to match - in any modern transmission I know of, so it would take some real
determination to get it into reverse. Why anybody would do that and then let
out the clutch so it would make a difference is anybody's guess.

Short answer - it would warn you mightily with harsh noises if you try.

Mike

 

Cool! It probably saves a lot of gear grinding. My last work truck had
reverse right beside fourth gear. I had to concentrate on downshifts from
fifth or it would reward me with the "you are an idiot" sound.

Are all Honda manual trannies made that way?

Mike

 

As far as I know.

All the modern manual transmissions I've ever driven have had some sort
of lockout for reverse.

Some examples:
1) Reverse is off to one side, out of the forward gear shift pattern
2) Push the shift lever down while moving to Reverse
3) Pull the shift lever up while moving to Reverse
4) Pull a small two-finger handle up while moving to Reverse
5) Move lever to middle of Neutral before moving to Reverse


I drove an old Ford pickup once with a three-on-the-tree. There was no
Reverse lockout, so you had to be careful going from 1st to 2nd,
especially once the linkage developed a bit of slack.
Column 3-speeds are usually arranged this way:
R2
13

Some trivia here:
Most 4 and 5-speeds are arranged something like this:
13
24R

135
24R

But some manufacturers did this very oddly, notably International, which
once made truck gearboxes that had patterns like:
25R
341
If you didn't pay any attention to the plate on the dash with that
pattern embossed on it, you weren't going anywhere fast!

 

i think it was
24r
351
reason for offset first was, you didn't use it for normal driving, only
loaded starts on hills. it was a crawler gear.

what's the shift gate on the civic 4wd wagon? istr something like a
crawler gear on that.

maybe
r24
135

i don't recall.

the 4wd civic wagon was a damned fine utility vehicle btw. honda should
consider reviving something like that, or a 4wd accord wagon, for subaru
competition. and to compete with the volvos and audis. they should
also bring back the crx of course.

 

My pattern is correct. I'm looking at a photo of that dash plate now.
25R
341

 

Thanks for the replies. One more reason to just love manual trannies,
I guess.

One thing to note is that not many stick drivers had seen the weird
shift patterns mentioned above, but some will experience the back-and-
forth switching between a 5speed and a 6speed car transmissions. Isn't
the 6th in the same position as the reverse for the 5speed?

One last question I have is about my coworker's accident. How could
the automatic tranny actually engage into reverse from probably a 4th
speed?

Serban

 

they simply made a mistake and pushed the lever the wrong way. no way
is the transmission going to do that on its own.

 

gigelus2k3 wrote:

---------------------------

More likely it actually slammed into PARK (why was he shifting in the
wrong direction anyhow ?? ). Honda's auto won't let you engage a gear
that will over-rev the engine or otherwise mess things up, but
apparently you can still force it into PARK, at speed. There have been
other questions about that.

'Curly'

 

fair enough. 1 is still offset because it's a crawler though. it's a
"feature" on a number of older commercial vehicles - real fun if it's
one of the ones with no synchro!

 

the civic won't lock in park at speed - i know because a "friend"
demonstrated that to me on my new 2000 just after i'd got it.
fortunately it has a dog with ramps whose angles allow it to ratchet
unless a secondary locking pin pops into place, and that can't happen
unless the dog is stationary. makes a scary noise that i don't
recommend investigating for yourself.

 

I got my new work truck about a year ago. The previous Ford was from the
early '90s and had a 5 speed while the new Ford is an '05 with a turbo
diesel and a six speed. In the 5 speed reverse was in the back right corner
while in the 6 speed it is in the front left corner. I really learned to
hate that 5 speed shift pattern because of reverse. It reminded me of the
joke about the guy who was racing somebody away from the stop light... he
started out in "(D)rag" and ended up shifting into "(R)ace."

Mike

 

Ah! Like the old White 6x military vehicle one used to find in Civil
Defense in the early 60s. Of course, I had a 64 XKE which I am convinced
had an almost non-existent synchro -- those old Moss 4 speeds with the long
throw from 1st to 2nd.

 

I did it once ion my 198x chevvette. It wasnt from a high speed, I was
probably doing 25-30 mph. It did go into reverse with much dificulty. I
doubt it would have went into gear at highway speeds tho. YMMV...