Matt90V6SR5

Why does my 5spd sometimes grind when Im trying to find reverse? Im always completely stopped.Other than that my transmission works perfect all the time.Note: Im on a slight incline when it happens,if that has anything to do with it.

Kiroshu

Well alot of people don't believe and or know this, but your supose to be completely stopped when using reverse no matter what. If not, then its going to grind a bit. If your grinding no matter what then someone has abused it alot previously..... another thing that helps with yotas is to cycle to second then reverse. this usually helps it go in better. try doing that and see if it stops.... the inline should have nothing to do with it unless your not stopping and your rolling down the incline trying to ram it in reverse.....

peow130

The 5 speeds have a shifting mechanism, where you actually have to jiggle the stick in neutral before you put it in reverse. This prevents new users from thinking they're driving a 6 speed and throwing it into reverse at 60mph..

Just wiggle in neutral, from 1st gear side to reverse, then back to 1st gear side of neutral and into reverse. works every time.

MudHippy

Alot of it has to do with normal wear on the reverse gears(gear & counter gear) teeth. More wear/miles/shifts into reverse, more tendency to grind.

When your shifting into reverse your doing so without the aid of a synchro. This means, if your engine is turning as your shifting into reverse you've got about a 50% chance of catching the gear at exactly the right moment to seamlessly mesh the gears and not grind them a little. BECAUSE, even with the clutch fully engaged, the transmission input shaft will still be spun slightly by the flywheel rubbing against it(doesn't take much). SO, the transmission is nearly always turning, even without being in any gear or in nuetral, as long as the engine is also turning. The reason you can seemlessly shift into forward gears without worries is because ALL forward gears have synchros. Synchros are essential to meshing the gears with minimal effort, and without gears grinding, when they're functioning/used properly.

Don't believe my theory about all this?

O.K. then...click this link to the FSM and scroll down to the first line of the description.

http://personal.utulsa.edu/~nathan-b.../1descript.pdf

Matt90V6SR5

Ok peow I will try that,because I am always completely stopped before attempting reverse.Im one of those people that actually stops at stop signs to.Most people pause,pausing is not stopping: lol.Thanks guys!

Matt90V6SR5

Hey mudhippy thanks man,that makes sense to me especially since it doesnt grind but about half the time.Note: when I get home I usually back into parking space for easier departure which is good idea for 4Runner/truck owners : )

MudHippy

That's what I'm here for.

pruney81

This has already been said but just go 2nd then reverse, after owning toyota trucks I do this out of habit on any car that I drive that has a stick now.

xjdubber

no synchro and straight cut gears, things have to be lined up quite nicely for it to go in without a sound. and that probably happens about half the time.

Windsor

Yup, I do the second-then-reverse dance as well. This is done to quiet the input shaft (ref: MudHippy's write-up above).

Old Mazda RX-7s taught me that lesson.

Jay351

There you go. Works everytime in every yota I have ever driven. If it feels like it just doesnt wanna go into reverse sometimes (catching the high side of the teeth) let the clutch out a little and it'l pop riiight in.

And don't try and put it in reverse when moving backwards....

mmcpeck

How does 2nd "quiet" the input shaft, does it just slow it down and make it easier to get into Reverse?

I always hit 2nd before Reverse, I don't even realize I do it, just automatic, been doing it forever, and it always works.

Jay351

Shifting into any forward gear will do the same thing.

mmcpeck

Yeah I've used 1st and 4th to do it too, but how does any forward gear "quiet" the input shaft, is it just that it slows it down a bit before you hit Reverse?

MudHippy

Thanks for that verification.

To put it simply, the action of engaging/disengaging the clutch while shifting from one gear to another can slow down or stop the input shaft from rotating at all. So, in reality you could acheive the same effect by shifting "from" any gear into reverse. BUT, reverse has no constant mesh synchro and instead has a sliding mesh mechanism involving an additional gear(reverse idler gear)to not only reverse the rotation of the output shaft but mesh BOTH first gear(as reverse is not actually a gear on it's own, remember it's first gear reversed)and the counter shaft reverse gear teeth. SO, even if you can stop everything from turning and try shifting into reverse, you'll still have some chance of not getting the gears to mesh period. Ever have the problem of not being able to get it into reverse even though you've got the clutch all the way in, so you end up engaging(releasing the pedal)then disengaging the clutch and it works? This I find just as annoying as the grinding it into reverse, but demonstrates how a sliding mesh differs from a constant mesh sychronized in shifting qualities.

Righto!

Now you've got it!

mmcpeck

Thanks MudHippy. Makes total sense.

Any truth to when people say Reverse has more torque than 1st?

I always knew they were the same gear, just reversed, but never saw how the reverse idler gear could add any torque.

MudHippy

I have seen transmissions with lower gearing ratios listed for reverse. I don't believe that the one in question has any reduction though. In my mind I can see how it may be possible to do so, with a larger idler w/more teeth perhaps.

I'll look into that further...It's actually taken me quite some time reading about them, and a couple of self-guided R150F transmission disassemble/reassemblies, just to figure out exactly how they(manual transmissions)work.

I just pretend like I know everything about everything...ooops did I say that?

Windsor

correct.

(assuming clutch pedal is down...)

If you are stopped (meaning, driveshaft is not turning) and put the transmission in *any* gear, the input shaft is going to stop.

You're in gear, output rotation is 0, therefore input rotation is 0.

Transmission basics.

Matt90V6SR5

Hey I tried the jiggling in neutral and then putting it in reverse and it works great.Thanks guys for all your help,now I also have a better understanding of unseen moving parts and how they work : )

peow130

No problem.