Reverse grinding

[alexscof]

Hey guys, I just recently bought a 1989 mk3, 5 speed.
When I put it in reverse it grinds... sometimes. I've noticed when the motor is cold it doesn't grind at all. But once its been running the grinding starts and gets progressively worse. Any thoughts on what the problem may be?
Thanks

 

[Poodles]

Press clutch in, wait a few seconds, then try. Reverse isn't syncronized and as such the gear pack is still spinning (spins easier when warm).

 

[Dirgle]

Poodles got it, No synchro on reverse. Another method is to push in the clutch put it in first and then slid it back in to reverse.

 

[Poodles]

Any gear would work as it stops the pack from spinning (or just takes up the time to allow it to spin down)

 

[alexscof]

Thanks for the replys. Everyone I've talked to has said the same thing about the synchros and that's exactly what it feels like when I try to pull it into reverse. But I try to double clutch or do what you said and it continues to spin. I don't get it

 

[T-MA71]

I always put it in first then reverse. It Works almost everytime.

I have had some random days where i would have to do it like 3 times.

 

[ERA]

Yeah its "normal" as everyone else has said and that our cars reverse gear isnt sychronized.

There was a whole thread a while back of what rituals we all partake in to get that nice smooth shift.

Works for me as is, sliding straight into reverse no problem most of the time.

 

[hvyman]

3rd works for me every time if not 4th i find it easyier since my first is fucked up. both w58 and r154 3rd worked almost every time.

 

[Angry7M]

Press clutch in, wait a few seconds, then try. Reverse isn't syncronized and as such the gear pack is still spinning (spins easier when warm).

My trans would always grind when I put it in reverse. I just tried what you said and Wow, it really does work. Thanks

 

[gaboonviper85]

yup just pop it in a forward gear before going into R

 

[black89t]

LOL.


sorry but all you all are wrong!

read my post in this thread. if you don't understand after that then well......too bad. lol.

btw this applies to all manual transmissions. they all uses a straight cut rev gear that is the only gear that isn't constant mesh.

http://www.supramania.com/forums/showthread.php?t=96873&page=2&highlight=gear

 

[hvyman]

the e brake only holds the car from moving when stopped. how would the output shaft start spinning with the wheels no moving? the out put shaft will only spin when the tranny is in gear( not neutral) and the clutch is relased and then the wheels spin.

if you have a spare tranny put it neutral spin the input shaft the output shaft will spin hold it and it wont.

reverse is straight cut with no syncro hence why it does not always want to go in smoothly. syncros are only there to help put the tranny in gear smoother. and straight cut gears whine like a mofo thats why drive gears are not straight cut.

 

[IJ.]

LOL.


sorry but all you all are wrong!

read my post in this thread. if you don't understand after that then well......too bad. lol.

btw this applies to all manual transmissions. they all uses a straight cut rev gear that is the only gear that isn't constant mesh.

http://www.supramania.com/forums/showthread.php?t=96873&page=2&highlight=gear

NO in this case it's you that's wrong.

It's the input shaft friction driving the the cluster gear and straight cut reverse gears that is causing the clash, why is the input spinning? it's just clutch drag that can happen for a 100 different reasons selecting a gear stalls the clutch disc and input shaft allowing reverse to select without a crunch (I used to nudge the 5th syncro to stall it then pop it into reverse, you don't actually have to fully select the gear)

Normally there's enough drag in a trans that when you grab reverse at rest nothing is turning, as they wear they get looser.

 

[shaeff]

I always touched 4th quick, then reverse. Worked every time.

 

[alexscof]

Oh my god success, It took a lot of playing around with the gears but I find if I go from fifth to reverse it usually lines up. Thanks for your help

 

[hvyman]

are you going from 5th to n to reverse cause the tranny shouldn't let you go straight from 5th to reverse.

 

[black89t]

^well then i guess the technical literature i have is wrong. along with a majority of owners manuals. and the whole characteristics of straight cut gears is wrong also. lol.


this is all i can say. next time you have a tranny on the bench with the case split. see whats engages reverse better. having everything stationary or having the gears spinning. unless your lucky and everthing was already lined up you will hear a familiar grind when you force it with all gears stationary. which apparantly is what you want when going into reverse according to the above. :ugh2:

 

[IJ.]

Can't grind if it's NOT spinning

The straight cuts have chamfered leading edges to allow them to mesh easier if you grind it a lot it takes this edge off and gets worse.

 

[Guyana00]

The reverse gear is straight cut and doesn't have a synchro so that you can only go into reverse with the car stopped.

Meaning if you were rolling forward or driving forward and missed fourth and went into reverse, it wouldn't go, it would grind.

Also it's correct that the tranny shouldn't go from 5th straight to R in a linear motion.

 

[RazoE]

I just put it in 1st and move forward half and inch or so then shift into reverse, works all the time...

Usually if it won't go in, put it in neutral, let go of the clutch then clutch in and try again, only way to do it without damaging anything..