Reverse crunching on 6n 16v when being engaged

SD_polow · Post by **SD_polow** » Fri May 28, 2004 8:25 pm

My Reverse gear always crunches when trying to get it into reverse.
Just got my clutch done last week, and now this noise is driving me crazy!!

GroovyCarrot · Post by **GroovyCarrot** » Fri May 28, 2004 8:30 pm

This is more of a treatment than a cure, but if you press the gearlever against the syncromesh of 2nd gear just before you select reverse, it usually prevents the crunching.. it's what I always do with my mk2, otherwise it does it all the time.

SD_polow · Post by **SD_polow** » Fri May 28, 2004 8:32 pm

Cheers, GV. I'll give that a go!

Anybody else know what it may be?

Your help would be greatly appreciated!!

pettsy · Post by **pettsy** » Fri May 28, 2004 8:53 pm

my mk3 does that. i always go into 1st before i engage reverse now. i would be interested to knwo what it is.

Matt

Tahrey1043 · Post by **Tahrey1043** » Sat May 29, 2004 4:44 pm

How long do you leave it from stopping / putting clutch down before going for the gear? I can crunch mine any time in a hurry, but I find coming to a total halt, clutch right down, then waiting 1 or 2 seconds for all the gears to stop whirling results in a silent, smooth engagement

Remember that reverse doesn't have a synchro, so unless the speeds on either side of the gearset are exactly matched (in this case, both zero), it's going to grind like some kind of old London-Brighton runner!
The moving it through 1st or 2nd beforehand (not bringing clutch up in between) may have some effect with bringing the gearchain to a halt using the synchros, or it may just be because this leaves extra time for them to all spin-down before you try the gear!

Before I got the clutch fixed of course it was a different story - when i had it adjusted so it would only-just not slip, it was a bugger to get in reverse because it wouldnt fully disengage and the gears were still spinning slowly any time the engine was on.

Try giving your clutch cable bite point adjuster a tweak perhaps

Hey, it helped me get somewhat smoother starts with the new part compared to where the garage adjusted it - it might help with reverse.

hayesey · Post by **hayesey** » Sat May 29, 2004 6:02 pm

this isn't even a problem. it's just because the reverse gear is a straight cut gear (rather than a conical shape as the others are). putting it into 2nd just before will line the teeth on the gears up to avoid the crunch sound.

SD_polow · Post by **SD_polow** » Sat May 29, 2004 7:46 pm

Thankyou ppl, Putting into 2nd before engaging into reverse does help alot more...not as bad as normal.
Im always at a halt....it even happens when ive just started ther car and trying to reverse out of my drive!!

I'll try adjusting the clutch and see where that gets me.

Thanks again for now.....will report back on the result!!

carmadaaron · Post by **carmadaaron** » Sat May 29, 2004 8:26 pm

yeah, coming to a standstill 1st b4 selecting reverse helps for me!

GroovyCarrot · Post by **GroovyCarrot** » Sun May 30, 2004 12:24 am

hayesey wrote:it's just because the reverse gear is a straight cut gear (rather than a conical shape as the others are).

Ah, I guess that explains why you can always hear a whine whenever someone drives in reverse.. never knew what that was before, glad you said that

Learn something new every day..

ereeiz · Post by **ereeiz** » Sun May 30, 2004 2:31 am

Clutches sometimes need a little adjusting after a week or 2 anyway, so play with the cable a little to fine tune it.

Id say just bung it into 1st too, thats what i do instinctivly in any car (even the brand new beemers at work

) I learnt it after reading the manual in my dads Puma believe it or not t said do that or wait 7 secs before using reverse, f**k that, Id rather use 1st and get into reverse straight away

Tahrey1043 · Post by **Tahrey1043** » Sun May 30, 2004 7:39 am

I dont know if it being straight cut has anything to do with the crunch... I can crunch all the helical-cut forward gears too if i want with a bit of skilled abuse

I'm still hedging on a lack of synchro, and inertia.

Thinking of whining sounds though - is 1st a straight-cut on mk3 and earlier, especially 4 speed? That's pretty whiney as well, though of course not as bad as reverse (which is actually 3 straight cut gears vs the usual 2 helical ones - the extra one being to give the actual reverse effect.... techically to cancel the reversing effect that's in all forward gears

)

Tahrey1043 · Post by **Tahrey1043** » Sun May 30, 2004 7:40 am

I dont know if it being straight cut has anything to do with the crunch... I can crunch all the helical-cut forward gears too if i want with a bit of skilled abuse

I'm still hedging on a lack of synchro, and inertia.

Thinking of whining sounds though - is 1st a straight-cut on mk3 and earlier, especially 4 speed? That's pretty whiney as well, though of course not as bad as reverse (which is actually 3 straight cut gears vs the usual 2 helical ones - the extra one being to give the actual reverse effect.... techically to cancel the reversing effect that's in all forward gears

)

7 seconds to get reverse in a puma? What if you're trying to squeeze into a tight parking spot? you'd be there all day!

carmadaaron · Post by **carmadaaron** » Mon May 31, 2004 10:29 am

7 seconds? i rather do a handbrake turn into the parking space then!

John c · Post by **John c** » Mon May 31, 2004 5:47 pm

Most of the MK5 Polo,s we sell do have the crunching you describe, according to VW their factory manual states that you may have to wait up to 10 seconds before selecting reverse to avoid crunching.

John

SD_polow · Post by **SD_polow** » Mon May 31, 2004 9:57 pm

Ive tried waiting ten seconds plus before putting into reverse.....still crunches!!

John..where in harrow are you? Im always in that area and know of a number of polos there too!