MKIII(AAZ) with CHD gearbox.. reverse gear problems..

[Torchd]

Hey guys!

My car got stuck in sand and the only option was to go back while another person pushes it.

So I did that and I had to go hard of the gearbox..and all of a sudden i heard this really scary noise after which the reverse disengaged. And it kept on doing it and I kept on pushing it while holding the lever in place.

So now whenever I reverse I have to hold the lever otherwise it just pushes it out and if I am reverse it at an angle holding it doesnt help either.

I got it checked from a mechanic and he says the teeth on the reverse gear and/or teeth on the bigger gear onto which the reverse gear ehgages must have been bent. So that would need to be changed.

VW parts are almost impossible to source in here and I cant get the tranny. I have an AWY tranny from an MKII and my mechanic has a 4S from an mkII. Would it be possible to swap those two gear into a CHD from mkII trannies? Or from any other MKII/MKI tranny?

Appreciate the help!

[vanbcguy]

Take a look on this page:

http://brokevw.com/020ratios.html

It will show you what the ratio was for your old tranny and what the ratios are on the new one, along with a calculator to see what effect changing would have on your RPMs while driving. 

The reverse gear is definitely weak on the 020's - best advice I was ever given was to treat reverse on an 020 like it's made of glass.

[Rabbit on Roids]

Take a look on this page:

http://brokevw.com/020ratios.html

It will show you what the ratio was for your old tranny and what the ratios are on the new one, along with a calculator to see what effect changing would have on your RPMs while driving. 

The reverse gear is definitely weak on the 020's - best advice I was ever given was to treat reverse on an 020 like it's made of glass.

and never even really let the clutch completely out if you are backing up a hill, unless you have some speed built up. stupid things... i had one crap clear out on me, and one about to not too long from now.

[Torchd]

Thanks for the link Vanbcguy!!  Its really helpful.

I skimmed through it and as I understand I can change the reverse ratio and the Idler gear I just read somewhere on the page that all 020s have the same ratio for the reverse. Is that true?

And on the chart which gives ratios for all gears in various transmissions; I cant see the ratio for reverse? Is it not there or perhaps I cant tell if its there?

Cheers!

[Rabbit on Roids]

Thanks for the link Vanbcguy!!  Its really helpful.

I skimmed through it and as I understand I can change the reverse ratio and the Idler gear I just read somewhere on the page that all 020s have the same ratio for the reverse. Is that true?

And on the chart which gives ratios for all gears in various transmissions; I cant see the ratio for reverse? Is it not there or perhaps I cant tell if its there?

Cheers!

pretty sure a VW reverse gear set is the sane, no matter what trans it came out of. the only thing that makes the reverse feel "different" in certain trannies, is because of the final drive, being either higher or lower. not because of the actual reverse gears being different.

[Torchd]

Got the reverse gear swapped on the CHD from a 4S and it now works proper!! Old gear was in badd shape, hardly had any teeth left on it and therefull the magnet was coverd with metal filings!
I changed the oil with GL4 75w80. Is that the right oil to use?

And thanks guys, really appreciate the help!


http://www.flickr.com/photos/26223372@N06/4328338594/#

[smutts]

GL4 synthetic something or other seems to work well. In the UK Castrol SMX? Syntrans? from Halfrauds is good, for you gentlemen on the other side of the pond, Redline works well too. The reverse gear on these O20's is very fragile, a pause of two or three seconds in neutral to let shafts slow down will go a long way to preserving these teeth. It only took me once to forget this to chew off the teeth and reverse ever after was clack clack clack to remind me. But on the bright side, the O20 suicide rivets stopped me worrying about this three months later! IF the box needs stripping to install another reverse gear, GET A BOLT KIT FOR THAT STUPID F***ING CROWNWHEEL, it is a truely poor bit of engineering.

By the way, GET A BOLT KIT! you will probably regret it if you don't take the opportunity whilst the gearbox is being gutted. (where is the nag smiley? )

[smutts]

Oh sorry! I didn't see that it's too late! I will keep my fingers crossed!

[Torchd]

GL4 synthetic something or other seems to work well. In the UK Castrol SMX? Syntrans? from Halfrauds is good, for you gentlemen on the other side of the pond, Redline works well too. The reverse gear on these O20's is very fragile, a pause of two or three seconds in neutral to let shafts slow down will go a long way to preserving these teeth. It only took me once to forget this to chew off the teeth and reverse ever after was clack clack clack to remind me. But on the bright side, the O20 suicide rivets stopped me worrying about this three months later! IF the box needs stripping to install another reverse gear, GET A BOLT KIT FOR THAT STUPID F***ING CROWNWHEEL, it is a truely poor bit of engineering.

By the way, GET A BOLT KIT! you will probably regret it if you don't take the opportunity whilst the gearbox is being gutted. (where is the nag smiley? )

Thanks smutts for the input.

Which bolts are you talkin about??

[Rabbit on Roids]

he was referring to the bolt kit to replace the rivets holding the ring gear on. the rivets break, and then your screwed.

[Torchd]

Oh rite!

Where can I get the kit from? Do you guys have a souce/link?

[macka]

I've seen them on ebay, and maybe vwtransaxles dot com may sell them. I don't know any sources in Pakistan, or on the Indian sub continent.