CTN Gearbox- No reverse

[just_say_meth 0]

Hi guys, been struggling with this for a few days now and can't progress any further.

 

I've been rebuiding my '92 Corrado G60 for the last 3.5 years, to go along with the planned engine up grades I purchased a CTN diesel gearbox, removed from a 40k mile car, I checked it engaged gears etc but not thoroughly as at the time i just assumed it would be fine. Box is now in the car but I have been having bother engaging reverse, I thought this would be just cable adjustment but after numerous failed attempts I'm back to square one. I have read a few guides on selecting gears/setting cables so I started trying to select all gears from the gearbox selector but still no reverse! I've had the end plate off to inspect 5th gear because I read somewhere it shares the syncro-mesh with reverse but I can see no damage or anything out of the ordinary.

 

Not sure where to go from here other than to pull the box and get it rebuilt but I don't want to do this before I know for sure that reverse isn't there. To top it off the shift weight and the up/down cable hit each other, so I have had to remove the weight.

 

Anyone shed any light? know what I may be doing wrong? getting desperate now :headbang:

 

box is obviously a CTN, this I have checked

Cables are standard Corrado

Shifter is from the CTN box

Cable mount bracket is from the CTN box also.

 

Andy

[Yandards 0]

IIRC its the push down on the stick which selects reverse.

 

Right just checked both my car and the ASD (mk 3 diesel box) I have in the roof.

 

The reverse selection is made at the bottom end of the cable travel, if you push down on the shift weight and then push the weight in the direction of the rear of the car this should select reverse. This should at least confirm that the box is working ok.

 

I suspect its just a case of getting the cable to box alignment correct, it's not the easiest thing in the World and if your CTN shifter is a little sticky it wont help with getting the height cable set-up correctly.

[just_say_meth 0]

Cheers Yandards, unfortunately I can't even select it from the shift tower, I'm pushing the selector all the way down and then counter clockwise (as you say towards the rear of the car) and it just stops. even forcing it, it doesn't engage, if I am heavy handed sometimes it goes into gear but when I start the car to see what gear it is 1st.

 

It's as if its jammed or there's nothing there. A friend has suggested removing the shift tower and inspecting it, at the moment I'm fearing the worst :(

Edited February 6, 2011 by just_say_meth

[Yandards 0]

Might just be that the syncro on the reverse is very tight so its not letting you engage it.

 

Be worth pulling the tower for a look at it, its not too much work to do that.

[just_say_meth 0]

Cool, I'll lift the tower out tomorrow night then. How would I get round a tight syncro mesh? I have had the car up to temperature but still no joy? the box has been sat for about two years while I've been building up the rest of the car.

 

Andy

[Yandards 0]

Just use it will probably help although if you need to go backwards thats no help!

[just_say_meth 0]

Use the gears you mean? obviously can't use reverse if I can't get it! lol

 

Seem to be in a nightmare situation, car isn't road legal and not keen on using it if it needs the gearbox renewing! Will see how I get on with the shift tower, going out to do it now.

 

Andy

[Purple Tom 0]

Might be worth trying to turn the 'box a little bit. If I recall there isn't a synchro on reverse on those boxes so you'll need to get the dog teeth pretty well aligned to get it into reverse gear by hand from the shift tower.

 

Another thing to try (I assume the car is driveable as you've had it up to temp) is to safely support the front of the car on axle stands so the wheels are well clear of the ground. Chock the back wheels (or better still tie the car down) and then run it up and down the gears a bit to get at least a bit of oil pressure and temperature in the gearbox. Then see if you can get reverse...

[just_say_meth 0]

Thanks Tom, if I can get a friend to help sometime this week I can maybe try to mobe the box while trying to select reverse.

 

I have removed the shift tower and inspected it and the internals but there is nothing that was obvious to me. However I did think that the oil level looked rather low, my own stupid fault, last time I checked it was when it was on the gearbox stand and this may have given me a fasle reading. So I removed the fill plug and it is sitting quite low, possible meaning that reverse is hard to get beacuse its not be properly lurbicated?

 

Is it maybe worth a try to change the box oil over and run up to temp, maybe freeing off reverse gear??

[Yandards 0]

Thanks Tom, if I can get a friend to help sometime this week I can maybe try to mobe the box while trying to select reverse.

 

I have removed the shift tower and inspected it and the internals but there is nothing that was obvious to me. However I did think that the oil level looked rather low, my own stupid fault, last time I checked it was when it was on the gearbox stand and this may have given me a fasle reading. So I removed the fill plug and it is sitting quite low, possible meaning that reverse is hard to get beacuse its not be properly lurbicated?

 

Is it maybe worth a try to change the box oil over and run up to temp, maybe freeing off reverse gear??

 

Got to be worth sticking the front of the car on axle stands and running through the gears, should help to free the box up and move the oil around.

 

Don't be tempted to overfill the box either, too much oil will create too much pressure - this often makes 2nd gear difficult to select with a cold box.

[just_say_meth 0]

Ok, so after a lot of head scratching, referring to ETKA, bentley manual etc I have solved it!

 

Had myself convinced that it was something inside the gearbox and so I removed the 5th gear cover plate, to adjust the reverse gear selction bracket, this didn't work. So I traced back to the selector plates that surround the selector tower and a noticed the reverse gear selector bracket, I moved it with a flat blade and it engaged reverse! woohoo

 

So I started to suspect the selector tower and looked at the mechanism and why it wasn't selecting reverse, at this point I realise the the arm that rotates and moves up and down was sitting at a funny angle, stopping the arm fully moving downwards. I suspect that before I got the box it has had a bash or something dropped on it, bending the arm and stopping the travel needed to get reverse.

 

Thanks for all the help and advice folks, I wouldn't have got there without it! Big thanks to Tomie and Craig for the coffe and ETKA/Bentley session yesterday!

 

I can now select all gears and yes, I have filled it with fresh oil! Bring on the MOT!!