GT6 D-Type Overdrive Removal

[Russell1972]

Hi all,

Quick introduction, I'm Russell Banyard long-term TSSC member (28 years), current writer of the Suffolk Area monthly reports and this is my first topic creation on the TSSC board.

My current project is a MK3 GT6 that I've just returned to the road after 18months of gradual progress. The previous owner said the overdrive was sticking in and sure enough he was correct. Unfortunately it's not an electrical problem, that all seems to be working well. It's defininately mechanical, as once stuck it can only be freed by a sharp tap on the overdrive casing with a hide mallet.

Driving it about on Saturday with the tunnel off and repeated overdrive 'in/out/tap when stuck', seems to have improved matters. But when the overdrive has been in for longer than a minute or so, it won't release.

So my question is this, can you remove the D-Type overdrive from a GT6 without taking the gearbox out of the car? Having pulled my spare gearbox apart this evening on the bench, it looks like there might be enough room with the prop out of the way, but before I start, am I on a hiding to nothing?

Also, is there anything else I can try before pulling the box. I've checked the actuating lever, cleaned the filter and put new EP80/90 in the box.

Any help appreciated,

thanks,

Russell.

[ShaunW]

My issues were different but you might find something in here that you haven't tried. There's some comments about removal too. Bell, gbox & od come out together. 

 http://forum.tssc.org.uk/topic/2791-d-type-od-running-out-of-ideas/?tab=comments#comment-26485

[Russell1972]

Thanks Shaun, that's a really useful thread, loads of info in there. 

[Pete Lewis]

To get the od off in car it needs the tail lifting quite highto get itnto clear the tunnel 

Probably remove the handbrake lever,  we did this on my vitesse6 , not the easiest job getting it back on

Heights and angles all fight the alignments.you need a few extra hands and eyes 

One to refit one to pry the piston bars one to eye up the alignment and one to make tea

I would remove the solenoid and check its armature is free in the bore, and the switch in its end is operational

Do check the hole down the spool, valve under the top cap plug is clear

Pete

 

[Russell1972]

Thanks Pete, I'll check those. The overdrive seems to stick in at after engaging at higher revs, so could it possibly be holding on at higher pressure?

I'll report back after I've had a another chance to fiddle.

Russell

 

[Russell1972]

Thanks all for your ideas, but it looks like the gearbox will have to come out. 

For the top valve, I removed the cap, spring, pin and ball, the pulled out the tube. The tiny pin hole was clear, but I washed it out in white spirit anyway. Refitted everything, but it was the same. 

With use it has got better than when I first put it on the road, but just when I think it's fixed, it'll stick again then needs a clout with the hammer. 

Any last ideas before the 'box comes out? (that'll be after LeMans now). 

Russell. 

[Pete Lewis]

Give dave twigger a call always helpfull

http://www.odspares.com/phdi/p1.nsf/supppages/odspares?opendocument&part=5

Pete