J type Overdrive not disengaging

[4x4]

For all those who have overdrives that won't engage - the disengagement of mine is unpredictable.

I haven't even got as far as checking the gearbox oil level yet - but thought I'd ask if anyone has any ideas here.

It engages every time it is asked to.
Sometimes, it fails to disengage - until it feels like it - usually with a thump and when it's least expected (and in any gear).

As it engages every time when asked - I'm doubtful that it's electrical (well, the electrical feed to it at least).
Wouldn't take a lot to rig up a warning light alongside the feed to the solenoid to prove it - but I'm doubtful I would learn anything I don't expect from that.

I'm open to all sorts of ideas - as long as they do not entail removing the overdrive from the car.
That is a job just too horrible to contemplate doing, unless the person suggesting it lives not too far away and wants to come and help me do it


Thanks all.


Adrian.

[bunny]

Ade
My prob wasn't like yours but it could be the same fix.
She went into over drive ok till after 20 mins driving then she would go in if she felt like it, in the end it was the o rings on the over drive pistons.
And i live to far away
vince

[Goldstar]

I don't live too far away but I am willing to move...

Seriouly if you need some help, let me know

[4x4]

I don't live too far away but I am willing to move...

Seriouly if you need some help, let me know

You any good with errant mother in laws then??

[stagmuffin]

For all those who have overdrives that won't engage - the disengagement of mine is unpredictable.

I haven't even got as far as checking the gearbox oil level yet - but thought I'd ask if anyone has any ideas here.

It engages every time it is asked to.
Sometimes, it fails to disengage - until it feels like it - usually with a thump and when it's least expected (and in any gear).

As it engages every time when asked - I'm doubtful that it's electrical (well, the electrical feed to it at least).
Wouldn't take a lot to rig up a warning light alongside the feed to the solenoid to prove it - but I'm doubtful I would learn anything I don't expect from that.

I'm open to all sorts of ideas - as long as they do not entail removing the overdrive from the car.
That is a job just too horrible to contemplate doing, unless the person suggesting it lives not too far away and wants to come and help me do it


Thanks all.


Adrian.

remove the solenoid and replace the o rings , that is likely to be the cause .they do tend to swell up and things don't move so well then.its a fairly easy job you may need to muller a 1" spanner to fit ive made a tool to remove them if you need it pm me and I will post it to you.
steve

[jleyton]

Hi Adrian

I had exactly this and will post some ideas later, as I am going out now.

However it is ABSOLUTELY IMPERATIVE that you DO NOT go into reverse when the overdrive is stuck in. There is a one way clutch and you will definitely trash the overdrive unit and the pieces may well damage the gearbox.

I pulled the fuse on mine so I couldn't accidentally go into overdrive until I'd fixed it.

Cheers

Julian

[Stagdad]

Adrian,So it's probably to do with the oil pressure not releasing for some reason,once you have looked at the solenoid if that doesnt solve it ,probably worth checking the parts under the 3 plugs on the bottom of the OD for debris ,there is a filter in one of them and a pressure relief valve under another.

http://www.buckeyetriumphs.org/technical/jod/JOD2/JOD2.htm

Cheers Steve

[4x4]

Thank you all for your ideas and suggestions - none of which involve taking it out of the car!
I think it's time for a call to Overdrive Spares to procure some new O rings - and then take it to bits.

[jleyton]

Hi Adrian,

I was going to suggest that Buckeye site - it's brilliant and has just about all the answers you'll ever need.

As I mentioned, I had exactly the same symptoms as you and did a few things, some of which seemed to cure it, for a while. But now (famous last words) it has behaved itself for over a year.

So, the things I did were:

Drained and replaced gearbox/overdrive oil.

Exchanged the solenoid. As Steve (Stagmuffin) has mentioned, you'll need a special spanner - 1" AF, only about 2 1/2 " long and not much more than 0.1" thick ! I've also got one if you need to borrow one.

Removed and cleaned the filter that Steve (Stagdad) has mentioned. The book or words says that you need a pin wrench to do this but I've always succeeded by using two drills (unpointed end) that fit snugly into the holes and then put a screwdriver between them and twist.

I'm not quite sure which bit cured mine but I hope this is some help.

However, I cannot stress enough how you must NOT go into reverse when overdrive is engaged. The trouble is (and those who have not experienced the problem won't appreciate this) in first or second it is surprisingly hard to tell if it is in overdrive or not.

If I can help any further then just ask

Cheers

Julian

[Marco Polo]

I would go for the o rings on the solenoid shuttle valve too.
Regards,
Raoul

[Mike Stevens]

However, I cannot stress enough how you must NOT go into reverse when overdrive is engaged.

Absolutely agree with Julian as sadly, I have done this in the past with an 'A' type. What happens is that the car won't move, so you put a bit more power in and then it does move, having broken the uni-directional clutch inner CAM (I don't know what it's proper name is!) and the cage around the rollers.

Luckily, at the time, Triumph was still going and so new bits were available and I successfully rebuilt it all. These days spares are probably harder to get although I still have some of the wire spring clips that hold the whole lot together. Somewhere.

I've been very careful since and - so far - have not done it again. Yet.

Cheers,
Mike.

[4x4]

Bunch of O rings and gaskets on the way.
Hopefully here by the weekend so I can get mucky.

Thanks all for your advice - and dire warnings!

[PhilG]

I've noticed that the brothers parts list for the solenoid only show one O ring NKC107 but you actually need 2.
How do I know? I've just taken the solenoid out & I only ordered one O ring. B****r!
Repair now delayed to later in the week.
Phil

[new to this]

theres a plate on the bottom of the overdrive unit, inside are a couple of filters they will need cleaning

dave