Jump to content

Overdrive disengage delay


StagNL

Recommended Posts

Posted

Hi folks!  

Back to driving the Stag after having my somewhat large health scare.  

Got something to ask as well.....  Took the car out for a good long drive and found the J-type OD was taking a long time to disengage.  This happens after a good 20-30 minutes so I'm guessing the temperature may have something to do with it.
It did this in the past but the delay would be in the region of 2-3 seconds - which was noticeable but not worrying.  Today sometimes it took more than a minute to disengage.  Had a look at the Buckeye tech pages and found this:

"Mechanical such as the sliding clutch sticking in the brake ring.  This happens sometimes in the A type -- usually after driving an extended period with OD engaged.  It is probably aggravated  by weak release springs.  (An improper operating valve adjustment can also cause this problem in the A type but is not a problem in the J type)   The stuck clutch in the brake ring usually comes loose when it cools or with a sharp rap of a hammer on the side of the brake ring."

Interestingly, when stopping at an intersection, takeoff in 1st seemed normal but 2nd was most definitely with OD engaged - never had that happen before and clearly pointing toward the OD not yet having disengaged.  Why 2nd and not 1st or may I be mistaken about 1st OD?  One would think that if in 2nd it would also be in 1st as the inhibitor switch works for both.

Anyone else had this?  Oh, OD unit rebuilt nearly 2 years ago.

Julian

Posted

Julian,

Glad you are out and about again. I don't know the answer to your question, but if you have any doubt that the o/d is still engaged when it is not supposed to be then don't under any circumstance select reverse. You will wreck the internals of the o/d.

Best regards

Mike

Posted

Julian,

Great that you are well enough to be driving the Stag again  :)

I think this is due to a sticking solenoid.  I say this because of your remarks about moving off and first gear being normal but overdrive engaging in second.  If the OD was mechanically stuck, it would be engaged in all gears.  If the solenoid is stuck, it won't engage until you are going fast enough to generate hydraulic pressure.  In this scenario you'd get away with rolling backwards or even reversing slowly, though you'd need to be pretty sure!

Nick

Posted

Thanks Nick, that seems plausible.  I was think about crawling underneath to clean out the filters and valves as that shouldn't be a bad thing to do anyway.

On my return trip yesterday it didn't have the problem so much - maybe I just need to drive it more.....  Got another longer trip planned next week so I'll what that does to it.

Julian

Posted

I have had similar problems before with the J-type OD on my old Herald.  It only used to do it when really, properly hot (long hard run on a hot day) but at it's worst it would stay in for minutes after being switched out and would only drop out at about 15mph (normally when slowing for the Stonehenge roundabout going west) when the pump couldn't maintain pressure, only to come back in when speed climbed back above about 20mph.  Used to worry me because of the reverse issue, but as it did drop out when you slowed down I figured it would be ok provided I reversed slowly - and I never had an issue, though I don't expect I did ever have go backwards while it was stuck.  I swapped the whole gearbox out eventually for other reasons - they were cheap and readily available then.

Nick

Posted

always worth a call  to dave twigger at ODspares

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

but this sounds solenoid , swollen O rings etc.


I think reverse in a J type is less dramatic. to the one way clutch .

Pete

Posted

Mine has started to do this recently. Like Nick's it only sticks once it's got really, really hot during a long run on a warm day. Takes about 30 to 40 minutes before it starts to misbehave and once it's started it the OD doesn't resume normal behaviour until the car's been stopped for a while.

I suspect the solenoid (most of symptoms are right) but not 100% sure. I've also noticed that sometimes, once the OD has started sticking and has been switched off, on the overrun (or coasting) at speed rather than just sticking on the OD hunts between on and partially off (engine revs falling and rising). Putting the foot down generally gets it back to stuck on.

The other thing that's stopping me being 100% sure about the solenoid diagnosis in my case is that OD drops out at low speed every time and once it's dropped out it has to be switched on again. It doesn't "automatically" pop back in again in the way I would expect if the solenoid was stuck.

One for the winter I expect. Will try and have a proper look at it when the Spit's garaged for a couple of months at the end of the year -- or maybe earlier if we get another winter like we did the last two years  :X

  • 2 weeks later...
Posted

Spitfire2500 wrote:
Mine has started to do this recently. Like Nick's it only sticks once it's got really, really hot during a long run on a warm day. Takes about 30 to 40 minutes before it starts to misbehave and once it's started it the OD doesn't resume normal behaviour until the car's been stopped for a while.

I suspect the solenoid (most of symptoms are right) but not 100% sure. I've also noticed that sometimes, once the OD has started sticking and has been switched off, on the overrun (or coasting) at speed rather than just sticking on the OD hunts between on and partially off (engine revs falling and rising). Putting the foot down generally gets it back to stuck on.

The other thing that's stopping me being 100% sure about the solenoid diagnosis in my case is that OD drops out at low speed every time and once it's dropped out it has to be switched on again. It doesn't "automatically" pop back in again in the way I would expect if the solenoid was stuck.

I did that longer drive last Friday.  Seems very much like the above symptoms.  Interestingly it is though it initially takes a long time to disengage but later on improves a little.  What I mean here is that after a motorway run of around 20 minutes it took a fair while to disengage but took less time (but still way more than normal) after a second run of 1 hr 20 mins.

I guess I might as well just get a solenoid and if it doesn't cure the problem I would then have a nice addition to my spares pile.

Julian

Posted

J, try this wee test, as some times the actuall switch can be at fault,  ie,switching in,but no engageing.
try and by pass the switch whenst on a drive, just short the wirse together.
Ive had a few dodgey switches,give similar resuts as you are saying.
worth a  try,,as its the easiest to try fust

worn contacts, or dirty contacts, or crap stopping the switch frae actually getting  to go to                the engagement area.

rgds M

Posted

Marcus, I too have my share of duff OD switches.  Fairly certain it isn't the case right now.
Today it worked fine but then I didn't get it all nice'n'hot like the other days.

Julian

Posted

My J-type did this when I got it - exactly like Bill describes it would stick on after a long drive on a hot day.

As I recall it just stopped doing it on its own - the car had only done about 200 miles in the previous 2 years so I guess use seemed to resolve it.

Probably just luck  :)


Posted

why not stick a small bulb on the solenoid feed down near the solenoid and observe whilst driving,  you will soon see if the circuit/switch is dropping out.???

the fact that it does not re enegage sounds like a relay fault but in general the J type doesnt have one ( only used on D types)

Peter

Posted

Peter, I think that there is confusion regarding re engagement.  If the delay occurs and I leave the unit switched off, it will eventually disengage.  However if I switch it back 'on' again before it has disengaged it will remain in the OD position.
Still not addressed the problem yet as I have heard since of several persons experiencing the same only for it to go away on its own.  Mondays 40 miles on the motorway should have got the lot all warm but OD performed faultlessly - maybe due to the cold ambient temp.

Julian

Posted

I had a similar problem on the sprint - not sure what type of OD that would be? anyway after proving the electrical circuit was fine removed the solenoid and cleaned it up ie got  the plunger moving freely etc and it worked a treat after that

Posted

The overdrive on my 2000 estate would do that.  It switched in and out as you'd expect until the gearbox was warmed up then, if the overdrive was engaged, it wouldn't disengage until the whole car had cooled down, i.e. overnight.

Reverse overdrive was a bit juddery and it seemed to slip a bit in 2nd overdrive.

One day, I just waited until it had disengaged and disconnected the bloody thing so it couldn't be switched on.  I think it transpired that the overdrive unit itself was knackered.

Posted

Another 25 miles on the motorway today and it stuck again.  Just had a look at the distance travelled before it eventually kicked out - 500-600 meters - that is coming off the motorway at 60mph dropping down to 25 going through an intersection.  Disengagement was slower in action that normal too.  Thereafter it performed flawlessly.

It'll be a few days before I can crawl underneath to clean and assess the solenoid.  

  • 3 weeks later...
Posted

Still have not been under the car but OD has completely failed work today.  First 8 miles or so it was fine then disengaged around 10 seconds after engaging and as not engaged since.
Switch on stick is OK, the rest I'll have to check tomorrow.  Hopefully it is something like a bit of grit blocking the system.

Posted

Julian,  it may be that the actuall cone clutch is so worn,that is gon to far in,!!!
OR, the bigg circlip at the front of the bearing, the one you can see looking at it, has either snapped,or come off  / bent a little,     this will make the OD stay in.
how doo I no,  cos the darn thing snapped on one of mine, and sort of twisted in it housing, but it was enough to stop it going oot.

Steeve Tiggerous had similar probs, and tried every thing going, but gave up in the end.
and got another yan,.
when you used to it, its a real bad miss.

good luck, rgds M

Posted

Marcus, I rebuilt mine around two years ago so shouldn't be worn out yet....
Plan of attack it first check the electrical side including the solenoid, then check the solenoid valve part and then the other relief valves etc.  
I just need the space to do it as out on the side of the street ain't fun in this weather, nor in my condition, mind.

Julian

Posted

796 wrote:
Julian,  it may be that the actuall cone clutch is so worn,that is gon to far in,!!!
OR, the bigg circlip at the front of the bearing, the one you can see looking at it, has either snapped,or come off  / bent a little,     this will make the OD stay in.
how doo I no,  cos the darn thing snapped on one of mine, and sort of twisted in it housing, but it was enough to stop it going oot.

Steeve Tiggerous had similar probs, and tried every thing going, but gave up in the end.
and got another yan,.
when you used to it, its a real bad miss.

good luck, rgds M



Julian,

Here is the thread that Mr Tinkerous was referring to

http://www.club.triumph.org.uk/cgi-bin/forum10/Blah.pl?m-1314647169/s-0/

I still have to sort it out but have another overdrive to fit, just need to get around to it :B :B :B

Posted

I used my tuit this evening and managed to get my carcass under the car to measure the leccy stuff.
Found no 12v at the solenoid so went to look at inhibitor switch - lo and behold the Lucar connectors had worked themselves off the poles.  How that happened I do not know but is the reason for failure to engage OD.
But is it the reason for the slow disengage when hot?  Time will tell - this weekend.  Methinks that when hot the contacts (wiring) were sufficently warm to let them sag a bit and thus breaking contact.
Anyway, OD works for the time being.

Julian

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...