Clutch lever issues and mystery overdrive

[Papa Smurf]

Just now, Papa Smurf said:

Hi Roger, sorry for not acknowledging this earlier but can you explain what you mean by the fact it’s not a Triumph fitment?  Will this effect how it works?  It’s all back together and have done a few test runs at about 40-50mph and flicking the OD switch has no discernible effect on engine revs.

Also, to the wider group, have an odd phenomenon, the clutch lever pin seems to “walk” upwards when driving.  After a 20 min country lane drive I checked and it was sticking half way out the top, which made the clutch a bit noisy when pressed.  Managed to bash it back in with a hammer before it came out completely.  Anyone seen that before?

[NonMember]

What Roger meant was that overdrives were available in different gear ratios (and with many different pressure settings) to suit the application. Triumph fitted 25% units to Spitfires (they did use a few 28% ones on late saloons). Because yours is a 28% it's not what the factory would have fitted. Whether this matters depends on what's less easy to see - the operating pressure. Odds are it's fine - the Spitfire is a relatively low torque application so if anything it's probably on the high side and you're just wasting a tiny bit of power pumping more clamping force than you need.

As to the pivot pin, yes, it happens. Things move when shaken. Am I remembering right that you have a mushroom head one? If so, it can't move down so it moves up. That's why the original spec had crinkle bits to hold the pin firmly.

[Papa Smurf]

40 minutes ago, NonMember said:

What Roger meant was that overdrives were available in different gear ratios (and with many different pressure settings) to suit the application. Triumph fitted 25% units to Spitfires (they did use a few 28% ones on late saloons). Because yours is a 28% it's not what the factory would have fitted. Whether this matters depends on what's less easy to see - the operating pressure. Odds are it's fine - the Spitfire is a relatively low torque application so if anything it's probably on the high side and you're just wasting a tiny bit of power pumping more clamping force than you need.

As to the pivot pin, yes, it happens. Things move when shaken. Am I remembering right that you have a mushroom head one? If so, it can't move down so it moves up. That's why the original spec had crinkle bits to hold the pin firmly.

Hi Nonmember, I fitted a new crinkly washer and used the Rimmer Bros pivot pin with a circlip at the top that stops it dropping out the bottom.  I was thinking I might try and drill a hole through the bottom of the pivot pin and insert a single split pin that would limit upward movement.

[NonMember]

Hmm.... OK, so you've done all that would be expected. If the crinkly tube bit isn't holding the pin firmly enough then drilling for a split pin (or and R-pin or whatever they're called) seems the best option.

I confess my Toledo ended up with a long bolt and a nyloc nut.

[Papa Smurf]

16 minutes ago, NonMember said:

Hmm.... OK, so you've done all that would be expected. If the crinkly tube bit isn't holding the pin firmly enough then drilling for a split pin (or and R-pin or whatever they're called) seems the best option.

I confess my Toledo ended up with a long bolt and a nyloc nut.

Much better solution! shame you did not work for Triumph engineering about 60 odd years ago…

[rogerguzzi]

2 hours ago, Papa Smurf said:

Hi Roger, sorry for not acknowledging this earlier but can you explain what you mean by the fact it’s not a Triumph fitment?  Will this effect how it works?  It’s all back together and have done a few test runs at about 40-50mph and flicking the OD switch has no discernible effect on engine revs.

Hello

         The engine revs should drop by about 500 when you put it into overdrive or rise when taken out!

If not I suspect it is not working!

Roger

[Mjit]

Check you're getting power to the O/D solenoid.  Engine off/ignition on/in 3rd or 4th you should be able to hear the solenoid make a faint 'click' when you flick the switch on/off.  If no click try a more direct 12v feed to the solenoid.  If you get a click with a direct feed but not via the switch change it so your direct feed goes via the switch.

If you get a click from the switch but no drop in RPM when driving it's probably the solenoid seals that have perished, so it's switching in/out but rather than changing where the oil flows to engage the o/d the oild just flowing around the seals.  I'd have to hunt for the 3 different sizes but you they are just 'O' rings and you can pick up oil proof ones easily on eBay in packs of 5, then replace them (straight forward - though disassembling the solenoid piston is a bit fiddly, first getting the tiny circlip off and second getting the piston out).

If it works for both it's probably the inhibitor switch on the gearbox that's at fault.  You MIGHT get lucky and find it just needs tightening or a shim adding/removing but I'd just replace it as they are cheap and don't last forever.

If it works direct but not via the switch, it's probably the switch so replace it.

If you get an electric shock, it's the wiring.

If there's no click, even powered direct you're probably looking at a new solenoid.

If everything works and clicks wire a tell-tell bulb across the solenoid, so you can see if it's still getting power when you're driving and flicking o/d on/off.

If that's working then you probably need a recon overdrive - probably just the oil pump but o/d units are very much marked "Here be mosters" on my DIY map.

[NonMember]

Just one thing to add to Mjit's list. If the OD hasn't been used in a while then it may just be sticky. The first one I ever fitted, I got absolutely no response at all on my test drive. But I was going somewhere, so I carried on. On the way home, I tried again, still no response, but this time gave up with the switch at the "in" position. About a mile of open road later, it suddenly kicked in. After that it worked fine.

[Pete Lewis]

its quite common the spool valve piston inside the solenoid sticks  , you need to unscrew the solenoid (1" af thin spanner )

catch a little oil ,  give it a shake the spool inside should rattle back and forth 

access is easy remove the small 10mm circlip in th end and shake the plunger out  it will probably need new 0 rings 

these are important little rings  many just change the bigger ones you can see on the snout of the sol  

its the inside ones that mess with you head 

Pete

[68vitesse]

As this if J type.

Regards

Paul.

 

[Mjit]

1 hour ago, Pete Lewis said:

its quite common the spool valve piston inside the solenoid sticks  , you need to unscrew the solenoid (1" af thin spanner )

A special spanner most Triumph parts will sell you that has a 1" 'handle' with a 1/2" drive hold in it...that I've never worked out how you're meant to use!  Thankfully hand tight (with the special, stubby spanner) is tight-enough.

1 hour ago, Pete Lewis said:

access is easy remove the small 10mm circlip in th end and shake the plunger out

Easy he says!  Had to work through all my pairs of circlip pliers to find a pair that would go small-enough to fit and still squeeze enough to compress the circlip.

And as for "shake the plunger out"...  Done 3 recently* and 2 of them would rattle back and forth quite happily...but one of the O rings would catch somewhere inside and they were buggers to get more than 1mm of the piston to expose past the end of the solenoid body!

 

 

* Done 3...to discover it was an intermittent inhibitor switch 😒

[Pete Lewis]

well we need to keep you occupied now theres no lock down 

rule of thumb   always do the simple  jobs  first 

  pleased you have it all working 

Pete

[Papa Smurf]

6 hours ago, rogerguzzi said:

Hello

         The engine revs should drop by about 500 when you put it into overdrive or rise when taken out!

If not I suspect it is not working!

Roger

Nope, so it is non-functioning at present..

[Papa Smurf]

5 hours ago, Mjit said:

If you get an electric shock, it's the wiring.

Could I use a multimeter to test this instead of myself? 😉

Using a multimeter I have tested gear lever switch and inhibitor switch and both seem good.  I get 12V across solemnoid and click sound when in 3rd or 4th and flick switch, but not in 1st or 2nd.

Heading to solenoid service next I think..

 

[Papa Smurf]

5 hours ago, NonMember said:

Just one thing to add to Mjit's list. If the OD hasn't been used in a while then it may just be sticky. The first one I ever fitted, I got absolutely no response at all on my test drive. But I was going somewhere, so I carried on. On the way home, I tried again, still no response, but this time gave up with the switch at the "in" position. About a mile of open road later, it suddenly kicked in. After that it worked fine.

This is possible as the O/D was disconnected when I got it and suspect it had been like that for 1-2 years.  

[Papa Smurf]

3 hours ago, Pete Lewis said:

its quite common the spool valve piston inside the solenoid sticks  , you need to unscrew the solenoid (1" af thin spanner )

catch a little oil ,  give it a shake the spool inside should rattle back and forth 

access is easy remove the small 10mm circlip in th end and shake the plunger out  it will probably need new 0 rings 

these are important little rings  many just change the bigger ones you can see on the snout of the sol  

its the inside ones that mess with you head 

Pete

Thanks Pete, will have a look at that

[Pete Lewis]

please check the simples first  Jump  a feed to  the solenoid  to eliminate switch , broken wires and the inhibitor switch setting and is it working  and oil levels 

have you removed and cleaned the filter ???  

Pete

 

[Mjit]

22 hours ago, Mjit said:

If you get an electric shock, it's the wiring.
 

16 hours ago, Papa Smurf said:

Could I use a multimeter to test this instead of myself? 😉

Yes - but I found it wasn't really a matter of choice, more flick o/d 'in', touch metal spoke of steering wheel, swear and stop touching metal spoke, flick o/d 'out' and think .oO(That will be the wires up the gearstick shorting then)Oo.

[Papa Smurf]

Pleased to report that after correcting gearbox oil level (I had accidentally overfilled it as had filled it on the bench with it sitting on its tail) and cleaning contacts in gear lever mounted switch, the overdrive has sprung to life.  It occasionally seems to take few switch flicks before kicking in.  I suspect that is because the switch contacts are still a little grotty.  I was about to remove solenoid but think may leave that alone now.

[Colin Lindsay]

12 hours ago, Papa Smurf said:

It occasionally seems to take few switch flicks before kicking in.  I suspect that is because the switch contacts are still a little grotty. 

In my GT6 where the J-type was working very well it always had a slight delay in kicking in. It went off instantly but there was a very slight delay, maybe just a second or two, before you felt it engage.

[Papa Smurf]

A follow up on this.  After reading around and driving some more I think I have what seems to be the problem of the clutch release bearing “rattling” on the fingers rather than being a firm fit.

when clutch is out there is a rattling sound from clutch that stops if I rest my foot on the clutch pedal

I suspect this may be the issue (have seen elsewhere) of a “short” (15mm) replacement release bearing rather than the “longer” (19mm) one.  But I thought I compared old and new and they looked the same (kicking myself that did not take a picture of the new assembly!)

just want a bit of reassurance I am not totally bonkers in thinking about taking out gearbox again… (Have just put the last bits of interior trim back in 😢)

[johny]

There is a spring inside the slave cylinder that pushes its piston and the push rod out so that the release bearing is always kept in contact with the pressure plate fingers. Its got to be like this as otherwise the pedal would be floppy until any gap was taken up and even a thinner bearing should still be held up against the fingers. 

That said a rattle is quite common (good gearbox sound deadening helps) and it's thought it could be the release bearing 'skipping' on the fingers? However another possibility is that the noise is actually coming from the gearbox input or lay gear which, in neutral, are spinning unloaded until the clutch is disengaged....

 

[Pete Lewis]

having a budgie in the clutch is not unusual  as Jonny says  its the lack of pressure and a stiff bearing  skidding on the fingers that makes the racket 

some add a spring to assist in keeping the coltact firmer  as the brg gets looser it will reduce the skid ( not that easy on a 4 cyl set up )

and the skid will wear the fingers and can groove the bearing  that adds pedal load as the fingers have to ride out the wear groove 

that takes a long while to happen ,dont rush to rip it all apart 

Pete

[Papa Smurf]

Thanks Pete, something for another day.  Was concerned it would destroy itself too quickly

[Pete Lewis]

9 hours ago, Papa Smurf said:

would destroy itself too quickly

if  it does i said ................nuffing 

 

Pete