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Posted

I have a single rail OD gearbox in my 1500 herald. I am having a problem with the synchromesh on 2nd gear. It works fine (easy to get into gear) when its cold but once the car is warm
the synchromesh doesn't work very well, to get it into gear you have to change gear slowly otherwise it will crunch.
I though it might be a hydraulic problem but have replaced the master cylinder and replace the seals in the slave cylinder and held the cylinder up when bleeding it to make sure all
the air is out of the system.

Any suggestion or of what else i can try apart from a gearbox rebuild ;(

cheers

mike

Posted

if it engages cold but not hot, does it engage easy engine off and  baulk a bit when idleing

this sounds more clutch related than synchro 

how far do you lift the pedal to get reverse without a crunch.??  does the pedal return to its stop, not held down a bit by a seized pivot pin ??

always bets to remove the slave and tilt to let air up near the bleeder and push the piston fully back down its bore then bleed, 

the bleed must be at top the feed underneath it 

this reduces the volume in the cyl to a minimum and aid expelling trapped wind .

the spring inside should return the piston to contact the push rod , or it will take a few pumps to refill the slave .

Pete

 

Posted

Thanks Pete

Yes I did take the slave out to tilt it to vent the air out of it. But it is a very old slave cylinder (but with new seals), I wonder if the spring has got weak.

I will try pumping the clutch to see if that helps. Happy to replace the slave cylinder if needed. 
My herald has suffered from not enough TLC due to a GT6 and TR6 now she is on her own and getting some over due care and working though one or two issues!

Cheers

Mike

Posted

If you can get 1st easily and reverse without a crunch immediately after dipping the clutch while sitting stationary with the engine idling, there's not much to worry about on the clutch front.

2nd gear synchro is usually the first to die as it gets works quite hard in both directions.  The working less well when hot than cold is a bit unusual though - tends to be the other way around when the baulk rings are worn.  Possibly the detent springs in the hub are getting weak.  Is it worse going up or down the gears? You could try a different gear oil (Redline MT90 is good with tired syncros), otherwise I reckon it's double de-clutch or overhaul time.

Nick

Posted

Thanks Nick

Will try a few of your suggestions tomorrow, probably rely on double declutching, hoping not to have to rebuild the gearbox yet.... 
We are off on a tour of Scotland doing the 500 mile route around the highlands with friends  (from CT, TSSC 10CR etc) in April.

BTW the EFI  is great she is running very nicely. Really impressed with the hardware and tuning  software.

regards

mike

Posted

1) Thanks Pete, might get back to you.

I now think the problem is not the syncro on second gear  but that the clutch is not disengaging completely,  if I look at the clutch arm moving in the bell housing I can get more movement if I take the carpets out thus the pedal is moving further.
I have taken the clutch pedal out and realise that the large pin was not turning in the bushing but in the bracket and has worn the bracket and the pin. The pivot point at the end of the arm where it drives the clutch master cylinder is also worn (the pin is fine as I remade some time ago). So basically I have a number of places where the mechanism is worn and I think I am not getting a full movement of the clutch master cylinder due to a build up of unexpected/undesigned clearances!

The pivot pin holding the clutch arm looks fine and is still in place.

BTW There is a good article on Canleys web page suggesting that this can be a problem.

I don't think I can buy parts to replace the pedal and bracket so will look and see if I can do some machining to repair it.

cheers
Mike

 

Posted

They are a bit notorious for seizing , this reduces recouperation  of the master cly as the pedal gets held down from being fully off.

Ive have repaired some pedal, brackets where the pin has rotated by welding a washer or plate drilled to  take the pin ends

You could  add a greaser to the pedal boss  but plenty of grease on reassy should last another 40 yrs.

You may need some new pedal  bushes 

 

Pete

 

Posted

HI

I would tend to agree that the issue could be more related to wear in the clutch mechanism, if the movement is less than as was designed, then clutch drag will be more noticeable, and might tend to highlight any "normal" wear in the Gearbox as a side effect?. If you can return the operating system to near "new". and it has no effect, you have carried out a needed "repair" anyway. So it`s not a lost cause, but could potentially delay a gearbox overhaul.? which IMV would be a bonus?.

 

Pete

Posted

PeteH

I think you right. It needed doing, I have opened up the bushing in the pedal slightly and made a new shaft and added an anti rotation pin so that the pedal rotates on the shaft instead of the shaft rotating in the bracket. Also drilled out the pivot hole between the pedal and clutch master cylinder and made an oversize pivot pin. All back in and feels good. But havent had a chance to try it yet, we have cold wet snow here in Cambridge, yesterday 15C today 1C!

mike

Posted

I’m living life on the edge and gone out in the “snow” in the bmw. I could be some time ?

sounds a good result on the clutch though Mike - hope it does the trick ?

Posted
34 minutes ago, Pete Lewis said:

Anti rotation,  i thought the  pin had a flat to locate in a D hole , when seized it all goes  round and wrecks the hole 

We await your test drive 

Pete

OH, no sign of a D hole! I think it has been worn away.
Actually I did look at it and thought this is not a good design, whats to stop the pin rotating? So the Triumph engineers did know what they were doing its just 50 years of use (**)
that has broken the design!
But I expect it was not designed to last for 50 years....

Mike

** just got a build certificate for the car, it was made on the 27 Dec 1967 and supplied to a garage in Jersey, and then back to the UK on 1 Mar 1971, hence the J reg.
So quite on early 13/60, supplied with a heater and 520 *13 tyres.

Posted
11 hours ago, Anglefire said:

I’m living life on the edge and gone out in the “snow” in the bmw. I could be some time ?

sounds a good result on the clutch though Mike - hope it does the trick ?

I`ve just come back from the pub, And the feeling that "Captain Oats" is out there is quite Eerie. Mind I was only gone for 3 pints!:D

 

Posted
4 minutes ago, PeteH said:

I`ve just come back from the pub, And the feeling that "Captain Oats" is out there is quite Eerie. Mind I was only gone for 3 pints!:D

 

3 pints? I’d be pissed as a fart on that !

Posted

quick update.

Clutch is much better, definitely disengaging when pressed so much easier thru the gears.  Worth the time and effort.
I think second gear sync is knackered but a bit of double declutching and all works. I will have to overhaul the gearbox at some stage but I can live with it for the moment at least until it has done Scotland!
I also pulled the gear lever to bit and cleaned and greased everything and now have a nice smooth gear change, I had forgotten how nice it can be!  Just makes me realise how much I have neglected the maintenance on the Herald... ;(

Cheers

Mike

 

Posted
On ‎17‎/‎03‎/‎2018 at 8:51 PM, Anglefire said:

3 pints? I’d be pissed as a fart on that !

I could drink 3 pints, but my bladder and prostate would make me pay.:(

db

Posted
9 hours ago, dougbgt6 said:

I could drink 3 pints, but my bladder and prostate would make me pay.:(

db

Ah!. Another member of the "Old Farts Club"?. 3am is about as good as I can do if I`ve been "naughty". I don`t remember signing up for that?. The biggest "Problem" is that my local has several decent hand pulled ales on tap at any one time!.:rolleyes:

Glad to hear you have an improved gear change, Mike, I won`t know what Mine is like till the "Meccano" goes back together!.

Pete

  • Haha 1
Posted

Yep had a nice drive around yesterday and then meet my mate in the Red Lion, Histon for our regular Wednesday night pints. :)
Old cars and beer seem to go together very well.

Cheers

mike 

Posted

But, unfortunately, only the one? :(

Our beloved East Berks  leader, Mark,  is looking for a new house and came to see next door. How good would that be? MIG welding skills next door and a lift to the area meeting! :lol:

Doug

Posted

yes you need long arms if its one man band    you need a secretary to twiddle the bolts and nuts while you support the assy. 

 it should all align OK   easy once a couple are fitted

 

Posted
1 hour ago, daverclasper said:

Hi. How much of a faf is it to refit the pedals to bulkhead, (lining up the screws a 2 person job)? please.

Cheers, Dave

PITA! I used a block of wood to lift the pedal/bracket and then a couple of long bolts to get things started. Once you have one in its fairly easy!

mike

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