Clutch Drag on gear changes

[brian buttimore]

Hi All

Trying to diagnose my MOD Stag with difficult notchy gear changes.

Mostly 1st to 2nd gear and back down.

Lots of various comments when searching on this site, mostly to do with bleeding and getting air out of hydraulics.
Which I hope I have achieved.

The clutch and slave and master cylinders were replaced approx. 15,000km ago

The bleed nipple is on top of slave cylinder and the piston was bottomed out during bleeding to reduce air in system.
.
The gear changes have never great but have no other MOD Stags cars to compare.
Currently with full clutch pedal travel getting approx. 15mm of rod movement from the slave cylinder.
Is this normal?

Trying to establish if a hydraulics or clutch issue!

I see some talk of smaller bore slave cylinders to give more travel, has others experience of these and their results.

Thank you in advance for all suggestions.

Cheers
Brian

[flying farmer]

I had a problem with one of my cars clutch after replacing the master cylinder.

The problem was that the push rod to the master cylinder was slightly too short which left the clutch pedal a couple of inches below the brake pedal when not pressed.

The pedal was hitting the floor before the clutch was clearing properly. The only solution was to lengthen the push rod which I did by cutting the rod in half and welding on a longer bit cut from another old push rod. A real PITA to do but it solved the problem.

I am not sure why the problem occurred, both push rods were the same length when removed from the cylinder which suggests either the lugs on the master cylinder were in a slightly different place or the internal design of the cylinder was different. Didn't see any point in returning the cylinder as I suspect the whole batch would be the same, and I don't know where I sourced the original cylinder or if it was even a Stag one

[brian buttimore]

Thank you Neil,

can anyone kindly help with the distance the clutch slave should extend/ return with full pedal travel.

thank you in advance

[Chris01573]

Hi Bryan it only moves about 15-20mm from memory. With the engine running can you get into reverse and if so how far from the floor is the clutch biting...?

[brian buttimore]

Thank you Chris,

as best I can figure the clutch is engaging fully at less than an inch off the carpet.
Or in my terms my fat toe from my other foot bearly under the pedal whilst in the car park with hand brake on.
Not sure this is a scientific term.

The 15mm seems like nothing at all, so now I turn my attention to mechanics of clutch or gear box.

Any thoughts on how to diagnose one from the other.

thanks and regards
Brian

[mikethemechanic]

Re clutch gearbox problem - if clutch is bled properly and clevis has no wear and fitted to middle hole the diagnosis is - start and run engine to warm i.e. no choke, check idle revs at 750 or less engage reverse and if engages with little effort and only alignment crunch then clutch is o.k. and first second synchro is suspect -drive car and if third and fourth engage easily still suspect synchro's on 1/2 recheck reverse engagement and again if clean with slight alignment noise you need gearbox overhaul or you manage with it - gear oil change may give limited help - ensure correct oil spec is used ( ? 70/90gear oil)

[Alacrity]

Clutch clearance is a common issue on the Stag. The mechanics of the clutch wear & you end up with lost motion & you will never sort it without repairing the linkage. The cross shaft in the bellhousing wears badly on the slave cylinder side as do the bushes it runs on, replacements are available. The clutch fork pins that engage in the grove in the release bearing carrier also wear, as does the groove in the bearing carrier. Unfortunately to sort these items is a gearbox out job so be sure to check the other suggestions 1st in case you can sort it without removing the gearbox.

Good luck

Geoff

[Chris01573]

Hi Bryan so assuming the rod from the slave cylinder is in the middle hole on the shaft. I would be first checking you have a fully bled clutch and also that your master and slave are ok. If they are then it's gearbox out time. I would fit a Wards recon clutch if it does come to this.

[jbuckl]

From a design perspective, there’s a rule of thumb for system travel:-

1/3 nominal operation.

1/3 tolerance.

1/3 wear.

often there are reasons why this isn’t adhered to.

it appears triumph didn’t allow 3 times nominal travel in the system…. Or if they did, new parts don’t allow this amount.

sorry I don’t know the actual amount or the place to check.

i think there is a value somewhere though.

try The highest hole (shortest) on the lever to increase the travel.

load will increase though.

only consider increasing the pushrod length if the system is leak free and fully bled.

[brian buttimore]

Thank you all.
will start process of checking gear engagements as Mike suggested.

When the new clutch fitted, cross shaft bushes and shaft replaced.

This mostly about me trying to avoid a gearbox out. pita.

Disappointing as gearbox was sent out to be overhauled at same time, as clutch and reported as good only the bearings needing replaced.

Will keep you posted.

Thank you for all contributions
Cheers

[DJT]

I had a similar problem with my first Stag. I eventually bought an adjustable push rod for a TR2-3 (I think - it was a long time ago) it took out the slack and made the clutch operate smoothly.

Cross shaft play can be helped by fitting two bushes each side, there is plenty of room for them. Check for play in the clutch pedal bush and/or clevis pin.

IMG_0602.jpg

[Lingen]

Brian.
One final suggestion. Is the carpet caught up behind the clutch pedal? I have always needed the full travel of the pedal to get mine to clear, and a double thickness of carpet is enough to make engaging reverse a painful process.
Mike.

[brian buttimore]

Thank you will investigate and keep you posted