Quick Question for TR4A Experts.

[John Morrison]

Am I correct in thinking that the Clutch slave cylinder pushrod, should

locate in the middle hole of the drop arm?

..... and is the pushrod on a 4A adjustable?

Thanks,

John.

[ctc77965o]

Yes its adjustable...yes middle hole preferred.

if you are running out of 'throw' it may be a master cyl issue..the small seal at the end could be a suspect

[John Morrison]

thank You,

God I just love this forum.

John.

[peejay4A]

Is it supposed to be adjustable on a 4A?  I thought it was the same as the 6, ie no return spring and non adjustable operating rod. That’s how mine is. 

[Lebro]

+1 That's what I thought, but, no harm in having it that way.

Bob.

[John Morrison]

Thanks guys,

swopped a group members gearbox back in a 4A. Put the slave assembly back, just as removed

i.e. adjustable pushrod and no  return spring!

Clutch slave was solid, and car slips in top.

Took it back, with a shortened pushrod, checked stuff was back correctly, i.e. slave mounting bracket, and slave cyl. in that bracket, and adjusted up the pushrod, to allow 1/16in play

as per the TR4 manual, car is now fine?

Still with no return spring, thats where we are now.

John.

 

[Lebro]

If you have an adjustable pushrod (as per early cars) then you should also have the return spring, or there is no point.

If you do not use a spring, then shorten the rod to give a larger gap so it can self adjust, which is how the later (diaphram) clutches usually work

Bob.

 

(I use a diaphram clutch in my '3 with adjustable rod + spring.)

[Fireman049]

I also have a Diaphragm clutch in my 3A with adjustable rod and spring.

Tom.

[ianc]

I have a TR6 diaphragm clutch with adjustable rod & return spring - as fitted during the re-build by Revington TR in the early 1990s.

The car has been on the road since the IWE in 1993, and seems perfectly happy with this arrangement.

Ian Cornish

[Hamish]

1 hour ago, ianc said:

I have a TR6 diaphragm clutch with adjustable rod & return spring -..........

Ian Cornish

Phew

thats just what I have fitted. 

H

[tim hunt]

In answer to John's original question Figure 17 on Page 20 of the Owner's Manual supplied with my 1966 4A clearly shows an adjustable push rod attached to the central of the three holes in the operating shaft lever. In addition no return spring is to be seen.

Tim

[peejay4A]

At the risk of sounding like a cracked record, if you fit a return spring to on a diaphragm spring clutch setup you will lose its self adjusting nature.  

[Lebro]

Yes, but the release bearing should last longer

Bob.

[peejay4A]

Maybe. 

[Tr4aJim]

The Tr4a owners manual does show the threaded rod, as does the Tr4a Stanpart catalogue (though neither shows a return spring). However the owners manual maintenance section makes no reference to clutch adjustments, nor does the Tr4a supplement in the shop manual. Perhaps they just continued to use the rod from the Tr4.

Jim

[John Morrison]

Onc e again,

thanks to all, the car had an adjustable pushrod and no spring,

now thats what it has again, I adjusted the rod so it had  - say a mm of play,

All seems well just now.

John.

[TR4Geoff]

John

I've just looked at my Workshop Manual and it confirms a gap of an (old fashioned) 0.1" approx 2.5mm.  I seem to remember my gearbox being reinstalled a few years ago and the "technician" didn't check the gap (basically there wasn't much of one!) Clutch operation was not good -so suggest you widen the gap a bit as I did, to above.

Cheers

Geoff

[peejay4A]

Without a return spring the gap will close up the first time you operate the clutch.  If you keep adjusting it without recognising that's the way it works you'll be stuck in a never ending loop.

 

Edited November 30, 2018 by peejay4A