Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Rover gearbox - difficulties in engaging gears

Hi, our 1973 +8 RHD is fitted it's original Rover 4-speed gearbox. It's not noisy and the syncromesh is fine. But, it's getting increasingly difficult to engage especially 1st and sometimes 2nd and reverse at stand still. I've tried revsering it a bit and then trying again and it works - sometimes, but not always. Most times it will engage 1st and 2nd when the car is rolling, however. No difference if it's hot or cold. Oil is 20W/50 as recommended in the Owners manual and it's Valvoline VR1, which has done some 1.500 km, There are no leaks in the hydraulic clutch engaging system. What could be wrong and how to rectify the malfunction? Cheers /Finn

Have you pulled the slave cylinder boot back to see if it’s leaking but not showing? I had the same problem last year on my +8, a new cylinder cured it.

Sounds like clutch drag to me

Try getting in touch with John Beskeen. Contact details are in the Technical Services list inside Miscellany back cover. (Brown background box listing contacts).He is the early Plus8 guru. A Taffmog member and very helpful. He has a superb early Moss box Plus8.

It does sound like clutch drag to me too.

However, many years ago I had a Rover 2200TC with a similar (same internals but no oil pump) 4 speed gearbox and that suffered from a similar problem to that described by the OP which turned out to be a problem with the gear lever remote assembly. It was a long time ago so I am afraid I cannot remember the detail.

The Rover P6 club has some information on the gearbox:
http://p6club.com/content/rover-p6-manual-gearbox

agree with Graham, if the gears are engaging whilst the motor is NOT running i would be pluming for clutch, or working on the principal the clutch is not engaging correctly which might be slave cylinder rod worn also.

Finn


A good friend of mine down under (John Merton) , who is a lurker on this forum, asked me to post this on his behalf here , I hope it helps you.

Quote:
I noticed on Talk Morgan that someone had raised the issue of difficulties in his ‘73 Plus 8 in selecting first and reverse gear from rest.

This was also raised on “The Morgan Experience, possibly by the same person( I don’t subscribe to it either). I sent something to Duncan Charlton on it which he posted.

But mainly to help others the most common cause of this problem is the engine idling too fast. Mine’s fine around 800 rpm but over 1,000rpm it starts to play up and becomes more difficult as the revs rise further. I suspect the spigot bush( which I think is oilite starts to pick up a bit and when the clutch then starts spinning it adds centrifugal force.

Another issue. Despite all the service data recommendations, NEVER use engine all in this gearbox. When I first got my Plus 8 23 years ago I wondered about the advisability of this in a helical gearbox of this nature with this power potentially driving it. I searched high and low through the Castrol data ( hard to find relevant data on it even in 1990) but eventually found their recommendation was for VMX80. This makes a lot more sense given it’s a gearbox oil designed for this type of application.
Unquote

Thanks all for your inputs and advise. So far I've changed the oil from 20W/50 Valvoline VR1 engine oil, to Motul 80W GL-4. The Castrol VMX 80 suggested is not readily available in Europe it seems. Not a big difference, if any. Then I changed the hydraulic fluid for the clutch, it seems as it has not been done for ages btw. No difference. The clutch engage/disengage at the top 1/3 of the travel towards the floor and it doesn't drag during hard acceleration. Next I will check the idle speed and see if that helps.

If I have to change the clutch, is that an engine-out operation?

Many thanks

Cheers /Finn

Finn

Do check the idle speed as that is possibly the most important factor , the correct oil will prolong the life of the box but would not affect your issues, however the idle speed is a likely cause. While you are setting the idle speed have a good lock at the HIF6 SU carbs, as they have known issues around the mixture adjustment lever.

If the worst does come to the worst then a new clutch is definitely an engine out job. This is a big job in every sense of the word, so try the simple fixes first before contemplating a task like this.

Hi again,

Adjusted the clutch linkage to the maximum, and idle speed is around 8-900 rpm.but still no improvement.

If I have to change the clutch, we are seriously considering another gearbox, as we really dislike the 4-speed Rover box. The shifting is sloppy and the gearing is low, meaning too many rpm on the high way.

The obvious choice might be the 5-speed box, but what will that take? Another bell house I guess and propeller shaft? What would the price implications be?

Or the excellent Mazda MX-5 5-speed box, which comes as a complete kit at Euro 4.800 from Vitesse Ltd in the UK. https://www.vitesse-ltd.com/product...-kit-morgan-plus8?variant=21482028236883 But not exactly cheap....

Any other alternatives?

And a new clutch, which brand to choose?

Cheers

/Finn