Various transmission questions

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James k
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Various transmission questions

Post by James k »

Hi,

Since buying my Traveller in 2014 I have done/had done a lot of work on it, including:

-Full engine rebuild
-Front and rear suspension completely replaced
-Carb overhauled
-Alternator and electronics ignition upgrade
-Chassis overhauled with replacement crossmember and various panels, blasted back and refinished
-Full respray
-Full wood replacement
-various other bits I can't remember!

Anyway, I think now the only bit that hasn't been touched yet is the transmission (aside from replacing the clutch when I fitted the new engine. This is now what I need to turn my attention to, I think.

The gearbox is in reasonably good shape, shifts smoothly and doesn't jump out of gear or do anything else strange but it is noisier than I think it ought to be and I can hear that the bearings are worn. I intend to rebuild it fully at some point although working out the logistics of doing so is hard as it is my daily driver and I don't have a garage to work in.

The clutch is horrific to operate and makes me dread being in stop-start traffic as it is difficult to control accurately.

There is a metallic 'clink' sound when pulling off, shifting up or accelerating suddenly, from the back of the car.

So, I have a few questions:

- What parts of the clutch mechanism are likely to be causing horrible action? I suspect it may be due to worn bushes on the relay shaft but could the pedal shaft itself also be the culprit? If it is the relay shaft bushes, are these relatively straightforward to replace? I intent to fit Declan's rose-jointed linkage, assuming it is still available.

- I suspect that the 'clink' from the back is from the propshaft UJ and that this will need to be replaced. Is it possible though that it is also due to the differential? I had a look under the car today to check the play in the prop and couldn't feel any side-to-side movement but there is quite a lot of rotational play. Is this normal or should it be tight when attempting to turn it by hand?

I don't think a gearbox rebuild will be possible for a while but I'm hoping I can get the clutch mechanism and UJs done soon if they are not too difficult to do.

Thanks,
James
Wearytraveller
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Re: Various transmission questions

Post by Wearytraveller »

Regards the propshaft, there are three areas of wear- Two UJs, and the splines.

To check for wear, out of gear and handbrake on. You need to grip the main body of the propshaft in one hand and the rear flange in the other and try and twist them relative to each other, and check for up and down or side to side play in the shaft. Do the same for the front yoke. Also, if the the front yoke is sound, look for play in the splines in the telescopic section, by attempting to turn the shaft in relation to the telescoping section.

UJs can be replaced in an afternoon by an amatuer, in an hour or two by somebody experienced. Read the workshop manual first to make sure you have the required tools and understand the process.

If the splines are worn, a new good quality propshaft is the way to go.

The play being mentioned above is all within the propshaft itself. The entire propshaft should be able to rotate a small amount (1/4"?) in relation to the rear wheels with the handbrake on, this is normal and is due to the backlash (free play) in the diff. Excessive backlash due to thrust washer or crownwheel and pinnion wear in the diff will make a deep dull 'clunk' on power take-up, rather thank a 'clink'. You mention rear suspension was overhauled, check your rear axle U-bolts are tight too in this case, these can end up loose as things settle and allow the axle to move slightly, making a clunk.

Worn UJs can cause a tinkling or clattering noise on power take up, almost like driving over a loose manhole cover...

Universal joints come with or without grease nipples- go for those which can be greased, and grease regularly to drive out used, contaminated grease, and keep out water (just as important). GKN are a good quality OEM manufacturer of propshafts and UJs, GUJ115 is the part number although please double check yourself.

Kind regards, Chris.
James k
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Re: Various transmission questions

Post by James k »

Hi,

Thanks very much for your detailed reply!

I will attempt to get under the car on ramps this weekend or next to properly examine the propshaft and check for play as you describe. Driving over a loose manhole cover is EXACTLY what it sounds like. It's not enormously loud and is most audible when you have the windows open.

Another noise I forgot to mention was a 'thud' and a jolt at the back when I depress the clutch from stationary sometimes. The car is in neutral and at a stand-still so I'm not really sure what this could be caused by.

I've managed to improve the clutch action somewhat by just spraying all the joints on the linkage with WD40. It's still not great but it's a lot better just from that. I imagine that overhauling the mechanism will yield much better results.

Thanks,
James
Wearytraveller
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Re: Various transmission questions

Post by Wearytraveller »

Sounds like it might well be the propshaft, although we should always be prepared to be suprised, best as you say to check it to either eliminate it or overhaul it if required, then see what noises if any are left.

Yes an overhaul of the clutch mechanism should certainly improve things and may well remove the thud/jolt. Dismantle, inspect and replace anything with elongated holes, worn bushes, worn shaft, worn/perished rubber bush. Slop and possibility of binding will then be removed, giving a smooth action. Some have converted to a rose joint system (search this forum and morrisminorforum.com for more info) and report a smoother action. I haven't tried this compared to a standard setup without wear, so can't comment, but the standard setup does most people fine when it is in good order.

Given that the quality of modern rubber components tends to be pretty awful, a polyurethane bush for the clutch relay shaft may be a sound investment- for longevity. Discussed briefly here: viewtopic.php?t=56618

Kind regards, Chris.
don58van
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Re: Various transmission questions

Post by don58van »

rose joint system
Declan Burns, who is a member of this club and a hobbyist manufacturer of Minor improvement parts, supplies rose-joint kits.

Don
philthehill
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Re: Various transmission questions

Post by philthehill »

Way back before the availability of poly bushes I used a slightly modified Land Rover Series 1/2/3 damper eye bush which was much harder than the Minor item - then latterly used a hard plastic bush from Minor Mania. Both made the clutch operation so mush better. Now fitted with a hydraulically operated clutch which is even better.
The overhaul of the clutch linkage and the fitment of the relay shaft poly bush is relatively easy and should not take too long to complete.

Wearytraveller
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Re: Various transmission questions

Post by Wearytraveller »

Although a good option back in the day no doubt, the Land Rover option is probably not so great now- lots of trouble reported in the Land Rover world (and trouble in my own experience) of even genuine LR rubber bushes now, let alone the aftermarket alternatives. Thank goodness we now have polyurethane as an alternative.

Kind regards, Chris.
Chipper
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Re: Various transmission questions

Post by Chipper »

To improve the clutch operation, you could try squirting a few drops of engine oil down all the swivelling parts of the clutch/brake pedal shaft, and also grease the relay mechanism, and adjust if necessary.

It could be that your clutch release bearing is worn; remove one of the rubber bungs in the side of the gearbox (if fitted) to inspect it - you'll probably need a strong torch and a mirror to see how worn it is.

I fitted a new one just 12,000 miles ago on an MG Midget diaphragm clutch in my Traveller and it was down to the last 1-2 mm or so already! :o
Maurice, E. Kent
(1970 Traveller)
philthehill
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Re: Various transmission questions

Post by philthehill »

The Morris Minor clutch release mechanism is really an anachronism as a means of transmitting the leverage from the pedal to the clutch release arm. Even with the poly bush fitted into the chassis rail pivot it is not perfect but better than the original rubber bush. If the rubber bush is to be replaced a hard plastic or poly bush with a shore hardness of plus 80 is to be preferred.
The genuine Girling damper (L/R Series) eye bush shown on the right below has a Shore hardness of 90. The L/R bush has to be reduced in height at its outer end to suit the bush holder. The other bush is a Minor Mania NOS hard plastic relay shaft bush.
relay shaft bush.JPG
relay shaft bush.JPG (677.08 KiB) Viewed 641 times
I have tried all four solutions before deciding on the hydraulic clutch release system.
The only solution for a effortless clutch pedal is to fit a hydraulic clutch conversion which is relatively easy to do.
Here is the ESM hydraulic clutch conversion which is similar to my conversion.
https://www.morrisminorspares.com/clutc ... ly-p829580

kevin s
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Re: Various transmission questions

Post by kevin s »

We have a hydraulic system on ours and the clutch is fantastic, lighter than most modern cars and progressive. Still a bit of judder when heavily laden though but I think that is more down to the engine mounts having no end stops, I'm thinking of making some mounts similar to the escort world cup ones or some travel limiting cups like an MX5.
James k
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Re: Various transmission questions

Post by James k »

I'm currently in the process of ordering a rose jointed linkage from Declan. I'll disassemble the clutch linkage and inspect all the parts. I expect to replace the bushes at the very least, and potentially the relay shaft depending on wear. With any luck this sorts out the clutch, otherwise I imagine I'll have to start looking at the clutch itself as the culprit, which I really don't want to have to do!

I had the opportunity yesterday to operate the clutch pedal on another Minor at a car show and it was indeed far lighter and nicer than mine. I at least now know that there is something wrong with mine and it's not just a matter of 'that's what Minors are like'.

Once the clutch is sorted I can move on to the propshaft UJs. In an ideal world I'd just pull out the entire engine and transmission, rebuild the gearbox, sort out the prop, have the diff rebuilt, replace all the wheel bearings and sort out the oil leaks on the engine. Unfortunately it's got to be bit by bit.

When I come to replacing the UJs, if I get the propshaft balanced, does that negate the need to mark up where it connects when removing it?

Thanks,
James
philthehill
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Re: Various transmission questions

Post by philthehill »

If you mark the prop shaft yokes and re-assemble in the same relative positions that should negate the need to re-balance the prop shaft unless you are seriously concerned that the prop shaft is out of balance. Just replacing the U/Js does not require the prop shaft to be re-balanced.
Mark the diff flange and the prop shaft flange adjacent to each other so that the prop shaft is fitted back to the diff in the same place. There is no real need to align the flanges but it makes good engineering sense.

James k
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Re: Various transmission questions

Post by James k »

I do have a strong vibration at around 70mph. I've had the wheels balanced and the tracking set so I suspected it might be the prop.
nutsandbolts
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Re: Various transmission questions

Post by nutsandbolts »

A vibration at 70mph! my fillings come loose over 55mph!
the most unreliable part of a car is the nut holding the steering wheel!
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