Classic cars forum & vehicle restoration.

bjacko · Posted: Wed Apr 16, 2014 8:02 am Post subject: Morris 8 Vibration

I have a bad vibration when the engine is in overrun. When it idles it is very smooth and quiet. When I accelerate it is OK until I lift my foot then it vibrates. I have checked the engine mounts and the structure supporting them. I have the gear box out currently and the shaft with the synchros seems to fairly loose and can be moved side to side and the synchros moved fore and aft slightly more than I would expect. Could this be excess wear thet is causing the vibration.? The clutch and flywheel have not been touched since before the vibration started so I do not expect them to be causing it.

Timstopp · Joined: 16 Oct 2008 Posts: 98 Location: colchester, essex

If it is of any help, I had exactly the same symptoms on my Wolseley - turned out to be one of the propshaft UJ bearings has collapsed. Smooth on acceleration and mad vibration on overun............
Worth checking as these are an easy fix.
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North Essex,UK - Morris 8 tourer 1936 - Jaguar x350

bjacko · Posted: Thu Apr 17, 2014 2:17 pm Post subject: Morris 8 Vibration

The universals are OK. It vibrates when it is stationary after revving the engine on run down.

goneps · Posted: Fri Apr 18, 2014 12:01 am Post subject:

This is most interesting, since I've been beset by this annoyance for as long as I can remember. It has persisted over the years despite fitting:

1. An expensively-overhauled and fully balanced engine.
2. Complete new clutch.
3. Reconditioned four-speed gearbox, which obviously necessitated a different rear mounting.
4. Reconditioned, balanced, and shortened (spare) prop shaft to accommodate the four-speed 'box.
5. Differential head with NOS CWP.

It did improve a little after fitting the Series E gearbox, which I put down to the firmer mounting used, but has recently become worse again. It happens in a rev band around 35-40mph in top.

I've long suspected cracks in the chassis around the front engine mountings, but have never found any.

Richard

bjacko · Posted: Sat Apr 19, 2014 4:31 am Post subject: Morris 8 vibration

I know of some cases where a cracked generator support bracket caused vibration.

goneps · Posted: Sat Apr 19, 2014 5:58 am Post subject:

I can well believe it. I've even run without the fan belt in case the dynamo or fan were the cause, but it made no difference.

bjacko · Posted: Sat Apr 19, 2014 1:47 pm Post subject: Morris 8 vibration

Sometimes the chassis cracks where the cross member joins the side member. Mine has quite a few repairs.