Loose feeling drivetrain

[Subareubs]

Hi team, I have a 1998 Lancaster (BH9, EJ254, manual w/ Hi/Lo) with a shade over 125,000kms on the clock. I have only owned this for a 3-4 months and when I bought it it had blown HGs. Fixed the HGs but haven't really driven it much as i mostly use my motorbike for the commute to work. Also the clutch is coming up due for replacement in the next 15,000km (plate is getting skinny but not slipping yet)

HOWEVER... I have noticed when driving at a steady speed that if i let off the gas slightly then gently apply the gas again sometimes the drivetrain will feel loose and shunt a little, kind of feels like weight transfer or similar. This has happened on the flat, going up and down hills, sometimes changing gears- basically small shifts in power/weight front to back or vice versa.

Its not quite like surging (fuel or timing advance problems), feels like its in the drivetrain and not the engine.

So my questions are:

Is it normal to have this kind of drivetrain slop (or whatever it is)?

If it is not normal, what is it a symptom of? Clutch worn out? Diffs? Box?

Any points in the right direction, or tests to perform, general help would be greatly appreciated!

[Koom]

Check the engine mounts. They often fall apart and would cause that type of feeling.

[Guest]

Turning corners do you get a slight tug on the steering wheel? Or turning full lock both ways in a parking light do you get any weird noises or feeling? Have it always done it and if not have you had a different sized spare wheel on in your ownership?

As above and also pitch mount and gearbox mount.

[Subareubs]

Cheers fellas, no weird noises and turning full lock is resistance free. I am fairly certain that I did all of the engine/trans mounts back up after the engine was out, but will check to be sure. All wheels and tyres are the same - even all tread depth is the same!

Turning is fine as far as I can tell, the wheel alignment though not perfect still feels good, so might be something to get looked at. How obvious is this slight tug? what would it be a sign of?

Ive no idea when the trans was last serviced so will look at doing gear and diff service in the near future...

[Subareubs]

Oh and just to be clear (my bad if it wasn't clear enough), by shunting I mean that I get the shift in weight and it "bounces" a little so not just a single bump but multiple bumps that usually diminish after a second or two...

Make sense? Ill see if I can get a video that shows it but it will likely be hard to tell as its more of a feel thing than a visual thing.

[Guest]

Turn a long sweeping corner at 90kmh or so and turn in holding the steering wheel very lightly. Pick a decent corner so you can hold your line then do it going round it the other way. Will feel like someone gently tugging on the steering wheel. Points to centre diff issues which are commonish in your shape wagon and also after someone throws a funny size wheel on.

[Rosssub]

This is what Koom means by stuffed engine mounts:

Put a flat block of wood under the sump, jack the engine up slightly and look for splits or tears. Then do the same to the gearbox mounts.

[Subareubs]

Cheers Ross, will do exactly that. I figure that at least the engine mounts are ok as I just got a WoF a couple of days ago. Will see how she goes...