Auto shuddering

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Originally Posted by BIG O

Obvious no one else ever had this go one with their auto...

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I've just stumbled across your thread (and am pleased to see that you might have it resolved), but...

My MY99 Td5 has a similar problem.

I describe it as a "rough shift from 2nd to 3rd". The 'box seems to hang onto the gear a little longer than it should and then there's a fairly loud "clunk" that could also be described as a "bang" and it'll shift up.

This has never happened on a downshift, only ever on an upshift.

It appears intermittently too - I can drive for 3 hours and not have it happen once, or drive for 5 minutes and it'll do it once.

I thought it might have been a worn/loose/damaged uni on the front propshaft. Upon removing the shaft and replacing it with a Tom Woods shaft I thought I'd solved the issue. But it still does it occasionally.

What is this Lucas additive you refer to please? If it can't damage anything by being added to my 'box I'll give it a go.

Edit: Sorry, just re-read the post earlier. Lucas Trans Fix. Added to shopping list.

The Lucas helped . I guess more time will tell . The shudder has been diminished but still did it a couple of times in 5 hours driving . The interesting thing was most driving was up hill some quite steep and it never missed a beat. The times it played up was driving in traffic btw lights.!? Shifts were as a whole notably smoother.

Maybe look at cleaning out the cooler lines and cooler or upgrading the cooling system. Seems like it's heat related there.

Hey fellahs
I thought I would post something that might be relevant but its also a generic thing when it comes to auto transmissions.

I have a section in my shop which used to do alot of transmission overhauls, I do less of it these days due to profit margins specializing in just a few marques like LR and Prius transmission units.

On thing to takes into account is that transmission fluid is alkaline in nature and as it ages with use it turn acidic.
If you neglect the PM on the unit, then suddenly have brain storm & change it, it basically shocks the transmission; possibly causing all sorts of junk like gums and particles to get stripped off often collecting in vital shifting parts causing shift delay and other contretemps like shudder.

I don't know what it is like "down under" but I will usually get a punter looking for a tranny service on the forecourt. Most of the time he has a problem but says nothing. Before I will put a wrench on it I go for a test up the street and test the unit for shift quality and do a stall test.
Its CYA thing!

If it passes and he has some sort of service record I will change it & filter , BUT if the fluid looks very old, varnished, burnt, and generally bad looking, I leave it well alone.

Experience has tought me to do partial changes on fluid when there is no history, but the box looks good, but I don't want to risk a shock situation.

Hence I will change a third of the fluid , do a repeat in 500 hundred miles and again at a further 500, then go for the whole Kahuna and service the unit if all is running well.

I have for years avoided the angry customer who has had a service done in my shop then accuses me of ruining his tranny a few days later!:wasntme:

If you buy a used LR with no service history and it has an auto transmission you might want to bear my shop experiences in mind.
Cheers Dennis

Nothing worse than being accused of ruining someone's tranny.