Bad oil leak - Bellhousing

ok guys looking for some advice. Have recently got a Disco 300TDi which after some worse than expected laning developed a bad oil leak from bellhousing drain hole.

No.1 suspect has gotta be cranckshaft rear oil seal. I have noticed that the oil level in the engine is a bit high (planning an oil change this week).

Is it possible that the leak may reduce / stop with the correct oil level or is it more likely that the seal is just shot????

The Haynes book of lies says the seal can be replaced in situ by dropping the gearbox, however another paragraph suggests leaving the box in place an pullin the engine . I think I'll go for the box option unless the wiser peeps on here think the engine is the better plan.

If I'm dropping the box, are there any tips on offer to help or is it just a case of follow the instructions from Haynes. They recommend using an engine crane thru door and lower box on straps????

Is there anything else to consider with the box out. Clutch obviously but anything else?

Thanks in advance for any advice you can offer.

its gorra be either the crankshaft rear oil seal or the input shaft seal on the gearbox.

I have heard of overfilling causing pressurisation of the sump - so, i spose it is possible that could force the oil out, but sods law says it wont be that, and once oil gets past that seal, it will continue to leak until fixed.

from wot i remember from HB's box - they weigh a ton and it is easier to break the gbox/tbox apart, but others know better than I on that one.

Although it may seem alot more work, the engine out is often preferred to gearbox out! Nearly every landy i have had has had to have one or the other out, and the last time (defender) after removing what must have been a billion and one bolts to get the seatbox, floor etc out the engine option would have been better!
Don't skimp on a cheap seal, buy a genuine one, or a year later you might be back in the same boat!
If you have the engine out, if you haven't already had it done, have the timing belt done.
And yes either way, i would have the clutch examined and a new one whilts it's all apart.

Am I right in thinking the clutch release lever arm thing is a known weakness on these units and can be upgraded or have I just made that up??

Just to confirm it is the R380 gearbox.

MHM - I did consider dropping the transfer box off before taking the main box out, but that looks a difficult job with the main box still in situ. maybe someone can confirm if its possible to split the 2 units whist still in the car.

it is a known weakness on the lt77 box (clutch) dunno about the R380 - but assume the worst - modify it to be on the safe side.

dunno on the R380 - i only got experience fur about an hour with HB's LT77 in her defender - Discos are a bit of a bugger - 'parently.

When we did my gearbox, we dropped the whole thing out in one lump, then split it, then put gear box back, then tranny box. Mine's an LT77 and not as heavy as the R380. If you've got access to an engine hoist, it mite well be easier to go in that way. But if you are limited with tools and the like, you can get the box out with trolley jacks, but yer gonna need help!

Have got access to enjin hoist, so can use it on either lump, gearbox or engine. With the suspension lift I've got, am thinking dropping the box will be easier than getting the enjin out as I'm not sure if the hoist will lift high enough!!!

Dorset VogueSE said:

Have got access to enjin hoist, so can use it on either lump, gearbox or engine. With the suspension lift I've got, am thinking dropping the box will be easier than getting the enjin out as I'm not sure if the hoist will lift high enough!!!

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Ahhh! Yer sorted then me dear! It'll be a piece o **** . I had to 'modify' a 'gearbox hoist' fer mine!

engine out every time, do any work required to the lump also while its out, only a few wires, hoses, exhaust clamp one bolt either side of chassis rail and its out once you removed the bellhousing bolts, top bolt is a bugger!!!!!

Dorset VogueSE said:

Am I right in thinking the clutch release lever arm thing is a known weakness on these units and can be upgraded or have I just made that up??

Just to confirm it is the R380 gearbox.

MHM - I did consider dropping the transfer box off before taking the main box out, but that looks a difficult job with the main box still in situ. maybe someone can confirm if its possible to split the 2 units whist still in the car.

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if you replace the tranny box mounting bolts with some (at least) 20 cm long bolts which have had their heads cut off and a slot (for a screwdriver) cut into them you can slide the tranny box out and then drop it down yourself - you might need to do a bit of bench press work if your one of them who gets blown over in the wind types - it's then much easier to get the GB out on your own

i much prefer taking the seatbox out to do this type of task but each to their own

Sean said:

i much prefer taking the seatbox out to do this type of task but each to their own

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Thanks for the advice Sean, I will have a look at that option, reducing the weight I have to shift about sounds like a better plan. I'm sure I can cope with a stiff breeze and a tranny box (no Pikey, thats nothing to do with you) shouldn't be too difficult.

Just a shame LR didn't fit a seat box in the Disco to make life easier accessing the top bolts.

when yu gonna do this then, DV?

The Mad Hat Man said:

when yu gonna do this then, DV?

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Not til after the BBQ thats for sure, aint got enough time.

Sure it'll get there but the AA can always take it home for me.

couple of links from another forum that might help

Discovery clutch change - LR4x4 - The Land Rover Forum
Gearbox/Clutch/Rear Crank seal on a Defender - LR4x4 - The Land Rover Forum

Thanks Sean, will have a read of those links later.

Dorset VogueSE said:

Thanks Sean, will have a read of those links later.

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tut

could of had it all done before it gets dark tonight

Nah, already out tonight, an haven't ordered up new bits yet.

well volunteered Sean - yu got time to make it to Dorset on satdee and have it fixed by Sunday morning.

think you could buy a whole landy fer what it would cost me in fuel to get down there

well that's me normal excuse fer not visiting the relatives