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LandRoverAnorak

Member Since: 17 Jul 2011
Location: Surrey
Posts: 11324

No, no at all. Apart from the fact that the presence of oil would prevent corrosion and debris forming in the first place, there's no mechanism that would draw the oil back into the 'box. Darren

110 USW BUILD THREAD - EXPEDITION TRAILER - 200tdi 90 BUILD THREAD - SANKEY TRAILER - IG@landroveranorak

"You came in that thing? You're braver than I thought!" - Princess Leia

4th Jan 2022 8:47am

Caterham

Member Since: 06 Nov 2008
Location: Birmingham
Posts: 6298

2011 Defender 110 Puma 2.4 XS CSW Stornoway Grey

not sure I agree with the first part of your response tho

if no corrosion etc would that not assume the shaft - hasn/t / wouldn't fail?

4th Jan 2022 10:00am

LandRoverAnorak

Member Since: 17 Jul 2011
Location: Surrey
Posts: 11324

Not necessarily. From what I've seen corrosion is merely a consequence of lack of lubrication and not in itself the prime cause of failure. There are several reasons why failure can occur including poor installation, although the prime suspect seems to be some sort of misalignment. Darren

110 USW BUILD THREAD - EXPEDITION TRAILER - 200tdi 90 BUILD THREAD - SANKEY TRAILER - IG@landroveranorak

"You came in that thing? You're braver than I thought!" - Princess Leia

4th Jan 2022 10:26am

Caterham

Member Since: 06 Nov 2008
Location: Birmingham
Posts: 6298

personally if I had the time I'd be looking into the possibilities of removing the mt82 + adapter shaft and replace with the tremec t56 magnum. It's longer and hopefully long enough to do away with the adapter altogether. connecting this to the lt230 has been done many times it just the clutch end / bell housing?

granted it wouldn't be cheap but resale on the gearbox and not having to pay for a replacement shaft every so often / reliability would for me be worth several thousand pounds? hmm

4th Jan 2022 10:56am

Caterham

Member Since: 06 Nov 2008
Location: Birmingham
Posts: 6298

thinking about it.
as said elsewhere;
the mt82 is well proven,
the lt230 is well proven,
the method of connecting the two ie an adapter shaft is a well proven principle.

therefore the only possible problem is the adapter shaft housing. surely there are people out there that could both verify this and build a replacement housing to the necessary tolerances?

isn't this a preferential route to take over the ashcroft adapter and the one piece offerings out there?
granted such a thing is not currently available and hence the above options are preferrable.

4th Jan 2022 11:01am

LandRoverAnorak

Member Since: 17 Jul 2011
Location: Surrey
Posts: 11324

I suspect that you're right but imagine that an adapter housing is much more complicated to manufacture than a revised shaft. As the latter seems to solve the problem in the majority of vehicles that suffer, it's also a very limited market. I appreciate that's no comfort for those with a vehicle that eats shafts more regularly, though.

If you do have such a vehicle then I guess it'd be worth finding somebody that could properly investigate the 'box alignment and undertake the necessary machining to cure it. Doesn't sound cheap though, unfortunately. Darren

110 USW BUILD THREAD - EXPEDITION TRAILER - 200tdi 90 BUILD THREAD - SANKEY TRAILER - IG@landroveranorak

"You came in that thing? You're braver than I thought!" - Princess Leia

4th Jan 2022 11:14am

blackwolf

Member Since: 03 Nov 2009
Location: South West England
Posts: 17336

2007 Defender 110 Puma 2.4 DCPU Stornoway Grey

I know this has all been said before, but it perhaps worth restating. The immediate cause of failure is a process known as fretting, i.e., the gradual erosion of the parts as a result of rubbing. For failure to occur there must be a continuous repetitive movement within the joint.

There are several factors which will determine how fast this occurs, namely:

Item (a) will primarily be down to the alignment of the parts, and will depend on how parallel the rear of the gearbox is with the front face of the transfer box and how accurate is the axial alignment of the gearbox mainshaft with the transfer box input gear (and I suspect that this is the most significant variable).

Item (b) will primarily come into play as the coupling starts to fail and the surfaces wear, but there is also evidence of the two parts coming apart in many failures (i.e., the spring ring fails to retain the male part in the female part), which may be as a result of incorrect assembly, or may be the result of the parts simply separating as a result of (a) and a lack of lubrication. As soon as separation begins the contact forces will be massively increased and any wear will accelerate in proportion to the reduction in contact area.

Item (c) is largely self-explanatory, but it should be noted that a coupling of this type should never be assembled without suitable lubrication and that fact that Landrover evidently did so for a long time or over many discrete periods is simply appalling (sadly not unexpected though). Unless a continuous oil feed can bee provided (as in the Ashcroft modification) the lubricant must be a suitable grease (Molybdenum Disulphide being probably the most suitable), but it should be remembered that all greases dry out over time and grease will tend to be ejected from the places where it is needed, and therefore periodic re-greasing will be necessary. With the right grease this can probably be done as infrequently as the clutch is replaced. Lubrication will not prevent wear from occurring if there is movement, however it may well slow the rate of wear to the point where it ceases to be a problem.

Item (d) will mainly be the result of a failure to lubricate, with the result that rust can form and, in the absence of lubrication, form an abrasive paste or powder within the joint. Once again there are many examples of this happening.

There is ample evidence to support the above, for example there are vehicles with high mileages on their original shafts (my own had no evidence of lubrication at all when I first took it apart at 150k miles, and since being lubricated then it has now done well over 250k miles in total. This can only have happened if I have parts which result in near perfect alignment), yet there are vehicles such as Keith's which have good lubrication and still fail at low mileages.

I believe that ultimately there can be no doubt that this joint will fail eventually if there is any significant misalignment in the gearboxes. Correct assembly and suitable lubrication will postpone this, but only correct alignment will prevent it.

4th Jan 2022 11:21am

blackwolf

Member Since: 03 Nov 2009
Location: South West England
Posts: 17336

Caterham wrote:
thinking about it.
as said elsewhere;
the mt82 is well proven,
the lt230 is well proven,
the method of connecting the two ie an adapter shaft is a well proven principle.

therefore the only possible problem is the adapter shaft housing. surely there are people out there that could both verify this and build a replacement housing to the necessary tolerances?

isn't this a preferential route to take over the ashcroft adapter and the one piece offerings out there?
granted such a thing is not currently available and hence the above options are preferrable.

I tend to agree with you, and supporting evidence includes that fact that I have changed my transfer box and doing so does not appear to have affected the longevity of my coupling (which as I tend to repeat with boring regularity has now done more than 250k miles).

It should be noted however that the housing is a very tricky shape to measure accurately. Although checking the front and rear faces for parallelism is easy enough, if the dowel holes in either face are machined inaccurately it would be incredibly difficult to tell but would result in the two ends of the shaft not being aligned axially. I suspect that this is what is happening.

Since only Landrover and the manufacturer of the part, who was, presumably, supplied with the a CAD file or drawings including tolerances, know where the dowel holes should be, it is hard to check. Measurements would have to be accurate in two axes, of course.

It would be possible to carry out comparative measurements between a known good part and a known coupling-eater, if one had access to them, but even this would require access to some fairly fancy equipment. If I had the time it is something I would be fascinated to delve into, I would love to be able to prove my theory. I probably have the equipment to do it, but not the time to dismantle my transmission, make some tooling, and take the measurements, and I don't have a known bad adaptor housing for comparison.

4th Jan 2022 11:37am

MK

Member Since: 28 Aug 2008
Location: Santiago
Posts: 2410

2007 Defender 110 Puma 2.4 SW Chawton White

I believe the rate of failure of the ashcroft kit so far =0. Disregarding some oil leak problems in the early models. Puma 110" SW

.............................................................
Earth first. Other planets later

4th Jan 2022 11:49am

LandRoverAnorak

Member Since: 17 Jul 2011
Location: Surrey
Posts: 11324

Unfortunately that's no longer the case. See Keith's post towards the end of page 20. Darren

110 USW BUILD THREAD - EXPEDITION TRAILER - 200tdi 90 BUILD THREAD - SANKEY TRAILER - IG@landroveranorak

"You came in that thing? You're braver than I thought!" - Princess Leia

4th Jan 2022 11:55am

MK

Member Since: 28 Aug 2008
Location: Santiago
Posts: 2410

OK but I believe we have not seen the shaft etc yet (?) Not sure Puma 110" SW

.............................................................
Earth first. Other planets later

4th Jan 2022 11:59am

Caterham

Member Since: 06 Nov 2008
Location: Birmingham
Posts: 6298

hi BW and a very happy new year to you.

just a thought - and again I'm not suggesting this is going to be easy.....

could a rig not be made up on a good set up ie yours - remind me how many adapter shafts have you got through and at what mileage

could a rig mounted on the gearbox externals locate the position of the lt230. I appreciate this might not be as accurate as it should be but presumably close enough to establish if a 'bad one' isn't in the same position?

4th Jan 2022 12:05pm

Caterham

Member Since: 06 Nov 2008
Location: Birmingham
Posts: 6298

just another thought on this?

is it possible its a simple case of the shaft isn't balanced?
especially bearing in mind it has that plastic cover on it.

I know prop shafts have to be balanced - I appreciate they are a lot heavier and far more likely to be out of balance - just a thought?

4th Jan 2022 12:10pm

jpboost

Member Since: 13 Apr 2021
Location: Gatwick
Posts: 377

2014 Defender 110 Puma 2.2 SW Keswick Green

I think the nature of the failures would suggest it wasn't the quality (balancing or otherwise) of the actual shafts.

As others have said above (and probably clearer than i am), if some cars get through multiple shafts in relatively short mileages, but others are fine for huge mileage, you can discount variance in the shafts themselves. The difference has to be something relating to the vehicles we're fitting them into.

4th Jan 2022 12:33pm

Bluest

Member Since: 23 Apr 2016
Location: Lancashire
Posts: 4203

2007 Defender 110 Puma 2.4 XS CSW Java Black

Something I would do if I had a car that was chomping through shafts quickly is replace the adapter housing with another used one from a breakers, higher mileage the better. This is on the basis that the replacement should be better, and if it is not it is unlikely to be worse. 2007 110 TDCi Station Wagon XS

4th Jan 2022 12:34pm

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