Home > Puma (Tdci) > Output shaft failure, Forum Survey |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3403 |
JLR already knew that the Defender days were countable when they were ending the TD5. So why bother spending a fortune in development and testing... it only need to last as long as the warranty. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black |
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19th Jan 2022 1:57pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6295 |
if the extension casting was on a budget (which I'm sure it would have been) is if fair to assume some have warped during the casting process?
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19th Jan 2022 2:35pm |
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DSC-off Member Since: 16 Oct 2014 Location: North East Posts: 1394 |
All of the important features of the adapter casting are machined after casting to eliminate the inaccuracies of the casting process (supposedly). That is, the faces and the locating dowel holes at both ends.
Whether the machining is accurate enough to ensure alignment, or not, is the question here. Also relevant is the machining of the corresponding features on the back of the gearbox and front of the transfer box. It all has to go together to achieve an acceptable condition when assembled. I would suggest that nobody, JLR included, knows what the acceptable limit is for misalignment in this application. Indeed it is an arbitrary point as to where that limit is, should the life be 100K, 200K miles or more? The only things we do know is 20K miles or 50K miles is not acceptable, neither is sudden, complete and unpredictable failure. |
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19th Jan 2022 4:25pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17320 |
You are joking, right? The company with possibly the worst record of any for acknowledging the possibility of faults with its products. |
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19th Jan 2022 4:29pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17320 |
Some/most/all of us have been wondering about a QC issue for over a decade now! As far as the fitting is concerned the transfer case is identical to any other LT230, it is not modified in any way specific to the Puma. The MT82 is different to (I think) all others since it has a mating face for the adaptor housing and has no propshaft fitted. It is however relatively unlikely that there is any widespread manufacturing issue with the MT82 since generally gearboxes are manufactured to tight tolerances and the MT82 is not a bad gearbox (except for those specially made to annoy Mustang owners by having optional defects built in). It is most plausible that if there is a manufacturing tolerance issue it concerns the adaptor housing, which is a specific-to-the-Puma part, we don't know who makes it, we don't know the dimensional specification or tolerances, we don't know the QC processes, and it is exceptionally difficult to measure it for accuracy. Any errors in the manufacture of the housing could introduce a number of alignment issues - the gearbox and transfer box shafts axes may be parallel but offset, or they may not be parallel whether or not offset, and any of these or any combination of these will destroy the coupling. Nige's measuring technique on his video only measure offset, not angular misalignment. It would be difficult to measure the accuracy of this part without manufacturing special (precision) tooling. Finally we should remember that this is actually all speculation, albeit informed speculation based on sound engineering. Indeed, is there actually a problem at all? Landrover says not. |
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19th Jan 2022 4:44pm |
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Supacat Member Since: 16 Oct 2012 Location: West Yorkshire Posts: 11018 |
Is it correct that there's no know failure of the Ashcroft kit?
If that's the case, and their kit does nothing to address any type of alignment issue but rather changes the mating splines from dry to wet, then is it possible to hypothesise that this is the issue? The fact that the LR instructions make reference to and include grease in the repair kit might also support this notion. Albeit, it does not have a way to hold the grease insitu or replenish (as per the Ashcroft kit) and thus there have been repeat failures? Last edited by Supacat on 20th Jan 2022 6:04am. Edited 1 time in total |
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19th Jan 2022 4:58pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17320 |
I don't really think that there is anything to add to the preceding 26 pages of this thread as far as hypothesising on the cause.
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19th Jan 2022 5:43pm |
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MK Member Since: 28 Aug 2008 Location: Santiago Posts: 2408 |
There is evidence some shafts disengages and moves backwards from the female adaptor. Puma 110" SW
............................................................. Earth first. Other planets later |
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19th Jan 2022 5:51pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6295 |
I wasn't but I probably should have been. |
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19th Jan 2022 6:43pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6295 |
FIXED IT.
when replacing your next adapter shaft first get it on a lathe. Cut a groove into the mid-part of the shaft. the groove needs to be deep enough such to introduce some flex. This will allow for any mis-alignment. |
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19th Jan 2022 6:48pm |
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ashtrans Site Sponsor Member Since: 08 Nov 2008 Location: Harpenden Posts: 257 |
I would agree with this, we don’t fix the misalignment, we just wet the spline so it doesn’t wear out as the spline faces rub with each revolution. Dave |
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19th Jan 2022 7:16pm |
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nitram17 Member Since: 08 Jun 2014 Location: newcastle Posts: 2261 |
Is it April 1st? |
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19th Jan 2022 7:25pm |
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nitram17 Member Since: 08 Jun 2014 Location: newcastle Posts: 2261 |
The guy who tapped his shaft (steady matron)and fitted grease nipples i don't think is on the forum anymore ......so no update ..i wonder if anybody else has done it?I wondered also if it was worth drilling and tapping two high tensile bolts at 90degrees to the grease nipples to minimize movement and extend life of shaft. |
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19th Jan 2022 7:46pm |
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blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17320 |
No, but I fear Caterham's come off his meds too soon! |
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19th Jan 2022 8:24pm |
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