Home > Maintenance & Modifications > Another Puma clutch failure |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
yes the transfer box is in neutral for the video.
It does indeed sound like chatter. Nothing chatters in neutral with the clutch engaged or disengaged. In the video it chatters in 4,5,6 gear and calms when i raise the rpms toward 1500. When driving, the chatter is quite loud and increases with larger amounts of torque. I can drive 80kmh in 5th with no noise, but if I shift to sixth I have a lot of noise. If I give it some boot in 5th its loud, but tends to go away by 2800 rpm (or is no longer the loudest noise in the truck, hard to tell) Roaming around 🇳🇴🇨🇠|
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3rd Sep 2021 8:59am |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
Re your comment "When driving, the chatter is quite loud and increases with larger amounts of torque"
Does it go away on overrun (engine brake). 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing 2012 90 CSW, 2.2TDCI, Santorini Black |
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3rd Sep 2021 9:07am |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
Hmm, thats an interesting idea. With the PTO cover off the output shaft should be basically right there? Would it also be possible to (with a mallet and block of wood) knock the output shaft to make sure it is seated firmly? The LOF part has an adapter that screws into the output shaft at 75nm and the draw bolt torques to 57nm. btw, is the PTO cover above the oil line? Roaming around 🇳🇴🇨🇠|
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3rd Sep 2021 9:08am |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
Yes, dead silent on over run in all gears. Roaming around 🇳🇴🇨🇠|
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3rd Sep 2021 9:10am |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
Based on your description, I would start with checking that that the LOF output shaft did not come undone (or worse case it has stretched the bolt). Keep in mind that the gears in the gearbox are helical, so they not only transmit torque, they also generate an axial (in the direction of the mainshaft) force.
When the shaft was replaced, I think the internal components are already pulled together, so no need to do any tapping action. Actually I would not recommend to tap anything, even with a soft hammer, because the design is that you pull the mainshaft while pushing the bearing inner race. I think the lof adaptor is not doing anything other than just being an adaptor to reduce thread size. But I stand to be corrected. Yes, the PTO cover is below the oil level, but expect a few drips. When LOF released the single piece shaft, I did have concern about the lack of flexibility in the shaft itself, and the higher flexibility from the long thin bolt. But my concerns are unfounded (yet). I understand LOF have tested the shaft behind a Coyote, but do not underestimate the pulsing torque from a little 4 cylinder diesel (V8 is much smoother). There was another topic about this subject, when the tdci was compared to the smoother 5 cyclinder Td5 with overlapping power strokes. Good luck. Edit.. If the internals of the MT82 have become loose, then I am not sure if the 57Nm from an M12 bolt (different thread pitch create different pulling force) is enough to pull the internals together. But I would not try to tap anything together again. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing 2012 90 CSW, 2.2TDCI, Santorini Black |
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3rd Sep 2021 9:26am |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
The PTO cover goes back with rtv silicone only. You will not mess up the TC input gear bearing preload. You do not need to remove the input gear bearing holder, unless you see a problem that would need removal of the input gear as well. But even if that is necessary, the preload would still be ok. Puma TC do not use gaskets. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black |
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3rd Sep 2021 9:43am |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
PTO cover off (actually, the whole bearing holder as the cover was glued on so well with Black RTV that they both came out together).
The bolt on the end of the output shaft is very tight, probably due to locktite. Rather than break it loose only to retighten to 57nm again, I decided that was enough to say "the shaft is not loose". Edit: given the bolt does not seem to have changed since it was installed, I dont presently think the gears have loosened up in the box. If they have, I will need to remove the output shaft, put a cup back on, and then do the 230 / 180nm torque process. Given that the lof one-piece is drifted on with a hammer I suppose that this could be the case. But keep in mind this problem manifested itself only, and immediately, with the replacement clutch. I explained the situation to a site vendor here and he said he couldnt tell exactly what was causing it and that I would probably have to put a stock clutch in to check...and it seems like I am running out of other things to check Roaming around 🇳🇴🇨🇠|
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3rd Sep 2021 12:59pm |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
Good that it is not the lof shaft.
But bad that you have to hunt another possibility. What I noticed from the video is that the speed of the chattering is faster on 6th gear, and progressively gets slower as you go down to 5th and 4th. I am not talking about loudness, but the frequency of the chattering. To me that means that whatever the cause of the noise is, it is something 'behind' the gearbox. Input shaft and lay gears are constant speed (relative to engine speed at least). So is the clutch. So I guess it should be something with the gearbox main shaft or the transfer case. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing 2012 90 CSW, 2.2TDCI, Santorini Black |
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3rd Sep 2021 4:41pm |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
.. Roaming around 🇳🇴🇨ðŸ‡
Last edited by Angus_Beef on 4th Sep 2021 12:50am. Edited 1 time in total |
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3rd Sep 2021 5:11pm |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
Pm sent. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black |
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3rd Sep 2021 5:37pm |
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Dinnu Member Since: 24 Dec 2019 Location: Lija Posts: 3425 |
Last night I did the same test. There was no knocking nor chattering on 4th, 5th or 6th. 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black |
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4th Sep 2021 5:13am |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
Hi all, thought I'd give an update here, to make for a complete thread.
After checking and double checking everything and speaking to two transmission rebuilders, in the end all is well. The symptoms displayed by the new clutch with uprated springs was something that I underestimated and best summed up in a thread from only a year ago:
The clutch now has about 3000 miles on it and the springs have loosened up considerably. There is still more vibration than the standard clutch, but its not too bad. The rattle at idle comes and goes. Interestingly, it did not do this initially, but has developed over time. NVH aside, the box shifts beautifully. The pedal is light and there is no dragging of the friction plate making for a very nice shifting experience. thanks again for the guidance on the nuts and bolts! The job really wasn't bad at all and I'm actually rather looking forward to the next one (perhaps SACHS 3000 950 727 in the spring). Roaming around 🇳🇴🇨🇠|
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1st Nov 2021 10:37am |
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Angus_Beef Member Since: 30 Apr 2015 Location: Oslo Posts: 434 |
SACHS 3000.950.727 ordered from autodoc and on the way. I now have 14'000 km on the lof roadspec, so it is thoroughly broken in and familiar. Looking forward to comparing the two back-to-back. Roaming around 🇳🇴🇨ðŸ‡
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7th Feb 2022 4:58pm |
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LUKE-FITZSIMONS Member Since: 22 Mar 2019 Location: Leicestershire Posts: 8 |
Hi guys, sorry I do not get onto here too often due to being so busy!
Regarding MT82 chatter I have found 3 core reasons: 1. Clutch springs on the worn AP original clutch design. 2. Backlash in the MT82 (hate to tell you, you all have a sophisticated Series 3 LR style box! 3. Output shaft chatter on a worn original unit. I have found over the years that maybe 1 in 20 TDCI vehicles tend to rattle after changing the clutch (obviously they were rattling before too from the loose clutch springs) After some work I have concluded that the reason for this is Layshaft/inputshaft rattle between the gear faces. With the MT82 running on roller ball bearings rather than Taper bearings, the 2 gearbox shafts have no pre-load. Meaning when a brand new clutch is fitted, it can move some noise/backlash down to the MT82! (PS if your injector washers are blowing/ PCV valve knackered/ MAP sensory etc etc, it will run rough at idle and make it worse) The SOLUTION: In my POWERspec clutch kit, I have increased the pre-dampener (central clutch springs) from 10 degrees of travel (Ap clutch and roadspec clutch design) and the POWERspec is built with a 20degree pre dampener. Allowing for more oscillation at idle for use of a better term. So far proving very good, only 12 months in but probably over 1000 of them out there! Hope this helps some to understand the concept- as I say the MT82 is age old by design, it does not even have an oil pump!! Thanks for reading, feel free to fire me an email if you need any help! Cheers Luke |
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16th Feb 2022 5:38pm |
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