Roamerdrive (Defender) noise

[Northwards]

Well.... I have some scrap oven trays, and if I choose a day that my wife is working in the office then..... 🤠. She's been talking of wanting a new oven anyway. Maybe I'll persuade her to wait until the RD is reassembled! She might not even notice the strange parcels in the freezer.... 

Baulk rings - grand. The TBox is going down to Ashcrofts anyway, so I'll get them to stick a couple on with it on the way back. 

On tapping the sunshaft assembly out, wasn't there a question about the holes in outer cover being threaded?? I have to say I can't see how that would work, with two threads working against each other. Maybe I mis-understood? 

[Peaklander]

Yes I thought they were threaded but of course they can't be, otherwise tapping it out wouldn't work. Send a baulk ring with the TBox and Ashcrofts will have them. I have been trying to find their LR part numbers but I can't, sorry.

[FridgeFreezer]

Coming from the opposite direction, an aerosol can of freezer spray can work to shrink whatever the bearing's on.

[Northwards]

Further progress this afternoon and I'm at the point now where I can take two or three of the parts down to somewhere in town to get the old bearing removed, and new ones pressed on. I could probably press/tap on two of the ball race ones, but the big one would still be beyond me. 

I'll try not to simply repeat all the pics that Peaklander has already put up, just where they might add something for further reference or comparison.

To keep it vaguely chronological, we were discussing the rear casing and whether it had threads. It doesn't but there seemed to be a ring of excess metal around the outer end of the holes, which the bolts needed to be threaded onto - maybe by design or something in the casting. A few minutes work with a round file soon sorts that out. 

You might be able to make out in the pic above that the holes on the left have been filed out, the ones on the right haven't yet. 

Those bolts were very definitely FT. I had to go and buy a good set of AF hex keys, and still put a piece of tube over it to get enough leverage, but once they 'cracked off' they all came fine. I was planning to buy some longer ones to tap out the sun shaft carrier, but a few quite gentle experimental taps on the bolt heads had the assembly moving. When the short bolts were stopping it going any further I removed them and tried three drifts down the holes, again with quite gentle taps. The whole thing dropped out nicely. 

This is more or less the whole assembly in bits, minus a few circlips and the on/off shifter rod and synchro ring. 

I'm more content than I was yesterday that all I'm going to need to do is replace the bearings on this unit. The planetary gears are a long way from Peaklanders horror show; the sun shaft gear is in very good nick. 

Next was the b****d circlip down the planetary shaft. That wasn't easy. The pliers might get used once more to get the circlip nearly there on the rebuild, but I think that's all they'll be good for. 

I ended up grinding away about the top 1cm of the tips to create thicker, stronger tips as the originals were just bending, but I was still getting nowhere fast. The 'game changer' was to grind and then hacksaw a retaining notch onto the tips. As soon as I did this, the clip came out at the next attempt. 

The sun shaft roller bearing is OK I think, as is the bearing surface on the shaft, but as I know nothing about the provenance of this bearing I'll change it for one of the Shaefler ones Peaklander showed above. 

That's about it. Here are the four bearings that will be changed. 

On my unit, the middle ball bearing, on the end of the sun shaft is 'so so' - OK, but not great. It probably wasn't making a lot of noise yet. The middle sized ball race, on the right hand side, which was the really noisy one on Peaklanders unit is OK on mine. It runs a little notchy, but again I probably wouldn't have been annoyed by this for a while yet. It's the big one on the left that is poor. 

So next steps are to get those two sub-assemblies to somewhere local which will get the bearings off, and hopefully press on the new ones, then I can 'just' do the rebuild. 

[Peaklander]

Excellent work! It looks so easy now 😀. Well done with that 'impossible' circlip. Did you need to grind some thickness off the circlips? I certainly did but maybe they are longer.

The rear bearing (6205) came out really easily then with no heat - that's great. That was the first problem that I encountered.

Bearing costs:

K20x26x20 caged roller (Schaffler) £8.69 (local supplier)

6017 (SKF Explorer) £56.40 (local supplier)

6009 (FAG) £13.39 (local supplier)

6205 a quality brand -  I forget the cost..

Also I bought 18790/18720 (Timken) for the input gear £22.68 - Bearings online

Adding this to my thread is definitely a benefit.

 

I wonder if there's an automatic, synchronous update of the copy in the Technical archive????? Only one way to check...

[FridgeFreezer]

Great write-ups chaps.

My question for those in the know is can the rear bearing oiling mod be done without dismantling or with only minimal dismantling?

Drilling & tapping a fitting into the back of the casing without having to disturb too much is quite appealing - I've done that sort of thing before by going very carefully with a drill bit dipped in grease to catch all the swarf, if I can do the same on the OD I'd do the oiling mod in the blink of an eye.

[Peaklander]

I have edited this post and deleted my answer to @FridgeFreezeras he was referring to a modification to the case that could provide an external connection to an oil circulation pump.

I was showing the use of an upgraded synchro cone that locates in the rear case. Here's a picture showing an old and new one. I remember wondering why they didn't change the part number, even with just a suffix.

 

 

 

 

 

 

 

Edited January 14, 2023 by western
Corrections & edited on behalf of Peaklander

[Snagger]

I keep saying it: replace ALL of the gears with high quality branded items, whether the unit has failed yet or not, as they are of dire quality and the the Achilles heel of the units.  Leaving the cheap Chinese bearings in will jeopardise the other parts and lead to a much more complex and expensive rebuild like mine or Tim’s.

John, I think that would be entirely possible, drilling and tapping the centre of the aft cover (as seen in Tim’s third photo above) for a threaded union.  That will keep the aft bearing well lubricated, which is where my early SX unit initially failed.  It does contradict the advice I keep giving regarding rebuilding with decent bearings, though.  Best to bite the bullet and do the job properly, if for no other reason than the small amount of aluminium swarf that might get into the rear bearing is probably tougher than the bearings are!

[Peaklander]

4 minutes ago, Snagger said:

drilling and tapping the centre of the aft cover for a threaded union

I must have missed that mod! I thought you meant the mod on the rear carrier.

 

4 minutes ago, Snagger said:

replace ALL of the gears

typo - you mean bearings. That is what @Northwardssaid he's doing.

[Northwards]

8 hours ago, Peaklander said:

 Well done with that 'impossible' circlip. Did you need to grind some thickness off the circlips? I certainly did but maybe they are longer.

I wonder if there's an automatic, synchronous update of the copy in the Technical archive????? Only one way to check...

I effectively had to 'dish' the pliers around the pivot pin to get them anywhere near the circlip. I'll maybe take another pic to highlight that. The pliers I knackered were actually quite short - uncomfortably short I felt. It needed a really strong grip to get the circlip moving, and it was just pinging off the ends of the pliers until I cut that notch.

It looks as if this thread isn't in the archive at the moment? Maybe 'de-archived' while being updated?? 

6 hours ago, Peaklander said:

This is the modification @FridgeFreezerand it is right at the back.

 

I noticed these oilways, but hadn't realised until seeing the picture above that this was a modification. When I realised what they were, and that they are supplying oil to that important rear bearing I was surprised how shallow they were. I'd imagine that could easily block up - but then I'm not a mechanical design engineer. (Edit - when I looked at the 1st and 3rd of Peaklanders photos above, my first thought was that the oilways in the casting lined up with the oilways in the sun carrier but they don't. I think that means the modified design now has 6 smaller oilways feeding the rear bearing instead of just three.)

 

6 hours ago, Snagger said:

I keep saying it: replace ALL of the gears with high quality branded items, whether the unit has failed yet or not, as they are of dire quality and the the Achilles heel of the units.  Leaving the cheap Chinese bearings in will jeopardise the other parts and lead to a much more complex and expensive rebuild like mine or Tim’s.

 

100% - as Peaklander has pointed out, I'm already completely onboard with that. There is no way I am leaving any of that in place even if it 'might' be serviceable. My intention in highlighting their condition was more for others who find this and wonder what might be going on inside their units.

It is interesting to consider that Roamerdrive, in their material say that "all the bearings are easily available 'locally'", and that the unit can be serviced by a competent mechanic; but then as Snagger has said "that the unit wasn't designed to be taken apart". I think there's a contradiction in there somewhere. 

So far, having done it once, I'd have much less concern doing it again - though I've no intention of doing so! 

 

[FridgeFreezer]

5 hours ago, Snagger said:

I keep saying it: replace ALL of the gears with high quality branded items

Did you mean bearings?

[Peaklander]

17 minutes ago, FridgeFreezer said:

Did you mean bearings

Keep up lad!

23 minutes ago, Northwards said:

I noticed these oilways,

If your unit has them then that’s good. Global Roamer seem to think they are an improvement.

[Northwards]

On 2/10/2022 at 1:11 PM, Peaklander said:

Global Roamer have modified the design of the synchro cone that is at the planetary end of the sun shaft, in order to improve oil flow into that assembly. That will be replaced too but it is the only item that I haven't yet removed from the carrier. Yesterday the badly worn plant shafts were punched out.

--

This is the synchro cone that is sitting on the planet gear carrier. Its dog teeth are in beautiful condition but I may as well fit the upgraded one. I guess there are some oil slots or holes. I will find out when it arrives.

 

 

I've been going back and forward on this thread for ages, comparing photos, and trying to identify oil flows and channels, and perhaps any tiny, incremental improvements that might be made. I started with the sun shaft carrier and the rear bearing - my unit does have the modified carrier at the back, but looks slightly different again to the one you received Peaklander. (I'll post pics when I get that bearing off the shaft). 

Then I saw this reference to improved oil flow through a redesigned planetary assembly syncro cone. Peaklander - did the new cone and carrier come to you as an assembled unit? Did you get a chance to make any direct comparisons to see what the differences were? Why? Because if this is a modification that came after my unit, and because I'll also be waiting for and then running my rebuilt LT230 without the O/D, I'd have time to order any replacements, perhaps especially if it's something that Ray himself is particularly happy with. 

(Mods - these photos below came into the post because they were cached in the post-editor. I've tried to delete them twice, but can't. Maybe some kind soul could use their forum super-powers to remove them? Ta.)

[Peaklander]

2 hours ago, Northwards said:

Then I saw this reference to improved oil flow through a redesigned planetary assembly syncro cone

Hi, not sure about your reference. Those little oil slots, shown in the pics I posted earlier today, are at the rear carrier which locates in the rear case.

I did rebuild the planetary carrier; I had to rebuild the entire unit! I showed photos of the needle rollers being glued with grease to the three shafts.

Why did my planetary needle bearings fail? That's the $64,000 dollar question and Global Roamer say the answer is overheating. They also say that my 300TDi couldn't be driven hard enough to cause it. However since the rebuild, I have already measured around 100C on the case during a motorway trip and that concerns me.

[Northwards]

Quite possibly my mistake, sorry. I've been trying to be very careful to tell my sun shafts apart from my planets and this one might have slipped through the net. 

The carrier with the modified slots is at the casing end of the sun-shaft. I think it's clear what the modifications are there - those additional oilways.

You'd also said a few pages before that there was an additional modification to the "design of the synchro cone that is at the planetary end of the sun shaft" - i.e. the opposite end to the casing. I was just trying to find out what those modifications were, if any. 

This could all be a misunderstanding on my part. If so, my apologies. 

 

[Peaklander]

Ah ok. I will check when I get a moment and report back. 

[Peaklander]

I have looked through my photos and this thread. It isn't a good morning. The modified synchro cone should be used at the planetary end, not the rear case. The instructions GR Corp. were clear - The replacement synchro cone fits on the epicycle assembly and incorporates a significant improvement in the internal oil passages that increase oil flow to the planet gears by utilizing centrifugal force.  This modification was introduced in 2007 to offset the effects of running the overdrives beyond their design limit with chipped TD5 engines.  You can choose not to make the change as the additional benefit is not needed in a 300 Tdi installation.

Somewhere between February when the parts arrived and October when I was able to do the re-build, I forgot that detail. I built the unit but mixed the two over, using the newly supplied modified cone at the rear position. Here's the proof. I have confused matters further by incorrectly referring to this when I replied to @FridgeFreezer. You have correctly questioned this and now I can see my problem.

I might ask help from the forum administrators and get my incorrect post above deleted.

 

@Northwardscan you check your two synchro cones to see if you have the oilways? I assume the rear one is blank but at the planetary housing I think you might be able to feel the end of the slots from the inside.

I was feeling confused this morning but writing this post has cleared my mind a little, although I now need to think about removing the unit and going a swift disassembly.

[Northwards]

Hi Peaklander - my sincere apologies if I've caused you this concern and irritation. For what it's worth, based on your picture above, I'm quite confident that your unit is correctly assembled. I think there have been TWO modifications that are confusing matters. 

I'll take the time to explain properly, but it might take me an hour or two to get there, so I'll just put this up here now. I don't think there's any need to remove your unit whatsoever.

[Peaklander]

On the contrary @Northwards I am happy that you have caused me to look again. There’s no irritation, just a little frustration on my part that I think I’ve made a mistake. I have already calmly prepared myself to remove and check!

I am refitting my dash at the moment so I’m doing electrical checks. There’s no rush but I will wait for your thoughts. Thank you.  

[Northwards]

Last night, after I’d asked Peaklander about this planetary carrier/syncro cone modification I also emailed Ray Wood at Gloabal Roamer. This was on the basis that on their website they say they have a process of continuous and incremental improvement. I thought I’d ask if anything else had been introduced that I might usefully fit to my unit while it was off the car and in bits.

He said that this planetary carrier oilway modification is the only major thing they’ve done in the last 5 years.

In his words: “The change is subtle and involves replacing the rotating synchromesh cone with a new one.  Externally the cone looks identical but inside the bore is a radial groove and three connecting holes that distribute the oil directly to the planet gear rollers through a flower shaped thrust washer. The oil in the grove is forced out radially by centrifugal force and enters the planet rollers in spurts as the washer rotates.” (Dodgy arrow and line are my addition)

Ray goes on to say: “Two earlier versions of the part are shown in pictures on your discussion group. The one with no lubrication provision is based on General Motors practice and uses a Bat shaped thrust washer.  The later plate with grooves is intermediate influenced by German practice. The latest one with holes is my own design carries the development to a logical conclusion . The introduction of this improvement was accompanied by drilling an oil way through the front cover to accept oil from the PTO port.”

Hopefully this explains the modification that was made to the planetary carrier/syncro cone.

Then on Peaklander’s pic in the last but one reply you can see the picture of his unit while he was rebuilding it. It’s quite clear that this is the modified version - with the radial groove. I’ve (clumsily!) marked it up to show the oil flow.

Oil enters the radial groove (green arrow); as the ‘bat wing’ and circular washer rotate (red arrows), oil gets spurted through the hole in the carrier up into the roller pin bearings inside the planetary gears (blue arrow).

So (assuming that you continued to build up the planetary gears and bearing on that carrier?) Peaklander absolutely has the modified planetary carrier properly installed. Yay!

Then there’s the ‘other’ modification which caused the confusion. This is to the almost identical carrier at the rear of the unit, which carries the sun shaft. Peaklanders pic – but quite clearly shows that additional oilways had been added. (Note - no radial groove inside the bore of these items).

Now as I was working this out I found myself wondering why, from a manufacturing and supply chain point of view, you would have what were originally two identical and interchangeable parts now being made and installed differently. It would make no sense.

So I checked my unit. This is the carrier at the end of the unit, which carries the sun shaft/gear. You can quite clearly see the holes showing it’s the modified plate, even if you can’t see the radial groove as the thing hasn’t been disassembled yet I'm sure it's in there. As I say, it would make no sense not to be. 

I've literally just realised that, although the carriers are the same, with the same modification, this one immediately above (the sun carrier) is completely static in use. It is bolted to the rear casing and does not rotate. So, centrifugal force will not feed/push oil through the holes in the same way as it will when used as the planetary carrier. In that instance it is moving and rotating. 

Be that as it may, the sun shaft will be rotating inside that hole and I'd assume there must be some additional feed of oil through to the bearing. 

So I wonder if this is some sort of answer to the question of oil supply to the rear bearing (where tapping, additional pump and coolers are used/discussed). In my unit, bought in June ’21, oil will reach that bearing via the original oilways in the rear of the casing, and now, through this syncro hub modification. I wonder if that’s sufficient to stave off problems with that bearing in these later units?

[FridgeFreezer]

That's some top work @Northwards, and thanks to Roy for taking the time to clarify things a little - it would be fantastic if Roy could provide serial numbers for when these various changes came in so we don't have to guess / dismantle units / wait for a failure.

[Snagger]

On 1/12/2023 at 3:08 PM, Peaklander said:

I must have missed that mod! I thought you meant the mod on the rear carrier.

 

typo - you mean bearings. That is what @Northwardssaid he's doing.

Yes, bearings, not gears.  Sorry. 
 

I haven’t modified mine, other than replacing the front casing with the later type with big oil slots and then changing back again.  I just floated the idea of an oil pump taking transfer box oil through a coil of cunifer pipe for cooling to the rear bearing area to ensure that bearing was well doused and cooled.

[Snagger]

20 hours ago, FridgeFreezer said:

Did you mean bearings?

Yep.

[Snagger]

21 hours ago, Northwards said:

 

It is interesting to consider that Roamerdrive, in their material say that "all the bearings are easily available 'locally'", and that the unit can be serviced by a competent mechanic; but then as Snagger has said "that the unit wasn't designed to be taken apart". I think there's a contradiction in there somewhere. 

So far, having done it once, I'd have much less concern doing it again - though I've no intention of doing so! 

 

I don’t know about the later versions, but Ray said to me directly when I contacted him for advice on how to strip my early Series model that they hadn’t been designed with strip down in mind and he hadn’t heard at that time of anyone else doing it.  This was summer of 2009.  I see some significant differences between the model you and Tim have and mine, but still many close similarities.

I can’t see any benefit in the sun shaft support/rear cone having the oil feeds to the stud that locate in the casing.  I presume it is nothing more than a simplification of the manufacturing  line that the planet carrier and rear cone are dimensionally the same, just with different length rods fitted either as dowels for the rear cone or planet gear shafts for the carrier, that they have the part machined identically to avoid possibility of fitting a carrier without oilways and so the part manufacturer has only one design to work on.  As for the two styles of modified carrier, with radial grooves and later the trench and drillings, I wouldn’t expect there to be much difference in performance, but they may have tested them and found a reason for the second iteration.  Tim’s recorded temperatures behind an unmodified Tdi suggest they underestimated running temperatures, though.  A fully synthetic oil may help with that, but the added cooled oil feed to the rear bearing would definitely help.

[Peaklander]

After reading @Northwardscomments and investigations and re-reading my posts and emails from Ray, I felt that I should take a look at my unit again. So I removed it but not before I cursed myself for putting just a bit too much Dirko on the mating face with the Transferbox. The mag plug had collected a little debris and the drained oil has lost a lot of its gold colour but I was running-in a refurbished LT230 with new ATB, so guess that this is OK.

 

With confidence gained from the original disassembly, I slightly warmed the rear casing and then tapped out the sunshaft, just using the original screws which have enough length to get it moving forwards and out.

 

Now one thing that has been on my mind and I haven't mentioned until now, is that when this new 6205 bearing was fitted in April, it was a sealed version. I didn't think about it at the time but when I came to reassemble in October I noticed it and pulled the seal of the accessible rear face. As the nut was tight and my press is useless, I decided to run with it sealed on the other side, which is up against the synchro cone and not go back to Mister Gearbox to rectify.

As far as I know, this is the only assembly problem that might have contributed to the higher than expected temperatures. The work by @Northwardsin identifying the three variants of the synchro cone and discussions with Ray at Global Roamer this week have confirmed that the first development was the radial oil slots and the most recent one has the oil holes. So I had built-up my planetary unit with the correct one.

Other possible assembly mistakes were the dog washers. I fitted the new ones, as the old ones had been fitted, with the grooves facing up into the planetary gears. I asked Ray this week if this was correct. He initially said no but a day later came back to say that he'd made a mistake and that they are correct.

 

 

Ray Wood did say that there have been other reports of "cases where (on older units like this) a unit has run hotter than normal and the cause has been that the tension on the main bearing has been too tight due to the crush washer bottoming out.  This might also have something to do with the manufacturers clearances on  the bearing you are using. It would do no harm to try running with a thicker mounting gasket (or two gaskets) and see if this has a positive effect on the temperature".

I have measured my crush washer and it has a good shape / depth when compared with two older ones so I doubt this is a significant issue.

I nipped into Mister Gearbox for a 4th time (https://mistergearbox.co.uk) and the bearing was pulled by pressing the sunshaft out of the synchro cone. The rear seal was removed and then both pressed back. It took 5 mins. Interestingly I had tried to remove the nut myself with a 32mm socket on a breaker bar and the sunshaft held on the flats with an open-ender in the vice and I couldn't budge it. The big Milwaukee took it off easily.

 

Inside, my unit looks perfect, as it should, after less than 1,000 miles and so I am re-assembling and refitting with new oil. Ray confirmed that it is perfectly capable of use as a gear splitter between 4th and 5th with no reason to fear overheating. Honestly, if I can't drop into 4th with the Roamerdrive engaged then it would take away half of its usefulness.

I did think about the idea of an oil feed at the rear of the case and whilst I don't have the ability to just do this on a whim, I have taken some measurements. The gap between the rear bearing's rear face and the inner face of the case is about 15mm and bearing face to the end of the shaft is 12mm. So there is plenty of space in there for oil but also it would be no problem to drill into the back with the unit in-situ, as proposed by @FridgeFreezer, to fit some sort of union.

 

 

 

I warmed the case in the Aga bottom oven (100C) for 10 mins and it was at 30C when I took it outside and mated with the sunshaft which was at about 2C. The two slipped together with a few encouraging taps and a pull with three of the six rear screws.

I now just need to re-fit the hub slippers but I had a lot of practise the first time and then the OD will be ready to re-fit. The frustrating part of that is that the handbrake cable gets in the way and I have previously had to disconnect it at the top. This time I have tried to tie-wrap it down and away because the OD won't locate if it is out of line at all.

That will happen tomorrow, as today we have a three-way family birthday party and I am one of them - 7 / 35 / 64 No prizes for guessing which one is me.