Help with rear springs please

Dave do not put your self down and just flip flying finger of fate to the ignorant misunderstanding by others who have not faced off what you have now encountered. It may be IMPOSSIBLE to remove a spindle this rusted and fussed with likely also lipped and grooved spindle that has totally trapped it, so nothing for it but torch off the swing arm to save the cradle and take to a big equipment shop that has 30-40 ton press as used to remove bulldozer size stuff.

I have faced this level 3 times now, 1st was pre-Peel, used truck shock mount bolt hardened and necked down to the correct treads pulled on so hard its threads almost gave up, to pretension a tiny bit of pull which i used a 3 lb sledge and drift on the DS to beat both the drift to mushroom and broke at least 3 bones in hand on the severe strikes time and time again - d/t wearing fatigue- over almost a week, to find the off set lips and rust expansion had dragged deep grooves in the hardened spindle surface that a carbide drill will not scratch. I then found that the swing arm was too distorted to pass a new spindle, so sent it off to Vernon of GT Frame fame, who sent it back 'fixed' but still would not pass the spindle - so broke down and bough an 850 upgrade swingarm that solved it.

Next was New Orleans Trixie, after about an hour of same results as above, I knew I was beat, so torched off swingarm, took to dozer shop and watched the pressure gauge climb to 24,000 lb before it moved and lowerest pressure to keep it moving was 18,000 lb. We had to block well the cradle or it would have curled up like chewing gum. Trixie got Peel's hand me down swing arm and Peel got RGM Al one.

Third time was Wes's '71, that had almost 3/8" gap of slack so worn, with one of us pulling the shock mount bolt [2nd one btw as frist was too traumatized to use any more] and one of us SLAMMING sledge with all our might and will power, IT Did Not Bulge ONE ITOA.
So we quite before too much damage to cradle and arm, Wes just put on two collars and forgot about it.

Commando's are a real man's hobby in too many ways to test your ego and image others have of your competence. If no one else has mentioned what I just did then they have not yet enjoyed the full scope of what can go wrong just following the manual and normal common advise that worked so well for them. You may be able to remove everything on cradle and frame to twist out the trapped swing arm and cradle to deal with on bench or dozer shop, but i was not able to on Trixie Combat.

PS, all 3 fussed/lipped swing arms above were able to get to twist in its rust swollen grave, but nothing else. Don't be fooled just because you can turn it. I have a wooden BS grinder in my clinic with a handle on it to allow fast free flying function that is fun to do but does nothing that matters at all but waste time and energy.
http://www.woosk.com/2009/02/bs-grinder.html

There are better penetrating oils to use than WD40. Fuel oil works too. Also try heat. Have patience. Hold off on the killer sledgehammer for a week or so.

It is not uncommon for the inner primary case to have marks from the swingarm so not necessarily the DPO's fault. Sometimes caused by not enough shims under the inner primary case mounting stud.

Just lack of lube and sitting is enough to cause your problem. My swingarm pivot was horrendously scored and corroded by the late 70s. It still rotated on the bushings but wouldn't move sideways. Yes it probably was because I was young then and well, maybe a partial dipshit. It eventually came out. Oh, don't forget to take out the center 1/4-26 bolt!

I've measured the rate of springs by puttting a bathroom scale on the drill press, a big drill in the collett to contain the spring (sorta) and pulled down; the scale on the drill press measures the travel and the scale on the bathroom scale tells me the pressure.

Thanks guys, will try patience and different penetrating oils. I've seen Acetone and ATF mentioned quite a lot here, might mix up a batch and give that a go. Will also try applying some heat. There's got to be an easier way than brute force - always. You're going to give me nightmares Hobot!
That's exactly the method I used XBackSlider, brilliantly simple and obvious once someone suggests it to you. Just don't let the missus know you've borrowed her bathroom scales (or that you've been washing parts in the dishwasher when she's out). I also used the drill press recently to compress valve springs so's I could remove the collets. Great pieces of gear.

Hope yours is as mild as batrider and have removed the top bolt tough as his was. It took most of a week beating and pulling on pre-Peel to get it 2/3rd out to understand what I was up against - then a just a couple more to finish gouging a groove in its famously hard spindle surface. At what point do you give in. In my case I still have whitish scars on back of R hand where I got fatigued>inaccurate and bashed off the skin go bleed -through blacksmiths super heavy leather gloves as it also fractured the bones, but I persisted after cussing and swooning in pain and misery, since everyone else got get theirs out so why can't I...

For a case like this only thing to get in there that might help is candle wax or strong acid. Heat may help bust up rust crust, then may luck out rotating and beating or pulling till ya see some give to let ya know most a lip has cleared bush edge.

I admit in the wee hours I had time to work on it, I found I could lose it to run out of shed screaming in infantile tantrum. Nightmares are part of my C'do hobby. I do believe my crying to other world wide lists focused their mental energy on this and other just as murderous stuck up stuff, to alter reality of quantum states and parts would release w/o near the prior failure level of effort. Weird but watch for it in your own growth into a Commandoneer.

Dave Don't forget to remove the 1/4 inch bolt through the swingarm tube at the top between the two gearbox mounting plates. Once this bolt is out you may be able to get some movement out of the swingarm as the swingarm through pin is generally seized to the bushes. I recomend removing the primary drive and using a soft metal drift and some heat to remove the swingarm pin. If all else fails you will indeed have to remove the assembly and use a hydraulic press - the engine does not have to come out for this operation, although the gearbox obviously does.

Thans Hobot. Acid ya reckon - interesting idea. Yep, the 1/4" bolt is out Dave. There's nothing holding it in bar corrosion. I stripped the internal thread last night using my extractor, gives you some idea of the forces involved. I'm now going to tap it out to M13 and make it a lot deeper and then get some thread stock ("all thread") and have another go. Various ideas are floating through my head including a couple of cheap (hydraulic maybe) car jacks to try and extract. Then if all else fails, gearbox out as you say. Like Hobot, if others can do it, so can I. Just hope it doesn't mean breaking any bones!

There's nothing holding it in bar corrosion.

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I hope above is not same wishful thinking I had for about a week the first time blood letting. The rust can eventually be ground down to power by heat cycles and twisting the spindle and BANGING on it, but little help it spindle has worn edges. I do forward to read/see you escalating attempt devices.

Acids like nitric wiil eat steel but not Al or brass/bronze hardly at all, might eat the rust if that's all that binds it, but pulling out the tough internal spindle threads don't bode well. I can tell ya that spindle is tough enough to mushroom hardened 1/2 dia drift.

Managed to move the axle out over 2cm so far. Long way to go, but it gets easier all the time. Tell you all about it (if and) when I get it out all the way, it's a slow process.

Hehe, ok my respects for what you are gaining on mm by silly hard earned mm. Notice no one else is relating to your muscle and will power. The spindle is trash, so I'd JBW in a hardend grade 8 to 12 bolt and give it a couple days to set up even helped by heat to put a god awful pull force on then I'd heat the snot out of the cradle area and when feeling refreshed and frisky or down and depressed take it out by smacking the living daylights out of the poor mushrooming hardend drift from the other side. I replaced mine with the slightly over size replacement and put in grease zerks to at least keep a grease lay on for rust but can't say how much better or not grease is in the long run as some say it's failed them, ugh.

Worry about getting it out when the time comes hobot

It is done. Thing is Hobot, I'm not some muscle-bound knuckle-dragger, so I have to use what brains I still have! And of course, what engineer doesn't like a serious problem to get their mental teeth into.

Here's the little blighter, you can see how far gone it was. I had to put my weight on the swingarms to move them! (Be careful, the swingarm is apparently not that strong. Apply force equally to both sides to avoid distorting it.)



So... here we go. I'll give metric dimensions, but you can substitute the nearest imperial equivalents.

The method I used was to pull the axle out using spacers, washers and bolts. I'd poured a fair whack of WD40 in the locknut hole during the week, but I'm not sure it was of much use. Some other formulations may be better.

First step was to buy a 14 x 2 starter tap (about $30) and tap the hole in the end of the axle as deep as you can go. Now if you reckon that step is easy, then you haven't used a 14mm tap before! You must NOT use a single-sided tapping tool like a spanner to get enough leverage, you must provide a pure torque to the tap or you will snap it. I used a (x - shaped) wheel brace and a spark-plug socket back-to-back to make a 1/2" drive adapter. The wrench socket coupled to the plug socket with an M14 screw with locked nuts on it. Carefully tap away. Wind back every half turn or so to remove the spur. The wheel brace provides what is known as a "couple" in mech speak - a pair of moments. Sorry if this is obvious to those in the know, but it's important if you don't know! The brace comes in handy later on too.

Next step is to cut some pipe lengths. This is to make spacers that fit on the end of the swingarm and allow the axle to be pulled through. Pipe I used is 42mm OD and 3mm wall thickness. In the end I made 3 different lengths and used them both alone and in combination:



Ready to rock, spacer goes up against the end of the swingarm, washers on the M14 bolt and then through the spacer into the end of the axle. I used a stack of washers, lubricated with grease so that they didn't bind when screwing away. You want that effort to be transmitted to the axle, not lost as friction.



Again I used the wheel brace, but this time I added a piece of stout wood to increase the length and leverage and to go easier on my dainty little engineer's mits. Even so, I twisted the brace with the torque I applied when starting. Put a lot of "back" into it and I'll be sore tomorrow. Good thing it's Dads' day tomorrow, I'll get a cuppa in bed! In the early part I alternated between the two bolts to share any stretch or stress around. Dunno if it was warranted, but I didn't want one to jam in the thread or worse - to snap!



Took a couple of hours, but it sure gets easier as it progresses. I also applied heat to the swingarm boss on the extraction (right hand) side using a hot-air gun. There's no need to heat the other side. Flame might have been better, but I'm not that keen on waving naked flames around engines.



Be patient and allow finesse to triumph over force.

Congrats! Now progress can continue,,,,,

GRM 450 said:

Congrats!

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Thanks Graeme, but what a drama. Oh, forgot to mention, tried my rattle gun on the bolt, thought the "rattle" would help too, but not enough torque. Strange that, but I've never used it before. Big compressor too.

GRM 450 said:

Now progress can continue,,,,,

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That's right, I was taking the engine out to sort the rear iso wasn't I.



Groan...

Engine out:



rear iso bits at the bottom of the pic.
All of this crap came out of each side, washed it in petrol.



It's the remains of the (now disintegrated) PTFE plastic washers. rubber bits don't look too bad. Should be able to replace the broken bits and shim it up properly.

The front is a completely different deal though. No gaiters, there's no end caps at all, no spacers and no shims. Words fail me.



This is going to be a completely different machine once it's back together. Should handle properly and be vibration-free.

Very good show for a weak built big brainy engineering effort on merely moderately fussed spindle with such wimpy little bolts and soft T-bar torquer. On pre-Peel and Trixie those wadded up like chewing gum. Only truck shock bolt whoose narrowest OD was the treaded end into the spindle could take my torque on it and then only by breaker bar on the turning socket. All above was just to get a bit of pull to help with the sledge hammering and drift, which both mushroomed the drift to need grinding down half dozen times and scared up the sledge hammer face. I won that one but ruined the swing arm that didn't look bad or had any other force applied than the drag of the spindle. Both my truamatic swingarm moved pretty easy up/dn, and why wouldn't they are they cut the wear diameters rather below the width of the rest of the spindle. To save New Orleans salt air cradle I just sacrificed the swing arm as it was a lost cause and maybe even harder to extract than 1st one. So this muscle bound small brain mechanic don't hardly sweat the 2nd one via cutting torch and bull dozer shop press. I don't ever intend to do any more thank you and keep an eye on the lube with thoughts of those that will come after me.

Glad to see you're sorting this out Dave, are you going to use mk3 type isos or stick with the shim type? Graeme

Cheers Hobot, I see where you're coming from, but I just didn't have the money to contemplate torching the swingarm. With two other bikes also crying out for money at the moment, my ambitions outweigh my income, so had no choice but to take the path I did. Seems your previous experiences were for swingarms in far worse condition than mine, so perhaps I've been lucky in being able to avoid the heat.

I always read and appreciate your comments, in most areas of Commando repair and modification, you've been there, done that and have valuable advice which you freely pass on. For that - much thanks. In the same way I hope that my experience and my solution may contribute to the gestalt and be of use to someone else in the future.

Graeme, I'd love to switch to the MK3 rear, but I can see no real point in doing so, it all looks in pretty good condition, apart from the damaged plastic washers - perhaps the result of not being shimmed right - so I'll just be buying the missing parts and re-assembling. (I presume it can be set up off the bike???) Looks like there's plenty of use left in it and once set up right should be ok for some years yet. The front... well, easy to set up, so again, just the missing bits.