Lambretta LD Mag Flange Removal

This news post is under development. Review the Oct21 for the latest update.

This new post assume that you have removed the Flywheel

For indexing purposes, this post applies to Lambretta LD 1950, 1951, 1952, 1953, 1954, 1955, 1956, 1957, 1958 Clutch Removal using a special clutch removal tool.

The You Tube video link below shows me removing a 1958 LD Lambretta Mag Flange.

VIDEO TO FOLLOW – WORKING PROGRESS

Information and Notes

Notes on this removal and issues:

125 LD Mk3 1958 removal of a Mag Flange. The engine is out and striped as much as I can at the moment. I have heard that Mk3’s are difficult to get off. During a two week period in June 2018, so far I have:

(Flywheel) Removed magneto cover and spring,
(Flywheel) Removed the 19mm nut and washer,
(Flywheel) Used the tool to remove / pop the flywheel off
(Flywheel) Remove stator (x3 screws) and placed into the flywheel to aid me in not loosing magnetism on the flywheel unit.
Remove mag flange bolts (x6 small bolts)
Bent the locking washer down and removed the large nut, washer and circlip, so that I can now see the oil seal
Using a Stanley blade, cut into the mag flange gasket as much as I could around the edge of the outside of the casing
Placed my mag flange removal tool over the crankshaft end (GP / SX / LI fitted good and I just needed difference bolts!) and using three bolts, slightly bigger than the original ones used on the stator, screwed the tool on over the crankshaft and into the stator holes as far as they would go, to prevent thread damage on the stator holes when applying pressure to pop off.
Attempted to tighten to no avail. I have also used heat for 20 minutes around the mag housing area and tapping the side with a mallet to no avail. I have also used a long pipe for additional leverage on the tool to tighten it up and pop it off and ended up bending the very big bolt slightly with the force I used.

My thoughts now are perseverance and time. Over several days, leaving the tool on with pressure applied and on and off over the next week or two, continue heating up the mag flange area and using a mallet, taping at the mag flange around the side.

I have posted this onto the LCGB Forum for some views from other people that may have had a similar problem:

http://www.ilambretta.co.uk/forum/viewtopic.php?f=12&t=10357

Jun18 – I received a reply via the forum and am now taking this approach:

Steve J wrote:It’s not just the Mk3 mag flanges which are a pig to remove, the earlier ones are much the same! The problem is that the grey (asbestos-based?) mag flange gasket seems to stick to the crankcase and the mag flange, and with a bit of corrosion, the whole lot seems to seize solid. I’ve had some success in the past by getting the mag flange to rotate back and forth very slightly, just enough to persuade the gasket to part company with the alloy. I’ve done this my tapping the mag flange with a medium size hammer, using a drift (brass or alloy bar) between hammer and flange. The place to tap is the raised section on the mag flange casting, where the wires from the stator plate exit the flange. Unlike the Li mag flange, using long screws in place of the stator plate retaining screws as extractors doesn’t work too well, as the ends of the screws won’t have a solid piece of crankcase to press against. If you can get the mag flange to rotate slightly, it’s possible to move it to a position where there is solid metal for the stator plate retaining screws to press against. You will probably mark the gasket seating area on the crankcase, but it’s easy enough to clean up afterwards. If you can get the flange to move at all, it might help to use penetrating oil or similar to assist in getting the gasket to release its grip. Don’t use excessive force – I’ve seen lots of badly damaged mag flanges with the outer rim broken, through trying to directly tap the flange out of the crankcase. Heat may also help, as would the correct extractor, once you’ve persuaded the gasket to let go!

Lambretta Journey – Hi Steve J – Thanks for the detailed reply. It’s good to read about your experiences with LD mag flanges and suggested solutions. There good ideas to try next. I will remove the tool and persevere with heat and take my time over the next few weeks with trying to rotate it left or right a little, with some “tapping” on the case. Currently, with heat and the tool loaded on, I am trying to tap it off, rather than tap it to the left or right to loosen it. I will also see if I can get a Stanley blade around the areas of the gasket I can’t get to with ease, to try to separate the gasket further.

Update Jul18

I have left the entire mag flange and part of the engine in soak in diesel for at least three weeks now, taking it out every so often for a review and attempted removal. I have a few LD’s and am therefore working on two others while I sort this beast out and leave it in soak, coming back to it in between jobs.

For attempted removal, I have removed my mag flange tool you see in the images (to follow) and placed some long bolts into the x3 stator plate holes, not too tight, but tight enough to aid in applying some pressure, while I use heat on the top and side of the mag flange.

I have used heat (Blow torch – two and a half canisters) for at least 2 hours on and off over the last few weeks and continued to use Stanley blades to cut into the gasket as much as I can. When the engine is very hot, holding it with a cloth, I have also used a rubber mallet and tapped the mag flange to try to get it to move a little. In all honesty, I am probably using more force than I should with the rubber mallet.

As well as using heat around the side of the mag flange and on the top, when applying heat on top and through the bolt holes, I can now see a flame come out the side of the mag flange. The other way, if applying heat from the side, I can now see a flame coming out of most of the mag flange bolt holes. The Stanley blades helped with this. I think I have managed to get around 35% of the gasket released looking at the amount of flame that seems to be coming out of the side.

I am also using plenty of a rust penetrating fluid on it and down the holes to aid, which of course gets set on fire when reapplying the heat.

I have heard a few positive whispers of a crack with the heat, implying the flange expanding with the heat thus aiding with the releasing it from the casing.

After waiting a long time for it to cool down, I put it back into the diesel to continue to soak.

With all the heat I am applying and tapping of the mag flange, I am realistic and do understand that I may end up causing some damage to something and am happy to take this risk based on how stubborn it is to get off. I’m also as careful as I can be under the circumstances.

I think that once I have 100% flame coming out of the sides, it will indicate that the gasket is release as much as it can be and I may be able to use the mag flange tool to aid in it’s removal (Or continue with trying to tap it off with a mallet!).

I’m hoping a few more weeks should do the trick and will report back, hopefully with some positive news and not about damage caused!

Update May20

I have exhausted every option to remove the Mag Flange. I am at the stage where I have little hope of getting it off, without breaking it, which is fine by me.

I have broken several tools, including a proper Mag Flange removal tool (at £50) and applied much pressure and hitting it with rubber and wooden mallets and heating it up with blow torches and gas, to no avail. I have spent hours on it to no avail.

Leaving the engine in Diesel for over a year had no impact at all, apart from leaving a thick sticky substance all over the engine.

My next step, when I have time is to put the engine in a spare oven I have for a while and then take it out and trying to hit it off. Yes, I may break it, but I also have spares fortunately. My next update may be 2020 or 2021, depending on the other rebuilds I am carrying out at present. It’s now become a very low priority.

Update Oct21

The information below was kindly supplied by Richard (a fellow Lambretta owner)

Having read with interest your trouble removing the Magneto flange, I would like to share my experience with my 1953 D150.I have a 1953 Lambretta D150 (with the same engine as a LD150) which had starting issues. Having checked all the normal problem areas it was suggested the crank case seals may have perished thus allowing air into the crank case and preventing crankcase compression to occur. Removing the crank case is not for the faint hearted!

Having searched on-line as much as possible the general opinion is to leave well alone however needs must.

The most difficult part according to on-line blogs is removing the magneto flange, however before getting to the flange the nut holding the splined hub (mine was LH thread so beware) on the front as well as the nut on the crank shaft on the magneto side need to be removed. These are almost as hard to remove as the magneto flange.

Both have locking washers so these need to be bent back carefully to prevent them stopping the nut from turning.

Once these nuts have been removed carefully remove the circlips and oil seal.

To remove the magneto cover I manufactured a domed tool with 3 arms screwed into the small holes in the casing with a nut welded to the centre. The bolt threaded through the centre locates onto the crankshaft end. Apart from carefully applying increased pressure to the extractor you have to constantly reheat the centre of the flange (not the outside) and hammer carefully on the flange itself using a wooden block. To remove the flange it took me a couple of days heating, hammering and increasing the pressure slowly so as not to strip the thread on the small bolts..

I did not find the gasket between the housing and the flange (crankcase) stopping the two parts separating however it is the bearing mounted on the crankshaft which is very tight and prevents separation.

I also made a tool to hold the splined hub to allow sufficient leverage to undo the nut – on my engine this was a LH thread.

Beware, there were definitely two bolts which were LH thread on my engine.

END

Oct21 – My update. This / my Lambretta still has the Mag Flange attached. Some Mag Flanges continue to come off with ease, while others are impossible. It remains “luck of the draw”, if you have a particular stubborn one. If your reading this post, you have an issue in this area and if you succeed and use a different approach, I would be delighted to hear and will update this News Post with your solution. To date, I have broken two mag flange housing units trying to get them off. Six have come off with (hard effort but) ease.