Fixing seized Forks

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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BultacoBen
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Re: Fixing seized Forks

Post by BultacoBen »

After chatting with a few members at the local section meet last night including the very resourceful John Allen I'm pretty confident with proceeding now. Only current hitch is the forks are jammed in the yoke... Currently soaking in penetrant to be attacked again tomorrow.

Removing wheel and mudguards proved that as anticipated it's just one fork that is seized, the other seems reasonably healthy, but I'll be replacing the oil seal and plastic bush anyway as there's an awful lot of corrosion down there :roll:

Does seem to be some detectable motion in the steering head, but I can't figure out the manual instructions on adjustment!

EDIT: Looking back at my own photos I see that the high domed nut from the upper diagram is being used as the lock nut as in the lower diagram. The adjusting nut beneath it I mistook for the washer that is usual beneath the high domed nut... If that all makes sense?? So I can adjust using the high domed nut which is the lock nut, and the adjustment nut beneath it. Realised this after looking in the Owner's manual rather than the workshop manual, it's rather more clear and which forks went with which G2, and the scans in the digital quality are certainly more legible.

(I've got the high domed nut at the top of the stem as in the diagrams 1959 and 1960-62 type forks below but can't spot the head stem adjusting nut (34) and lock nut (35) I should be using to adjust. Are they meant to be accessible without any disassembly? Diagram isn't overly clear and I'm not familiar with head stems...)
teledraulic1 copy.jpg
(Or have am I working from the wrong diagram and in fact have the setup below? You can see from my photo of the domed nut in my first post that it looks different to the one below...)
teledraulic2 copy.jpg
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1966 Matchless G2 CSR scrambler
1986 Suzuki DR600 long-range explorer
1971 BSA B50T street tracker
56G80S
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Re: Fixing seized Forks

Post by 56G80S »

Have to say that I have resorted to a broad blade screwdriver (or on one occasion a wide back scrap kitchen knife (or it is scrap now) and gently tapped it into the "split" in the yoke - assuming it's the bottom one. This will spread it a bit but don't bash it too hard, it's sometimes good to do a bit, leave it for a 5 - 10 minutes to take effect and come back.

Otherwise, if desperate I have used the home made puller (old top nut with lip removed and some threaded rod) used for re-assembling, screwed it fully into the threads at the top and tapped the end; but it needs to be fully screwed in or the threads will get damaged and still will if you are too energetic.

Johnny B
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Rob Harknett
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Re: Fixing seized Forks

Post by Rob Harknett »

The thin nut is the steering head bearing adjuster nut, dome nut locks it. Did your stiff forks loosen when you undid the mudguard bolts, If so use washers to lessen the strain on the forks ( all as stated in the manual )
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Duncan
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Re: Fixing seized Forks

Post by Duncan »

Ben

Your forks are the second drawing, although you appear to have an alloy top yoke with possibly a four bolt handle bar clamp opposed to the three bolt one in the drawing.
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BultacoBen
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Re: Fixing seized Forks

Post by BultacoBen »

56G80S wrote:Have to say that I have resorted to a broad blade screwdriver ...
Otherwise, if desperate I have used the home made puller...
Johnny B
Hoping to borrow a puller from another member today so will try both.
Rob Harknett wrote:The thin nut is the steering head bearing adjuster nut, dome nut locks it. Did your stiff forks loosen when you undid the mudguard bolts, If so use washers to lessen the strain on the forks ( all as stated in the manual )
Thanks Rob, yep, found that in the manual and tried before I resorted to rebuilding them but one of them is seized absolutely solid.
Duncan wrote: Your forks are the second drawing, although you appear to have an alloy top yoke with possibly a four bolt handle bar clamp opposed to the three bolt one in the drawing.
Well that explains my initial confusion then!

Thanks all for your help so far
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1966 Matchless G2 CSR scrambler
1986 Suzuki DR600 long-range explorer
1971 BSA B50T street tracker
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Rob Harknett
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Re: Fixing seized Forks

Post by Rob Harknett »

I have some very large ring spanners, use one on the nut, a larger one linked onto it. That gives at least 30" of leverage.
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BultacoBen
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Re: Fixing seized Forks

Post by BultacoBen »

Have attacked the forks with your recommended methods (spreading the lower yoke with a screwdriver forced on) to no avail. A friend also leant me a turned down top nut that he uses to pull stanchions up into the top yoke, but can also be used to bash them down, however it doesn't fit. Presume it must be for 1 1/4 forks instead.

wI decided to remove the top yoke to get the forks off the bike, as advised by Ken De-Groome in such a situation. http://www.jampot.com/forum/viewtopic.php?f=8&t=7260
Rob Harknett wrote:I have some very large ring spanners, use one on the nut, a larger one linked onto it. That gives at least 30" of leverage.
Thanks Rob, that got the nuts off nicely.

Commenced bashing upards on the top yoke to no avail and so resorted to using a sash clamp in reverse between the yokes to spread them apart. This revealed that the yoke was coming off nicely on one side, but the other stanchion was jammed firmly into it. This stanchion was sliding in the bottom yoke instead. Doing up the pinch bolt to transfer the force to removing the stanchion from the top yoke promptly broke my sash clamp... Serves me right for using a tool in a way it's absolutely not designed for?

Will applying some heat to the alloy top yoke help me in freeing the stanchion from its grasp?
http://www.ben-eddings.com
1966 Matchless G2 CSR scrambler
1986 Suzuki DR600 long-range explorer
1971 BSA B50T street tracker
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Rob Harknett
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Re: Fixing seized Forks

Post by Rob Harknett »

Give it a good soak with diesel or the likes and just leave it for a day or two. When you next try, what usually happens you give it a bash, and the part comes off straight away onto your big toe.
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BultacoBen
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Re: Fixing seized Forks

Post by BultacoBen »

Soaking came to no avail so approached it with a large blowtorch on the yoke and it popped off with a few good smacks from below.

Meeting another member with better workshop facilities in the coming week to tackle the rebuild now.

:beer:
http://www.ben-eddings.com
1966 Matchless G2 CSR scrambler
1986 Suzuki DR600 long-range explorer
1971 BSA B50T street tracker
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BultacoBen
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Re: Fixing seized Forks

Post by BultacoBen »

Rebuild came off well, front end is now happily sprung! Many thanks to Tony of the Bristol section for his help.

One oddity was that the 'plastic' bushes that came out were in fact steel! And very well attached to the stanchion... Now replaced with plastic bushes from spares.

Stanchion could have been in better nick but considering how much they are to replace we cleaned it up pretty well and will just wait and see quite how much oil they leak past the seal...
http://www.ben-eddings.com
1966 Matchless G2 CSR scrambler
1986 Suzuki DR600 long-range explorer
1971 BSA B50T street tracker
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