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General => Douglas Motorcycle Discussion => Topic started by: cjt on 09 Sep 2020 at 03:10

Title: T35 Mk 3 Sports forks
Post by: cjt on 09 Sep 2020 at 03:10
Hi All,
I am presently restoring a 1948 T35 Mk3 sports in India,while working on the forks , noticed that the Fine threads for the bottom cap on one of the  fork tube is damaged ( about 4 threads from the bottom) , I made two end caps by turning aluminium round bars with 26tpi pitch .
Can anyone please advise if it is possible to dismantle the fork leg ?if so , the procedure to dismantle it,so that I can mount that fork leg on a lathe and clear the threads.
Appreciate any help in the matter
Thanks
Clement
Title: Re: T35 Mk 3 Sports forks
Post by: eddie on 09 Sep 2020 at 06:48
Clement,
               It is not possible to dismantle the front fork assembly, but another way of tidying up the thread would be to use a 'thread file' - they are quite a crude tool, but used carefully, they do make a good job of cleaning up damaged threads without making the thread undersize.

  Regards,
                 Eddie.
Title: Re: T35 Mk 3 Sports forks
Post by: cjt on 09 Sep 2020 at 08:39
Thanks a lot for the prompt reply Eddie, much appreciate the effort you put in this forum to help other Douglas owners, I was actually tackling the threads using a half round and triangular needle file, are these the same as a thread file or is a thread file different ?Anyway , it’s going to test my patience
Thanks
Clement
Title: Re: T35 Mk 3 Sports forks
Post by: eddie on 09 Sep 2020 at 09:09
Clement,
                A thread file is basically a piece of 10mm square bar with different thread pitches machined down each end of each side, then grooves are cut across the thread forms to provide cutting edges. By engaging the file with the threads, and pushing it backward and forward, it cleans up any damage to the thread but doesn't cut effectively enough to affect the actual thread.   (See attached photo). They come in 2 types - metric and imperial!

  Regards,
                 Eddie.
Title: Re: T35 Mk 3 Sports forks
Post by: cjt on 09 Sep 2020 at 15:09
Thanks for the photo of the tool, I checked on Amazon and they have a similar tool , I will be getting that
Clement
Title: Re: T35 Mk 3 Sports forks
Post by: Neville Heath on 10 Sep 2020 at 09:24
Hi Clement
Having just made a fork cap your lathe is set up to cut the thread. Why not now make a steel ring about an inch long, cut it into two parts slightly less than half, clamp it onto the good thread higher up on the fork with maybe a jubilee clip and work it down like a die. Just a thought. 
I still have your parts in a box ready to post but delayed due to the virus. Will contact you by EMail
Neville
Title: Re: T35 Mk 3 Sports forks
Post by: cjt on 11 Sep 2020 at 04:41
Hi Neville,
The idea is worth a go, will try it, just don’t know when things with the pandemic will improve, I have made a flanges for the manifolds to fit Mikuni VM20 for now, I also had a small batch of valves , pushrods and cam followers made  here , as I did not see regular international flights starting anytime soon, however soon as international postal service start I will contact you for the items, as I am keen getting the original parts.
Thanks
Clement
Title: Re: T35 Mk 3 Sports forks
Post by: flea on 11 Sep 2020 at 22:31
as far as sending parts from o/seas iv just got a box of parts from england that arrived in normal shipping time , wasnt sent in any fancy way so might be worth checking for the country you want sent from