Author Topic: Dougles 350 1925 Gear (Read 3211 times)

anfänger · « **on:** 24 Feb 2022 at 18:31 »

I whant change all bearing from gearbox, but i can not dismantel the chainweehl side!

Hutch · « **Reply #1 on:** 24 Feb 2022 at 23:30 »

Hi anfänger,

The nut "A" that is part of the kickstart ratchet is Left Hand Thread i.e. undo clockwise direction. It is usually very tight due to the tightening action of the kickstart lever on the gear via the ratchet

My (rough) method is to place locking ring "B" in the end of a vice using "soft" jaws for protection and using a socket or ring spanner on nut "A" and attempting to undo it clockwise (after flattening the tab washer locking B in place). Application of a bit of heat and/or penetrating oil usually necessary. Sometimes nut "A" comes off and other times the whole kickstart ratchet unscrews as part "C" also has a left hand thread onto the gearbox input gear. Don't be too heavy handed as the thread on nut "A" is short and you do not want to damage it as the repair will be difficult but it still may take a bit of effort.

If ring "B" comes undone instead that is ok as it will come off over the kickstart gear and then you can hold onto part "D" in a vice with soft jaws, make a tool or hold the cush drive/shock absorber plate in a vice etc.

(Edit - I may also have held the cush drive in the vice with soft jaws and then just undone A - but see edit comment below)

If you get the nut "A" off "C" then you will need a thin deep socket to undo "C" from the input gear. It is left hand thread as mentioned before.

They are usually very tight and have been together for a long time so patience is required rather than brute strength.

A less crude method of holding locking ring "B" in a vice would be to make a proper tool to hold it securely - I might get around to that one day :-) !. I'm sure some forum members will cringe when they read my method so I do recommend making proper tools to do the job!

Best of luck with it but it should come apart without damage with a little persistence and patience.

(Edit:- Thinking about this a little more it may be preferential to take off locking ring B first, remove cush drive and chainwheel from D, then undo C from input gear (using nut A and holding D) and finally take A off C but in my experience (three CW gearboxes) it doesn't always unscrew in this order easily. Some other forum members may have some other tricks tho' :-)

I guess the slots in C are usually damaged as people hold the cush drive in a vice and use a cold chisel to undo / do up B! - I'm not quite that rough! C should move freely on D and locked in place by the tab washer on re-assembly after adjusting cush drive tension)

-Hutch

anfänger · « **Reply #2 on:** 02 Mar 2022 at 15:18 »

Hi Hutch,Thank you for your great description. That's how I got it done
jetzt sind die 4Lager das nächste problem.
I think all 4 bearings are built in inch size,is there a list of required bearings??

Hutch · « **Reply #3 on:** 03 Mar 2022 at 22:58 »

Hi anfänger,

I have not seen a list of the bearings for the CW gearbox, but when I rebuilt one of the gearboxes I have, I measured the old ones and came up with these equivalents;

6201 (I purchased SKF Brand)
1203TV (FAG )
98204 (MRC)
KLNJ 7/8 (SNR)

You may want to measure your old ones and compare them to these - hopefully they should match!.

The only one i had difficulty getting at the time was the 98204 and could only source two of them easily. You may not be able to get the 98204 in MRC (made in USA) brand but a quick search on Google shows that SKF may be supplying them. Looks like they may be a bearing used on Vespa Scooters so putting that into the search engine may help locate them. I would recommend buying quality bearings (i.e. FAG/SKF etc) from a reputable supplier as there are plenty of counterfeit bearings around (i.e. sold on ebay) ,unbranded and of very low quality.

As you may be aware things have been rather damp in our part of the world but if I get a chance I will double check these on the weekend ( as it was a while ago that I bought these bearings).

I'm not sure if you have had any problems getting the bearings out of the gearbox case halves (I did), but heating the cases gently and then tapping the outside of the case (not heavily, with a piece of wood or soft faced hammer) with the bearing side down, usually caused the bearings simply to fall out of the casings. If you heat for too long the heat will transfer to the bearing and it will expand and partially defeat the expansion of the case (the aluminium / bronze reinforcement ring of the case should still expand more than the steel bearing tho'). I start by heating and tapping gently at the same time and when the case expands enough, but the bearing has not had a chance to, it usually just falls out. If this doesn't work I heat the casing but tap the whole case half down onto a piece of wood (i.e. gasket face flat onto the flat surface of the wood).

Cheers

Hutch

Alan · « **Reply #4 on:** 04 Mar 2022 at 04:56 »

Re bearings, one time saving way is to simply send the details of each bearing,...o/d, I/d, width, type of bearing etc to a vintage bearing company and let them search their manuals and shelves for NOS and/or modern equivalents. I did this for my CW box rebuild and also gives you a chance to buy modern sealed equivalents if available ( seal removed on inner side) to minimise lubricant leakage...

Hutch · « **Reply #5 on:** 04 Mar 2022 at 05:29 »

Great suggestion Alan, I have also used this method but sometimes the price of NOS bearings from the vintage bearing companies has made my eyes water! :-)

cheers

Hutch

cardan · « **Reply #6 on:** 04 Mar 2022 at 09:30 »

Quote from: Alan on 04 Mar 2022 at 04:56

... gives you a chance to buy modern sealed equivalents if available ( seal removed on inner side) to minimise lubricant leakage...

Hi Alan,

I used to do this until a knowledgeable friend told me to leave both seals in place when using sealed bearings in a gearbox - the inner ones keep the scraps of metal from the gears out of the bearing, which is lubricated for life. In engines, with fewer "floaties", I pull the inner seals out.

Cheers

Leon

Doug · « **Reply #7 on:** 05 Mar 2022 at 23:09 »

Quote from: cardan

...leave both seals in place...

Agreed. Especially at the lower rotational speeds of the gearbox. Ditto wheel hubs, if you are able to replace the original cone and ball or taper roller bearing type with a sealed ball bearing. Refit the grease fitting for cosmetics only and leave the factory seals in place. Pulling them out so you can manually grease them is more likely to allow contaminants and moisture in than prolong the life of the ball bearing.

-Doug

anfänger · « **Reply #8 on:** 06 Mar 2022 at 17:47 »

Hello,

I would like to install the bearing (7/8x1-7/8x3/8) in version RS or 2RS - unfortunately it is not available for purchase anywhere!

Hutch · « **Reply #9 on:** 06 Mar 2022 at 22:42 »

Hi anfänger,

Thinking back to the time I bought the bearings for the CW gearbox I remember this was possibly the reason I just ended up buying open versions of the 4 bearings :-) . I think I had the same thoughts as Alan, Leon and Doug at the time, but like you, I was also thwarted by the lack of a sealed version for the 7/8 x 1 7/8 x 3/8 deep groove ball race so didn't bother with RS or 2RS versions of the others. I guess tho' having any sealed bearing in the case would help longevity, but as the non-sealed ones will probably outlast me, I guess that is a moot point in my case! :-)

I will do some searching and see if I can find a sealed version of this bearing size........

cheers

Ian

Doug · « **Reply #10 on:** 06 Mar 2022 at 22:47 »

Come to think upon it, those diameters in such a narrow width are going to be practically impossible to incorporate seals. So like wining the lottery, would be nice but unlikely to happen!

-Doug

Hutch · « **Reply #11 on:** 07 Mar 2022 at 07:12 »

Yes I suspect you are correct Doug, :-( ,no seals avail. on the narrow bearings. That is what I found originally but thought it was worth another quick look.

Seems the KLNJ.7/8 is a Ransome and Marle designator that was carried over to RHP (when they amalgamated with Hoffman and Pollard). The open version is 3/8" wide while the (later, I presume) sealed varieties appear to be 1/2" wide but still use the same designator - causing some confusion!

I have not found an old R & M catalogue yet to look up what the original specifications were. Have found some other equivalents; Hoffman S9, Pollard SC9, Skefko EE8J and Fischer EE8.

Cheers

Hutch

anfänger · « **Reply #12 on:** 07 Mar 2022 at 09:35 »

Hello,
many thanks, i will tray to get ZZ Bearing, they shoudl be better than open version !

BR, Ernst

Hutch · « **Reply #13 on:** 08 Mar 2022 at 03:03 »

Hi Ernst,

Unfortunately I think you may run into the same problem with the Z and ZZ metal shielded versions as the RS and 2 RS versions in that they are 1/2" wide not 3/8"?

Pity that Walter Moore, who designed the gearbox in 1913, before he worked for Douglas, (patent GB191310523) and Douglas in later iterations, didn't put in wider bearings to make our life easier! :-).

cheers

Ian

anfänger · « **Reply #14 on:** 08 Mar 2022 at 07:56 »

Hi Hutch,Hi Hutch,
yesterday i found Bearing R14 ZZ 22,22x47,62x9,52mm at "kugellage king" !In my opinion it should be OK.,and my old one
it was in 1Z builded.
(http://www.kugellagerking.eu/)

Further i will try to lubricat this Gear with Fath not Oil!!

Greatings from Austria
Ernst

Hutch · « **Reply #15 on:** 08 Mar 2022 at 09:00 »

Well found Ernst! I had a quick look but all the ones I found were 1/2" wide.

cheers

Hutch

anfänger · « **Reply #16 on:** 11 Mar 2022 at 19:21 »

Hi,
this Bearing is not availabel futher - its a wrong list! Sorry!
My main question is, how should the gearbox be sealed? There are no Seals - open Bearing and other Parts where Oil
is wearing out permanent. Is there a solution for this.

Nice Weeekend,
Ernst

Hutch · « **Reply #17 on:** 11 Mar 2022 at 23:11 »

Ernst,

Pity the bearing is not avail.......such is life!

The lubricant used is called Semi Fluid Grease. It is quite viscous so doesn't leak out like oil alone would, but is not so thick that it won't seep to where it is needed and also leave the gears dry. I have bought the Penrite product as it is easily obtainable here. There are quite a few posts on this forum about this topic and a search for "Semi Fluid Grease" should come up with them;

i.e.
https://www.douglasmotorcycles.net/index.php?topic=1731.msg6243#msg6243
https://www.douglasmotorcycles.net/index.php?topic=5710.msg20764#msg20764
https://www.douglasmotorcycles.net/index.php?topic=8786.msg34530#msg34530 etc etc

https://penriteoil.com.au/assets/pis_pdfs/SEMI%20FLUID%20GREASE.pdf

cheers

Ian

anfänger · « **Reply #18 on:** 05 Apr 2022 at 19:11 »

Hello.
now i am searging right dimension of chain .

Many thanks for nelp
Ernst

Alan · « **Reply #19 on:** 06 Apr 2022 at 23:19 »

At the back of the 2 3/4 maintenance manual, there is a listing of parts required for maintenance purposes and there are details of the chain(s) required for TS and CW models , even down to number of links . Still available and just in case worth getting an extra half link as well.

anfänger · « **Reply #20 on:** 09 Apr 2022 at 19:44 »

Where can I order the maintenance manuel for CW ?

Hutch · « **Reply #21 on:** 10 Apr 2022 at 00:38 »

Hi anfänger,

You can get copies of The Handbook of the Douglas Motorcycle 2 3/4 hp (and other Douglas Literature) from the London Douglas Motorcycle Club but you will need to become a member.

There is a copy of the circa 1925 Manual here that can be downloaded;

https://www.barnstormers.co.nz/barnstormers/wp-content/uploads/2013/10/Douglas-350-PDF.pdf

Note that there are variations in roller diameters, width of chain and side plate thickness that need to be taken into consideration as there are different versions of the chain designated 1/2" x 3/16". So you may need to measure your sprocket widths etc and find the best fit.

There has been several discussions on this topic on this forum (they appear to be mainly for the EW model tho') - try a search on the forum for "110044", "415" or "primary chain". There are some good posts on this topic by Chris, Leon and others.

cheers

Hutch

anfänger · « **Reply #22 on:** 08 Apr 2023 at 19:40 »

Hello, I'm looking for support for my newly emerged gearbox problem.
Everything worked, of course, and the rest of the work was done during the winter - also on the gearbox (3 gears). Replacing the drive chains and then setting the 1st gear (according to the manual, page 50 - I've done it several times.
always worked)
During the test run I had problems when starting - I thought it was the clutch - I checked the clutch and everything was OK
Next test - same problem. starting was like when you want to start with the 2nd gear - i.e. transmission first gear again
adjust - test run - same problem !!
How can I find FIRST gear again??? Please help

Thank you greeting Ernst