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model B jumping out of gear

PostPosted: Fri Jul 28, 2023 4:02 pm
by Thackers
Hi, can anyone give me some advice on my model B jumping out of 2nd gear? I've replaced the gear for a N.O.S cog as the three dogs were worn but that hasn't cured it. I have tried adjusting the selector housing box fully both ways but the problem still persists. Could it be the Teleflex cable? I dont see how that could cause the jump but i'm about out of ideas.
Please help if you can.
Thanks

Re: model B jumping out of gear

PostPosted: Wed Aug 02, 2023 12:33 am
by jbcollier
Unfortunately, both parts wear. Check the slider and see how its teeth are. If they are worn and now angled, it will keep slipping.

Re: model B jumping out of gear

PostPosted: Wed Aug 02, 2023 4:02 pm
by Thackers
jbcollier wrote:Unfortunately, both parts wear. Check the slider and see how its teeth are. If they are worn and now angled, it will keep slipping.

Hi Thank you for the reply. 8-) 8-)
When you say "slider" is that the cog that the three dogs go into? could it be called the neutral gear? as i've seen these advertised, Please forgive my lack of know how on this.
Image
Is this the part you refer to?
Perhaps this might be easier to pinpoint the part

Image

Re: model B jumping out of gear

PostPosted: Thu Aug 03, 2023 3:27 pm
by jbcollier
Take it apart and examine the where the "dogs" engage. They need to be crisp and true. They usually wear making a slanted surface which allows/pushes the gear to pop out of engagement. A good machine shop might be able to grind things true again, or, even better, under cut them. This creates a "reverse slant" which pulls the gears into engagement.

Re: model B jumping out of gear

PostPosted: Wed Aug 09, 2023 3:02 pm
by Thackers
jbcollier wrote:Take it apart and examine the where the "dogs" engage. They need to be crisp and true. They usually wear making a slanted surface which allows/pushes the gear to pop out of engagement. A good machine shop might be able to grind things true again, or, even better, under cut them. This creates a "reverse slant" which pulls the gears into engagement.

So which part are you calling the slider? I have already replaced the 2nd gear so it's dogs are in good shape.
Thanks

Re: model B jumping out of gear

PostPosted: Mon Aug 14, 2023 1:06 pm
by jbcollier
Here is the D gearbox. It is similar to the B box which is good enough for discussion purposes. When it is slipping out of gear, the mating "notches" (called "dogs") have worn so that pressure forces them apart. BOTH parts wear so you need to change both the gear and whatever it engages. Changing just the gear will not solve the problem and, worse, the new gear will quickly wear out as it is having extreme pressure applied to a small area.


Image

Re: model B jumping out of gear

PostPosted: Thu Aug 17, 2023 12:23 am
by Thackers
Thank you 8-)