BMW K1200 / K1300 transmission issue

This is a real quick glance at what I found when I pulled a K1200GT transmission apart.

[@alec-s]

The issue is the dog gear teeth wearing and roundening, generating an axial force on the gear and generating thrust on forks, which wears out by consequence. I fix them with a special steel here in Italy, refacing and rebuilding all the worn out parts.

[@bzen5917]

I have heard of tons of issues w/ K1200 and that the K1300 solved these issues. I have a K1200R Sport that slips out of 2nd and 3rd and now possibly 4th under "hard" acceleration. I am planning on buying a K1300 transmission and swap it out. It is supposed to be "easy" and would like to see vid on removing/installing transmission. Solid explanation by the way! Cheers!

[@daveintheshade]

Hey B Zen - I want to do the same - have you found instructions? Was it easy?

[@alec-s]

I can repair those transmissions, i regenerate and modify forks and teeth...

[@carlspiers7709]

@@alec-s where are you based?

[@alec-s]

BWG Racing, colleverde (Rome), Italy

[@carlspiers7709]

@@alec-s what's the approximate cost?

[@maseratifittipaldi]

Had the same experience. Replaced box from K 1300 of which dogs were undercut - eliminating tendency to "jump out of gear" and thus causing damage to selector forks.

[@techworks2090]

Good day all! I'd like to apologize for not responding sooner! I noticed my notifications were off for some reason.... The fix is to swap to the 1300 forks BEFORE the 1200 forks do their damage... Or just swap in the 1300 trans... The part number is 23007726370 for the whole trans... It fits K40 "S bikes" (04/03-09/15), K43 "R bikes" (03/04-07/15), and our "GT bikes" (11/04-10/10).... I'll have to check, but I'm fairly confident you can pull the trans out of the block after removing all the clutch components and the 8 ISA screws... The driveshaft will need to come out... And the shifter rod... I'll try to get a vid done these next few days off for you guys and gals!

[@FryChicken]

Appreciate this. I just installed a K1300S trans in mine. You’re absolutely right, should have done this before the shift fork bent. Have you found replacement shift forks?

[@techworks2090]

@@FryChicken Good day! I pulled up all three part numbers and I did find all three at the first online place that came up under a search... Each fork runs about $250... So,$750 plus shipping and tax... They aren't hard to swap into the trans, but it might be a great idea to check the gears where the forks sit... If those are over heated, it might just be best to get the whole trans! Here are the part numbers for the forks... 2nd and 3rd gear fork (23007719148), 1st and 4th gear fork (23007719146), 5th and 6th gear fork (23007719150).... Cheers all!!!

[@tijmeng8550]

Just bough mine at an auction, a 1200 R sport. I was very dissapointed about he gearbox shooting from 3 to 2 on power. But very happy there are a lot avaible and really easy swappeble. Hope ur video will be here soon, so i can take a look :)

[@riccardovezzosi]

I would say the fork has been held in tension while either the quickshift didn't engage or the clutch was never pulled to overheat the surface so badly...or possbly it was bent in very rough downshift and it went bad from there...

[@alec-s]

It roundens the dog teeth due to a bad hardening process and then it pushes on the fork , creating heat and wearing the fork itself.

[@Chris.Mechanic]

If problems finding neutral on running emgine im K12s 2005, is it already an issue with fork or something else? 1, 2, 3 switch up with a clunk. Expensive to repair?

[@suazuki]

Is it normal to have 2nd gear problem with k1200r 80k mile? Is there any issue riding the bike with the 2nd gear problem?

[@FryChicken]

What weight oil were you running?

[@randomfixesandrebuilds]

Hi, I'm currently "restoring" my BMW K1200R Sport and I really need help. Can you explain/show how to remove the gear shafts from the housing?! I got as far as to removing the selector cylinder and forks and fork shafts but no luck with the gear shafts, what am I missing?!

[@techworks2090]

Well, I'm doing this from memory, but there is a plate at the bottom of the main shaft. There are four or five bolts that keep things aligned. It also keeps the main bearings installed. I don't remember exactly how I got them out, but it took some time. I think I pried them out but only because they were already bent. The two need to come out at the same time! I'll put it on my list to investigate how I did it exactly... I'll try to get something out this weekend on it, but I'm pretty packed on the "honey-do-list"...

[@randomfixesandrebuilds]

@@techworks2090 Thanks for the reply. I've already took the plate and bolts that you mention. Can you remember after that if it's just a pressure fit of the two bearings?

[@techworks2090]

@@randomfixesandrebuilds good day!! Indeed, it is a press fit for them... I'm pretty sure they both need to come out together since they interfer with one another... I think I was going to make a puller, but I found a good used trans to put in my bike instead...

[@randomfixesandrebuilds]

@@techworks2090 I’m trying to figure that out, if I should go with a spare trans, because one of the forks shows signs of being under pressure and heat and before my bike blown the engine it was kind of “jumping” out of gear in 2nd, like a violent cut of power like it had skipped 2 or 3 tooth on the gear.

[@randomfixesandrebuilds]

@@techworks2090 I got it!!! Oven at 250 Celsius, put the whole trans in there for 30 min and booth shafts came right out 🥳🥳 I’ll post a video about it on my channel soon. Still, thanks for the help anyway. 😉

[@FryChicken]

I think this exact same thing happened to my bike. It’s wedged into 3rd gear. What’s the “solution” for this?

[@alec-s]

If you send me the transmission here in Italy I can overhaul it

[@FryChicken]

@@alec-s I’ve already replaced my transmission... I shudder to think how much shipping to Italy from the States would cost 😨

[@alec-s]

@@FryChicken hou much did you spent for switching it? Just to say, i ask about 600€ to rebuild and overhauling it completely (refacing gears and forks, heat treating and changing bearings) but it is just for the time I have spent on it, is a complex job be done fine. I did it for mine the first time and now I'm helping k owners to not throw away their bike...😉 After the overhaul the shifting completely changes, due to custom reduced plays on every component.

[@alec-s]

I checked, FedEx has a 10kg box for 150€ or a 25kg box for 270.... I think if someone needs to replace the transmission, it would be probably better to get their own as new for 1200€ included shipping... Do you think is too much?

[@FryChicken]

@@alec-s Well I already bought a K1300S transmission for $1k and installed it. Would you be interesting in outright buying my old transmission?

[@Hopeless_and_Forlorn]

Is it possible that bike was dropped on left side and shift lever forced up by contact with ground?

[@alec-s]

No, it has to do with worn dog gear, worn teeth make the gear thrust outwards. The fork is there and keep it in place as long as it wears out and the gear can disengage. It depends on a bad heat threating on dog gears teeth...