2nd gear

Im kinda suprised I have not yet heard anyone talk about second gear going to shit,,,its my understanding that this is a common problem. My xj750 maxim is now a 4 speed. I can down shift into 2nd,,,but if I apply power while in 2nd, she skips bumps plunks and grinds. Click it into 3rd,,,4th,,,5th,,,they all work great,,,its just 2nd gear. its my understanding that the company yamaha used for a few years for that particular gear were making junk product,,,but they only used them for the second gear,,,the other gears were made by a different company.

this is what I have been told anyway.

 

I have heard of the second gear problem but I never heard about the gear being made by a different company.... don't know why they would do that. Anyways, I too am wondering about 2nd gear as my engine is about ready for a rebuild so I might as well do everything at once. My 2nd gear is semi-ok for now but ever since I snapped the clutch cable and had to do 1,000 miles of clutchless shifts it sometimes pops out of 2nd gear.

 

I'm not sure about the change in companies but I do know that the 2nd gear selector fork was redesigned for later years. When I replaced my 2nd gear selector fork the replacement looked quite a bit different.

 

I've been through 4 engines with second gear failures. I would attribute them to hard riding since they don't have many miles on them. I'm not sure what the cost to fix them but I charge $500 to go through a set of vmax gears and undercut them (makes smoother and more positive shifting). Add another $300 for them for an overdrive 5th.

Sean
one2dmax@aol.com

 

So what actually needs replacement when 2nd goes out?

 

The teeth in the gear is probably fine. What the problem normally is are the "dogs" of the gears which are the protrusions that mesh with the gears that ride beside the gear in question with the main shaft. If it's bad enough they can hard weld and recut the dog otherwise you have to replace the gear.

You can try to either get a good trans or have your trans rebuilt and upgraded. replacing the one or two gears may not be a bad option and is probably a little cheaper. I like to get it undercut on the full set which makes them shift smoother and more positive but it's expensive as I noted before.

Sean

 

Heard another Xj with second gear woes. Is this common or are we noticing it more?

 

OK I have been doing some research on this, and before I go to the expense of buying new gears I will try my hand at some gear modification.

I have borrowed text and linked images from the XJ mailing list archive and also XS11.com.

Others have modified and improved there clunky and slipping second gear by whipping out the dremel and the square file.

IMAGE ONE: DOG


IMAGE 2: SLOT

 

Both the gears are worn pretty badly. The upper edges should almost be sharp. Shaping the gears by hand is very risky since all three dogs (or more for some gears) need to contact at the same time on the gear to spread the load.

Not only that but if you have a bad enough gear the gear needs to be hard welded up before cutting it back to shape. Some will just go ahead and cut the gear but that exposes the "Soft" inner metal that was not hardened. This only makes it wear sooner.

Sean Morley

 

Good info, thanks for posting that.

In my research I have found 5 people who have cut back the dogs, and so far they have all held. The pics are from a fellow on XS11.com, as Yamaha seems to have a bit of an issue with this in allits models from this vintage.

 

I offer undercutting (through Fast By Gast) on all my Vmax engines we build and I see no reason why they can't do the same for these engines. We've done a couple of Fazer (FZX) engines as well.

They shift much smoother then stock it isn't funny.

Sean Morley

 

If second gear actually was made by an inferior maker, it might be worth it for us to see if another gear company can make a much better one that we can fix the problem once and ride off into the sunset with no more problems. Just a thought.

 

the XS11 tutorial to fix the second gear slippage. How similar are the XJ750R Seca compared to this? Do you have to split the case? Does anyone have a tutorial for the XJ750?

 

i've read about the second gear fix before, never had to deal with it myself yet, but undercutting the dogs, thereby angling the contact surface so they pull together instead of apart when engaged does work in theory but it also cuts away the hardened surface layer of the metal and will wear faster as mentioned above. the only real solution IMO is to either reharden the metal after undercutting or buy replacement gears from Yamaha, which i've read are already undercut to fix the problem (don't quote me on that though!).

cheers,

Trev

 

Hi all
I just bought a 1981 XJ650 (Oceania model) with the 2nd gear slipping problem, and i find it very hard to select 1st gear.
I have bought a new 2nd gear from ebay. but after reading this i don't know if it can be fix.

Can any one tell me which oil to use in the engine, as I would like to change the oil as well.

Thanks all

kinen

 

hey guys.

I just found this on the XS11 forum.
http://www.xs11.com/forum/showthread.php?t=5090
I am gonna try and fix my 2nd gear.

let me know if any one else is gonna fix their and share some TIPS to make the job easier.

cheers

kinen1

 

Castrol 4T works fine and is well priced

Even though the write up is very comprehensive, you may want to take pictures as you go.

 

thanks adrian1.

I will take ur advise and take a lot of pictures while i m doing it.

will change oil then too!

cheers

kinen1

 

Hi all,

had the engine apart to look for the slipping problem......but to my SURPRISE it's NOT the gear! it's the Shift Drum. This looks like a full strip down of the Engine/Gear Box rebuild.


kinen1

 

Lovely. Somebody's been jamming second gear, probably power shifting.

You'll probably find that the gearset has taken a beating too.

 

hey bigfitz,

from what i can see the gearset has got a beating alright!!!
I will do a closer inspection when i get the gearset out & post pics!

kinen1

 

Yeah doesn't look pretty the selector fork's quite possibly bent/worn/burnt out too. Not seen abuse like that for a while... (since stripping an old YZ250 that also had no 2nd gear. That was an '83 model actually!)

Looking forward to pics of the carnage, although I'm sure you're not :/