fifth gear broke?



13 replies to this topic
  • Taffy

Posted February 23, 2001 - 10:16 PM

#1

half way through my tests today i discovered that my misfire wasn't!!!

the engine was still pulling but that i appear to have lost several teeth off one or both of the pinions.

any info from previously poor bleeders would be of help before Dr Lloyd goes to the operating theatre on his poor blue beasty!

Taffy

  • James_Dean

Posted February 23, 2001 - 02:12 PM

#2

Could it be clutch slipping?

A countershaft loose and jumping teeth?

Hope its not 5th pinion & wheel gears, that could be serious down time. :)

James

  • Hick

Posted February 23, 2001 - 03:04 PM

#3

Wish I could help, Taffy. I had a few teeth chunk off both fourth gearwheels in my YZ but the whole thing locked up before I had time to make note of any tell-tale noises or symptoms.

When I put it back together I couldn’t help but notice that third pinion, which engages dogs of fifth pinion, was binding on the main shaft splines and not engaging dogs fully. This may have been what caused third pinion to come apart at the dogs and spit it’s shift fork into the crank (thus the CLUNK and seize). The missing teeth on both fourth gears may have been pure coincidence, or some fragments may have interfered with third/fifth gear dogs.

The binding is probably what was causing the occasional “wander” between fourth and fifth that I was experiencing. I polished the main shaft (by hand) until the new gear slid easily and haven’t had the “wander” since.

Maybe you’ve only got some issues with the shift shaft and segment not fully engaging fourth and allowing dogs to skip, otherwise it looks as though you’ll have to split the cases to see what’s what.

I’ve had the cases split twice on my ’00 YZF, once to replace both halves, and had few real problems so I’m sure you’ll be able to manage. They came apart and reinstalled relatively easily, with no pressing or pulling.

Sorry about your (apparent) misfortune.

  • Taffy

Posted February 28, 2001 - 01:55 PM

#4

the bloke repairing my bike says that my bike needs a new 3rd & 5th gear in the input shaft. the middle selector is bent & the dogs are shagged. says he thought the manufacturers got over this kind of thing years ago.

i guess i'm looking at a lot of money when i have the least.

now i back track to all my test figures & i start to wonder if i ever had a misfire on the last two runs.

Taffy

  • Hick

Posted February 28, 2001 - 04:10 PM

#5

Taffy,

Sounds more or less like what happened to my bike.

When you see him next, ask about the condition of both your fourth gear wheels. Mine had pitted faces on thrust side of every tooth.

  • James_Dean

Posted March 01, 2001 - 09:55 AM

#6

Taffy,

Sorry to hear this. A costly problem and down time on top of that. Hope they get you back on 2 wheels quick.

James

  • Guest_Guest_*

Posted March 01, 2001 - 10:13 PM

#7

<font size=6 colour=######>HI TAFF

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Taffy

Posted March 08, 2001 - 02:06 PM

#8

delivered the bits to my mechanic friend tonight & saw the gears.

most of all the new selctor fork is beefed up on the original, this was buckled on the polished tip. the gear had been grinding into the side of the bent selector.

we also discussed the possibility that a YZ & WR gearbox would probably have interchangable gear wheels.

i noted the other day that the change could be done for under $300.

YZ owners interested?

Taffy

  • Guest_Guest_*

Posted March 08, 2001 - 05:27 PM

#9

<h1>HEY THAT IS COOL!</h1>

  • Hick

Posted March 09, 2001 - 11:01 AM

#10

Originally posted by Taffy:
we also discussed the possibility that a YZ & WR gearbox would probably have interchangeable gear wheels.

I noted the other day that the change could be done for under $300.

YZ owners interested?

Taffy


I was on the verge of putting a WR 5th in my YZ when the tranny grenaded, unfortunately I let a mech. at North County Yamaha talk me out of it. He thought it couldn’t be done without changing ALL the gears. At the time that was enough to scare me off, but his opinion makes no sense to me now.

I’ve gotten so much good advice from them I’m surprised they got this wrong. I should ask for the smart mech. by name from now on…

Anyway why would it cost $300? Is a new shaft needed? New shifting fork? I was going to buy the gear wheels only…

So maybe it is good I didn’t try it. Please post what parts you added up to get the “under $300.”

Thanks!

  • Taffy

Posted March 09, 2001 - 09:02 PM

#11

here's the place i had a look at;

http://216.37.204.20...EM/YamahaDB.asp

try & have a look into it. the blokes at NCY were really friendly when i got some stuff shipped over (clarke tank for $125!!!) but who is going to pay them for all that piddling about. it's a job for "D.I.Y. MAN!"

if you purchase input shaft with 1st gear built in & then get all the other 9 gears it comes to $332.78.

the reason i said $300 is because 3rd gear is very close on the YZ & WR & if you look at it 3rd gears may not be necessary.

how much for the two shafts complete?

[B]99WR400 vs 98 or 99YZ

99WR
1st 29/12
2nd 26/15
3rd 21/16
4th 21/20
5th 21/25

98 or 99 YZ
1st 27/14
2nd 25/16
3rd 23/18
4th 24/22
5th 20/21

Which means the WR 1st gear is 25% lower, 2nd gear is 13% lower, 3rd gear is 2.67% lower, 4th gear is 3.74% taller and 5th is 11.8% taller.

I know the 426 1st and 2nd are even taller than the YZ 400 which makes the bike basically useless on tight snotty trails. This was proven out by a guy I know who tried to ride one on hard ways on the last Dual Dogs Dual Sport ride, he was swearing all day a frying his clutch.

Clark[B/]

Taffy



[This message has been edited by Taffy (edited 03-09-2001).]

  • Taffy

Posted March 10, 2001 - 12:02 AM

#12

here's the place i had a look at;

http://216.37.204.20...EM/YamahaDB.asp

try & have a look into it. the blokes at NCY were really friendly when i got some stuff shipped over (clarke tank for $125!!!) but who is going to pay them for all that piddling about. it's a job for "D.I.Y. MAN!"

if you purchase input shaft with 1st gear built in & then get all the other 9 gears it comes to $332.78.

the reason i said $300 is because 3rd gear is very close on the YZ & WR & if you look at it 3rd gears may not be necessary.

how much for the two shafts complete?

99WR400 vs 98 or 99YZ

99WR
1st 29/12
2nd 26/15
3rd 21/16
4th 21/20
5th 21/25

98 or 99 YZ
1st 27/14
2nd 25/16
3rd 23/18
4th 24/22
5th 20/21

Which means the WR 1st gear is 25% lower, 2nd gear is 13% lower, 3rd gear is 2.67% lower, 4th gear is 3.74% taller and 5th is 11.8% taller.

I know the 426 1st and 2nd are even taller than the YZ 400 which makes the bike basically useless on tight snotty trails. This was proven out by a guy I know who tried to ride one on hard ways on the last Dual Dogs Dual Sport ride, he was swearing all day a frying his clutch.

Clark


Taffy

  • wrsm

Posted March 11, 2001 - 12:46 PM

#13

Hey Taffy,
do you find it cheaper to ship genuine parts to the UK from the US?
What % saving do you make when carriage & taxes are included?
I live in UK and hope I never have to buy loads of gearbox parts like you need, but just wondered about other consumables (cables, filter, swing arm bearings etc)
Hope the rebuild goes OK. In my experience it NEVER pays to skimp on gears, any marks or wear on components you leave in the box will catch come back to haunt you very soon!

  • Taffy

Posted March 11, 2001 - 01:01 PM

#14

i believe it makes a heck of a difference if the parcel is under 5KG (11lb).

over half the parcels are stopped by C & E. i've had 1 from 2 get through so far.

my stuff takes two weeks to arrive as the us post office is far chearper.

if you know someone who will bring a little parcel back it saves a lot of postage & tax.

i've now got to buy the bushes for my rear sussie. loadsa money!!

i'll see if i save on this one & let y'all know.

Taffy




 
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