What HONDA must have known

[chad502ex]

The first image is the crank bearings on a TRX450R stock crank

the right side of the crank in the TRX is a roller bearing
the left side of the crank in the TRX is a radial (ball) bearing

[chad502ex]

the second image is a breakout of the crank bearings in a CRF450R

the right side of the crank is a radial (ball) bearing
the left side of the crank is a roller bearing


TOTALLY OPPOSITE DESIGN- hmmmmmm

[chad502ex]

now, I'm no bearing expert but i know that the roller bearing is usually setup for heavy loads, and I would guess that the load on cranks is on the cam chain side with the valve train load and flywheel wobble in the higher RPM's.

Additionally, I havn't heard of any crf crank bearing failures like i've heard of trx crank bearing failures so this has intrigued my interest so this is what i've found

Now, why did honda make the switch and why did honda change the bearing manufacture and part number from the trx 04' model to the trx 05' model to compensate. I think this is in error.

Another error that I've discovered in the documentation HONDA provides to consumers is how the spacer on the cam chain tensioner is installed. In the service manual the cam chain spacer is pictured flat facing outward, but in the parts breakdown illustration this same spacer is facing inwards. Another goof. If this spacer is installed incorrectly it will cause the came chain to be flexed side to side too much and cause pre-mature wear.

[chad502ex]

been thinking about it a bit more, and just maybe HONDA did this intentionally for the increase in load with traction through the tranny on the right side of the crank. There is a big difference in dirt bike tire traction and a rear quad tire traction. Maybe they should have compensated with adjusting the tranny gear ratio a bit instead of trying to bearing rotation (if done intentionally). :confused:

Either way an obvious change in design not favoring the TRX....
:(


any input is encouraged.

[Out_Sider]

is there anyway to install the crf bearings on the 450r in the way they are normally in the crf? if someone is willing to try this it'd be a great experiment

[chad502ex]

Originally posted by Out_Sider
is there anyway to install the crf bearings on the 450r in the way they are normally in the crf? if someone is willing to try this it'd be a great experiment

it's funny you are asking, but hopefully i will be able to provide additional light for you this weekend when i measure the two

[Out_Sider]

i am a new owner of a 2005 450r, and the fact that all these bearing problems are arising, its scaring me. but please keep me informed about the bearing sizes, if they are the same it would be very interesting

[Punk'd]

thats intresting.. keep us informed

[chad502ex]

Originally posted by Out_Sider
is there anyway to install the crf bearings on the 450r in the way they are normally in the crf? if someone is willing to try this it'd be a great experiment

Oh, well ya might be able to rotate these bearings in the same order as the crf, but you cannot use the crf bearing on the trx crank. Apparently, these TRX crank bearings are a very unique and odd size.

[Out_Sider]

well, you would think Honda would have known there would be a bearing problem, i did not hear of any (or very little) 04 bearing problems, so why would honda change it like that?

[chad502ex]

Originally posted by Out_Sider
well, you would think Honda would have known there would be a bearing problem, i did not hear of any (or very little) 04 bearing problems, so why would honda change it like that?

from what i understand HONDA changed the manufacture and part number during 05' model year. maybe they found a cheaper part available and thought it would hold up to the added pressure and stress :confused:

[Flynbryan19]

I'd be curious to know what it is they're doing to fix the ones brought in under warranty. The people I've heard from that took them in under warranty have not had the problem reoccur.

[chad502ex]

Originally posted by Flynbryan19
I'd be curious to know what it is they're doing to fix the ones brought in under warranty. The people I've heard from that took them in under warranty have not had the problem reoccur.

Yes, I wonder what the technical bulletin says too!

Does anyone have access to the HONDA technical bulletin on this issue?

[450Racer]

i don't think this will help any but it's worth a try...my 2004 crank bearing went out...and my engine builder found why. he said that the steel edge on the race was very brital. he said a very smal peice chipped off causing the chip to chip off other peices until half of the race was destroyed and chipped up. does this have anything to do with the vibrations in the crank that could have possibly caused the first chip? i'm no mechanic, but i figured i'd suggest it.

[chad502ex]

Originally posted by 450Racer
i don't think this will help any but it's worth a try...my 2004 crank bearing went out...and my engine builder found why. he said that the steel edge on the race was very brital. he said a very smal peice chipped off causing the chip to chip off other peices until half of the race was destroyed and chipped up. does this have anything to do with the vibrations in the crank that could have possibly caused the first chip? i'm no mechanic, but i figured i'd suggest it.

thanks for your input.

[chad502ex]

does anyone know a friend that works in a HONDA shop that has access that HONDA technical bulletin on the crank bearings issue?

[Smoker]

I doubt it's a design flaw, just a machining error. Like what was said in earlier in the post, the race was brittle, improper heat treatment causing it the chip apart. That's my guess anyway.

[chad502ex]

Originally posted by Smoker
I doubt it's a design flaw, just a machining error. Like what was said in earlier in the post, the race was brittle, improper heat treatment causing it the chip apart. That's my guess anyway.

Yea I agree that sounds logical of what happens. I heard rumors on the installation procedure being slightly off from the factory when they install the bearings into the case and its slightly tweeked.

Oh and I looked up the parts breakdown on a xr400 and trx400 and the crank bearings are exactly the same.:huh

[TWISTED]

Chad, You're too smart for your own good!!! Wish I could figure that stuff out..

[Doibugu2]

Originally posted by TWISTED
Chad, You're too smart for your own good!!! Wish I could figure that stuff out..

Naw he really isn't that smart. He took his whole engine apart and he just can't figure out how to put it back together:devil:

Just kiddn Chad

Originally posted by chad502ex
Yea I agree that sounds logical of what happens. I heard rumors on the installation procedure being slightly off from the factory when they install the bearings into the case and its slightly tweeked.

Oh and I looked up the parts breakdown on a xr400 and trx400 and the crank bearings are exactly the same.:huh

i talked to 3 or 4 honda dealers, they all told me it was installation errors, if it really was or not i dont know, but i think it was installation, otherwise y would only say 30 peoples bikes on exriders get jacked up but the rest r fine, and y did most happen almost instantly instead of over time, im betting on installation, maybe it was a faulty part somewhat, but another thing the dealers told me is that the 05 bearings are fine, which makes me think more of it being installation, jus my 2 cents :macho

[chad502ex]

ok- good enough info xxx.

today, i pulled my old crank out of the storage bid and measured "the load" side inner diameter of the radial ball bearing and it measured 3mm bigger than the clutch side roller bearing. In other words, these bearings are not the same size and the bigger of the two is on the flywheels side. Maybe this has alot to do with flywheel wobble ????, but just because one side of the crank wobble is reduced that doesn't mean the other side of the crank is still. It's the "other" side that ppl are having problems with,....

[cals400ex]

so where the cranks modified in 05 too or where the bearings just changed from 04 to 05? i don't know where i can look up the 05 parts. service honda only has them up for 04.

[chad502ex]

Originally posted by cals400ex
so where the cranks modified in 05 too or where the bearings just changed from 04 to 05? i don't know where i can look up the 05 parts. service honda only has them up for 04.

the cranks were not modified from 04 to 05, it was the crank bearing that was changed. If you were to order a new bearing from service honda, or any oem parts house, you order a

91008-HP1-671
but your shipped
91008-HP1-672

second bearing revision.

BTW: I looked up this bearing part number on the micro-fische and the bearing above is the bearing on the right side of the engine- or tranny side. This is the roller "load" bearing and not the radial "Ball" bearing on the flywheel side.

[TrX450rKiD]

I'm confused at to why people are referring to a change for the better from 04 to 05. Every failure I have heard of was within the first 20hrs ride time on 05's. From what I understand it was simply a bad batch with some of the 05's and is taken care of now. I'm guessing that if we got VIN #'s from people with failures we could narrow down the bad batch if thats what the problem was ...

[chad502ex]

Originally posted by TrX450rKiD
I'm confused at to why people are referring to a change for the better from 04 to 05. Every failure I have heard of was within the first 20hrs ride time on 05's. From what I understand it was simply a bad batch with some of the 05's and is taken care of now. I'm guessing that if we got VIN #'s from people with failures we could narrow down the bad batch if thats what the problem was ...

the change from 04 to 05 was not for the better- it was obviously for the worse. Personally, I think it was honda way of saving a few bucks per engine built (but over thousands equals big bucks) on a cheaper alternative. Maybe it was a bad batch of bearings, or poor installation, but either way a bearing usually goes bad because of lack of lubrication and/or extreme pressures.

maybe the vins is a good idea, i havn't heard too many failures lately either

[TrX450rKiD]

So, anyone that sees this that had a bearing failure .. post up the last 5 digits of your VIN. Maybe we can figure out if this was a bad batch or what ...


(Can you guys believe .. me and Chad both took part in a thread WITHOUT arguing .. and, the unthinkable, agreeing! Definately a milestone in our relationship! :D :blah: )

[Doak450r]

my quad locked up today i think it may be my crank bearing. i noticed it was realy hard to start today and took about 20 kicks to get started and then it started then i drove it for about 2-3 hours and stoped to take a break and then it wouldnt start the kicker woulnd not move at all. snd worse of all i had to have my dads banshee pull me out of the woods

[chad502ex]

Originally posted by Doak450r
my quad locked up today i think it may be my crank bearing. i noticed it was realy hard to start today and took about 20 kicks to get started and then it started then i drove it for about 2-3 hours and stoped to take a break and then it wouldnt start the kicker woulnd not move at all. snd worse of all i had to have my dads banshee pull me out of the woods

bummer man- sorry for the bad day. You'll get her fixed. when you do let us all know what happened to here.

thanks in advance.

[awj8074]

I dont know why they did it but it dosent seem to be working. My bearing went at around the 50hour mark and the engine was rebuilt by the dealer for free. Now about 20 hours later im hearing the same noise agian. Guess im gonna bring it back but this time im getting a new motor not a rebuilt one. I change my oil every 10-15hours and its always clean when i drain it. I do every thing honda says to and i still have problems.

[chad502ex]

Originally posted by awj8074
I dont know why they did it but it dosent seem to be working. My bearing went at around the 50hour mark and the engine was rebuilt by the dealer for free. Now about 20 hours later im hearing the same noise agian. Guess im gonna bring it back but this time im getting a new motor not a rebuilt one. I change my oil every 10-15hours and its always clean when i drain it. I do every thing honda says to and i still have problems.

what noise do you hear?

strange that your bearing would disappear and the oil is clean too hmmm:confused:

[awj8074]

Originally posted by chad502ex
what noise do you hear?

strange that your bearing would disappear and the oil is clean too hmmm:confused: its a grinding noise the same as before when it went. The oil was clean last time too and i cut the filter apart and there were noting in it either. If you rev the engine its grinds alittle and hangs then goes back to idle

[Jersey450R]

Yo Chad, i used to doubt your posts and knowledge, but i respect you now and you DO know your chit. word.

[chad502ex]

Originally posted by Jersey450R
Yo Chad, i used to doubt your posts and knowledge, but i respect you now and you DO know your chit. word.

thank you very much- i really do appreciate your kind words. I really do care to help the members of this site. I figure that with all the BS aside where else can ppl get technical information without having to pay one cent?

Thanks again. Let me know if i can ever lend ya a hand.

your friend,
Chad

[chad502ex]

Since the 530 was down until new rebuild 550R next week, I had the opportunity to help some on what to check for on crank bearing preventative maintenance and took a few snaps for visual. This can be checked while the engine is in the frame- just drop your oil and anti-freeze and remove the right or left side with crank bearing seal if you start hearing noises like some ppl claim to hear

this may help ppl a bit to double check any suspect crank bearing failure BEFORE the failure occurs. Preferably, before the failure and before total rebuild is nessecary (not after- chaching $$). After failure lots of damage can occur. If you check before failure, the only cost would be cost of gasket(s), new crank bearing seals and time involved for peace of mind...

:D

[chad502ex]

the other side

thanks chad :macho