consequences of a Bad ISB
 

So my ISB(input Shaft Bearing) has been making noise since i bought the car in August on 07, i have no idea how long it was before i bought it but it has not got any louder, i had first thought it was the throw-out/release bearing but not the case, anyway i dont really wanna replace it if it doesnt really need to be as i really dont wannt have the tran apart or pay the $1000 cost to the dealer to fix it.

Anyway i'm just wondering, whats the consequences on leaving it as it is, it it does get louder/worse then yes i will replace it, but if it doesnt what could happen?

This seems to be a very common problem with these hondas from what i can gaver, i tried searching here for topics on this but the search doesnt seem to be working right now, it wont give me any results for anything i search. only says "Improve your search results: Click here for Search Commands, Tips & Tricks.
InternetBrands.com ibSearch Discussion Forum Search Engine"

anyway thoughts or comments anyone?

Re: consequences of a Bad ISB
 

Look at the thread titled 2001 dx, gear oil. I think I have the same problem, and its explained there.

Re: consequences of a Bad ISB
 

If the bearing fails, it will score the mainshaft and gouge the transmission case, essentially rendering the transmission junk. The car will be undriveable; you won't be able to shift gears and the clutch will be soaked in oil because the main seal will sustain damage from the bearing and shaft. At that point, you're looking at sourcing a used transmission and a new clutch disc, all because you procrastinated replacing a $25 bearing and a $7 seal.

If you're mechanically handy and have tools, you can do it yourself. I would highly recommend buying a Helm factory service manual here to check torque specs and reassembly order. The entire procedure is outlined in detail with diagrams. If it's been a while since you had the clutch replaced, check the wear on the disc and replace parts as necessary while you have the transmission off.

The bearing part number is 91002-PS0-003 and the main seal behind it is 91216-PL3-005.

Re: consequences of a Bad ISB
 

thats exactly what i wanted to know.
thanks for the input, i have a new clutch and bearings going in on the 17th and my plan to to pry that case apart while the tranny is out and have it replaced, nothing bugs me more than knowing theres something wrong with my car, i had first thought it was the throw-out/release bearing but i was wrong, knowing now that the ISB is bad and what could happen i almost dont wanna drive the car untill its fixed.

Re: consequences of a Bad ISB
 

How do you tell if it's bad? When I press my clutch to the point of pressure, I can tell something is wrong because it makes a "whirring" noise like a soft hum. The noise fluctuates as the clutch is further depressed and is almost like the noise of a buzzing doorbell when you tap the clutch a few inches down..

Re: consequences of a Bad ISB
 

If you're only getting noise when you push the pedal in, the problem is likely a bad release bearing or pilot bearing.

Re: consequences of a Bad ISB
 

x2 i have repalce quite a few at work. i work for a honda dealer. its not to bad to replace as long as you are handy with tools and have the proper tools to do the job. i would rec. using a lift it would be much easier to remove the subframe and trans.

good luck

Re: consequences of a Bad ISB
 

Please feel free to correct me if i'm wrong, but the pilot bearing spins with the fly wheel which is spinning at all times the engine is running, so have the clutch pedal in or out should make a difference correct?

Re: consequences of a Bad ISB
 

The pilot bearing only comes into play whenever the transmission mainshaft and the flywheel/engine have a difference in rotational speed. In other words, it will only spin when the engine and trans are disconnected by pushing the clutch pedal in.

Re: consequences of a Bad ISB
 

ahh ok gotcha

thanks for clearing that up, i wasnt 100% sure. :)

Re: consequences of a Bad ISB
 

I spent $2k on having the tranny rebuilt with a new clutch and flywheel. Had bad syncros, and other bad gears.

It will just get worse over time till you leave your tranny behind or just cant stay in any gear

Re: consequences of a Bad ISB
 

now i'm confused, i was at my buddies last night down in his garage, hes a parts manager at Honda, 2 of Honda's Mechanics were there also, anyway i brought my car in and they were going over it, the sound that i was sure was the Throw out bearing and later found out on here it could be the ISB, they say its is 100% definitly the throw out bearing and not the ISB as the ISB will still make some slight noise once the clutch is in, and the throw out will go silent when the clutch pedal is pushed in.
these guys have been working as mechanics at the local Honda dealer here for 8 and 14 years respectivitly.
Either way when my clutch goes in next weekend i'm gonna have the ISB checked just to be sure.

Re: consequences of a Bad ISB
 

I'm sorry, but that is totally wrong. I don't care who they are; if they told you the mainshaft bearings will still make noise with the clutch pedal pushed all the way to the floor and the car sitting completely still, then they have no mechanical knowledge of how a clutch and transmission work. How are the bearings going to make noise if the shaft isn't moving?

And the release bearing doesn't start spinning until it contacts the fingers of the pressure plate as you're pushing the pedal in, so how would it go silent?

Re: consequences of a Bad ISB
 

thats why i'm confused, I'm gonna take the tranny apart anyway just tp have a look just to be sure.

Re: consequences of a Bad ISB
 

Throwout bearing = makes noise when clutch is disengaged (clutch pedal depressed/to the floor) Input shaft bearing or other clutch parts = make noise when clutch is engaged (clutch pedal released/in the air)

Re: consequences of a Bad ISB
 

They're probably thinking of the pilot bearing. This leads me to believe that they've never done a mainshaft bearing replacement, which is rather amazing for a 10+ year Honda technician.

Re: consequences of a Bad ISB
 

Do you know what Parts i will need to properly replace this bearing? will i only need to replace the ISB, or is there any seals or other bearings that need to be replaced with this?

and might be a long shot but you wouldnt happen to know their part numbers would you?

Re: consequences of a Bad ISB
 

Order both of those. I always replace the main seal with the bearing just in case I damage the seal on removal.

You should get a tube of Hondabond or Honda Ultra Flange Sealant to seal up the trans case and shift cover plate too. Don't forget 2-3 quarts of Honda MTF when you're picking up parts.

You probably won't need any other internal bearings unless you're getting other noises, or unless you disassemble the case and find other bearings with play/roughness/noise. Pay special attention to the outboard mainshaft bearing and the differential carrier bearings.

For clutch replacement, you'll need a new clutch disc, pressure plate, release bearing, and pilot bearing (all of these parts plus an alignment tool come in the Exedy KHC08 clutch kit, which I recommend). Have the flywheel resurfaced while it's off to avoid clutch chatter. If the crank main seal appears leaky, replace it while you have the flywheel off.

Re: consequences of a Bad ISB
 

thanks a million man, you've been a great help.

Re: consequences of a Bad ISB
 

so i got all the work done today, my tranny was out, apart, the ISB was indeed bad, However the the throw out bearing was much worse was the the source of 60% of the noise, anyway both are changed, new clutch, new coolant lines(another common problem) andnew exhaust flange.
all of this work was done in 5 hours, really glad to have it all done finally, it was myself and 2 friends (both mechanics).
the car feels like its brand new again.

Re: consequences of a Bad ISB
 

I have been searching and searching on this problem as I am experiencing the same in my 97 dx. I'm fixing to order the Exedy KHC08 clutch kit, as I see is recommended, and have the flywheel resurfaced. How much did it cost you in all to do the threout bearing, isb, coolant lines, and exhaust flange? Again, I am for sure having the same problem, after research and reading this thread.