Pilot bearing or Input shaft bearing?
09-10-13, 02:20 PM
#1
Pilot bearing or Input shaft bearing?
I have a 'growling' noise when idling in neutral with the clutch out. 'Growling' pitch changes with rpm and goes away completely with the clutch depressed. It seems to be loudest when cold and is noticibly quieter once everything is warmed up.
From searching I understand this is either the pilot bearing or the input shaft bearing. But is there any way to diagnose it beyond that? I figure on pulling the transmission out at the end of this driving season, and changing the pilot bearing doesn't concern me. But I don't have the pullers for that input shaft bearing and would probably have to take it to a transmission shop. I'd rather not go to that expense if isn't necessary. And obviously I don't want to pull the transmission a second time in the event it isn't (just) the pilot.
From searching I understand this is either the pilot bearing or the input shaft bearing. But is there any way to diagnose it beyond that? I figure on pulling the transmission out at the end of this driving season, and changing the pilot bearing doesn't concern me. But I don't have the pullers for that input shaft bearing and would probably have to take it to a transmission shop. I'd rather not go to that expense if isn't necessary. And obviously I don't want to pull the transmission a second time in the event it isn't (just) the pilot.
09-10-13, 03:01 PM
#2
I have a 'growling' noise when idling in neutral with the clutch out. 'Growling' pitch changes with rpm and goes away completely with the clutch depressed. It seems to be loudest when cold and is noticibly quieter once everything is warmed up.
From searching I understand this is either the pilot bearing or the input shaft bearing. But is there any way to diagnose it beyond that? I figure on pulling the transmission out at the end of this driving season, and changing the pilot bearing doesn't concern me. But I don't have the pullers for that input shaft bearing and would probably have to take it to a transmission shop. I'd rather not go to that expense if isn't necessary. And obviously I don't want to pull the transmission a second time in the event it isn't (just) the pilot.
From searching I understand this is either the pilot bearing or the input shaft bearing. But is there any way to diagnose it beyond that? I figure on pulling the transmission out at the end of this driving season, and changing the pilot bearing doesn't concern me. But I don't have the pullers for that input shaft bearing and would probably have to take it to a transmission shop. I'd rather not go to that expense if isn't necessary. And obviously I don't want to pull the transmission a second time in the event it isn't (just) the pilot.
I have this same issue . I have the engine out so I'm gonna try the pilot bearing first , and if that doesn't do it . i'll be in the market for a new tranny since from what i've looked it it seems cheaper to swap the trans for a low millage JDM one then it is to rebuild .
09-10-13, 07:02 PM
#5
Appreciate responses, but I've no intention of sticking a used transmission in the car, especially a JDM version. I just want to know if there's a way to know if it's the pilot or input shaft bearing...either before or after the transmission has been dropped.
09-10-13, 09:52 PM
#6
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If you-all understood how and when each of the two bearings worked, you would know the answer.
When the clutch is engaged, does not matter if the trans is in neutral or in gear, the trans input shaft is locked through the clutch disc to the flywheel. Thus the pilot bearing is not being rotated/used.
One correct answer before me. You have a bad trans input shaft bearing.
When the clutch is engaged, does not matter if the trans is in neutral or in gear, the trans input shaft is locked through the clutch disc to the flywheel. Thus the pilot bearing is not being rotated/used.
One correct answer before me. You have a bad trans input shaft bearing.
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09-11-13, 05:15 PM
#9
If you-all understood how and when each of the two bearings worked, you would know the answer.
When the clutch is engaged, does not matter if the trans is in neutral or in gear, the trans input shaft is locked through the clutch disc to the flywheel. Thus the pilot bearing is not being rotated/used.
One correct answer before me. You have a bad trans input shaft bearing.
When the clutch is engaged, does not matter if the trans is in neutral or in gear, the trans input shaft is locked through the clutch disc to the flywheel. Thus the pilot bearing is not being rotated/used.
One correct answer before me. You have a bad trans input shaft bearing.
At any rate I checked with a trusted local shop. He confirmed it, but it doesn't sound like it's going to be as expensive as I thought to replace that bearing with me R & R'ing the transmission myself. Have been considering a Street-lite FW anyway. Maybe this winter is the time.
09-19-13, 07:59 PM
#11
I guess "Bad" is a matter of degree - At about 30,000 miles I noticed that the bearing was louder than I would like. I asked the best FD mechanic I knew to listen to it. He said it sounded normal and was not a problem. In the 20,000 miles since then it hasn't failed or even gotten noticeably louder. All bearings make some noise, and they get louder with mileage and use. The transmission still runs and shifts fine. If the noise gets worse or other symptoms develop, I'll just replace the bearing or the transmission.
09-19-13, 08:23 PM
#12
I don't think that's the input shaft bearing. I had a Triumph TR3A with that problem. That model did not have syncromesh in 1st, and mine was missing a few teeth on one of the gears. Big clunk in 1st and Reverse. I drove it for quite a while until one really cold morning when one of the loose teeth got caught up and jammed the transmission. I replaced it with a full-syncro transmission from a TR4.
09-19-13, 09:57 PM
#13
09-19-13, 10:25 PM
#14
Ahhh, the ol' FD input shaft bearing....
My input shaft bearing was noisy from the very beginning; when brand spanking new. I took the car to Mazda for warranty service and almost got a new tranny from them until one of the techs noticed that all of the FD's seemed to have the problem....and so they called it normal operation, which in reality, it is--for the FD. Don't know why these particular bearings are so noisy. Still regret not getting a new tranny under warranty (at about 45k miles). Lol.
My input shaft bearing was noisy from the very beginning; when brand spanking new. I took the car to Mazda for warranty service and almost got a new tranny from them until one of the techs noticed that all of the FD's seemed to have the problem....and so they called it normal operation, which in reality, it is--for the FD. Don't know why these particular bearings are so noisy. Still regret not getting a new tranny under warranty (at about 45k miles). Lol.
09-20-13, 09:10 AM
#15
I replaced my clutch & flywheel in March of 2003. I installed new pilot & throwout bearings. Before I did the job, I had no noise. After installation, I had the noise you are referring to. I still have the same noise, and it has not gotten worse in more than 10 years of driving, which is around 24,000 miles. Although the miles are low, there have been many autocrosses, and a lot of spirited driving. I have no intention of doing anything about it.
09-25-13, 03:00 PM
#19
If you plan to fix it, you mine as well rebuild the transmision because the input bearing is the last bearing on the shaft so everything must come apart. I did mine in 2008 and all new bearings and synchros were about $500 from Malloy.
Shortly after I went single turbo and with less than 4K miles on the rebuild stripped 3 or 4 teeth off 3rd gear. In retrospect, the low milage JDM transmission people are suggesting is not a bad idea.
Jack
Shortly after I went single turbo and with less than 4K miles on the rebuild stripped 3 or 4 teeth off 3rd gear. In retrospect, the low milage JDM transmission people are suggesting is not a bad idea.
Jack
09-27-13, 02:30 PM
#21
It wasn't quiet but the video makes it sound much worse because I was actually using a remote microphone plugged into the camera and the mic was literally sitting on the floor under the tranny (you can see it in the beginning of the video).
rocker switch controls my intercooler and oil cooler fans, I only use those when I'm at the track
rocker switch controls my intercooler and oil cooler fans, I only use those when I'm at the track
09-27-13, 11:28 PM
#22
Mine seems to quiet alot once wamed up.
If I absolutely was certain of mileage on a jdm trans. that would be one thing. Trouble is... EVERY JDM trans. seems to be low mileage but no guarantees. Since I KNOW how many miles and treatment mine has had, I plan on fixing it. Besides...I like the taller 5th.
If I absolutely was certain of mileage on a jdm trans. that would be one thing. Trouble is... EVERY JDM trans. seems to be low mileage but no guarantees. Since I KNOW how many miles and treatment mine has had, I plan on fixing it. Besides...I like the taller 5th.
