Gear Grind??? What's the real deal???
02-17-2002, 09:57 AM
#11
Demands on the S2000 syncro
02-17-2002, 10:39 AM
#12
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dlq04 is exactly describing my experience/guess about this.
Chris: I too said it was a transmission flaw in the last sentence of the second paragraph.
Try and read the whole post before you tell me I don't know what I'm talking about. There is time enough then...
Chris: I too said it was a transmission flaw in the last sentence of the second paragraph.
Try and read the whole post before you tell me I don't know what I'm talking about. There is time enough then...
02-17-2002, 03:26 PM
#14
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The problem was evident in my car was evident early on. In the first couple of months.
At first I thought it was my driving. After to talking to a Honda person at a club event I was further convinced that it was my driving. But of couse this was just another dumb Honda rep that did not know what he was talking about.
I had to demo the problem to my dealer. I made sure the car was at full temp (i.e. 45Min drive). My dealer said they could not check out the problem. I pushed them to check the car anyway just to confirm that it was not my driving technique.
The dealer then arranged Honda techs to review the problem.
I then had to wait over a month for the fix to come from Japan as my car was one of the first fixed.
The bottom line is to know how to recreate the problem, and then demonstrate to your dealer.
Cheers
At first I thought it was my driving. After to talking to a Honda person at a club event I was further convinced that it was my driving. But of couse this was just another dumb Honda rep that did not know what he was talking about.
I had to demo the problem to my dealer. I made sure the car was at full temp (i.e. 45Min drive). My dealer said they could not check out the problem. I pushed them to check the car anyway just to confirm that it was not my driving technique.
The dealer then arranged Honda techs to review the problem.
I then had to wait over a month for the fix to come from Japan as my car was one of the first fixed.
The bottom line is to know how to recreate the problem, and then demonstrate to your dealer.
Cheers
02-17-2002, 03:26 PM
#15
Originally posted by markpenske
FOLLOWUP QUESTION: On the cars with the problem, Is this a problem that is there from day one? or is it something that develops over time?
Thamks
FOLLOWUP QUESTION: On the cars with the problem, Is this a problem that is there from day one? or is it something that develops over time?
Thamks
02-17-2002, 03:42 PM
#16
I have not had the grind problem (knock on wood) except for that rare sloppy shift we all do from time to time. However, I have had a notchy intermitant shift between 2nd and 3rd from the time I picked up the car, so I have followed the issue. My condition has improved with wear-in (8,000 miles) and with the fractional pausing in 2-3 shifts described above.
Like cdelena has suggested I think it may be a close tolerance issue. I plan a fluid change in the spring. If things don't get worse, I won't complain. Time will tell.
Like cdelena has suggested I think it may be a close tolerance issue. I plan a fluid change in the spring. If things don't get worse, I won't complain. Time will tell.
02-17-2002, 06:14 PM
#19
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Been reading the posts and couldn't resist...
dlq04 and his Honda engineer have explained the situation quite well...but it's actually WORSE than described.
Most people don't know this but NO gears change actually change position when you shift. What happens is the shifter fork slides a sleeve over a portion of the gear that then connects it to the main or countershaft which then fixes its position allowing force to be conducted from the engine to the wheels. Any time that a gear is engaged, a PAIR of gears is connected....one fixed to the shaft (either main or countershaft), the other fixed to the shaft (either main or countershaft) by a sleeve that slides into position over the brass synchronizer ring(s).
Yes, the mainshaft is rotating at 9000rpm when you disengage the clutch to shift. However, I believe 1st and 2nd gear and their synchros sit on the COUNTERSHAFT on Honda 6-speeds, not the main shaft....so at the instant the clutch is released 1st gear is engaged, 2nd gear is freewheeling but CONNECTED to 2nd gear on the mainshaft which means 2nd gear on the countershaft is spinning well over 9000rpm! So when you smash through the 1/2 gate into 2nd in 3 nanoseconds you have to slow 2nd gear down from approx. 10000prm to 6500rpm which means you have to also slow 2nd gear on the mainshaft and 1st gear on the mainshaft and the mass of the mainshaft and the clutch disc spinning at 9000rpm. That's why many trannies have two synchronizers for first and second.
That's a LOT of work for a brass synchronizer that's a half inch thick and the sliver of the synchronizer ring that accompanies it.
Also, let's say the tranny wasn't shimmed right and 3rd gear (which sits right "above") second gear has too close a gap to allow free movement. THEN 3rd, 4th, 5th and 6th gear have a "slight" connection to second gear and THEY also have to be slowed down for 2nd gear to engage.
This might also explain why there is more grinding when the tranny oil heats up. It is less viscous and the synchro require more force to produce friction and slow 2nd gear down.
After taking one of these 6-speeds apart in an NSX I'm surprised the gears don't grind MORE given the RPMs they run at and the torque they transmit.
Wei-Shen
01 Spa Yellow
dlq04 and his Honda engineer have explained the situation quite well...but it's actually WORSE than described.
Most people don't know this but NO gears change actually change position when you shift. What happens is the shifter fork slides a sleeve over a portion of the gear that then connects it to the main or countershaft which then fixes its position allowing force to be conducted from the engine to the wheels. Any time that a gear is engaged, a PAIR of gears is connected....one fixed to the shaft (either main or countershaft), the other fixed to the shaft (either main or countershaft) by a sleeve that slides into position over the brass synchronizer ring(s).
Yes, the mainshaft is rotating at 9000rpm when you disengage the clutch to shift. However, I believe 1st and 2nd gear and their synchros sit on the COUNTERSHAFT on Honda 6-speeds, not the main shaft....so at the instant the clutch is released 1st gear is engaged, 2nd gear is freewheeling but CONNECTED to 2nd gear on the mainshaft which means 2nd gear on the countershaft is spinning well over 9000rpm! So when you smash through the 1/2 gate into 2nd in 3 nanoseconds you have to slow 2nd gear down from approx. 10000prm to 6500rpm which means you have to also slow 2nd gear on the mainshaft and 1st gear on the mainshaft and the mass of the mainshaft and the clutch disc spinning at 9000rpm. That's why many trannies have two synchronizers for first and second.
That's a LOT of work for a brass synchronizer that's a half inch thick and the sliver of the synchronizer ring that accompanies it.
Also, let's say the tranny wasn't shimmed right and 3rd gear (which sits right "above") second gear has too close a gap to allow free movement. THEN 3rd, 4th, 5th and 6th gear have a "slight" connection to second gear and THEY also have to be slowed down for 2nd gear to engage.
This might also explain why there is more grinding when the tranny oil heats up. It is less viscous and the synchro require more force to produce friction and slow 2nd gear down.
After taking one of these 6-speeds apart in an NSX I'm surprised the gears don't grind MORE given the RPMs they run at and the torque they transmit.
Wei-Shen
01 Spa Yellow
02-17-2002, 06:21 PM
#20
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This problem is in no way a driver related error. It is a flaw with the transmission. People have shifted with the clutch all the way in and they still get the grind sometimes. The transmission on this car needs alot of improvement in terms of smoothness and the grind problem. Do a search on the 1-2 grind and you'll see how many owners have experienced this problem. The ones who don't have it always think it's a driver related error!