rpm vs speed
#11
05-11-2017, 12:13 PM
I drove it on side rural roads yesterday to get a feel for the shifting. there are for sure 4 speeds of motion. 1-2 is pretty obvious. but it goes into 3 pretty fast and will wind up to 4k before it will shift to 4. I can lift off and make it shift to 4th and the rpms will drop by 1000 at least. I can cruise in 4th gear at 40 mph @2500rpm? and than shift to 3 and it will rev up to 3200 or so. is it slipping in all gears?
#12
05-11-2017, 12:16 PM
I'm 95% sure there is no TC lockup in 1st gear and more like 60% sure there is no lockup in 2nd. As for a two to three hundred RPM delta, that varies depending upon load; as I wrote in my post earlier today, I saw 500 RPMs below and 450 RPMs above the steady-state 2000 RPMs at an indicated 60 mph.
#13
05-11-2017, 03:25 PM
Thinking back to this morning, the tach needle was just above 2000 at an indicated 60, so maybe somewhere in the 2000-2050 RPM range. I then did the math on the 205/65 R15 tire size and came up with a circumference of 80.086", and this in turn works out to 791.1507 tire revolutions per mile. Assuming the engine to wheel revolution ratio of 2.562 is correct, then my math suggests the engine revolutions per mile should be 2,027 (which at 60 mph would equate to 2,027 RPMs).
#14
05-11-2017, 04:29 PM
In a 4-speed automatic there aren't 4 actual shifts (post #5).
With 3k rpm at 60mph, it seems plausible that the "shifts" felt by Cavell are really:
1st-to-2nd
2nd-to 3rd
3rd-locking up
So..... the REAL question is what wrong with his transmission?
With 3k rpm at 60mph, it seems plausible that the "shifts" felt by Cavell are really:
1st-to-2nd
2nd-to 3rd
3rd-locking up
So..... the REAL question is what wrong with his transmission?
#15
05-11-2017, 05:05 PM
2000 rpm at 60mph in 4th with a 0.61 overdrive
so what rpm would you be at in 3rd gear at 60 mph?
4.20 -- Final Drive Ratio
2.53 -- 1st Gear
1.50 -- 2nd Gear
0.95 -- 3rd Gear
0.61 -- 4th Gear
so what rpm would you be at in 3rd gear at 60 mph?
4.20 -- Final Drive Ratio
2.53 -- 1st Gear
1.50 -- 2nd Gear
0.95 -- 3rd Gear
0.61 -- 4th Gear
Last edited by Cavell; 05-12-2017 at 12:06 PM.
#17
05-17-2017, 06:29 PM
The issue could be the PCM is faulty and not sending the signal to shift at the right time.
I know you have a few threads going, but have you checked for codes?
Check that G101 (#26 in the attached picture) has a clean and secure connection. You may want to disconnect the battery, disconnect G101, clean the eyelet, bolt, etc. with a wire brush or sandpaper, the reconnect.
I know you have a few threads going, but have you checked for codes?
Check that G101 (#26 in the attached picture) has a clean and secure connection. You may want to disconnect the battery, disconnect G101, clean the eyelet, bolt, etc. with a wire brush or sandpaper, the reconnect.
#20
05-18-2017, 07:56 AM
thermo housing has a temp sensor too. which I believe is for the cooling fans. lots of info online about the G101 ground. I will check any and all grounds that I can find. interesting that pic has battery removed to show this view. maybe motor is on engine stand at Honda?
Last edited by Cavell; 05-18-2017 at 09:22 AM.
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