H vs F speed sensor

[preludeman92]

Hey guys, my h22 trans grinds really bad (into 2,3,5, can't find first, and pops out of 4th) and leaks from to input seal. I need to do a clutch in the near future so I'm gonna put in a new trans while I'm there. Being a prelude chassis it and all it's electronics are designed for the h trans. The trans I have my eye on is an f23 trans because it's cheap and has long gears for highway cruising... I drive 100+ miles on the highway everyday so I'd like lower revs and high mpgs to go with it.
I know the trans physically fits but I'm concerned with the speedometer being wrong.

When you guys go from an F trans to an H trans is your speedo still correct? I ask only because the speedo sensor is driven off the final drive which is different between h and f. Didn't know if the sensor needs to be swapped to make sure the correct sensor is in he chassis or on the trans.

[GreenMadness]

to keep it simple, use the sensor with the transmission. so if you put the f23 in keep the sensor that came on the transmission.

Honda speed sensors are driven off a separate plastic gear that is on the differential. not the actual final drive gear.

*** Not sure, but the gear pitches may vary between speedometer gears on different transmissions, if that is the case, than the sensor will only mate up correctly with the gear of the right pitch. if you mixed them you would chew up the plastic teeth on either the senor of the transmission.

*** Other theory (more likely), still not sure, but they could have just kept the pitch the same and sized the gears different, in that case the gear would mate up, but possible give and error in speed.

either way, i think the speed compensation is taken care of in the transmission and the dash board is just a gauge, it only shows the "speed" the sensor sees.

i have gone to an h23 transmission, kept the sensor and just plugged it in. Its good enough to obey speed limits with. But i never run the right ratio tires anyways (its always cheaper to run civic ratios)

so unless you know for a fact that your ratios are properly sized to the stock ratio your speedometer isn't correct anyways.



*edit, also sounds like your running your transmission dry. its a little late now but with a leaky seal you should keep a close eye on the fluid level.

[preludeman92]

Yeah, I agree the trans isn't staying full and that's part of the problem, but it would always grind 5th since I've had it. Stupid 5th gen prelude transmissions have weak shift arms. The other factor in the prooblem is the previous idiot owner(s). It's only gotten really bad in the last week or so when it apparently got low enough to be a problem. I put about a 1/2 quart into the trans and only caused the leak to show back up.

It occured to me when I saw my mom's accord today... those accords have taller tires than CB's and preludes. I wonder if that'll cause problems for me. I know a couple people that have put an h22 trans into those accords, but I can't ask them questions now since their forum is offline right now.

I run stock wheels and correct tires since this is supposed to be my reliably daily driver.

[CB7xTURBO]

yes put the f23 speed sensor.. tho the f23 speed sensor doesnt have the hoses that the power steering fluid goes through ( well for cbs we have these ps hoses going in and out of vss ) .. so u have to loop it.. i made that mistake since i have a f23 trans i used my f22 speed sensor and it messed up the gear on the f22 one..

[preludeman92]

I'm pretty sure the VSS lines aren't hooked up on my car anyways due to the incompetence of whoever did the manual trans swap.

[bruno8747]

Yeah, I agree the trans isn't staying full and that's part of the problem, but it would always grind 5th since I've had it. Stupid 5th gen prelude transmissions have weak shift arms. The other factor in the prooblem is the previous idiot owner(s). It's only gotten really bad in the last week or so when it apparently got low enough to be a problem. I put about a 1/2 quart into the trans and only caused the leak to show back up.

It occured to me when I saw my mom's accord today... those accords have taller tires than CB's and preludes. I wonder if that'll cause problems for me. I know a couple people that have put an h22 trans into those accords, but I can't ask them questions now since their forum is offline right now.

I run stock wheels and correct tires since this is supposed to be my reliably daily driver.

I've never seen a plastic gear in the speed sensor area.

And the 2 lines that are on the vss are for the power steering. If you want to use the new sensor without the ports, Just loop the 2 lines on the crossmember and you will be fine. There was never a problem that i have seen with the speed being off with using different vss with different f/h tranny.

[GreenMadness]

I've never seen a plastic gear in the speed sensor area.

you may be right, i broke one on a d16 transmission when putting diff bearings on, but when i was swaping cases i think the diff did only have one gear.

in that case a VSS would only work from a car with the same final drive.

[Losiracer2]

I've got a H23 VSS in my H22 5spd trans and it still reads right? I think the OBD 1 sensors are interchangeable. Don't know about the F23 though.

[preludeman92]

^^^The H23 and H22 transmissions use idential final drives. Nothing to do with OBD1/OBD2. I looked at my mom's accord last night when I was fixing a flat tire on it. The plug to the speed sensor looks the same as the one on my prelude.

I just checked a couple tire size calcs and it looks like the difference between actual speed and indicated speed will be very small if the speed sensor ends up reading like it belongs on the newer accord. I can live with that.

Just to be clear, people with H transmissions don't have speedometer problems (assuming correct tire size)

[CB7Man]

If it bolts in it works!
I have a USDM H23 speed sensor on my T2T4...(Basicly an F23 tranny, except F20B)
The gear for the speed sensor was shorter, but I've never had a problem and I've been driving it for 10K+ miles now

[NAiL05]

Its the same I had no issue with speedo being off.