Help Tranny Problem

willysunit5 · #1 02-19-2007, 11:50 AM

I WANNA KNOW IF A 88-91 HF CIVIC/CRX 5 speed TRANSMISSION WOULD FIT MY 91 civic HATCHBACK

and if it does fit would it be good for racing

CRXperiment · #2 02-19-2007, 02:09 PM

Yes it will. Make sure you know the year of the tranny as the 88 uses a different spline count clutch as the other years. Is your hatch currently an STD? Because i wouldn't even consider going through the trouble unless your current tranny is 4 spd. The HF tranny has a LOW final drive and LONG gears. It will not be good for performance, but you'll get great gas mileage.

FrodoGT · #3 02-19-2007, 02:16 PM

VERY BAD for racing.

willysunit5 · #4 02-19-2007, 02:26 PM

Quote:

Originally Posted by CRXperiment

Yes it will. Make sure you know the year of the tranny as the 88 uses a different spline count clutch as the other years. Is your hatch currently an STD? Because i wouldn't even consider going through the trouble unless your current tranny is 4 spd. The HF tranny has a LOW final drive and LONG gears. It will not be good for performance, but you'll get great gas mileage.

yea my current tranny is a 4 seed

willysunit5 · #5 02-19-2007, 02:29 PM

Quote:

Originally Posted by CRXperiment

Yes it will. Make sure you know the year of the tranny as the 88 uses a different spline count clutch as the other years. Is your hatch currently an STD? Because i wouldn't even consider going through the trouble unless your current tranny is 4 spd. The HF tranny has a LOW final drive and LONG gears. It will not be good for performance, but you'll get great gas mileage.

yea it is a std

91S10 · #6 02-21-2007, 09:01 AM

So your saying that the 4 spd is better for racing then the 5spd cause you can run the gears longer?

FrodoGT · #7 02-21-2007, 11:14 AM

Not saying EITHER are good for racing lol. although I have seen inctances where because a car had a longer gear, it got faster times because he didnt have to shift again before he hit the 1/4 mi. While the shorter geared car had to hit 3rd. But still, the hf trans blows unless your planning on riding the interstate, and even then it has no balls as far as gearing goes. Try running 2.5k rpm down the highway and trying to pass anything lol

Tony · #8 02-21-2007, 12:10 PM

The DX(I'm assuming the HF is the same) tranny is pretty much your 4 spd with an overdrive. don't expect 5th gear to really get you any speed. I have hit 105-110 in 4th gear before, shifted to 5th and drop below 100, it ended up picking back up, but took awhile to do it.

From what I understand, I know the SI tranny has shorter gears and I believe the EX is in between the SI and DX trannies.

But a general rule on swapping transmissions on Hondas, if its for the same engine series(D series for this case), they will usually interchange. There are a few exceptions like the 88 transmissions, and the 92+ will fit, but gotta convert to hydraulic.

CRXperiment · #9 02-21-2007, 01:38 PM

Quote:

Originally Posted by Tony

The DX(I'm assuming the HF is the same) tranny is pretty much your 4 spd with an overdrive. don't expect 5th gear to really get you any speed. I have hit 105-110 in 4th gear before, shifted to 5th and drop below 100, it ended up picking back up, but took awhile to do it.

From what I understand, I know the SI tranny has shorter gears and I believe the EX is in between the SI and DX trannies.

The HF tranny has completey different gearing than the DX and has the lowest final drive of all trannies (around like 2.93:1). The DX and SI actually have the same gearing but the SI tranny has a much high FD (around 4.35:1). Bottom line, if you want to build a turbo/ all motor D, your best bet is picking up an SI tranny, hard to find now a days.

Tony · #10 02-21-2007, 04:39 PM

Ok, thanks for correcting that CRXeperiment. That final drive makes a big difference between the DX and the SI. The 5th gear on the DX is pretty much overdrive, nothing more.

mudbuddha · #11 02-25-2007, 10:28 PM

I have the PL3 - 000A 5 speed, 89 tranny with 20 splines variety... Not sure if this is an SI tranny or not - can anyone tell me? Anyways, it's pretty zippy and I get 27mpg mostly with highway use.

mudbuddha · #12 02-25-2007, 10:28 PM

I have the PL3 - 000A 5 speed, 89 tranny with 20 splines variety... Not sure if this is an SI tranny or not - can anyone tell me? Anyways, it's pretty zippy and I get 27mpg mostly with highway use.

CRXperiment · #13 02-26-2007, 12:54 AM

Quote:

Originally Posted by mudbuddha

I have the PL3 - 000A 5 speed, 89 tranny with 20 splines variety... Not sure if this is an SI tranny or not - can anyone tell me? Anyways, it's pretty zippy and I get 27mpg mostly with highway use.

Generally ID numbers won't tell you what kind of tranny you have. There is a way to figure out exactly what tranny it is by rotating the crank and counting the number of turns at the differential. You can also just tell us what rpm your at when doing like 75. It sounds like you have an SI tranny though.

DuiSonOfDarp · #14 02-27-2007, 10:08 AM

Woah only 27 on hwy, I'm gonna stick with my HF tranny I did a little over 100 miles on two maybe two and a half gallons, mostly hwy.

CRXperiment · #15 02-27-2007, 12:43 PM

Quote:

Originally Posted by DuiSonOfDarp

Woah only 27 on hwy, I'm gonna stick with my HF tranny I did a little over 100 miles on two maybe two and a half gallons, mostly hwy.

Yeah for gas mileage definitely stick with the HF tranny. Granted, its slow and all but its a commuter car so it was built that way. I miss the gas mileage my old std civic used do get with a dx tranny. Now my crx gets nowhere near what I used to get. Unfortunately, Si rexes are heavy (better stuff) and the si trans is geared too quick, even on the highway.

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