s13 tranny swap

[Dream240]

Okay, did the search, no luck, and I have tons of backup paperwork but, no clarification on the compatibility of the trannys. I have a 91' hatch and I have all the parts I need save the tranny.

I had a s14 tranny a while back but the rebuild attempt failed due to my laziness, rain, and alot of rust......so I'm currently looking for another tranny.

I have been searching for a DOHC tranny but I'm noticing that there's alot of SOHC trannys out there. Now are these compatible? Is it just a matter of the bell housings being different? If so that's an easy swap. Also is the gearing different?

Any info would be greatly appreciated.

[dct223]

s13 sohc tranny will work on your dohc engine without a prob. you dont need to swap bell housings. not sure if there was a difference between s13 dohc and sohc gearing though.

[Jadeskyline]

^^That is correct i drove around with a sohc tranny for three months no problems. Third gear felt a little different to me but i'm weird like that:cool:

[SochBAT]

KA tranny = KA tranny. Only difference is the mating of different engines.

I also read somewhere the KA tranny is the same as the SR tranny, just different bellhousings. I've got a feeling its true, but can't find the sourcing. Just a tidbit of random info.

[dct223]

yes... all KA tranny's use the same bell housings..

yes a KA tranny will work on a SR and vice versa if you swap bell housings..

no, not all trannys have the same gear ratios.

[Dream240]

thanks guys for the help.

I'm going to see if I can find the gear ratio differences. I'll post them up if I find anything.

[orion::S14]

All KA trans are the same...the difference is the sensors. If you use a SOHC trans on a S14, you'll be missing a sensor or 2, and you'll have the wrong VSS.

VSS's are expensive, so it's often cheaper to buy a trans that has the correct speed sensor...even if it's $50 more.

The SR trans has minor difference like a double synchro on 2nd, and a slightly different 5th gear ratio.

That's it.

- Brian

[Dream240]

okay that was easy....

got this from 240sxforums.com, great forum BTW...

KA24DE Gear Ratios:
Manual
1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.759
Rev 3.657
Final Drive Ratio: 4.083

SR20DET Gear Ratios
Manual
1st 3.214
2nd 1.925
3rd 1.302
4th 1.000
5th 0.752
Reverse 3.369

CA18DET gear ratios
Manual
1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.838

I will find the KA24E ratios somewhere....

":edit:" .......2 HOURS LATER.

5 speed manual
KA24E
1st gear ratio: 3.285
2nd gear ratio: 1.850
3rd gear ratio: 1.272
4th gear ratio: 0.954
5th gear ratio: 0.740
reverse gear ratio: 3.428
diff ratio: 3.895

WHEW....

[Jung918]

Does anyone have the specs for the VSS for each year?

[orion::S14]

":edit:" .......2 HOURS LATER.

5 speed manual
KA24E
1st gear ratio: 3.285
2nd gear ratio: 1.850
3rd gear ratio: 1.272
4th gear ratio: 0.954
5th gear ratio: 0.740
reverse gear ratio: 3.428
diff ratio: 3.895

Sorry, that's bad info...looks like Z31 T5 ratios to me (?).

Notice the final drive is listed as 3.895...EVERY SINLGE USDM 240SX came with 4.083...no exceptions.

FWIW.

- Brian

[orion::S14]

Does anyone have the specs for the VSS for each year?

Huh?

The VSS matches the gauge cluster and ECU.

They are physically interchangeable for all the 5-speed models...but do not swap into auto trans or vise-versa.

SO -

'89-90
'91-94
'95-98

- Brian

[Dream240]

Sorry, that's bad info...looks like Z31 T5 ratios to me (?).

Notice the final drive is listed as 3.895...EVERY SINLGE USDM 240SX came with 4.083...no exceptions.

FWIW.

- Brian

hmph....

I was a little leary posting those KA24E specs based on the source. I'll keep looking.... And yeah you're right about the final drive gearing....

[Dream240]

okay I fail at searching......

This thread was my post from waaaay back in the newbie days.

http://www.zilvia.net/f/showthread.php?t=40204&highlight=GEAR+RATIOS

And this one answers all my questions. So....yeah I am an idiot.

http://www.zilvia.net/f/showthread.php?t=24153&highlight=GEAR+RATIOS

You'd think since I've been around the block I'd be more adept at this forum, but I've been taking a break from my 240s for the past year due to financial and work issues. Kinda sucks cause I'm feeling like I'm outgrowing cars, but then again I know all it will take is my next purcahse or upgrade and I'll be hooked again.

Thanks to all for the help. And I'm taking my own advice....SEARCH FIRST!!!

Later.

[projectRDM]

Huh?

The VSS matches the gauge cluster and ECU.

They are physically interchangeable for all the 5-speed models...but do not swap into auto trans or vise-versa.

SO -

'89-90
'91-94
'95-98

- Brian

Actually Brian, the SOHC uses the same unit, so it's 89-94.