Help Identifying Transmission: KA Motor, Non-KA Transmission

[Dzaster]

I was told my previous owner that he thinks the transmission was from a late 70's Datsun truck. The motor and trans are in the car so I just have a few pics of what I can capture with what little is revealing.

 

Anybody know from the pics or can suggest a way to ID while transmission installed?

 

Thanks

 

[datzenmike]

Pictures don't show much. You should have mentioned it was an S13 motor.

 

FS5W71C 5 speed. (there were 71C 4 speeds but unlikely used here)   Make it an FS5W71B from a Z22 or Z24 720. The 510 slave will work but it's different to use the 510 4 speed's adjustable clutch arm.

[Dzaster]

I'm not even sure its a 240sx motor. That was going to be another ID thread, but I was looking over some other discussions about the block differences. It's a little vague to me, but I think I recall the PO being a little unsure if it was car or truck KA.

 

BTW, it is 5spd I believe. lol I haven't driven much highway so don't recall if I put it in 5th. I may have, don't recall.

 

Here's another pic and from the looks of it--didn't notice at first--the lower portion of the bellhousing here is open. I'll need to confirm when I get home, but that sure does look to be the case in this pic.

 

 

 

 

 

 

 

Also, the shifter is pushed back several inches from stock 510 location.

 

 

 

 

 

 

I'm only home weekends so just last weekend I thought it wise to snap a bit of pics to help research putting this thing together.

[datzenmike]

 

This shows it's definitely a KA car block. I'm assuming a KA24E and not a DE by the curve of the intake runners.

 

 

 

 

Custom oil pan fooled me.

 

The most likely and sensible transmission is the one that came with this motor, which would be some kind of 71C. For sure the one in the picture was made after October '80 and clearly not a 70s truck. But it's too short for an S13 5 speed so lets make that an FS5W71B from a 720. It's from a truck as the previous owner seemed to recall and the earlier Z series transmissions will bolt perfectly to the KA motor.

.

[Dzaster]

Right on! I'll dig around some see what I can find.

 

First thing I was wondering was roughly how much HP the tranny would be good for. Its been rebuikt I was told and it shifts fine no grinds so nothing to make me think otherwise.

[datzenmike]

Well about 150 (gross) hp on the 240z back in '72 (as a 4 speed) and 180 (net) hp on the non turbo 280zx in '83. It's always been used on the Z24 810/Maxima and 620 and 720 trucks. But it's the torque that really stresses a transmission. In '85 a larger counter gear and better oiling for it was added as engines were getting larger. But it was only to last another year and a half anyway. Say 180 -200 ft lbs. It was fully replaced by the 71C in '86.5 although first used on the new 300zx VG30 non turbo motor in '84. The 71C is so strong it is used to replace exploded T-5 300zx turbo 5 speeds and reliably handles 400 hp

 

The 71B will handle an n/a KA24E or DE.

[Dzaster]

Great info thank you.

 

And the 71C is dimensionally different from the 71B? I know my driveshaft was shortened for this current transmission.

 

Also, my pan, that's a custom piece right? it's gotta have a modded pickup too right?

[datzenmike]

The driveshaft would have had to be shortened by 5 1/2", yes.

 

The 71C are at least two lengths and both are slightly longer than the 71Cs.

 

The KA pan will not clear a 510 front crossmember. The way around that is to cut a section out turn 180 and weld back in. Course then your sway bar does not fit. Another is a custom oil pan... welded up like yours. The oil pickup on a car KA is to the front so possibly a truck KA pickup was used or custom made

[Dzaster]

Right on Mike! Thanks for the info. Gives me a good base to start my research on beefing up drivetrain. I'd like to be able to bang on gears and not be too concerned because I hadnt done anything to strengthen drivetrain.

 

So the 71C's should bolt up to block. Wonder if trans mount will bolt up as well?

[Xnke]

I would say that's a post 81, pre 84 71b transmission. If it's bolted up in the stock truck, on the stock mounts, it's probably a Z22 or Z24 transmission.

 

The 71C debuted in the US 1984, and recieved incremental upgrades throughout its life. Basically, the 71B was over when the countershaft bearing went to 62mm. There are some of the 71B type shifters on what is actually a 71C gearset, these were mostly just 71B replacement transmissions...what you would get going to nissan to buy a new trans after they ran out of 71B stuff. I have one of these "OEM Replacement frankensteins" in my garage floor.

 

In 1984, the 71C got a nicer shifter and the bigger countershaft bearing, which it needed since one of the major failure points of the 71B was the front countershaft bearing. These boxes have basically the same gears and synchros as the 71B. The big bearings came to play when Nissan put this box behind the VG30E in the 300ZX and in the torqueier truck motors.

 

In 1986.5, the synchros change up, and the 2nd gear synchro becomes a double-cone unit in most applications. Still got the big countershaft bearing, still have the nicer shifter. Bolt pattern for the shifter is the same as the 1984 models...but that changes in 1989. 200SX shifter and 240SX shifter are not quite the same...but can be worked to interchange them, if you have a file or a die grinder and a drill press.

 

Along the way, the gears get stronger and thicker, starting in 1972 with 16.6mm thick, 1981 the input shaft and counter drive go to 18mm, but the rest of the gears remain 16.6mm. In 1984, the gears become 18mm thick, with the input shaft set 20mm or 22mm depending on application. In 1987, the gears are still 18mm thick, with the exception of 1st, which is 20mm, and the input shaft set is 20mm or 22mm, car or truck. I don't have a car transmission to measure yet for the 1989-1997 years, but I do have a 1997-98 truck transmission apart right now.

 

Input shaft gear is 24mm thick, but counter drive is 22mm with 2mm spacer gear, 1st gear 24mm thick, 2-3 gears are 22mm, 5th is 18mm thick. Synchros are larger diameter for 1-2 starting in 87 or 89...I've seen transmissions from both years with the bigger 1-2 synchros, but can't say for sure they are original to the year. 2nd gear is a "double" cone, but actually has 3 friction surfaces, making it equal to a triple-cone synchro you hear about in the new boxes, in this 1997 box. 1st gear also has a lower helix angle, making it stronger but noisier.

 

In all of these boxes, the transmission mainshaft length is a variable. Trucks got shorter tailshafts up to the D21 hardbody, then trucks and cars usually got the 33.5" OAL boxes. The 200SX from 1984 to 1988 got a 31.5" length box, but the 300ZX got the 33.5" unit too.

 

The 200SX box is the same length as a 1970-1983 Z car box, but like the 33.5" OAL boxes, the mount is two inches further back. I need to put a tape measure on the next 620/720 I see in the parts yard, because I can't remember the OAL or the transmission mount location for those gearboxes.

[Dzaster]

So further speculating this is, indeed, a 71B transmission, I'll assume its still as Mike suggested that this tranny be good for 150hp.

 

Xnke, I'm not sure if you're thinking its bolted up in a truck, but just in case, it isn't. Its in a '70 510 wagon, with a KA24e soon to be turbo'd. Hoping to be rolling with a good 250+hp.

 

In the event this tranny does give up the ghost, is there a certain year car I can pull a tranny from and have it bolt to the KA with maybe mount and driveshaft length modifications?

[Dzaster]

Found the raised stamp on gearbox stating its a 71B. Thanks guys.

 

Wonder why they never used the KA transmission?

 

Size....mount.....?

[datzenmike]

Availability. The S13/S14 71Cs are longer again than the 71B and will move the shifter back some.

 

I see it's a wagon. It's possible that the owner used the 71B because you can swap it into a goon by using a sedan driveshaft (it's shorter and within an inch of perfect length) so no shortening expense needed.

[Xnke]

All the 71-series transmission say "TA71B" or similar on the side of the front case. Even the 1997 box in my floor says 71B on it...it's clearly not. Think about it...the 71B transmission was retired in 1983, the KA didn't even exist till 1989...

 

If that trans is behind a KA24E engine, then it's had the bellhousing swapped over...that transmission tailshaft housing is older than the engine. Only reason I can think of to do that is the OAL of the transmission.

 

The transmission can handle more than 150HP...it was used behind 150HP L28's in the Z car, and there is always a safety factor built in. Usually the 71B can handle 250-275HP very reliably in a 2700lb car.

[datsunaholic]

The 71B wasn't retired in '83.  It was used in all manual 720s- through end of production in the '86 model year.  Probably later too.

[Dzaster]

One more question regarding my motor/transmission combo. I'm looking to upgrade my clutch, press. plate and possibly flywheel (since I'm in there).

 

Should I be looking at KA24 clutch kits or something else that matches transmission.

 

Im unsure what clutch kit is in there now.

[Dzaster]

Also, went out to look at the bell housing stamp again and found TL 71B #1.

 

In searching I found this little transmission specs compilation, but my stamping isn't listed.

 

http://www.ctteamtech.com/ct/Internal1/Trans_ID_Specs/Foreign/Manuals/FS5W71.htm

Anyone know what that might have come out of?

[datzenmike]

All the 71-series transmission say "TA71B" or similar on the side of the front case. Even the 1997 box in my floor says 71B on it...it's clearly not. Think about it...the 71B transmission was retired in 1983, the KA didn't even exist till 1989...

 

If that trans is behind a KA24E engine, then it's had the bellhousing swapped over...that transmission tailshaft housing is older than the engine. Only reason I can think of to do that is the OAL of the transmission.

 

The transmission can handle more than 150HP...it was used behind 150HP L28's in the Z car, and there is always a safety factor built in. Usually the 71B can handle 250-275HP very reliably in a 2700lb car.

.

Well one of my Bs had ZL71B

 

Another said CA71B

 

 

 

 

 

 

The 71B was retired from the 280zx non turbo in '83, but as Doug said it was used through '86.5 till the end of the 720 and the S12 switched to the 71C after '86.5. The Maxima also used the 71B through '84 when it changed to FWD.

[Dzaster]

I wound up just pickup up a KA24 clutch and flywheel and ARP bolts. Hopefully it goes together well. Thanks.

[datzenmike]

Measure the diameter of the clutch disc. If the replacement is the same diameter then the release collar on the clutch arm should work with it. Truck and car KA clutches were different diameters and the release collar is matched to the clutch size. They don't interchange.

[Dzaster]

Haven't pulled motor yet so not gonna to be able to measure until then, but I did check into that and you're right, its about a half inch in difference.

 

I bought clutch parts and flywheel for 240SX. The previous owner said they put the motor together as a car KAE and not a truck so hopefully that holds true for transmission components as well.

 

In the case it I find it has a truck collar and clutch kit, in order to get my car clutch kit to work, can I just change the collar to a car's?

 

Like this: http://www.frsport.com/Nissan-OEM-Clutch-Release-Sleeve--SR20DET--VG30--S13--KA_p_60127.html?gclid=CI6ws-jQmLcCFcF_QgodDBgAGw

[Dzaster]

I wasnt able to get the seller of the clutch I bought to offer me a cost effective shipping option so I'm being refunded. Was a little bothered at first but I think it works out in my favor. For the same price I'll put together a "White Bunny" kit but with Fidanza lightweight flywheel and Sachs clutch kit.

 

I think its a better option and the full faced clutch should make for a much more pleasant around town cruiser.

[datzenmike]

The only part of the transmission that is clutch related is the release bearing collar. You can run ANY clutch and flywheel combination as long as the collar matches it.... with any 4 or 5 speed that will bolt to the motor. The White Bunny is a good option.

[Dzaster]

Thanks a ton for the help Mike.

 

I scored it all with the Fidanza flywheel for $400 shipped to Hawaii. Pretty stoked about that.

 

And going back to one of your replies, being that I bought a D21 clutch kit, I will need a D21 compatible bearing collar. Sound about right?

 

Edit: I did a quick search and the few bearing collars I found being sold stated compatible with both D21 and 240SX.

[Dzaster]

Anyone know if a B&M Short Shifter Kit for the KA/SR transmission will work with my transmission (pictured and discussed here)?