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240 motor 5 speed swap


Guest Erich

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The previous owner of my car put an L28 motor and 5 speed transmission into it. I have blown up the motor purchased a nice running L24 motor that I am currently putting in and having a little trouble getting to mate up with the 5 speed.

 

I have seen a post that describes some 280z's having 4 speeds and some having 5 speeds put I want to make sure that this is a swap which can happen without any modifications.

 

So, is there a difference in the splines? are the pilot bearings different sizes? Is there anything that I would need to change before being able to seamlessly mate a 240 motor to a Datsun 5 speed? The 5 speed is out of a regular non turbo 280.

 

I was trying to get it in in the dark which could have been part of my problem and I also realize that the splines have to line up perfectly with the the clutch, I just want to make sure that is all that needs to happen.

 

Any advice would be greatly appreciated as I am doing this in my buddy's driveway and need to get that motor popped in ASAP.

 

Thank you for any knowledge you can provide

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When I posted this a link came up for similar articles that I did not find in my search, so if someone with the same question finds my post your question can be answered here, http://www.zhome.com/ZCMnL/tech/AandBtranny.htm, (thanks to Davy), apparently the 5 speed should bolt right up, "Either Transmission: will direct bolt to any of the "L" series six cylinder blocks." and you may have to modify the shifter a bit if you have a '71 and earlier 240z.

 

Still, it is vague as to whether they are talking about the later 4 speed or the 5 speed in th article so if anyone can confirm for me that the 5 speed will bolt directly into the L24 motor I would really appreciate it

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:flamedevi The 5-speed should bolt right in. Only problem that I know about is the collar for the shift fork. They have a couple of different sizes that will fit in it. They have to do with the use of the collar and different type pressure plates that have been made for it. The 280ZX had a smaller collar in it and is used in the five speed when it is used with a centerforce clutch system (I have it in my Z right now). Other then that it should just be a simple push together and then bolt it. The splines and clutch are the same and does not have to be changed. It was a very simple improvement for my Z. Good Luck, For your info, the 5-speed out of the 280ZX is the prefered one to get. The only problem with it is the shifter is moved forward in its hole and it has to be trimmed to fit :burnout:
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Still, it is vague as to whether they are talking about the later 4 speed or the 5 speed in th article so if anyone can confirm for me that the 5 speed will bolt directly into the L24 motor I would really appreciate it

 

 

Hi Erich:

Type "B" 4spd. or 5spd. use the same case -

 

The Type "A" or "B", 4spd or 5spd. used with the L24, L26, L28 is a direct bolt on to all.

 

FWIW,

Carl B.

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Only problem that I know about is the collar for the shift fork. They have a couple of different sizes that will fit in it. They have to do with the use of the collar and different type pressure plates that have been made for it. The 280ZX had a smaller collar in it and is used in the five speed when it is used with a centerforce clutch system (I have it in my Z right now).

 

 

I don't know about the CenterForce Clutch you used... but...

 

Basically there are three different throw-out bearing collar (sleeve) lengths... Actually there are about five, but two of them are so close to the other three, they really don't matter a lot. So lets call it three..

 

1. The shortest sleeve was found in the original 240-Z's - which had the thickest pressure plates.

2. The second shortest, or second longest came in the 280Z/ZX 2+2

3. The longest sleeve was found in the 280Z/ZX's... which had the thin'est pressure plates.

 

"Thickest Pressure Plate": Lay the pressure plate on a flat surface, measure the distance from the pressure plate "fingers" to the flat surface. The 240Z pressure plates will be 43mm to 46mm (1.75" aprox). The 280Z pressure plates will measure 34mm to 36mm (1.33" aprox).

 

For several years now - people have been ordering the 280Z/ZX pressure plates as replacements for the 240Z's anyway, as they provide slightly more clamping force than the original 240-Z's pressure plates. Likewise, many people swapped in the pressure plates and flywheels from the 280Z/ZX 2+2's - as they use larger diameter clutch disc and the machined surface in the 2+2 flywheel is a larger diameter. (so even more clamping force).

 

Unless you have owned the car since new - you usually have no idea what you'll find when you pull the engine or tranny for the first time in your Z.

 

The surest way to get it right the first time - is to simply buy a new 280Z/ZX OEM Clutch disc, pressure plate, throw-out bearing collar (sleeve) to begin with. A new throw-out bearing collar is about $18.00...

 

Or use ALL the same parts from a known good set-up.

 

If your clutch assembly etc was working fine with L28/5spd, and upon physical inspection it looks fine still - then just transfer the clutch disc and pressure plate from the L28 to the L24, and leave the existing throw-out bearing collar (sleeve) on the transmission.

 

 

FWIW,

Carl B.

 

 

Carl Beck

Clearwater, FL USA

http://ZHome.com

ClutchAssyForkThrowOut_thumb.jpg

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I have a 260z with a L28 motor but had the four speed tranny on it before it took a crap on me so i took it off and got a five speed tranny and wondered the same thing, would it work? I took off the old four speed asembely but kept the pressure plate on. Put the five speed on with the throw-out bearing collar (sleeve) it came with and it bolted right on with no problems. I did take the four speed clutch fork and put it on the five speed because the original five speed clutch fork was messed up. It worked with no problems and shifted great untill the clutch fork i swaped came loose from the throw-out bearing sleeve and i had no clutch :( Is the clutch forks different too? do i need to get a 280z five speed clutch fork to match the tranny? or is it those metal pins?

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I just remembered i had some trouble getting the tranny on too, it seemed like the shaft coming out of the transmission didn't want to go in the hole in the pressure plate so i figured it needed some leverage and moving around. I had limited resources but i did have a huge jack that was capable of lifting one end of the car at a time. It was better to jack the rear of the car up to get under the tranny and drive shaft, and it also made it easier on me to get a smaller jack and place the tranny on the small jack to raise the tranny into possition. Now that i had the tranny at the right hieght all i had to do was work the shaft through the pressure plate and alot of wiggling was neccessary, i even spun the tranny shaft a little untill finally with a shove forward it went into place so i could put some bolts in. One more thing take time to drain the old fluid out of the tranny and don't fill it with new "2 qts.GEAR OIL" untill it's on the car because it's that much heavier with all that fluid in thier. You probably already know all this but just thought it might help someone if it's thier first time swaping tranny's like it was mine.

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I have a 260z with a L28 motor but had the four speed tranny on it before it took a crap on me so i took it off and got a five speed tranny and wondered the same thing, would it work? I took off the old four speed asembely but kept the pressure plate on. Put the five speed on with the throw-out bearing collar (sleeve) it came with and it bolted right on with no problems. I did take the four speed clutch fork and put it on the five speed because the original five speed clutch fork was messed up. It worked with no problems and shifted great untill the clutch fork i swaped came loose from the throw-out bearing sleeve and i had no clutch :( Is the clutch forks different too? do i need to get a 280z five speed clutch fork to match the tranny? or is it those metal pins?

 

If you all ready had an L28 in the car, then chances were good that it also had a 280Z/ZX clutch assembly. In which case either the 4 spd. from a 260Z or the 5spd. from a 280Z/ZX would have had the matching throw-out bearing sleeve.

 

Yes, it sounds like either the retainer spring on the clutch fork was bad, or you simply didn't have it pushed fully over the pivot ball. Or the retainer spring at the throw-out bearing sleeve gave way.

 

The clutch forks for all the type "B" transmissions were the same, as are the throw-out bearings. There are really only two different clutch forks, one for the adjustable slave cylinder push rod, and another for the self adjusting slave cylinder push rods. The earlier type have a hole for the push rod to stick through.

 

FWIW,

Carl B.

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I just remembered i had some trouble getting the tranny on too, it seemed like the shaft coming out of the transmission didn't want to go in the hole in the pressure plate so i figured it needed some leverage and moving around.

 

 

If your going to pull and reinstall a first or second generation Z transmissions - the first thing you do is pull the two top bolts out of the transmission ... then you take them to the local hardware store. You buy two (I always get a couple extra, so I buy 4) matching bolts, only making them about two inches longer.

 

You take the longer bolts home, and cut the head off them. Then set them aside until you are ready to reinstall the tranny. Prior to reinstalling the tranny, you lubricate them, and then screw them into the lower part of the engine block finger tight (but fully in)... and using them as alignment guides, you slide the tranny over them and into place, keeping equidistance between the engine and the bellhousing all around...(move the small jack as necessary to line things up)... then push the tranny in...

 

The "Pressure Plate" has a huge hole - I think you had trouble getting the transmission input shaft through the clutch disc. You just have to make sure the transmission is in-gear, before you attempt to reinstall it, so you can rotate the input shaft slightly, by turning the output shaft - so you can align the splines between the input shaft and the clutch disc.

 

FWIW,

Carl B.

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Nice i never thought of that, nice to know the little things that can be done to spare hours of agony haha. I'll have to do that when i take mine off again because of the clutch fork and retaining springs. BTW nice info on the throw-out bearing collar and thanks for the help.

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