The F4W71B(4 speed)

[frankendat]

Good day all,

The search function is not producing results, so here is a easy one. Will a F4W71B(4 speed)  removed from a Z-car, bolt up to an L20B?

Thank you

[DanielC]

Yes, any transmission off of any 

L-engine will bolt to any other L -engine. 

The gear ratios may be less than ideal.

[datzenmike]

Very true. Keep in mind that the release bearing carrier, (or collar) the thing that holds the release bearing is matched to your clutch and not any transmission. If you replace the transmission keep and use YOUR collar and not the one that may come with the new transmission. Always replace the release bearing with a new one. While out replace the $5 rear driveshaft seal. It's old and may leak. You could replace when transmission is in, but a lot of bother so do it now. Fill with 2 liters of GL-4 80w90 NOT GL-5. I run a short length of garden hose down from beside the engine and into the fill hole. Put a dollar store kitchen funnel in the end. If cold out warm the oil in the house or you'll be there all day. You might find ATF a better choice and replace it next summer.

[frankendat]

Excellent information! Thanks for the guidance

 

I have been reading more/searching more. For transmissions, (for me)shorter is better, the shorter transmission of the  4x4 720 (which if I understand is NOT the same transmission as in the Z-car). 4 speed or 5 speed is not important (I look for the 4 speeds as they appear least desirable and therefore better deals) Also, if I understand, 720 4x4's from 1980-1986 have 26in transmissions.AND the transmissions out of 720 4x4's with Z20 (1980) Z22 (1981-1982) and (not sure on this) the Z24 (1983-1986) will bolt to the L20B with modification. (I have not found a detailed account of what modifications are necessary to place a Z series transmission on a L20B.)

 

There is snow on the ground in Boise and the pic and pulls have been mud messes, I can handle the mud, but the jacks sink and the yard owners get excited when I find "creative" methods to access the parts I desire. So, most of my transmission shopping has been online or classifieds and trying to decipher who has what part or even do I want the part they have, is proving challenging.

 

Thanks again for assistance

[datzenmike]

You don't want a 4x4 transmission as they don't have any speedometer drives.The 4xx4 speedo is driven by the transfer case. Always get a 2wd.

 

Only SOME 2wd and 4x4s have the shorter 26" length and only in 5 speeds. If you find a shorty you will need to swap the Z series front case half for an L series front case so it will bolt to the L series engine.

 

L series case..

 

 

Z series case. See the difference?

 

 

Here's a 'shorty' with an L series front case on it. Note the speedometer drive is on the left side the only 71B transmission that is this way...

 

 

 

The longer 31.5" 280z and 280zx 5 speeds are the same as the long 720 transmissions with the exception of the trucks having several extra switches on them and the later '80 and up 280zx having a closer ratio gear set with a very large 25% over drive.

[frankendat]

Thank you Datzenmike,

Quick followup questions: Above the last picture in the previous reply, you wrote,

 

"Here's a 'shorty' with an L series front case on it. Note the speedometer drive is on the left side the only 71B transmission that is this way."

Which year transmission is pictured?

 

Also, my project is 4wd. If the shorty transmission and the transfer case are sourced from the same 720, I thought the speedometer drive resides within the transfer case.

Is this correct?

 

I am seeking alternatives to locating a 1980 720 4x4. I have been seeking a 1980 720 4x4 since August and even being willing to fly to Portland or Seattle and drive home, but have found only high priced problematic junk. During this same time, I have found many right priced 4x4 720's, which I discounted, because they were 1981-1986. My hangups with these years is the crossflow head and emissions equipment and I like the L20B.

 

With the above information, what are the years of 720 4x4 that will contain a "short" transmission (either 4 or 5 speed) that will bolt directly (or with minimal modification) to an L20B?

 

Finally, if I understand correctly, it is simple (drilling a few coolant holes) to attach an L20B head to an Z22 or Z24 block, both increasing displacement and solving my L20B block transmission problem. As time passes this is  more tempting. My reservations are custom engines usually have custom problems  and, while extra HP and torque are always nice, a 100hp from a very mildly tuned L20B is more than enough for my project.

 

As always, I appreciate your thoughts

[frankendat]

Not to derail my own thread, (I am still very interested in the answers to my questions) For background, there was someone who I followed a project similar to mine (in concept, he chose the engine from a Ford Ranger) His is now for sale $6500. I will keep with mine, but like they say a picture is worth a thousand. Here is a picture of the direction I travel...

[datzenmike]

41 minutes ago, frankendat said:

Thank you Datzenmike,

Quick followup questions: Above the last picture in the previous reply, you wrote,

 

"Here's a 'shorty' with an L series front case on it. Note the speedometer drive is on the left side the only 71B transmission that is this way."

Which year transmission is pictured?

 

Also, my project is 4wd. If the shorty transmission and the transfer case are sourced from the same 720, I thought the speedometer drive resides within the transfer case.

Is this correct?

 

I am seeking alternatives to locating a 1980 720 4x4. I have been seeking a 1980 720 4x4 since August and even being willing to fly to Portland or Seattle and drive home, but have found only high priced problematic junk. During this same time, I have found many right priced 4x4 720's, which I discounted, because they were 1981-1986. My hangups with these years is the crossflow head and emissions equipment and I like the L20B.

 

With the above information, what are the years of 720 4x4 that will contain a "short" transmission (either 4 or 5 speed) that will bolt directly (or with minimal modification) to an L20B?

 

Finally, if I understand correctly, it is simple (drilling a few coolant holes) to attach an L20B head to an Z22 or Z24 block, both increasing displacement and solving my L20B block transmission problem. As time passes this is  more tempting. My reservations are custom engines usually have custom problems  and, while extra HP and torque are always nice, a 100hp from a very mildly tuned L20B is more than enough for my project.

 

As always, I appreciate your thoughts

 

Yes a 4x4 shorty doesn't have a speedometer drive, it's in the transfer case. I didn't know you were building for a 4x4.

 

Here is a shorty 4x4 from an '85? King Cab 720. Maybe all KCs have them...

 

I don't know what years or models had the shorty. wayno on here probably does.

 

You could put an L20B into a later 720 that has a Z series engine.

 

 

 

 

[frankendat]

23 hours ago, datzenmike said:

You could put an L20B into a later 720 that has a Z series engine.

 

Excellent news I think. If it is possible to put a L20B into a later 720, then is it safe to assume that a later 720 Z series transmission will bolt directly to a L20B?

Sorry to beat this to death, I just do not want to purchase a mistake.

 

Thank you for your help

[datzenmike]

On 1/9/2020 at 7:14 PM, datzenmike said:

 If you find a shorty you will need to swap the Z series front case half for an L series front case so it will bolt to the L series engine.

 

L series case..

 

 

Z series case. See the difference?

 

 

 

 

This is because the L series engine is positioned with a lean of about 12 degrees to the right and Z series are 5 or 6 degrees to the left of vertical. This is too much of a miss match for the rubber engine and transmission mounts to handle.