# 88 d21 z24 L4n71b swap with re4r401a transmission?



## foxkw (Dec 26, 2008)

I have an 88 D21 4cyl Z24 2wd HB P/U with a bad trans (more on that later) and I wanted to know if it's possible to put in an RE4R401A transmission from a later model pickup or other source. 

The existing L4N71B is pissing trans fluid all over the ground from the front seal. SInce I have to pull the transmission in order to replace the front seal (or discover that it's something far more nefarious like a bad input shaft), it occurs to me that this might be a good time to upgrade the trans from Light duty to medium duty.

The research I have done seems to indicate that I'd be able to put am E4N71B in place of the L4N71B transmission, but I am not sure whether the bell housings/bolt pattern's would work out. Similarly I see from my trusty Haynes manual that the RE4R401A replaced the E4N71B in later models.

The RE4R401A offers a couple improvements over the E4N71B - the primary being a lock up torque converter.

Assuming that two transmissions are physically interchangeable, I guess the only other issue would be one of electronics and the potential incompatabilities there.

I've looked around on the web for a few hours, and I did pick up a good bit of information, but nothing that is answering my questions. 

The questions the are: 

1. will an RE4R401A bolt up the to the Z24 motor?
2. If so, are there eletrical nightmares that make it more trouble than it's worth?
3. What are the sources (donor vehicles) for a 4cyl RE4R401A or E4N71B transmission?

Thanks -- Ken


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## zanegrey (Dec 5, 2005)

90 s and up have that trans for a donor.
yes i do beleive it will bolt up.
and yes the electronics will have to come with it.

ecm and wireharness..i think u r ok with the mounts and overall length of trans so the drive shaft will work as well..


is that innser mongolia a joke or do u really live there ?


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## foxkw (Dec 26, 2008)

*thanks for info*

Inner mongolia - that's a joke. I usually say outer mongolia, but I was in the city today <G>..


The d21 is a pretty decent ride, but I was towing stuff with it when the tranny seal blew back in august. It still drives VERY short distances though. The fluid is dumping out the drainage port in the bottom of the bell housing. I finally have the time to pull it. 

I'm in transmission mode this month my 96 camry with 310000Mi lost the #1 forward clutch and will no longer go forward under it's own power. Reverse works perfectly but I get strange looks when commuting to work plus a sore neck after the drive <G>.

WRT the swap, and this is more of a JATCO question than a Nissan question - I wonder if the bell housings are "universal" versus application specific because I know that the MAzda R4A-EL is the RE4R401A by any other name. It would be nice to be able to expand the donor range.


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## zanegrey (Dec 5, 2005)

List of Jatco transmissions - Wikipedia, the free encyclopedia

try this site..

i have the 89 d21 auto trans for sale.


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## foxkw (Dec 26, 2008)

*update -*

I did a little more research and discovered that the the L4n71b trans in my D21 has a lock up torque converter - I got a copy of the Nissan Service manual for the 88 model year on ebay for 10 bucks.

It was a royal PITA getting the transmission out because there is not enough room (front to back) to get it out without moving the motor forward a few inches. 

The real issue is getting the heavier duty version of the transmission - guts. I wonder if it's possible to just get the medium duty parts and rebuild the trans with them vice getting a whole new trans. It would not surprise me if the differences rested soley in the clutch packs and othe rfriction materials.


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## fredskidoo (Jan 15, 2013)

*My situation is similar - flex plate?*

I have a 1988 d31 4cyl 4x2 with a bad L4N71B and found a E4N71B from a 1989 d21 V6 4x2 to replace the L4N17B. Sadly I forgot to grab the flex plate and have been struggling to find the correct one. Did you use the E4N71B or did you go with the RE4R401A? 
I swapped out the V6 bell housing on the E4N71B with the existing L4N71B 4 cyl bell housing and everything lines up except that all I have to work with is the original L4N71B 4cyl flex plate which gets me to just short of 1/4 of an inch from the engine. I am unable to get any closer. I tried many times to get the fit but it won't go. Also, I have both motor and trans removed from the truck and on hoist and trans jack.
I believe it's the flex plate that is interfering. I ordered one that was compatible with the 1989 V6 and it's shallower but neither the torque converter holes or the 6 crank shaft holes line up. I have the torque converter for the E4N71B and it bolts to the L4N71B's flex plate perfectly. As a matter of fact both the L4N71b and the E4N71b's torque converters are identical in every way.
I'm hoping someone's been down this road and can shed some light on any differences in the flex plates used with the 4 cyl L4N71B and the V6 E4N71B.

Thanks all


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## smj999smj (Jan 1, 2006)

foxkw said:


> I have an 88 D21 4cyl Z24 2wd HB P/U with a bad trans (more on that later) and I wanted to know if it's possible to put in an RE4R401A transmission from a later model pickup or other source.
> 
> The existing L4N71B is pissing trans fluid all over the ground from the front seal. SInce I have to pull the transmission in order to replace the front seal (or discover that it's something far more nefarious like a bad input shaft), it occurs to me that this might be a good time to upgrade the trans from Light duty to medium duty.
> 
> ...


Bellhousings are different between the I4 and V6.


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