# Swapping L4N71B out for E4N71B - flex plate issue?



## fredskidoo (Jan 15, 2013)

I have a 1988 d31 4cyl 4x2 with a bad L4N71B and found a E4N71B from a 1989 d21 V6 4x2 at pick n pull to replace the L4N17B. Sadly I forgot to grab the flex plate and have been struggling to find the correct one. 

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)

Well, first of all, this is the first time I've ever heard of someone trying to use a Nissan Hardbody V6 A/T in a Hardbody I-4 A/T application. To my knowledge, the V6 and I-4 transmissions were non-compatible, largely due to the different bellhousing bolt patterns, but I would guess it "may" be possible if you swapped the bellhousing. Using the 4-cylinder engine with a 4-cylinder bellhousing would seem to suggest that the 4-cylinder flexplate would be the correct part. 
I'm assuming what your problem is that you cant get the engine and transmission to bolt "flush" with each other. The first thing I would check is to make sure the "nose" of the torque converter fits into the end of the crank properly, or, in other words, make sure the diameter and length of the torque converter "noses" are identical in size; I'm pretty sure they are, but it doesn't hurt to check. Another concern I have is if you have the torque converter fully seated into the transmission (usually there are two set of splines you need to engage, so you put the torque converter in, engaging the first set of splines, and then apply slight pressure to the torque converter while you turn to engage the second set of splines). A sign that this is your problem would be if the torque converter is touching the flexplate before you get the engine and trans flush. If fact, once the engine and trans are flush, you usually have a small gap still remaining between the flexplate and torque converter and might have to use your hand to pull forward the torque converter up to the flexplate a little. I'm assuming you have the flexplate installed in the correct direction and that you installed the spacer plate between the flexplate and bolts?


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