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Auto transmission engine into a manual Pathfinder


colinnwn
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I've seen this question come up before, but I don't remember there was a solid answer, and a forum search didn't come up with anything for me.

 

I'm looking at putting a new engine in my manual transmission Pathfinder for my father in law to use. The current engine is 2001 VQ35DE. It knocks bad when running, and it overheats. Research leans me to thinking it needs a timing chain, tensioner, guides replaced. But that is so much money to have done, my FIL suggested considering a new engine.

 

He's found several in the $800 range, but all have been from auto transmission Pathys. Has anyone replaced a manual transmissioned Pathy engine with one from an auto trans Pathy? Do you know how much extra work is required?

 

I know I'd have to keep my ECU, and swap over the intake tract from the old engine to the new (since the electronically controlled butterfly valves aren't used in the manual transmission). Then I'd need to swap over the throttle plate assembly if engine is later than 2001, since autos went to throttle by wire in 2002. Is it really that easy? Or is there likely more to it?

 

Along the same lines, I assume a VQ35 from any car based Nissan would probably be too much work to be worth swapping. Is the same true for the VQ40DE from the Xterra and Frontier? I don't want a project, though I've always wanted to do something like this for fun. But I've got enough personal projects now. I want something a reasonably competent independent shop can do in average time.

 

Thanks.

Edited by colinnwn
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I think DBW started in '03, but Nissan tends to change stuff over mid-year just to be that way. I would assume you're on the right track, and an auto trans engine from the same year with your old intake and the right pilot bearing would do the trick, but I don't know the VQ. Might be some good info here, though that's more between years than auto vs manual. The only other idea I've got is to check the service manual for your year and see how much in the EM section is marked as different for AT vs MT.

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That's one of the old threads I was thinking of. Thanks for finding it.

I don't want to get into the time and money odyssey RainGoat did right now. Based on reading the whole thread, sounds like the most straightforward would be a manual transmission 01 or 02 engine. If I can find one of those we will probably go forward.

If I can't, I may play around a little in my drive doing an oil change and letting it run a bit. But the old girl will likely be off to the scrapper. My wife is getting tired of it sitting in front of our house.

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It should be fairly straight forward. I know on the auto VG there is a thick bushing in the crank vs a pilot bearing. So you'll likely need to remove/swap that. The VQ is similar. Whenever I swap engines I always plan on using all the external components from the original engine unless they are damaged. Then you know you'll have the right parts.

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One thing I’d suggest is hitting up nissanpartsdeals.com. You can look at every single part and part number for each month of production for every year. You can put in a vin and it pulls up that particular factory build. This would be good for looking for any differences around the engine crank between auto and manual. Also would work for the intake stuff too. Also, 2001 and 2002 use throttle cables. Not sure what the cutoff on the throttle cable is but I know my April ‘00 (2001) has the cable and my November ‘01 (2002) . Additionally, one can look at the engine timing critical components such as timing sprockets, crank sprockets, cam Phasers, upper oil pan, timing chain cover, cams, flywheel, flywheel sensor and stuff all change part numbers and designs ever few months during the production. This stuff will be your biggest headache for engine swap compatibility. As far as the difficulty of turning wrenches goes, It’s not easy. I’ve pulled an engine before in salvage (haven’t installed yet). Took me 11 hours to get the trans out, then it was another 7 hours for the engine. Could probably go much faster with a second set of hands while in the comfort of your own driveway. As far as other Nissan engine swaps go, it’s not any easier than putting in something from any other car manufacturer. That’s how different the other vq35 and vq40 engines are. If you could somehow know for sure you don’t have rod knock, replacing the timing chain guides, chains and water pump will be much easier and cheaper than a new engine. You can also run a compression test, if it’s bad, you can consider pulling the engine and heads to put in a new head gasket.

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If you end up doing the swap, PLEASE document the process and share details about the differences.
 

I’ve been contemplating swapping a manual tranny into mine for a couple years now but I need to know if it’s possible without a major overhaul. My transmission is bound to fail sooner or later and I’d love to have a manual in it when it goes from being my daily driver to my second vehicle. 
 

Just to confirm, you have a manual SE 2001? I’ve yet to see the transmission from these unicorns listed on eBay or anything. Is it the same one from the VG33? I always thought the 3.5 had too much torque for it?

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Just to confirm, you have a manual SE 2001? I’ve yet to see the transmission from these unicorns listed on eBay or anything.

 

Yes. That's what I have. I see a couple manual transmissions on Ebay through a Google search right now, though typically listed as an 01-04. I was searching https://www.car-part.com/ for engines, not transmissions. But I found 3 in Texas last week that were specifically from manual transmissioned 01-03 Pathfinders.

 

Quote

Is it the same one from the VG33? I always thought the 3.5 had too much torque for it?

 

I searched a little online and could find zero information about it. I know many years ago I've seen threads on this forum about where it is sourced from. I don't believe it was the VG. I drove two different friend's manual VGs some, and the shifting behavior is worlds different.

 

Don't get your hopes up about me doing the swap unfortunately. I would if I was retired and had all the free time in the world. In this case once my father in law and I decide we are ready, I'm pretty sure we will just drive a couple hundred miles if required to get one of the manual transmissioned engines that seem to pop up semi-regularly on car-part.com, and bring it back for a local shop to do the swap, to make it as cheap and straightforward as possible. I've got too many honey-dos besides working, and the free time I have, we'd rather spend camping.

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8 hours ago, colinnwn said:

 

Yes. That's what I have. I see a couple manual transmissions on Ebay through a Google search right now, though typically listed as an 01-04. I was searching https://www.car-part.com/ for engines, not transmissions. But I found 3 in Texas last week that were specifically from manual transmissioned 01-03 Pathfinders.

 

 

I searched a little online and could find zero information about it. I know many years ago I've seen threads on this forum about where it is sourced from. I don't believe it was the VG. I drove two different friend's manual VGs some, and the shifting behavior is worlds different.

 

Don't get your hopes up about me doing the swap unfortunately. I would if I was retired and had all the free time in the world. In this case once my father in law and I decide we are ready, I'm pretty sure we will just drive a couple hundred miles if required to get one of the manual transmissioned engines that seem to pop up semi-regularly on car-part.com, and bring it back for a local shop to do the swap, to make it as cheap and straightforward as possible. I've got too many honey-dos besides working, and the free time I have, we'd rather spend camping.

No worries man, it’s all good if you don’t end up swapping it. I just meant that you IF you did, then make sure to document it

 

Anyway, I did some more digging and I think figured it out. The tranny is these seems to be part number 32010-JK41A, which is the transmission from the 350Z, also known as the FS6R31A. The manual from the VG33 pathys was the FS5R30A

 

I’m pretty happy now knowing if I buy one from a Z it should fit when I get around to doing the swap. They are pretty easy to find. The question remains how much of the other stuff will need to be modified though

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Just remember that the Z is a rear wheel drive and many Pathfinders are 4 wheel drive. 

The rear housing and output shafts are different between the 2wd and 4wd. Often the gear ratios can be different as well between a car and truck application. 

 

When I was a teenager, my first car was my 1977 Datsun 200sx with 5 speed transmission. My mom had a 1979 Datsun 620 pickup with a 5 speed transmission. Both were 2wd rear wheel drives with L20B engines, but the engines had different firing orders and internals. The trans in the car was much shorter, had a different gear pattern and different ratios. Made things interesting when jumping from one to the other, all the gears were in different places. Trying to go into reverse thinking it was 5th in the truck at 50 mph made bad noises.

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20 hours ago, Mr_Reverse said:

Just remember that the Z is a rear wheel drive and many Pathfinders are 4 wheel drive. 

The rear housing and output shafts are different between the 2wd and 4wd. Often the gear ratios can be different as well between a car and truck application. 

 

When I was a teenager, my first car was my 1977 Datsun 200sx with 5 speed transmission. My mom had a 1979 Datsun 620 pickup with a 5 speed transmission. Both were 2wd rear wheel drives with L20B engines, but the engines had different firing orders and internals. The trans in the car was much shorter, had a different gear pattern and different ratios. Made things interesting when jumping from one to the other, all the gears were in different places. Trying to go into reverse thinking it was 5th in the truck at 50 mph made bad noises.

Interesting. I hadn’t considered that. I guess the best way to go about it would be to either track down an 01 SE in a junkyard and compare, or find a Z with that tranny to check out. Preferably both for the sake of info gathering. Typically I think the part numbers are slightly different if they have different internals or housings, but I may be wrong and it could be completely impossible to tell without being inside of one. I’ll see what I can dig up on Z related forums maybe. I know there are different letters on the end of some, like I’ve come across a listing for a FS5R30D while looking for an A. Not sure of the difference though

 

 

Edited by PathyGig12
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As usual I would start with the service manuals for the Z and the R50. They won't come right out and say "yeah, you can totally bolt a transfer case to a Z tranny and here's the part number for the adapter," and they don't call out the part number unless there's more than one option, but the gear ratios are in the SDS at the end of the MT section and the exploded diagrams might give you some idea of whether the 2WD tailshaft unbolts and shares a bolt pattern with the transfer case. I wouldn't be shocked if you needed a different output shaft for the trans to couple it to the transfer if it does bolt up. You might also compare the Z to the 2WD R50. If they're built similarly, you might be able to find a 2WD to 4WD R50 thread explaining what's needed, though given the rarity of manual VQ R50s, you still might not find one to meet your specific needs.

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5 hours ago, Slartibartfast said:

As usual I would start with the service manuals for the Z and the R50. They won't come right out and say "yeah, you can totally bolt a transfer case to a Z tranny and here's the part number for the adapter," and they don't call out the part number unless there's more than one option, but the gear ratios are in the SDS at the end of the MT section and the exploded diagrams might give you some idea of whether the 2WD tailshaft unbolts and shares a bolt pattern with the transfer case. I wouldn't be shocked if you needed a different output shaft for the trans to couple it to the transfer if it does bolt up. You might also compare the Z to the 2WD R50. If they're built similarly, you might be able to find a 2WD to 4WD R50 thread explaining what's needed, though given the rarity of manual VQ R50s, you still might not find one to meet your specific needs.

Good points. I’ll make sure to update my build thread when I get around to starting this project. For now I’ve got some other stuff to work on, and I also don’t want to derail this thread any more than I already have. 

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