Engine & Transmission Swap.

My 2012 Prerunner 2.7L has over 200K and with the extent of all of my restoration efforts, I am considering my options where the engine and transmission are concerned. The idea is to maybe pick up a rebuildable match engine and transmission, take my time with their rebuild, and then do the swap when ready, meaning necessary.

But then too, I am left to wonder what the compatibility options maybe? I am not in love with my 4-speed tranny. And I know there is a five-speeds offered in or around that year. Question is, is it possible to swap transmissions from a 4 to a 5-speed model and have it operate as intended? And more out of curiosity, the same from a 4 to a 6 cylinder engine?

Is this commonplace or has anyone here done this mod? If so what are the cost and process considerations?

 

Not sure why you want to rebuild your engine and trans if you aren't having any issues, they should last well over 200k if they are well maintained.

The A340 (4 spd 2.7L only) and A750 (5 spd 4.0L only) are 2 totally different transmissions, I don't believe they can be interchanged in any way.
The A340 was the only automatic transmission offered with the 2.7l in 2nd gen trucks.
You could do an auto to manual swap if you were so inclined but 4 spd auto to 5 spd auto I don't think is possible without swapping in a 4.0L engine, wiring harness and PCM as well.

A750 Transmission Information
A340 Transmission Information
https://www.tacomaworld.com/threads...-4-wheel-drive-or-automatic-to-manual.702733/

 

Thanks, for your input. I guess I should start by clarifying, that though I would enjoy building a replacement engine. I would not swap it or the transmission until it makes sense to do so. This is simply a case where I like my truck enough, that I am willing to do this in place of sending it off to the junkyard.

I have no known issues to speak of and enjoy the reliability that my truck offers, but with over 200K on the odometer, it may not be a bad idea to start upping my knowledge game a little in this regard.

Back to the information, you provided. Now understanding the constraints of the 4-speed auto or manual being the only options where the 2.7L. What about the swap of engine and transmission as a matched unit from 4 to 6 cylinders?

 

Swapping to a V6 engine/trans would at a mimimum require the engine/trans harness and PCM from the donor truck.

I'm not sure about the crossmember and driveshaft, those are probably different too.

Another issue is most of the V6 trucks had an immobilizer and most 4 cyl trucks didn't so I'm not sure if the PCM can be programmed to not use one or if that would have to be added as well.

Those are only the differences I can think of off the top of my head, I'm sure there’s others.

People on here have done those kinds of swaps but IMO it would be cheaper and easier to find a V6 truck.

That's about the extent of my knowledge on the engine/transmission swapping, I would say if it's something your wanting to do then get in touch with a member that has done it and see what's all involved.

 

Yeah, most likely right. I have often wondered how sound the decisions are in other applications I have known of. Doing 2 to 4wd or 4 to 6 cyl, I'm referring to this sort of mods. etc. Seems like it's never completely problem-free.

 

I would recommend bringing truck to an engine shop and have them do quick tune up/check over. Then drive it for another 200k.

 

TUNE-UP SHOP!!!??? TUNE-UP SHOP!!!??? If I had my white gloves SIR I would USE THEM TO DEFEND MY HORNER!!! I'll have you know, that my truck is THURLEY SERVICED and all by my own hands! TUNE-UP SHOP, Jeez But, I do like the thought of another 200K before needing attention.

 

I do all my own work too. Though before headed across country I had a shop do a compression test and run it on a scanner. I am at 285k and like having the peace of mind that I did everything right.

 

Having an extra engine and transmission on stand by might seem like a good idea. Even better if you have more than 1 vehicle it could go in. But something to consider, it would only take one jackass with their face in a phone to ruin your plans.

 

My greatest fear with my truck.

 

200k is early in the lifespan of a 2tr. It's way less expensive and less time consuming to get a donor motor out of a wrecked vehicle than build one.

 

That sounds reasonable, I have yet to do a compression test and I am curious

This is so true, Austin is full of people who think that this only happens to someone else. I have seen people doing 85mph on the toll with their sun visor down putting on makeup. this horrifies me, being a father of a new driver. But if you confront someone doing this you are the A$$ hole and being silly. Pet peeve can you tell?

 

I would be open to this if it were to have low enough mileage. Not too costly to build one though, and I enjoy the process. Who knows what things will come, right?

 

Here’s a thread you may enjoy on the V6 rebuild:

https://www.tacomaworld.com/threads/1gr-fe-rebuild.743548/

 

I was quoted around 6k for new engine with 68k miles on it. i requested a few extras s like waterpump, motor mounts,hoses, etc.. Ls swap would be in 10 k range but would not include a new rear end.

 

Wow, don't do it! You are approaching or even maybe surpassing new Toyota Crate engine price at 6K. Jasper, Powertrain, and a few others offer complete rebuilds for just over $3500 and that is with like 5 years warranty.

 

https://www.car-part.com/

Many for $3k or near what a rebuild would be. OEM engine builds will outlast rebuilder engines with less miles for the most part. Bearings and other consumables usually are cheapest they can find in rebuilder engines.

 

I actually thought 6k was decent for swap and labor. I got the quote last fall for a mint low mileage 2008 with a blown moter (waterpump) that I tried to purchase. I also should have stated that the shop I use is very reputable for building race engines. that as well as doing LS for Toyota and Hellcrate swaps for Jeeps. Anyhow I am still pissed I did not buy said truck and just have them do a rebuild for a quick flip. I also missed a 2009 offroad last month 150k miles $4200 with a new frame but needing a new box, tail gate and rear bumper and timing belt. My neighbor's son bought it and he replaced everything cheap from craigslist. Dam nice truck

 

I must have missed the labor part. Truth is, there are so many factors to consider in such an undertaking that I would be hard-pressed to even have an opinion without first-hand knowledge of the goings-on. I'm sure it all made sense from where you were standing. As to the missed opportunities, I feel that you will know the one intended for you.

 

Yeah it sounded like you were stating the engine was $6k.