Stokes
Well-known member
- Joined
- Jun 10, 2020
- Member Number
- 1938
- Messages
- 58
Good afternoon guys!
I have followed many over awhile back and have just been to busy to share. I have had this swap up my sleeve for a year or two with a majority of the work done this last winter to make to have it completed for a shop trip to Moab. As I have been dragging my feet to build this thread due to time almost all of this has been done and is currently being abused, Bear with me as I get this all posted and work out any gaps in details!
First off, this YJ as it was setup was a fun rig and did great as a trail goat. Where the 4cyl fell short was all the in between driving like to and from the trail, back and forth on sunny days ect. I had felt like the rig simply worked depending on the owners common sense at the moment haha. But I have a hard time not switching it up!
As to why Toyota Power? I was on the hunt for a light weight v8 as the YJ was built around the idea of being weight conscious and geared correctly for its last gutless powerplant. Googling around got me looking towards the UZ engine lineup as it's known for lasting through quite a bit of abuse, plus the numbers appeared more budget friendly due to JDM imports than say Alloy LS options. The possibility to tick off any brand purists was an added plus.
Research lead me to Yuri with his company All4swap out of Moscow. After some conversation he suggested I steer towards the later 3UZ as they have had great success remapping these ECUs to fully work without the Key Immobilizer, Auto tuning (if going manual), Emissions items (if needed), along with rev limiter changes and other performance options depending on what you want. That is all of course with the added bump in HP/TQ over past variants.
Just a few quick details about the 3UZ:
There were a few details that I really wanted to make work on this swap other than the essentials of just completing an engine conversion:
Let's dive into some of the specifics:
Frankenstein R150f-AX15 trans combo
Keeping the manual drivetrain and adapting to my dual cases was a fun rabbit hole to dive through. The YJ's current setup was AX5 to NP241 as a range box followed by a D300 upside down for drivers side drop front drive shaft. There are a few options available for adapting the UZ engine to various Toyota gear boxes which one of them being the R150 which is close close cousins to the AX15. through a lot of digging across the marlin crawler forums there was a vast amount of discussion about how the AX15 and the R150 share much of the same parts and design minus the big differences needed for each vehicle such as the output housings/shaft and the input shafts bell housing. There is much discussion that can be had in this area, but for myself I started with what I believe was an early 90's R150 and an early AX15 that looked to be from a Cherokee that I had my friend combine the two to build me a trans that had a toyota R150 fine spline input shaft with a UZ bell housing and a 23 spline output with a 6 bolt round pattern that a AX15 usually has to keep my current cases.
There is good evidence that the toyota R150 puts up with a good deal more abuse than the AX15 so effort was given to use whatever R150 parts possible to gain its strength reputation. Seemed funny that both transmissions can use the same gears/bearings/syncros within their generations but one (R150) is known for putting up with 450+hp at the track but the other (AX15) seemed to fall apart above 300hp. Some of the primary differences noticed where the input shaft (which is already being used) and the transmission midplate as the R150 uses an Iron mid plate. This felt like a no brainer to use the R150 mid plate with the Toyota input shaft coupled with the AX15 gears/bearings/synros and output setup.
While we were in there, we used Marlin crawlers billet bearing mid plate retainer and billet shift forks (other than 2-3 as it was not avail ATM) to help beef things up.
Clutch
The flex plate bolt pattern on the UZ engine family is similar to the 3VZ/5VZ but some massaging of the bolt holes is needed but can be used as the OEM flex plate/fly wheel ID fits snug on the UZ rear snout (or whatever you want to call it). NWToys out of Oregon offers a Billet 3VZ flywheel that has the correct UZ bolt pattern and with 6-7lbs more (27lb) mass to help while crawling which seemed like the best option for my setup which I coupled with their dual friction LCE clutch which I was assured was well mannered for rock crawling and capable for the powerband of the 3UZ. To speak ahead, I really like this clutch/flywheel combo.
The bell housing I used placed the slave cylinder on the pass side and used the OEM 3VZ slave cylinder. 3/16" brake hard line used to go from OEM Jeep master cylinder by Tig welding a female brake hose flair fitting to the old swivel O-ring connection that goes into the master cylinder. The factory 3vz rubber hose used in the clutch system was also used and put in line down by the slave in case of any motor movement.
To sneak ahead some in the story, heres the current view under the hood:
I have followed many over awhile back and have just been to busy to share. I have had this swap up my sleeve for a year or two with a majority of the work done this last winter to make to have it completed for a shop trip to Moab. As I have been dragging my feet to build this thread due to time almost all of this has been done and is currently being abused, Bear with me as I get this all posted and work out any gaps in details!
First off, this YJ as it was setup was a fun rig and did great as a trail goat. Where the 4cyl fell short was all the in between driving like to and from the trail, back and forth on sunny days ect. I had felt like the rig simply worked depending on the owners common sense at the moment haha. But I have a hard time not switching it up!
As to why Toyota Power? I was on the hunt for a light weight v8 as the YJ was built around the idea of being weight conscious and geared correctly for its last gutless powerplant. Googling around got me looking towards the UZ engine lineup as it's known for lasting through quite a bit of abuse, plus the numbers appeared more budget friendly due to JDM imports than say Alloy LS options. The possibility to tick off any brand purists was an added plus.
Research lead me to Yuri with his company All4swap out of Moscow. After some conversation he suggested I steer towards the later 3UZ as they have had great success remapping these ECUs to fully work without the Key Immobilizer, Auto tuning (if going manual), Emissions items (if needed), along with rev limiter changes and other performance options depending on what you want. That is all of course with the added bump in HP/TQ over past variants.
Just a few quick details about the 3UZ:
- Up to 300hp/325ftlbs factory
- Roughly 380lbs intake to oilpan (roughly same as Iron 4Cyl)
- Alloy block with 6 bolt mains.
- Rev happy quad cam VVTI
There were a few details that I really wanted to make work on this swap other than the essentials of just completing an engine conversion:
- York OBA: The last motor had a York 210 for OBA, worth every effort to keep in my book for air
- On board welder: previously I had a ford 2G large case alt for OBW duty and wanted to improve over this old setup to make it use only one alt like premier power welder does.
- Mechanical Fan: I feel like mechanical fans are hard to beat cooling wise plus its one less item sucking amperage while the jeep is running on battery only while welding
Let's dive into some of the specifics:
Frankenstein R150f-AX15 trans combo
Keeping the manual drivetrain and adapting to my dual cases was a fun rabbit hole to dive through. The YJ's current setup was AX5 to NP241 as a range box followed by a D300 upside down for drivers side drop front drive shaft. There are a few options available for adapting the UZ engine to various Toyota gear boxes which one of them being the R150 which is close close cousins to the AX15. through a lot of digging across the marlin crawler forums there was a vast amount of discussion about how the AX15 and the R150 share much of the same parts and design minus the big differences needed for each vehicle such as the output housings/shaft and the input shafts bell housing. There is much discussion that can be had in this area, but for myself I started with what I believe was an early 90's R150 and an early AX15 that looked to be from a Cherokee that I had my friend combine the two to build me a trans that had a toyota R150 fine spline input shaft with a UZ bell housing and a 23 spline output with a 6 bolt round pattern that a AX15 usually has to keep my current cases.
There is good evidence that the toyota R150 puts up with a good deal more abuse than the AX15 so effort was given to use whatever R150 parts possible to gain its strength reputation. Seemed funny that both transmissions can use the same gears/bearings/syncros within their generations but one (R150) is known for putting up with 450+hp at the track but the other (AX15) seemed to fall apart above 300hp. Some of the primary differences noticed where the input shaft (which is already being used) and the transmission midplate as the R150 uses an Iron mid plate. This felt like a no brainer to use the R150 mid plate with the Toyota input shaft coupled with the AX15 gears/bearings/synros and output setup.
While we were in there, we used Marlin crawlers billet bearing mid plate retainer and billet shift forks (other than 2-3 as it was not avail ATM) to help beef things up.
Clutch
The flex plate bolt pattern on the UZ engine family is similar to the 3VZ/5VZ but some massaging of the bolt holes is needed but can be used as the OEM flex plate/fly wheel ID fits snug on the UZ rear snout (or whatever you want to call it). NWToys out of Oregon offers a Billet 3VZ flywheel that has the correct UZ bolt pattern and with 6-7lbs more (27lb) mass to help while crawling which seemed like the best option for my setup which I coupled with their dual friction LCE clutch which I was assured was well mannered for rock crawling and capable for the powerband of the 3UZ. To speak ahead, I really like this clutch/flywheel combo.
The bell housing I used placed the slave cylinder on the pass side and used the OEM 3VZ slave cylinder. 3/16" brake hard line used to go from OEM Jeep master cylinder by Tig welding a female brake hose flair fitting to the old swivel O-ring connection that goes into the master cylinder. The factory 3vz rubber hose used in the clutch system was also used and put in line down by the slave in case of any motor movement.
To sneak ahead some in the story, heres the current view under the hood:
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