other than getting the adapter to bolt the nv3550 to the 2.5l is there anything else id need??? i found a trans with everything to do a complete swap for $ 850.00 plus the adapter from high impact trans, plus this other stuff
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NV3550 upgrade for the AX5 5 speed
The 5 speed trans that Jeep supplies with the 2.5L 4cyl engine (1987- up, Wrangler, Cherokee) is known as the AX5. It is the little brother of the Ax15 5speed, used successfully in 4.0L Jeeps 1989-1999. It holds up pretty well behind the anemic 2.5L engine, as long as you drive mellow. The problem is, pretty much everyone with one of these Jeeps is driving it like Mario Andretti off every stop light just to keep up with the traffic. And it tends to got torn up on a regular basis. (For those of you who don’t remember Mario Andretti, he was a big time winning Indy car driver back in the 60s)
With proper off road gearing (Klune Extreme Underdrive, Atlas, things like that) the 2.5L engine supplies all the power you need for trails and rock crawling. It won’t win at comp hill in the dunes, but it will get around quite nicely in the sand. A fellow I used to wheel with had one, and with me in my 220 hp V8 equipped early Bronco could not keep up with him on sand or trail.
The light weight of the 2.5L makes it well worth keeping in a trail/rock rig. But after the AX5 had died for the second time we got the idea to put an NV3550 into the trusty 2.5L Jeep
NV4500 Conversion
There is one other popular replacement option for the AX5: The NV4500. This trans is way-oversize for the application, and requires a body lift or extensive floor pan modification to fit. The usual incentive for this conversion is to get the truck style wide ratio, almost granny 1st gear which can be useful for offroad use. On the other hand, this conversion will make a 4 cyl jeep drive more like a dump truck. If this looks like the option or you, High impact does have available a package using the NV4500 replacing the AX5.
NV3550 / Klune-V Extreme underdrive
Rather than a granny gear 4 or 5 speed, a more "premium" alternative to achieve extreme gearing would be an NV3550 combined with a Klune-V Extreme Underdrive.
NV3550 conversion
The NV3550 was the transmission that superceded the AX15. It comes in Jeeps 2000-2005 with a 4.0L engine. IT is generally considered a significantly better tranny than the quite decent AX15. It is rated conservatively at 300 ft lbs. We use them regularly behind small block V8s and the are reliable.
What you are up against in the conversion: The 2.5L motor has a very different bolt pattern than the 4.0L, and the AX5 has a different bellhousing bolt pattern than the NV3550. A second difference is that the NV3550 is about 2” longer than the AX5. Also, the AX5 has a 21 spline output shaft, while the 3550 has a 23 spline shaft.
Conversion Package
High Impact has available a package providing you with all the primary essential ingredients to this swap. Included are an NV3550 transmission, the necessary conversion bellhousing to bolt the NV3550 to the 2.5L bolt pattern. The NV3550 will fit under the stock body without a body lift. Only minor floor pan mods are needed where the shifter handle comes up.
Package:
*NOTE: The prices below are PACKAGE prices: The prices for the installation kit parts will be 10-20% higher when purchased separately
(We can also provide custom packages where needed)
Priced separately Package Price*
NV3550 into wrangler 4cyl replacing AX5 $2,475.06
1 NV3550 Jeep 5spd 4WD Transmission $1,750.00 $1,656.25
Adapter / Installation kit
1 Bellhousing NV3550 - 2.5L engine $342.70 incl
1 Tcase shifter bracket/linkage $33.81 incl
1 23 spline transfer case input gear $218.50 incl
1 Crossmember adapter plate $50.72 incl
1 Pilot Bearing $20.70 incl
Optional Items:
Clutch components: Your stock pressure plate should work. 95 and up T/O bearing and slave cyl should work. It recommended you replace these unless they are known to be fresh
Optional Items:
* 2nd row is priced in package
Clutch Disc $77.84 $71.00
Pressure Plate $173.43 $150.81
Jeep External Slave cylinder $89.70 $78.00
Throwout bearing $40.25 $35.00
