Jeep 4.0L Engine with 42RE Would Like to Convert to the CJ7 T5

[dabottle]

I am getting a 1994 XJ 4.0l with 42RE auto in it. The motor is complete, running and will have all the wiring harness.  I am putting this in my 86 CJ-7 and would like to keep the T5 with the D300. What is required for the bellhousing and what are any other problems that I will be running into. thx

[Moses Ludel]

dabottle...Do you mean a ZJ Grand Cherokee with the 42RE?  Either a ZJ 42RE or an XJ Aisin AW4 would be the same issue...You can mate a 4.0L to a T5 with a factory bellhousing.  However, the 4.0L engine needs a crankshaft position sensor, which did not show up until the EFI engines in 1987.  (Your 4.0L engine is a 1991-up Mopar MPI/EFI type.)  1987-up engines do not use a T5, they used a Peugeot (1987-early '89) or Aisin AX15 transmission.

There is a workaround if you have a 4.2L engine.  You can use the 4.2L "shim" spacer, flywheel, clutch assembly and bellhousing on the 4.0L engine.  The stock CJ release arm and linkage will work.  You need to add a crankshaft pilot bearing to the 4.0L crankshaft.  In addition to this, you need a crankshaft position sensor.  You can use a front damper/pulley and sensor pickup from HESCO.  These are Mopar EFI conversion parts for the 4.2L EFI Conversion Kit.

Here is a link to the damper and pickup.  You do need both pieces to get the signal you need.  This would replace the stock 4.0L CKS (crank position sensor) that normally fits at the converter or bellhousing of an MPI/EFI 4.0L engine:

https://hesco.us/products/30791/40l-conversion-parts/148640/42l-dampercrank-sensor-kit-hes42ved

Moses

[dabottle]

Sorry, yes meant to say ZJ grand Cherokee….going to pick it up Wednesday…seems like a mess of wiring! I have all the 4.2 parts so should be good. Thx Moses 

[Moses Ludel]

You're welcome...You'll be pleased to have the complete PCM harness, this is similar to the XJ/YJ 60-way (essentially 60 pins) PCM!  Plenty busy as you note.  Be grateful they salvaged what appears to be all of the wiring.

I would invest in a CD version of the '94 Jeep ZJ Grand Cherokee (official Mopar) service manual.  Here's one example of how to buy this information affordably:

https://www.ebay.com/itm/152791812463

These Bishko CD or direct download manuals are PDF format, and it's easy to print out procedure pages.  I like the CD or a download as an option to the hefty factory print manuals.  Navigation is much easier.  In addition to all of the tech for powertrain and the rest of the ZJ, this will include the wiring schematics for this maze of wires shown in the photo. 

I'm not affiliated with Bishko but support them because they are licensed to sell this OEM information.  You own it and can benefit!  For $33, how can you beat this?  You'll have everything you need to troubleshoot this 4.0L engine and all its sensors.

Moses

[dabottle]

The project is coming along and am ready to put the T5 and bell housing in. In researching the pilot bearing required for the T5 to the 4.0 crank I am getting some mixed info. Do I use the pilot bushing for the 4.2? Thx

[Moses Ludel]

dabottle...Best source for the pilot bearing and correct sizing is Advance Adapters.  Our friends at tech support are well versed on the T5, 4.2L and later 4.0L conversions.  They can provide the bushing or bearing (based on which style is recommended for the T5 and your 4.0L crankshaft pilot bore). 

Give Advance Adapters a ring at 1-800-350-2223 or use the contact form at:  https://www.advanceadapters.com/contact-us.  For decades, conversions involving the T5 and AMC/Jeep inline sixes have been a mainstay for Advance Adapters.

Let us know their recommendation and the "best practice" for mating your 4.0L to the T5.

Moses

[dabottle]

Moses,

I got this response:

“You should be able to use a factory pilot bearing from that86 CJ, if it doesn’t fit you can use our 716156GM.”

I will have to measure the input shaft and ensure that it will reach the factory pilot bearing.

 

[Moses Ludel]

dabottle...Glad you went to "the source".  This would mean that the 4.0L and 4.2L crankshaft pilot bores are the same O.D. and spacing from the transmission.  You're smart to confirm the "reach", as this is the input gear stick-out length for proper engagement in the clutch disc and pilot bearing.  This is the "stack height" for these parts.  You also need to use the "shim" between the bellhousing and engine block.  That's part of the stack height and helps determine the input gear nose depth into the pilot bearing. 

If the original crankshaft pilot is a needle bearing, you can use that style new bearing.  If a bushing, use a bushing.  The reason for a match-up here is material hardness of the input gear's nose.  If the OEM is needle bearing style, with the shaft running directly against the needle rollers, the input gear's nose end must have hardness to match.  A bronze bushing is softer material than needle bearing steel. 

In either case, put some moly grease in the crankshaft bore behind the bearing or bushing.  Do not use too much grease behind a bronze bushing:  It could prevent the input gear nose and transmission from engaging fully.  One way to remove a solid pilot bushing without a puller is to pack the cavity behind the bushing with grease then drive an old input gear or a sized rod into the bushing's center bore.  The grease and force act as a "hydraulic ram", driving the bushing out from the backside.

Pleased that you contacted Advance Adapters.  Keep us posted!

Moses