4.0 HO conversion and transmission questions

dj69firebird69 · 01-09-2010, 04:36 PM

I have a 1987 Wrangler with the 4.2 and I just bought a 1991 Cherokee with the idea of swapping the 4.0 HO into my YJ. I am trying not to spend too much because money is tight right now so I need to get some opinions on what I should do. If I use the trans out of the XJ it is an AW4 and i will have the CPS sensor and not have to buy the conversion kit for the front crank pulley. But it is a little longer so my driveshafts will be different. But then I have the TF999 from my wrangler which was rebuilt not too long ago but I believe it needs a new torque converter and I would have to buy the CPS conversion kit or make my own opening for the CPS. Or should I buy a different trans all together? If anybody has any suggestions it would be very helpful. I want to get this all figured out before I move any farther on the project. Thanks

WrenchMonkey · 01-09-2010, 05:43 PM

Sell the YJ. Build the XJ.

Robert

dj69firebird69 · 01-09-2010, 05:54 PM

XJ was wrecked in the front. The kid rearended somebody going 35mph. Its still fixable but I would rather build up my YJ.

jmb8813 · 01-09-2010, 06:56 PM

thats a terrible idea (to build a xj)

Coppertop · 01-09-2010, 11:51 PM

Quote:

Originally Posted by WrenchMonkey

Sell the YJ. Build the XJ.

Robert

X2
Jeep cherokees rule....

Nick

GPER · 01-10-2010, 09:51 AM

Sell them both and get a CJ, it will keep you busy.

http://www.cjoffroad.com/forums/default.asp
Go to the 4.0 section, there is a lot of info there for the swaps.

nick · 01-10-2010, 11:05 AM

I have been in the process of installing a 4.0 in a cj for about 5 years. It is my 2nd jeep. I was just goin to dd this one and wheel easy if my other was down. I cut the cj trans to accept the cps its easy. I would have rather used auto tranny but my transfer was passenger drop. You will have to get a yj water pump or go electric fan. Swap is only supposed to take a weekend. Good luck

WrenchMonkey · 01-10-2010, 02:22 PM

Quote:

Originally Posted by nick

I have been in the process of installing a 4.0 in a cj for about 5 years... Swap is only supposed to take a weekend. Good luck

That's good stuff right there...

But I think he hits on a valid point, that the rest of us were beating around:

Putting a computer controlled engine in a rig it was never intended for, is a pretty major undertaking. It's not likely to be quick, cheap, or easy.

Is your 23 year old YJ really worth it?

Robert

01-09-2010, 04:36 PM	#1
dj69firebird69 Join Date: Dec 2009 Posts: 15	4.0 HO conversion and transmission questions I have a 1987 Wrangler with the 4.2 and I just bought a 1991 Cherokee with the idea of swapping the 4.0 HO into my YJ. I am trying not to spend too much because money is tight right now so I need to get some opinions on what I should do. If I use the trans out of the XJ it is an AW4 and i will have the CPS sensor and not have to buy the conversion kit for the front crank pulley. But it is a little longer so my driveshafts will be different. But then I have the TF999 from my wrangler which was rebuilt not too long ago but I believe it needs a new torque converter and I would have to buy the CPS conversion kit or make my own opening for the CPS. Or should I buy a different trans all together? If anybody has any suggestions it would be very helpful. I want to get this all figured out before I move any farther on the project. Thanks

01-09-2010, 05:43 PM	#2
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	Sell the YJ. Build the XJ. Robert __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

01-09-2010, 05:54 PM	#3
dj69firebird69 Join Date: Dec 2009 Posts: 15	XJ was wrecked in the front. The kid rearended somebody going 35mph. Its still fixable but I would rather build up my YJ.

01-09-2010, 06:56 PM	#4
jmb8813 01 jeep tj Join Date: May 2009 Location: the city that offers nothing Posts: 153	thats a terrible idea (to build a xj)

01-10-2010, 09:51 AM	#6
GPER Join Date: Feb 2007 Location: Kettering, Ohio Posts: 811	Sell them both and get a CJ, it will keep you busy. http://www.cjoffroad.com/forums/default.asp Go to the 4.0 section, there is a lot of info there for the swaps.

01-10-2010, 11:05 AM	#7
nick wheeler Join Date: Jun 2008 Location: owingsville ky Posts: 25	I have been in the process of installing a 4.0 in a cj for about 5 years. It is my 2nd jeep. I was just goin to dd this one and wheel easy if my other was down. I cut the cj trans to accept the cps its easy. I would have rather used auto tranny but my transfer was passenger drop. You will have to get a yj water pump or go electric fan. Swap is only supposed to take a weekend. Good luck