I'm going to try and replace the flex plate by the end of this summer. I read on this forum that it is easier to remove the engine to replace it than the transmission, so I'll try to do it that way. When removing the engine, are there any parts that need to be replaced before it goes back in? Like gaskets or bolts? Are there cheap things that I can replace with the engine out for preventative maintenance? Are there any specialty tools I'll need other than an engine hoist and a special socket for the transmission bolts?

 

I gather yours is cracked?

I would replace the motor mounts if you're pulling the engine. Make damn sure the new one is identical to the old one, window locations, diameters, etc. There have been a few people here lately who didn't notice the new one was not the same, or the new one was poorly manufactured and had to pull things apart again. Maybe consider doing the oil seal in the front of the trans. Rear main seal if your ambitious.

 

Engine route - take this as an opportunity to address any subtle leaks or seaping gasket/seals. Especially the spacially challenged ones. Like mentioned, rear main, oil filter adapter, harmonic balancer.

When it comes to the flexplate, the windows is No Joke! My prior experience was with my replacement flexplate having stamped windows vs clean cutout windows. Stamped resulted in an inward flare vs the sharp edge. It was argued that I needed a better cps/stronger signal to read the stamped windows. I retained the original flexplate and continued as usual and returned the replacement flexplate.

 

Are you going to lift it out with manifolds still attached, makes it heavier and awkward. But then you don't need a new manifold gasket

 

What do you recommend? I was thinking about leaving it in as it is easier, but if it causes issues when pulling the engine out, I may remove them.

 

I dont remember the manifold gasket being more than 20 or 30 bucks...well worth the price to remove manifolds in my opinion

 

As I recall years ago I replaced the engine with a Jasper, on my 88 MJ.....The bolts on the bell housing to the engine were typical until I got to the two upper bolts behind the valve cover....I struggled & struggled to get a wrench on these bolts, nothing would fit, I had to do this by feel, as I could not see the bolts...After what seemed to be several hours I tipped the front of the engine down & discovered those two upper bolts were Torx !!!!!

 

I was looking under the car and it seems it would be easier to take the transmission out instead of the engine. Is it really easier? There is conflicting information both on this forum and on other sites. Which should I do?

 

I have done both. I wouldn't classify either as easier.

If you go the transmission route, you will have to deal with the two etorx bolts at the top of the transmission. As someone else mentioned, you will want to tilt the motor up and then get many extensions and a u-joint in there. Once you get those bolts out, it's not too bad to pull the trans/transfer case back and separate from the motor. The trans/transfer case is heavy and awkward to maneuver. I managed with two hydraulic jacks. Would be much easier with a true transmission jack like this one.

The etorx bolts are E12. There are plenty of threads on the topic. Here is an example one.

If you go the motor route, you'll still have to deal with those etorx bolts, but you will also have much easier access to the motor to replace gaskets etc. once it is out.

If you want to go through the motor, I would suggest you think about pulling the motor and trans together. Once you pull the radiator and get the condenser out of the way in the front, there is plenty of room to maneuver the motor or rmotor/trans out with a simple hoist. You will need to pull the transmisison support cross member and disconnect the drive shaft. Both are pretty easy compared to everything else.

One thing I would definitely replace is the transmission input shaft seal. It's an inexpensive seal and if it has never been replaced on your XJ, there is not doubt it is brittle and could go at any time. Very easy to replace with a seal puller. You can also easily replace it if you pull the motor.

On the motor side, I would replace the rear freeze plug that is behind the transmission bell housing. I had one leak on my '99 and you have to pull either the motor or trans to get to it.

 

I think the major consideration is if you do this on a lift, or on the ground on your back.... If you can't get the vehicle up in the air, I would opt for pulling the engine....On the ground you would probably need a second person to help....This is a nasty miserable job....

 

Just replaced my flexplate recently and I've never pulled the engine out of my XJ, but it seems like there would be a lot more to take apart vs going the trans route (more fluids to drain, more hoses and harnesses to unhook, more things to disconnect and 'disturb' and then have to put it all back together.) my 2 cents on the trans pull was that it isn't that bad, just requires time and patience and i'd opt to go that route, i had it up on ramps and with the 4.5" lift I had plenty of room to work. Although I did not have quite enough clearance to get the trans completely out from under the jeep, but didn't really need to.

The flip side is, to the point of all the conversations above, if you remove the motor you can go over a lot more things with it out and replace/upgrade before you reinstall the motor.

One thing I got bit by was somehow during this process my CPS finally quit on me, not sure if it was the unplugging, removal, or what, but if you have the original CPS in there, might be worth your time to throw a new MOPAR one on it while you've got it all apart since it will be easier and the CPS will likely go eventually on you.

 

I agree, if you're stock height, have a engine hoist handy, and plan to replace mounts and such, that's probably the way to go. If I had to do the flexplate on mine right now, I'd probably pull the xfer case and trans. No need to drain coolant, unhook fuel lines, wiring, etc. But I also have plenty of room underneath with almost 6" of lift and sitting 33s.

 

Id go trans removal too. You need to dismantle the whole front to get the engine out clean. Getting the trans out is less fluid mess, less wiring. The only things in your way are the exhaust, trans cooler lines, and crossmember. Which all need to come out to get the engine out anyway. Get a pack of the fuel and trans line disconnect clips. Be careful of the trans dipstick, they are bolted on to the bell housing by where you disconnect the trans and nss plug. The two top bolts are external torx, E12 i think. 4WD linkage can be time consuming too. get the azzy designs linkage or a cable swap if you dont wanna mess with it.

 

please explain why you would drop the crossmember when removing just the engine?

 

How you gonna reach all the bell housing bolts without lowering the transmission?