Flexplate/CPS alignment

I did a RMS on my "new" 94 XJ 4.0, AW4. After I was done, all the torque converter-to-Flexpalte bolts came out after 5 min of driving. All the bolt threads are messed up, I got new bolts for it, and chased the torque converter threads with a M10-1.5 chaser. I didn't remove the flexplate from the crankshaft.

My question is this: Will I need to find the same spot the flexpalte or converter was in orientation to the crank sensor? And if so, how do I know its right? Becuase I don't want to put it back togother only to find I gotta take it back apart. Any help would me much, much appreciated! :kissyou:

Since you didn't remove the flexplate, it's orientation with respect to TDC shouldn't have changed, so the Crank Sensor will be happy too!

McQue said:

Since you didn't remove the flexplate, it's orientation with respect to TDC shouldn't have changed, so the Crank Sensor will be happy too!

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Thats what I was hoping to hear. That makes me very happy! Thanks Mcque!:kissyou:

Even if you do have to remove the flexplate, one of the holes should be "indexed" slightly out of pattern - and the flexplate can only go on in one position. It's still a good habit to mark the thing before you take it off - remove the first screw, and give the hole a small blast of bright spray paint. Problem solved.

I did a RMS on my "new" 94 XJ 4.0, AW4. After I was done, all the torque converter-to-Flexpalte bolts came out after 5 min of driving.

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I've never done a rear main seal on an XJ, but I didn't think the flex plate had to be removed? :dunno:

Boatwrench said:

I've never done a rear main seal on an XJ, but I didn't think the flex plate had to be removed? :dunno:

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They don't - could be a freakish coincidence? They do loosen up from time to time - they're one of the things I check annually on a rig in service (along with manifold screws - there's usually one or two loose there as well.)

The RMS on an AMC242 is a two-piece job, rubber mould over a metal core. Easier to replace than the old Chevvy "rope seals," y'ask me...

Put some Thread-Lok on the bolts, but nothing to serious, you want to be able to get them out when the flex plate cracks.

dizzymac said:

Put some Thread-Lok on the bolts, but nothing to serious, you want to be able to get them out when the flex plate cracks.

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LocTite #242 (or equivalent) is what I use.

Ok, I just got done. The factory converter bolts looked like they had no thread locker on them. I found a set of torque converter bolts for GM RWD cars that fit, they had thread locker on them already but I put more on the leading thread. They went in pretty easy, 40 pounds of torque. Got the exhaust back on, starter and flexplate cover. Cranked it over, didn't fire. Checked the firing order, it was off by 1 on the cap. So I moved them all counter clockwise. Then it flooded. After holding the throttle WOT it fired right up, no knock, no leaks (With Mobil 1 HM)! It only took me from 9:00 AM to 2:30 AM to finish it, check tires and fill it up. All in all, I'm very, very happy with my $800 dollar 94 XJ that has nearly no rust!

I think what happened as far as the bolts coming out of the converter after the RMS, I backed out all the main bearing bolts, pryed on the crank a little so I could knock loose the rear seal. Maybe that shifted the flexplate a hair and made it worse. The guy I got it from said it had been knocking for a long time, so maybe I had it coming. BTW, the flywheel cover had a million scratches and burrs on it from the bolts rubbing against it!