Keith122

My 97 4rnr is making a hell of a racket. I thought it was a timing belt idler, but yesterday I got under it and the noise seems to be from the flex plate. It's the worst a idle, if I put a load on the engine it almost goes away. Is it possible to see damage to the flex plate by removing the lower cover, or do I have to pull the tranny?

ksti

You don't have to remove transmission, remove cover and inspect. Type in (flex plate) under search also.

Keith122

I removed the cover, I can't see any damage. But, you cant see much of the plate, and the noise really seems isolated to that area. I searched " flex plate" as well. I think ather people have had the same issue.

ksti

Yes it's an issue. To be more positive you might want to take it to someone who can lift it and check it while engine is running. Good Luck, hope you find the problem.

vital22re

iTrader: (2)

It's getting to be a more known problem. Don't really know the cause of it. Unfortunately you won't be able to see much until you pull the transmission.

Keith122

I had the engine running with the plate off and the truck lifted. Cant see much as you said. But the noise sure seems to come from there. Is it possible to slide the tranny back enough to access the bolts without total removal? Or maybe it's better to just get the tranny out of the way......

mt_goat

To access which bolts? The torque converter to flex plate bolts or the flex plate to engine shaft bolts? You can access the torque converter to flex plate bolts one at a time through the dust cover opening.

Maybe someone with a fancy scope can inspect for a cracked/broken flex plate through the opening without pulling the tranny.

Keith122

I think I'll give that a shot tommorow. I have some inspection mirrors. Maybe I can see enough with that. I'm sure I could see a crack. However, the flex plate is off the origional engine. I installed an engine from a 4rnr with a 5sp.... so we swapped over the flex plate. I didn't do that part of the install myself, and I'm pretty sure the helper I had didn't use a torque wrench on it. Maybe some bolts are loose. I'm not sure I could tell if I have loose bolts with out sliding the tranny back some.

Keith122

Got a good look at it today. Flex plate badly cracked. I had already bought a new one as well as new fasteners. Got the tranny out. What a pain! I run a body shop so I have lots of tools, but not a good lift for this so had to do it on the floor. Hopefully I'll have it back in tomorrow.

j2the-e

Inspect the torque converter while its apart. They can get cracks around the bolt holes from the vibrations and start to leak atf.

Keith122

The converter looks fine. Changing the seal on the front of the tranny just in case. Working on reassembly now.

mt_goat

Could you see it through the inspection without pulling the tranny back? Glad you figured it out.

Keith122

I couldn't see any damage at first, but after rotating the engine over with a socket and ratchet, I could see a crack. The flex plate fell apart when we were pulling the tranny back, so it was really really bad.I'm actually surprised the thing would still move under it's own power.The toughest part was getting the bolts back in the torque converter during reassembly. Very little room to work with, and we seemed to have trouble getting the alignment just right. But, it's nice and quiet now! Some valve ticking though.

mt_goat

One of the 6 bolts has a different shoulder, that one goes in first to help with alignment. It doesn't matter which hole it goes in.

Keith122

I bought all new bolts from the dealer. I know the bolt you're talking about, and we did use that one first. But, we still had issues. Just one of those things I guess. There's very little room to work with to access the torque converter bolts.... that didn't help either.

terminator

iTrader: (1)

Check out my thread on the same dealio:
https://www.yotatech.com/forums/f2/k...50/index2.html

Keith122

Update on this, I broke another flex plate a few weeks ago. I bought an OEM plate this time, instead of a napa part like the last time. The plate had a note saying to check that the engine has both knock pins installed. I checked and one was missing. I swapped out the engine when I first got the truck, so it was probably missing since then and caused my first flex plate failure. The pilot was broken off the torque converter, so I replaced that as well. This time, everthing lined right up and the flex plate to converter bolts went right in, unlike the last time when I has a lot of trouble getting the bolts to line up.....should have known then there was a problem.