4L60E Cracked Flexplate

[Phishin]

I'm 99% sure the "valve ticking" noise I've been hearing in my truck is from a cracked flexplate. I was complaining to a friend how bad the "ticking" is getting in my truck. We went out and had a listen. He is confident it's a cracked flexplate. That's all he said.

It ticks pretty loud, all the time now.

Do I need to get this repaired right away? Or is it just annoying? Could the truck just run fine, but remain noisy, for a very long time or is it just inevitable that soon there will be catastrophic failure/damage if I don't get it fixed very soon.

I always thought I had a huge valve train problem. I think it's been the flexplate all along.

 

[Turk]

Which vehicle, the 1990?

I got a ticking in my '03 Sierra 5.3L, thinking it's a cracked Exhaust Manifold.

 

[The_Eric]

If it is indeed a cracked flex plate, then fix it soon. Yes it can fail catastrophically. That being said, I'd be surprised if it was cracked, though stranger things have happened.

If your buddy is sure it's coming from that area, pull the inspection cover and check to make sure the torque converter bolts are tight, before you start doing anything too serious. They do come loose on rare occasions.

 

[Chris142]

I had one crack once. Sounded like a rod was going to exit stage left

 

[Astro14]

Yes, it can fail. When the crack gets worse, it will fail, and you will lose the connection between crankshaft and torque converter, rendering the truck undrivable. Some amount of damage will happen when the engine torque is applied to breaking parts that hit unbroken parts between block and transmission.

I wouldn't wait on fixing this, assuming your friend is actually correct in his diagnosis.

 

[Doog]

Originally Posted By: The_Eric
If it is indeed a cracked flex plate, then fix it soon. Yes it can fail catastrophically. That being said, I'd be surprised if it was cracked, though stranger things have happened.

If your buddy is sure it's coming from that area, pull the inspection cover and check to make sure the torque converter bolts are tight, before you start doing anything too serious. They do come loose on rare occasions.


do this first. But if it has a crack it is a gonner and may grenade the trans. If it's cracked it is time to pull the trans. Might as well rebuild it and get a new sunshell in there if you plan on keeping the truck.

http://www.summitracing.com/parts/tci-373900?seid=srese1&gclid=CNqhjb7Vmb0CFdBcMgodmAwAcg

 

[Propflux01]

YES!!! get it fixed. Now.

I had one crack on a Grand prix I had. Started out as a tick, like a valve, then progressively got worse, to the sound of a rod knock. When I figured it out, I pulled the tranny and the crack was from one bolt hole to another, then down to the ring gear.

 

[Phishin]

Originally Posted By: Turk
Which vehicle, the 1990?

I got a ticking in my '03 Sierra 5.3L, thinking it's a cracked Exhaust Manifold.



Yes in my 1990 K1500 truck.

If the flexplate is cracked, I was thinking a mechanic could replace the plate in like 3 hours. So, that's $180 in labor for my guy, plus a new plate. I'm looking at $300 perhaps. That's a significant amount of money for this old truck. I guess I need to look at what a new/remanufactured tranny would cost and compare the prices at this point.

Yes, I'm going to keep the truck. A new GM crate engine will be installed when this old/tired 350 dies and goes to SBC heaven.

 

[Doog]

Originally Posted By: Phishin
Originally Posted By: Turk
Which vehicle, the 1990?

I got a ticking in my '03 Sierra 5.3L, thinking it's a cracked Exhaust Manifold.



Yes in my 1990 K1500 truck.

If the flexplate is cracked, I was thinking a mechanic could replace the plate in like 3 hours. So, that's $180 in labor for my guy, plus a new plate. I'm looking at $300 perhaps. That's a significant amount of money for this old truck. I guess I need to look at what a new/remanufactured tranny would cost and compare the prices at this point.

Yes, I'm going to keep the truck. A new GM crate engine will be installed when this old/tired 350 dies and goes to SBC heaven.


Just make sure if you buy a rebuild that it has the heavy duty sunshell in it. The sunshell if the 4L60 weak point.

You can get a Monster performance trans for $1300

http://www.monstertransmission.com/produ...Zg#.UycCP6hdXTp

 

[Phishin]

Took it to my local Indy tranny shop just now on my lunch break (Randy's Trannies), and Paul is the lead guy there. Great dude. Very knowledgeable.

It rattles like CRAZY when it's a cold start and goes away after a few miles. I knew when I got to his shop, it wouldn't be rattling. And it wasn't.

He told me to jump in, put it in drive, and basically power brake it. And BINGO....it began rattling like it always does. He confirms, it's a cracked flexplate.

He said with the part, I'm looking at $400. He could rebuilt it for $1100 OTD. He suggested I just fix the flex plate....no reason to fix anything that isn't broken.

Made an appointment to have it fixed in a few weeks.

 

[Doog]

$400? yeah I would be doing that.