cLAYH

I just pulled my tranny to replace the flexplate that had recently let go. The middle was torn right out about an inch out from the crank mounting bolts. Anyone know what would cause this?

The truck has about 220,000kms on it and I bought it at 200,000kms. It was bone stock at that time and since then I have gradually upped the power.

What worries me is that the flex plate that came out(failed) looks exactly the same as the 2nd Gen flexplate I ordered direct from Cummins using the part number off of this website. Has my flexplate already been replaced once or did I get a 1st gen flex plate or are the 1st and 2nd Gen plates the same? Thanx for the help!

Rammer64

I've done mine too. It went at 220,000 kms. Manual downshifting will play a big part in breakage. Probably the best answer is "ENGINEERING DESIGN FAILURE". It's a common failure appearently and weak design can be the biggest culprit.
From what I can see from the posts on this site, the factory 1st gen flex plate is built right at it's maximun limit. So any excess power mods, excessive HD use or abuse, the FLEXPLATE will fail.
It's like it's designed with NO CUSHION for error on the owner's part. JMHO

Nuttymopar

The flex plate is a weak link since it is not a solid design. The 2nd gen looks the exact same but should hold up better due to NOT having metal fatigue from just sitting on a dealer's shelf somewhere for 12 years. (hopefully). I also purchased a 2nd gen one so time will tell. A lot of forward and backwards will hurt flex plates over time (plowing). Plus the power that these motors make now will really kill it. Original lasted for 150,000 miles and then replaced with another 1st gen one, that lasted 1 year (33,000 miles). This time around I bought the 2nd Gen style. Maybe it is my Right Foot that keeps breaking these things

John H

Hate to be the one to tell you this, but sitting on a shelf for 12 years won't give it metal fatigue. Using it might!

John

fishermansteve

I bought 2 from a junkyard. 1 looked just like the original & the other was a solid piece of metal without the cut-out design(I don't know what else to call it). I installed the one that was like the original & if it breaks I will put in the solid one. The junkyard guy said the solid one was from a 1990 & the cut-out one from an 89. My truck is an 89 thats pretty much stock except for K&N air filter.

TexasBlake

Oh I heard about that. Some of my 4x4 buddies went to it. I was in Waco this weekend on the way to Dallas, but my truck is in the paint shop.