Clutch mystery… what happened here??? 😳

I took the clutch out of the water hauler (6.9 IDI transplant) and saw this:





I am wondering if the friction disc was installed backwards? The other thing is this is a 6 bolt T-19 flywheel and pressure plate with a SMF style ZF friction disc. I’ve read this is fine to do as long as you order the 11” and not the 11.75” disc… but maybe that information is false. Any thoughts? The friction material is almost worn to the rivets but I still wouldn’t think that would allow the fasteners to contact like that 😬

I'm guessing that the clutch plate/friction disc was installed backwards, as you suggested.  The interference has apparently caused slippage and the flywheel looks to have been badly heated - and may be ruined.

If it isn't installed backwards then maybe the mismatch of parts caused the interference?

sure looks like a flipped disc to me.

Wow, that must have made a heck of a racket!

Why is one flange bolt missing?
Why are they G8 and not place bolts, like factory?

It does look like the disc was put inside out.

I guess Florida Man must have installed that clutch 😅. I did get the engine to run and it sounded good, but I never drove it so I don’t know about the noise. Maybe the guy thought it was really bad rattle from going to a SMF? It’s hard to imagine someone leaving that and driving it.

Naturally I’m going to replace all. I’m not wanting to cheap-out on the clutch for a water hauler that will live with a 1,050 gallon tank on its back. The 8 bolt 7.3 SMF has a 11.75” diameter option. I will take all I can get.

👍

Life's blood is nothing to screw around with.

ETA: I bought factory flywheel place bolts from u-haul's eBay  storefront.

Lemme see if they still have them

I've been all through uhaulteuckpartsonline and don't see the flywheel bolts anymore.  😕

Though I did find a lot of 10 pressure plate bolts, and a whole bunch of E4OD stuff, like shift correction kits and pumps.

There's still a bit of Bullnose goodness, but I think a lot of that went away when they were selling pallets of NOS for $100 each.

I’m hoping I still have an extra OEM bolt set in storage. If not I will have to dig up the part number for an ARP alternative. One of the IDI guys I used to talk to used hardware store grade 8 bolts and broke them all while taking off at a stop light. I’m a good vicarious learner and will pay for ARP chromoly if I don’t have OEM’s.

This (and other engine internals) are one of the few use cases for ARP and the like, if you can't find OEM.
Literally, nobody needs them for valve covers or a water pump.

I know that this isn't your first rodeo, Jonathan.
I hope I didn't come off the wrong way.  

Not at all Jim, I always appreciate your input. Hopefully I just have a set of OEM bolts and I can actually find them!

I noticed the odd bolt situation but it I played it safe and sat on my hands to learn from the group.

Well crap! The plot thickens… it turns out the flywheel on the engine was a DMF with 6 pressure plate bolts. I’ve not seen that before… I dismissed it as a standard T19 flywheel because of that.

…and the flywheel to crank bolts are longer than the SMF ones that I went to install. Those bolts were bent and galled in shipping… so it looks like I’m off to the hardware store. I definitely don’t have any OEM like these, and there never was an OEM single mass so they may not exist anyway. I just hope I can find some with a low profile head.



The bolts that I had in a zip lock labeled “flywheel” must be for the 300 six 😅. These definitely are not it!

ARP for a reason, Jonathan.

Don't screw around with something that can bite back, like it already has.  

Jim, I am going to see what I can find locally. The weather is warming up and the water hauling chore is about to double or triple to keep up with the swamp coolers and watering plants.

I am determined to get the big truck and big tank operational this season so I don’t spend my life driving in circles with the little IBC container. I am becoming a little disillusioned about the fasteners since 98% of ZF IDI’s are running aftermarket SMF’s and from what I am hearing from my fellow diesel owners is that these are supplied with ordinary grade 8 fasteners. I don’t mind paying for ARP but I don’t exactly want to wait another week just to get the bolts to hang the flywheel. I need to get the transmission mounted and figure out my drive line. Most likely I will be waiting on a drive shaft modification unless I get insanely lucky. I don’t want little delays to add up into another season without the big truck. 😞

The fact that almost EVERY IDI has a Smf means that almost any diesel shop should have them.
If not, there are plenty of places -like Amazon- that can deliver overnight.
I'm trying to understand your reluctance.
You saw what happened before! 💥

I would have had that stuff ordered the absolute moment I pulled the flywheel

Unfortunately these bolts are not something you can just order up on Amazon… and IDI’s being 30-41 years old now does not help.

I remember one guy saying he purchased ARP fasteners to replace the hardware store bolts that failed, but I have no idea what he bought. All of ARP’s actual low profile flywheel bolts are way too short. They do have a 3/16 16TPI 2.25” chromoly fastener but it is a flange bolt with an extraordinarily tall head (hex and 12 pt. versions seem the same). Maybe they would clear, but I’m not liking it:





I finally did find (and ordered) a set of “right” SMF bolts from Russ Repair. They look like the same plain iron oxide grade 8 bolts that come with the flywheels:

https://russrepair.com/single-mass-flywheel-bolts/



I just don’t know that these are actually any stronger or better than the coarse 3/16” x 2.25” grade 8 bolts that I bought from Napa (before finding Russ’ offering). Except that Russ does claim his product is American made.

My new Timkin clutch release bearing was supposed to be delivered today and didn’t show up either… so it’s not looking good for transmission install anyway 😞

You NEED place bolts (Belleville cup under the low profile castellated head)
Read what Carroll Smith has to say about Hewland transaxles... 🤨

You find them on REAL equipment like locomotives, Cat & Deere, Hitachi, Komatsu.

But if you're looking for UNC it's going to be vintage American iron.

I can't get to my equipment shop over the weekend, but if I find you "The Right Stuff" will you actually go for it?

I might find 2.25" and you'll have to grind a bit off the end, but the metallurgy WILL BE RIGHT, and they will be up to the task for indefinite abuse.

I'll also look at McMaster-Carr.
Maybe they have it?
Or Small Parts, which is now Amazon..  

What length shank do you need, to get through the flywheel and into the counterbore of the flange?
(So the thread run out can't become a shear stress riser at the clamping face)

https://www.amkproducts.com/product/b-12697/

Thank you Jim, I measured the flywheel thickness at the hub, and it is 1 3/8” thick.

The bolts supplied with the flywheel have a 13/16” unthreaded shoulder and the length of the shank length with threads is 2 1/8”.

I did some hunting through my parts and found the bolts that came out of my crew cab T19 flywheel when I disassembled it. They are identical to the bolts that I bought at Napa. They are gold colored grade 8 with a 1 1/8” unthreaded shoulder and a 2 1/4” shank length. They were fitted with two washers, possibly to bring the shank length closer to the original 2 1/8”.

Ooof.
G-8 and normal (not Belleville) washers as spacers?

I hope the very best with this driveline.