I had just installed the shiny resurfaced flywheel and reached for the clutch disc to install it next. Brand new Sachs clutch kit for a '00 Cummins, 12 1/4". Was amazed to see that all but one of the friction pads were cracked from the factory!

These are riveted on and there's a 'head' side and also the side of rivet that's peened in a depression. On the peened side all of these friction segments had two cracks clearly visible at the outside edges of pad all the way to where rivet enters pad! Looked like the cracks were also on the inner part of pads on this same side. These cracks were al the way through, the entire thickness of friction pads.

Local parts store took it back in exchange and needless to say I'll be checking the replacement VERY CLOSELY! Just wanted to give a heads up for anyone doing a clutch job with a stocker Sachs kit. I would have taken pics but didn't think of it 'til I had already returned the parts.....

JimmieD

 

why are you using the '00 cummins sachs when you can use the better oem 13" sachs clutch?

 

Well, far as I know this is the largest clutch that will fit this '00 flywheel, Cummins #3942799. If the 13" would fit in there I'd love to use it. Do you know for sure that it will fit?

They ordered me in another Sachs clutch kit, and it had the wrong pressure plate!

 

WHAT YEAR TRUCK DO YOU have ???? sachs 13 " is the way to go for a 89- 93,ctd tell us more

 

This is an engine swap conversion: '67 Dodge truck getting a Cummins 4BT, '00 bellhousing adapter, I think a '98 bellhousing, '00 flywheel, and a '96 NV4500 to custom driveshaft to 4.10 Dana 60HD. It appears at least that a 13" clutch would be a VERY tight fit but maybe the pressure plate configuration would allow clearance, don't know??? This flywheel had a 12 1/4" clutch stock. I know the 13" is only 3/8" difference at outer edge so maybe it would work but I don't have one to test fit....

 

The 1st Sachs clutch had ceramic button frictions on it [cracked] but was packaged in the wrong box. Should have been a standard disc type. The second one ordered had the right clutch plate mis-matched to an incorrect pressure plate. From the looks of it the 1st was indeed defective but may have been intentionally reboxed, and the second was most likely intentional too. The supplier is now looking into which employee is running a little business on the side at their expense!

Still doesn't excuse the horrendous quality control issue reflected in that bad ceramic clutch making it to a dealer's shelf! Also the second one had paperwork inside describing some fancy vibration damping system but with some fine print: No clutch disc could be returned for warranty if it had any damage to the vibration damping system of the disc. In other words a strong likelihood of 0 warrant overall because they must be experiencing frequent problems with that damping system!

Complicated.......

 

I know that you can put a 94+ clutch on a 93- flywheel, so i'm pretty sure that you should be able to put a 93- clutch on a 94+ flywheel. Keep in mind also that in 00 you could get the nv5600 and I believe that had a 13in clutch also.

 

Thanks, AP. Measuring between the clutch cover mounting holes in the flywheel I come up with about 13 3/8" so there might be 3/16" clearance around the edges. Don't know if that's enough or not? Got the flywheel through an auto wreckers and can only hope it's what I asked for....

It's all on a 4BT rather than a 6BT so even the 12 1/4" clutch should do the job. Many 4BT used a 10" clutch with no major problems and I'm hoping the extra 2 1/4" will make for a long lasting clutch that can do the job.

 

On my dad's truck, which is basically stock we put a 2nd gen 12 1/4" clutch in a couple years ago and it is holding up fine for him. It was much cheaper than a 1st gen clutch and car quest had one in stock. We figured if it was good enough for the stock 2nd gens it would be good enough for his underpowered 1st gen. lol He does use it to pull his dump trailer/skid steer around.

 

Yes, that's about how I've got it figured! The 4BT is not a torque monster as is, and even with extensive mods it won't be stratospheric on power. Good and strong, yes, but not a 6BT. Hoping the 12 1/4" will hold up for a very long time even towing. Time will tell I guess.

 

The 12 1/4'' should be fine behind your 4bt.


Most parts houses have the first gen clutches superceded with 2nd gen part #'s. The call it an 'upgrade', but it's most definitely not an upgrade when compared to the original 1st gen stuff. 200 bucks for an 'upgrade' clutch, or 650 for the original sachs...hmmmm. FWIW, to fit the early style sachs clutch on a later flywheel, I'd guess it wuld have to be machined to accept the bigger disk. Aside from that, everything should bolt up. I jsut recently re-shimmed my tranny, rebuilt my t-case, did a rear main etc etc. I opted to re-use my stock clutch, as opposed to the 'upgrade' 12 1/4''. She held 40psi in 5th today with nary a wimper

 

Thanks for the tips. That shimming of the trans: is that checking parallel runout on flywheel and then aligning trans with some kind of shims? If so what shim stock or parts are normally used? A machinist buddy offered to do something like this but I didn't think it was really necessary. Maybe I should rethink that...?

 

http://www.tdr1.com/forums/showthrea...43#post1432843
he says:
"The 12" clutch is no upgrade at all ! The only thing that improved was Chryslers profit margin ! The only reason the clutch was really changed was because we learned that the expensive 13 clutch that we used in the 1st gen trucks was not wearing out .... So it was decided that a cheap stamped steel cover would work just fine and that less friction material on the disc caused less chatter and wore out much faster ......

The fact of the matter is that many of the 1st gen trucks components were over built because we did not really know what was going to happen in the field yet.....By the time the second gen came out they had all the data needed to know which components could be cheapened and which needed improved to make it out of warr.

I hear many talk about changing out your 13" clutches to the double disc or other hot rod clutches....When or if you do please let me know before you throw away your stock 13" clutch....I would like to buy it from you..... "

 

I meant the bearing prelod shims inside the tranny. My countershaft bearings have wore some, so I added a few thousanths to keep everything within spec while I was right there.

 

Thanks for clarifying!

Friend explained to me last nite that he's referring to checking the runout on the hole in the center of belhousing and then using offset dowel pins if necessary to align input shaft perfectly wih pilot bearing. If trans is now slightly off center the alignment straight ahead will be effected so minor rotation of bellhousing will re-align to spec. He also mentioned shimming under bellhousing-to-block area if necessary to make input shaft straight on to pilot.