Who machines C3 apply plates these days?

oldred95

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Mar 17, 2013
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I've got a parts transmission with a good set of C4s in it. While I've got my trans out for a front pump seal I want to put in a transgo kit and address the C3 clutch. Basically recreate the TTS C3 upgrade kit, for better or for worse. Is there anyone that machines or sells an already machined C3 apply plate? Thanks in advance.
 

JoshH

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Are you looking to have yours machined and just add a clutch and steel like the old TTS kit used to do, or do you want to buy an upgraded clutch pack complete with a new plate?
 

PureHybrid

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Feb 15, 2012
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I had the local machine shop grind one, not a big deal. Used a Raybestos "Pro" pack that had the spacer as well. Just make sure it's smooth when it's done or it'll tear the friction up

Xcalliber sells the packs with a plate already machined.
 
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oldred95

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I'm not in a time crunch so I could send my plate out to be machined or purchase one already machined and send mine in as a core if needed. Yes just wanting to add an extra friction and steel to correct what Allison/GM should have from the get go.
 

Chevy1925

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I’ve cut a few on my lathe. The interrupted cut can play havoc on tools but doable. Actually really easy to get a nice finish on used plates cause all the impregnated trans fluid keeps coming out and making for a nice finish/cut
 

oldred95

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Mar 17, 2013
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I see Xcallibur offers the plate machined to .425 or .386 inches thick. I thought the rule of thumb was no thinner than .400?
 

Bdsankey

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I see Xcallibur offers the plate machined to .425 or .386 inches thick. I thought the rule of thumb was no thinner than .400?
You can certainly go thinner if you space the ring gear forward. If you cut the plate you need to shift the ring or else you will likely have a clutch fall off and be a nightmare.

I have talked to a few friends who've gone thinner and up until 0.340" you can run the conventional ring gear spacer and not risk a clutch falling off.




Typically when I try and do what TTS did I run the LML piston/return cage and run a 6 friction C3 pack. I've done it on a stock C3 plate to see what would happen on a close friend's truck and so far so good. I am not a huge fan of the thin steels I had to use but only time will tell. Now I run the cut C3 plate/spacer to run thicker steels even with a borg high energy clutch to help with heat management.
 

Dallas S

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Jun 17, 2009
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LML piston and spring, .120” spacer, 6 .076 frictions(stock LML thickness), 6 .098 steels, machine plate .415.

You can pretty much mirror this setup in the C4 too. Stock 01-10 backing plate works well here

We cut plates and spacers if needed. In Canada so shipping may hurt
 
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Bdsankey

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LML piston and spring, .120” spacer, 6 .076 frictions(stock LML thickness), 6 .098 steels, machine plate .415.

You can pretty much mirror this setup in the C4 too. Stock 01-10 backing plate works well here

We cut plates and spacers if needed. In Canada so shipping may hurt
That setup works insanely well up to the 550-600whp area which is where I like to switch clutch materials.
 

Dallas S

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That setup works insanely well up to the 550-600whp area which is where I like to switch clutch materials.
We have ran this reliably with raybestos high energy frictions and kolene steels to 1450ft/lbs with 280psi and no knock down. I’ve logged north of 1600ft with 320psi a few times aswell…
 

oldred95

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Mar 17, 2013
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Maybe I should have given some context on this. The truck in question has 345,000 miles on it. I limped it very hard a few times at around 270,000 miles on a race tune and have dealt with a wounded transmission ever since but on a lower power level of course. This truck will realistically never be taken past 450 HP again. It's just not worth the risk of depleting my bank account at this mileage and age.

Anyway it seems like there are countless ways to address the C3 clutch. My thoughts are the stock clutches are more than sufficient for me, I just need to up the plate count and increase the squeeze on the clutches. I should have just bought the TTS kit years ago and had it on hand for when I finally had the time and place to work on the transmission. The Allison is an easy trans to work on but I don't have enough knowledge with it to know what parts can be mixed and matched to make something really strong using stock components. I would prefer to buy a "kit" that includes all the pieces needed to open the trans up and address the C3 clutch if that helps narrow down the suggestions any. Thanks for the input so far guys.

Edit: My parts transmission is a 2008 Allison 1000 with what was said to be 200,000 miles on it. It has a flawless set of C1, C2 and C5 clutches in it. The C3 and C4 clutches are slightly discolored and have a few hot spots on the steels. I know the 6 speed trans addressed the balance piston issue in the C2 clutch that plagued the 5 speeds. I believe the C4 pack should be good as new in my 5 speed Allison as it's only used in 2nd gear in that application. I'm planning on taking two and making one good transmission with minimal parts being purchased. I know everyone on the Internet says you can't or shouldn't with an Allison but if 3 of the 5 clutch packs look like new and will hold all the power I will ever put through them and with room to spare I'm going to run them.
 
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juddski88

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Maybe I should have given some context on this. The truck in question has 345,000 miles on it. I limped it very hard a few times at around 270,000 miles on a race tune and have dealt with a wounded transmission ever since but on a lower power level of course. This truck will realistically never be taken past 450 HP again. It's just not worth the risk of depleting my bank account at this mileage and age.

Anyway it seems like there are countless ways to address the C3 clutch. My thoughts are the stock clutches are more than sufficient for me, I just need to up the plate count and increase the squeeze on the clutches. I should have just bought the TTS kit years ago and had it on hand for when I finally had the time and place to work on the transmission. The Allison is an easy trans to work on but I don't have enough knowledge with it to know what parts can be mixed and matched to make something really strong using stock components. I would prefer to buy a "kit" that includes all the pieces needed to open the trans up and address the C3 clutch if that helps narrow down the suggestions any. Thanks for the input so far guys

So order some parts from Evan at Inglewood. You won't be disappointed, and you'll learn a lot faster than if you try and piece stuff together on the forum.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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Running a stock converter? Running 6 frictions would be kind of pointless IMO. Just buy a Raybestos drop in kit to run 5 frictions in the c3
 

LBZ

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That setup works insanely well up to the 550-600whp area which is where I like to switch clutch materials.
It does. I have one of his trans in my truck with that setup. Shifts great drives great.
 

Bdsankey

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We have ran this reliably with raybestos high energy frictions and kolene steels to 1450ft/lbs with 280psi and no knock down. I’ve logged north of 1600ft with 320psi a few times aswell…
For something of that level I tend to run a more aggressive aftermarket friction but I can certainly believe it. High energy material does a pretty darn good job overall.

For a stock hard parts build (700-750whp) I'll run 16 single sided C1, 8 C2 with stock steels, 6 C3 with kolene steels, 6 C4 with kolene steels, and a stock C5 pack. I typically do no knockdown on all my builds as well as the line to lube modification. I usually run 280psi as well. Big builds get a bit more than that.