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4l80e clutch setups

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Old Nov 29, 2011 | 06:49 PM
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Default 4l80e clutch setups

Hi all, I'm stuck here, doin trans rebuild that shoulda took somewhere but wanna learn,,here's my issue, trans was just rebuilt, all looks great except direct clutch is fried,,metal to metal,, lip seal was blown or torn,, I got new kit, new wave plate, installed 5 steels and 5 frictions like book says, seems that has too much clearance I'm getting 80 thou between top friction and top plate. How much is ok and why do I have too much. This is an 02
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Old Nov 29, 2011 | 07:02 PM
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Did you install a transgo hd2 while you were in there?
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Old Nov 29, 2011 | 07:10 PM
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No got a diff kit haven't installed it yet it requires changing valve body springs and boost valves I think.
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Old Nov 29, 2011 | 07:57 PM
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Originally Posted by dajbbsf07
Hi all, I'm stuck here, doin trans rebuild that shoulda took somewhere but wanna learn,,here's my issue, trans was just rebuilt, all looks great except direct clutch is fried,,metal to metal,, lip seal was blown or torn,, I got new kit, new wave plate, installed 5 steels and 5 frictions like book says, seems that has too much clearance I'm getting 80 thou between top friction and top plate. How much is ok and why do I have too much. This is an 02
Generally .008-.010 per friction is a rule of thumb when building transmissions. With 5 fictions that would but your over all clutch clearance at .040-.050. With that pack personally I would like to see .040 but thats just me and I normally add a clutch. You should have .090 steels in that pack and if you are using .077 steels then this could very well be your issue with the clearance you have come up with. However per TransTec in there build sheet that comes in their kits, they say you are fine between .121-.186!!!! Not sure if I agree with their info but that is what is acceptable in a stock unit. I will say if you did not replace the factory bonded piston you will have added clutch clearance. Also if you pressure plate is dished you will get some additional clutch clearance. HTH Vince
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Old Dec 2, 2011 | 12:51 PM
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Got 5 steels at .915 new piston that came in kit. Frictions measure exactly what book says too , I measured piston travel , got 140 160 range which is on low side according to book and Mitchell. Only way to tighten it up would be order thicker steels or reorder steels and clutches from somewhere else. I'm confused. Everything is same as oem.
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Old Dec 2, 2011 | 07:10 PM
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Order thicker steels. You will need to measure the thickness of each one to know which ones you have.

Last edited by 1FastBrick; Dec 2, 2011 at 07:21 PM.
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Old Dec 4, 2011 | 01:33 PM
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If you are using factory thickness frictions and steels you should some with .850 plus. This is taking into effect that the steels should be .090 per steel and the friction plates are .080 = .850. I know that the steels and frictions will tend to run a little thicker than what the spec's are. I guess your measurement is close and you might have some pieces that are not exactly flat. If you would like to tighten this up you have a couple of options.

In my WIT book it shows three thickness steels that will fit the drum. You already have the .090 but you could order a couple of .077 or .060. By removing one of the .090 steels and adding two in combination of above mentioned steels you will be able to tighten up the pack anywhere from .030-.064. At the .080 that you mentioned in your original post you are really not that loose according to the spec's I posted in an earlier post from transtec.

Now lets take a step back here on the failure at hand. What caused the direct clutch failure? This is what you really need to figure out. Do you have issues with the rings not sealing in the direct drum? Two things to look at here are the center support and the direct drum. Make sure that the rings spin freely on the support and that there are not any burs in the lands for the rings.

Also make sure that the direct drum does not show any signs of wear. I have seen where drums are honed to clean up wear and this could be an issue it someone went a little to far. Take one of the loose rings and install it in the drum in all positions of the bore. By doing this you should be able to determine the fitment of the rings. I would also look at the check ball in the drum to make sure its sealing well.

From there we need to make sure that the center support is sealing well to the case. I have seen supports and cases get some wear on them and you might be loosing some oil pressure here as well. The next thing to look at is gasket impressions and also that the valve body and case are good and flat.

I know that this is a long post but all stuff you need to look at while doing your build. With just tossing another set of clutches at this unit the problem might show itself again in the near future. Keep in mind that you could have multiple issues and worn clutches are just a small part of it. With what I have mentioned I would also consider getting a pressure gauge on this unit the next time you take it down the road. I hope this info helps you some. Vince
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Old Dec 4, 2011 | 01:39 PM
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Excllent follow up Vince!!! Truely a master in your field!!!
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Old Dec 4, 2011 | 05:47 PM
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Great INFO...

bookmarked it!

Vince is the MAN!
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Old Dec 4, 2011 | 06:17 PM
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x10 you Rock Vince!
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