97 4l60e single piece case from a Camaro

the 3-4 input drum had a slight hairline crack between the shaft and case where it presses in. I purchased a new input drum - making sure it's the 298mm style shaft. They both have the same casting number 8678716 and look identical.

however, when I measure the input shaft it's a couple of mm longer then the original. I understand theres a few different sized inpit shaft lengths. Does this matter?

my second question is regarding the 3 4 clutch clearance. I'm using a feeler gauge between the last clutch and the end plate. Is that correct way to check? I'm getting about 45 thousands so thinking I might be a little on the tight side.

if I check the clearance between the end plate and snap ring, I have to apply a bit of downward pressure to fit the feeler guages in.

any help greatly appreciated

 

45 thou is loose

 

The Input shaft will be fine. As for the 3-4 clearance I like to see around .20 dry uncompressed to start with .35 max . Also make sure all your steel plates and clutches are flat not bent or waved,.

 

Excellent thanks! great news regarding the shaft

The ATSG says I should be between .060-.085", are you suggesting that this range is to loose? Granted we all like it tight, your suggesting seems tighter then the ATSG specs? I'm not disagreeing with you, i'm an amitaur, just trying to understand so I get it right

 

Atsg specs for the 60 are trash.
Run .003 clearance per friction plate

 

OK great, i'll get a slightly thicker plate to reduce the clearence.

Since i'm running a stock 4 friction setup, i'll aim for .012ish.

Thanks for your help sirs

 

there are more than 4 clutches in the 3-4 clutch pack

 

If you're planning on running a 4 friction setup, you should probably put the snap ring pliers down and read that atsg manual again.

I put 7 minimum in everything.

 

lol oops i meant to say 6 frictions, 5 steels

 

so i'm aiming for 0.018ish

 

Don't do that. You'll regret it.

If you have a .192 backing plate...run the following:
.223 apply
7x.080 clutch
6x.077 steel
.192 back
.092 snap

 

i agree.

 

hmm ok thanks for the advice, guess ill have to buy some more parts then.

My reason for sticking with 6 frictions is because i planned on keeping it stock. No interest in any performance modifications to the vehicle so was just trying to keep it the way it came from the factory. Having said that, i don't want to cut corners.

 

unless its a stock v6, you better not run just 6 frictions. 7 at the very least. but if you run 8 and your using thinner steels, at least run kolene steels. make sure you put the return springs back in, they are in there for a reason, to release the clutch pack. I see it all the time where builders dont put these back and the 3-4 clutches wear prematurely. You wouldnt leave out any of the other return springs would you? theres three other release spring assemblies in the trans.......I never see those left out. For good reason. I'm pretty sure if it wasnt needed, gm could have saved a pretty penny not having to include them.

 

using stock frictions from a kit will likely lead to more than .045 clearance.
Frictions and steels are very cheap...you're probably looking at less than $20 total to do a 7 clutch setup the proper way.

The stock 6 friction setup was a mistake...especially considering how damn easy and durable a 7 clutch setup is.

But...if the factory saved $2 on every trans they did...I'm sure that would be worth plenty when added all up

 

It's a stock LT1. It came with 6 frictions from the factory, which is why i intended to do it with 6. But i'll take the advise here and increase it to 7.

 

Yeah i'm not bothered about the money, was just trying to replicate the factory stacking. But I get what your saying so will change the stacking as recommend here.

Appreciate all your help.

Regarding the stock frictions from the kit clearence, yeah your probably right. I can actually fit a 55 thousands guage in there, but its a pretty tight fit.

 

Another note if your running the original apply and backing plates make sure they are flat . Many times the apply plate in particular will have high spots at each tab certainly if they have been hot the can make for ether a slow burn on one side of the first friction or I have seen single high spot literally burn up the whole friction set and you know that was why because every steel at that location will have a blue spot in it , And as mentioned use the return spring cages you might have to get some new springs , They help with release a little but mostly prevent drag when the 3-4 clutch is not applied

 

I second that 3-4 pack set up w/ Raybestos GPZ-100 Frictrions

 

I agree with the other builders, the ATSG spec are for bone stock purposes and I never build that loose even for stock builds. .015-.030 is best for all around shift feel and friction performance.