3 4 input drum comparability and clearance question
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On The Tree
Joined: Sep 2018
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From: New Zealand
3 4 input drum comparability and clearance question 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
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
Last edited by grasshopper645; Jan 28, 2019 at 04:05 AM.
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,.
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On The Tree
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From: New Zealand
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
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Thread Starter
On The Tree
Joined: Sep 2018
Posts: 161
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From: New Zealand
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.
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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
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
Thread Starter
On The Tree
Joined: Sep 2018
Posts: 161
Likes: 4
From: New Zealand
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.
Thread Starter
On The Tree
Joined: Sep 2018
Posts: 161
Likes: 4
From: New Zealand
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
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
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.
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
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
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From: Roxana, IL
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
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