999 front clutch clearance with 6 frictions

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Mopar69gts

Mopar69gts

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Hey there
I'm putting together a H. D. 904 / 999
It has a 5 disc front drum and most of the performance specs I've found say .060 to .070
Clearance With 5 discs.
I'm putting 6 thin discs in it.
Right now it has .078
I have a .010 thicker steel I could use to get it to .068
Any suggestions which way to go?
Thanks in advance!!
Thanks FABO
 
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If your not running a trans break I would say .010 per clutch should be great ! So when you put the .010 steel and you check it do you .068 or not ? If I were building it I would stay as close to .010 per clutch ! Will .068 work ! Yes it will ! Just wont last as long as it should ! IMO
 
Rmoore said:
If your not running a trans break I would say .010 per clutch should be great ! So when you put the .010 steel and you check it do you .068 or not ? If I were building it I would stay as close to .010 per clutch ! Will .068 work ! Yes it will ! Just wont last as long as it should ! IMO
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Thank you!
Yes I assembled it with the one thicker steel and got .068
And .078 with all std. Steels
The valve body is stock with a tf-2 kit.
I probably should mention this is going in a daily driver 400 ish hp. Dart
Not to the strip much.
Just wanted to make the transmission as crisp and hd. As possible.
 
Rmoore said:
If your not running a trans break I would say .010 per clutch should be great ! So when you put the .010 steel and you check it do you .068 or not ? If I were building it I would stay as close to .010 per clutch ! Will .068 work ! Yes it will ! Just wont last as long as it should ! IMO
Click to expand...
I agree.
I didnt get mine tight enough on my 1st 998/999 1st gear to 904 swap and I remember it didn't last long, like 4 months maybe.. I found the drum wobbled or something ...fricken sheared aluminum splinters fell off into the pan. Fixed it and then blew the planetary...couldn't win with that trans. Back In my Slant 6 days ..i hurt more trans missions than any other motor. Changing to a 833 4spd cured my automatic trans woes all together!
 
In Tom Hands book on the Torqueflight
There are several performance suggestions
Even from other professional rebuilders,
Which I think is Cool In his own book!
Anyway for the front drum, most recommend .012 to .015 per disc.
I was surprised that Tom recommends .020 to .022 per disc with a tf-2 kit?
 
Mopar69gts said:
In Tom Hands book on the Torqueflight
There are several performance suggestions
Even from other professional rebuilders,
Which I think is Cool In his own book!
Anyway for the front drum, most recommend .012 to .015 per disc.
I was surprised that Tom recommends .020 to .022 per disc with a tf-2 kit?
Click to expand...


If you had a trans brake yes you do want a lot of extra clearance!! A trans brake works off of release ! When you let go of the trans brake button I’m here to tell you if the drums doesn’t release immediately it will smoke every clutch in the drum !! But has far as a non trans brake transmission.010 per clutch will make you and awesome transmission and will last ! I always put all new bushing through out the transmission ! And I always put all new washers also !! On the 727 I always put the bolt in harden race on the rear sprag ! I also bevel both ends of each roller and double spring each roller !!
 
Mopar69gts said:
In Tom Hands book on the Torqueflight
There are several performance suggestions
Even from other professional rebuilders,
Which I think is Cool In his own book!
Anyway for the front drum, most recommend .012 to .015 per disc.
I was surprised that Tom recommends .020 to .022 per disc with a tf-2 kit?
Click to expand...
I never go less than .015 per clutch on a 727. when using the tf-2 kit Having .020 per clutch has nothing to do with the clutches burning out. I have taken factory trannys apart where there was .250 total clearance in the front drum and the clutches were mint. I would rather have a little too much clearance than not enough. I have built more than a hundred 727s with the -2 and -3 kits. Only a few 904-998/999 trannys. Kim
 
So just out of curiosity and maybe to learn a little
What are the advantages / disadvantages
Of a tighter vs looser clutch pack?
 
Too tight will burn up the clutches when the shifts are binding up. Usually on the 2Nd to 3rd shift. Especially with the TF-2/3 kits. Too loose not much unless it excessive. Kim
 
With four frictions, I still like to keep it looser. With five or six frictions, I'd drop it down a bit too. And if it is a little loose and you get a 2-3 shift flare, you can readjust the kick down band tighter.
If you do not have lot of spring in the clutch retainer, the looser clearance is a slight bit safer from what I have read and experienced anyway.
 
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Thanks guys!
I love this site!
I really enjoy working on my own stuff and I really appreciate all the advice and wealth of knowledge here.
P.s. I did install a reverse wound spring from ATI in the front drum.
I only spin it to 6000
But I guess that's when the factory spring can start to give up.

Thanks again, mike
 
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