Frank, you have the tooling why don't you just machine you own input drum and cap like the Sonnax drum. I have done this to a few drums. When using the end cap instead of a snap ring to hold the clutch pack in you gain space for a few more clutches. I used a very thin steel at the top of the pack to keep the wear off the end cap and made the cap from aluminum. I have never had the Sonnax drum in my had just went off the pic from Sonnax's instructions, but my version has been in service for 6 years or so with no issues.

 

I think maroon has a valve body and/spacer plate that does this. We were talking about this a while back but I forgot the details on it. I think one of the weaknesses of the 3-4 clutch pack is the flex of the cage fingers that push on the apply plate. That’s a cheese ball design in my opinion.

 

......he does. It just hasnt been high on his ****-o-meter lately

 

What are a few ways to block the holes in the spacer plate,I know Frank uses aluminum plugs,What other ways would work?I was thinking tig welding but I guess that would warp the plate.

 

I actually surprised
Sonnax have x3 screws in comparison to 4l75
I thint that screws work hard because only 5 of them hold full force of 3-4 piston
The cap should bent I think -too big step between screws

Weld will bend separator plate
It also much more difficult not to go sideways with welding and not cross with walls -too little space
I also use aluminum rivets (full body)
Works good and easy to install and remove

I think cut thread onto drum and make treaded cap from steel is best option for rigidity
Screw holes make weak spots onto cap and screws makes not even force to cap
Cap can and will bend under load and it will create overheated places

 

I have used the 4L79 drum a number of times No issues, Just a preference for a brand new drum at that price. But ifa customer wants one that is what they get. I just generally have them buy and ship to me.

 

I have considered but being that I work alone and have to make a living at it. Its a time issue.

 

"V8fan;20614605]I actually surprised
Sonnax have x3 screws in comparison to 4l75
I thint that screws work hard because only 5 of them hold full force of 3-4 piston
The cap should bent I think -too big step between screws"

Its 15 screws total and my issue is not the cap design though I think steel might be better, But rather the drum not being new. And the rigidity on the ring around and the hardened steel I think makes up for the screw placing, Never had any issues out of 1.


"Weld will bend separator plate
It also much more difficult not to go sideways with welding and not cross with walls -too little space
I also use aluminum rivets (full body)
Works good and easy to install and remove"
I have done that works well also.


"I think cut thread onto drum and make treaded cap from steel is best option for rigidity
Screw holes make weak spots onto cap and screws makes not even force to cap
Cap can and will bend under load and it will create overheated places"
Agreed hardened steel cap would be good and instead of the interference screw set use threaded holes in drum with a fixed final position to hold from spinning and a new drum and I think would be perfect (best of both worlds)
However I would worry with the very fine threads and the differential expansion rate of aluminum and steel might be an issue

 

I also looked into this years ago, But didn't follow up far It's simple enough in principle. . direct 3-4 clutch oil to the rev drum , Then release while directing 4th oil to the 3-4 set and OD servo.
Tricky part is timing and figuring a way to still direct rev oil to the rev drum.Cutting off oil in to second servo to get band released.
My other concern is if the splines where clutches woulds stand being aluminum and the constant shifting seeing how they have many times taken a pretty good beating being just reverse.
But yes MaroonMonster has gone further with this.
I did tear down a unit a few years ago that did indeed appear this had been done but did not have the time to study as I was PB one man show at the time . But did as I mentioned noted considerable wear on the splines on the drum where clutches hit . I kept the VB a while thinking I would get back to it but you know how that works out many times.
I can't remember now if it was a core or one someone sent in to have done. Had several performance updates in addition. Was probably back around 2014-2015 area.
But doing and making up stuff like that requires considerable time and dyno or test vehicle time and that was and now by myself not an option. So I stay with simple easy prove mods now days when thinking things up to do. Mostly on improving what already is known to work. Extravagant mods are fun and cool to work on but people dont wanna pay for that working for them and by yourself making a living unless rich just not practical to do.
Used to for instance get alot of calls asking about RMVB for the 60E very doable block of aluminum. custom manual valve, some holes and one way ***** drilled through and cut to shape of VB and milling machine and your all set. But none exist as far as I know as none who can do it can afford to and Those that do have the funding or time either don't have to know how or are busy enough and don't care to try. But I do indeed think a market would exist.
Sorry I talk to much sometimes.

 

Lead may work. I don't know how hard it is to get these days thought.

 

I have a few old lead wheel weights I could use lol, But I like the aluminum rivet idea.

 

Lead heated and melted into place does work well with none bonded plates. I use the bonded so a no go for me. Rivets with no holes work well if you have rivet gun. Me I just get 3/16th aluminum rod from hardware store cut and use them and hit with hammer on each side. Also solid core solder like used in plumbing works well just cut slide into hole and hit/ mash with hammer both sides.

 

Aluminum has higher rate of expansion than steel
And because steel will be at outer dia -it will work as a band for oak barrel
I see no problem here
Actually we have problem with input shaft with drum leaking because aluminum is outer dia of steel shaft and every F(or C) weakened this joint
Thats why is highly important to press shaft into new drum when drum is heated (like valve guides into alu head should be pressed when head is hot)
Its adds some overlap in dimensions and make joint tight
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By the way I blocked #4 checkball with rivet, drill 3rd feed to 0.140 and now 3-2(13) orifice works in both directions like 2-3 and 3-2 (and yep now my 3-2=2-3 as many people suggested here haha -but my way )
Its by default was 0.100 and I leaved it as is
And I like it
The only thing I dont like now
3-2 shifting below 20mi
Its little bit too late and it looks like 3-1-2 with bump
If speed is higher -all good
3-2 sol is blocked and 3-2 shifter in OEM config
Now I have 0.078 2nd feed and 0.109 band release with 0.065 -0.070 band clearance and OEM 2nd servo (its my second tranny because Im waiting some parts for my main)
I will enlarge to 0.093 as it was before but now I wanna add some pressure to 3-2 shift and test what will happen
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I also wanna disassemble shift solenoid to enlarge orifice inside
I think it will be like FRANK mod with spring added to 2-3 shifter

 

Measured today overrun to add extra clutch and I only can 'find' 0.100 gap
But I need 0.200 to install 3rd overrun disk with steel and achieve 0.03 clearance
So custom input piston with longer legs should help )
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I also measured input drum and shell to find that not so many place between em to make custom cap with tread like 4l79
And it also mean that output shaft needs support at the front to not let shell touch that custom cap due to excessive end play of shell

I also thinking about 07UP bearing to front planet carrier and It looks like full bearing assy will benefit shell up/down play if I make output shaft end play close to zero
2 things
Shell will be not lean down at low speed
And all side trust from planetary work will be locked into output shaft without additional load to small bearing between input drum and sun gear and parking gear to case (which is similar to old style front planet carrier bearing that failed 2 times in my tranny)
So I machined my front planet and reaction shaft to 07UP bearing and will cut groove to replace washer to bearing between shell and shaft but as little as it needs to achieve close to 0.005 or less end play of output shaft

 

maybe I’m not understanding you right, but you NEED a certain amount of end play. If it’s too tight it will kill the bearing. It has to have at least .015-.025 end play on the input and I think around .015 on the output. All that stuff grows from heat and if you set it at .005 or less, it’ll kill the bearing.
s.

 

Overall minimum endplay is 0.005 (input shaft but input connects to output)
Output shaft assy end play typical is 0.03-0.05
It means that even you get 0.015 per unit -output shaft can slide in and out
And side forces from planets goes thru all bearings to case
Minimum 0.005 divided to 8 bearings
Output assy has 5
So their part of clearance will be 0.003125
All parts of output assy made from steel and expands equally -so it will not changes significantly with heat
All bearing involving to withstand side load at output shaft (with sonnax smartshell that redirect load from rear planet captive bearing ) are bigger that 3 bearing at input and parking gear
It means that if we make output assy tighter than input shaft clearance -it will lock most of force inside assy and saves small bearings
It also helps to control shell from leaning down by gravitation (and all another components )
So output shafts with planets will be more solid and less damaging bushings
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And why minimum clearance ....
I I know you had situation when you needed to hit hard by hammer with very limiting space
And if its too tight no matter how hard you tried - you wasnt success because hammer cant got enough speed
Same with bearings -the more gap - the harder they hit when gears changed at WOT
So I prefer lowering gap close to minimum - it saves parts from hard hits

 

yea, unfortunately it doesn’t work that way. When the components grow, it closes the gap in the end play. If that happens then it takes the bearings out. That’s why there’s a specification on end play for the from and the rear. But have at it, close up that clearance and see what happens. I think you are trying to chase a problem that doesn’t exist. I’ve never had a problem caused by this clearance.

 

Totally agree

 

Agree while insanely high endplay can be an issue. Generally what's more important is that you have enough. It is certainly a case of a bit over spec would be much better than under.

 

yea I was reading his post and I’m shaking my head. At first I had to read it a couple times because I thought I might be misunderstanding him. But I wasn’t. I know how metal expansion works and if he set it up to have .005 endplay, thinking he was doing something good….he will find out in short order what happens when things start binding and crashing into each other. EVERY trans I build get a dial indicator on it and I set it as close to the minimum spec as I can. I will go out of my way, taking it apart several times if need be to get it to minimum factory spec. But NEVER any lower.