Input for improving a rebuild 2004r that has Transgo HD2 kit w/dual feed

Lil Truck

I spend to much time here....
#1
As the title says this was a standard performance 2004r that was rebuilt by a local trans shop and lasted a few thousand miles in a GN with approx 520/550 hp/tq. It started having 1-2-3 delayed shifting in manual and some flare in 2nd at wot. Fresh fluid and a shim in the servo improved the operation but not completely so I have removed it and tore it down to inspect and repair.

Here is what I have learned.

Non lock valve for PTC 9.5
Transgo HD2 kit using dual feed bushing, all kit modifications appear to done per the instructions.
Rebuilt valve body ?
Heat treated forward hub
OD piston for 3 clutch pack
8 clutch pack direct
6 clutch pack forward
Wide HD red band
Standard weight governor

2 of the OD frictions have some dark burn marks and spots of blue on steels
Direct clutch pack looks good but has at least 0.126 clearance to the snap ring
Forward clutch pack looks good but has at least 0.075 clearance to the snap ring
I did take pressure checks before removing the trans and they were reading good with max TV at 240psi

My goal is to repair and improve this transmission. I have a BRF valve body and governor and plan to reprogram it along with replacing the thin steel 8 clutch pack with a set up from Bison. I am concerned with the possible problems I might have with the TG dual feed and reprogramming the VB?
Looking for good input please!
 
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INEEDAGN

Seen Your Member
#3
Unless you plan to re-case the transmission, I don't see what choice you have but to re-install the transgo dual feed parts. At least not without jumping through more hurdles than it's worth to change it.

Ditch the 8 pack direct is a wise move. Forward can be pretty much anything if it's not hot spotted. Re-use the wide band as long as the lining is good. Alto had a problem a few years back with all the linings falling off their bands/frictions. Cost many builders a bunch of money in comebacks and no one trusts alto anymore.

They took transgo's instructions to heart even as far as the coarse crosshatch on the band surface. I'd probably polish the drum but it'll be fine if you have to leave it alone.

I'd have to go back through the hd2-a instructions to see if there's any huge no-no's in it. I believe they use the stock tv springs and that's a good thing. I think they stiffen line bias but probably not enough for max pressure to be achieved.
 

Lil Truck

I spend to much time here....
#4
Unless you plan to re-case the transmission, I don't see what choice you have but to re-install the transgo dual feed parts. At least not without jumping through more hurdles than it's worth to change it.

Ditch the 8 pack direct is a wise move. Forward can be pretty much anything if it's not hot spotted. Re-use the wide band as long as the lining is good. Alto had a problem a few years back with all the linings falling off their bands/frictions. Cost many builders a bunch of money in comebacks and no one trusts alto anymore.

They took transgo's instructions to heart even as far as the coarse crosshatch on the band surface. I'd probably polish the drum but it'll be fine if you have to leave it alone.

I'd have to go back through the hd2-a instructions to see if there's any huge no-no's in it. I believe they use the stock tv springs and that's a good thing. I think they stiffen line bias but probably not enough for max pressure to be achieved.
I do have another case it a complete TAF I was going to freshen up for a back up trans. I am only concerned with the band release or bind that has been mentioned in other threads and what I might be able to improve on? Maybe this should be the back up trans and put all the good parts in the TAF?
 

INEEDAGN

Seen Your Member
#5
I had a brief conversation with Lonnie about the transgo dual feed and he agreed when I theorized that they purposely left a small feed hole in that aluminum hat to reduce the part throttle bind and reduce stress on the stock or hardened drum. I've never used one so I can't tell you anything for sure. But I do have one of those kits here I found cheap on eBay and plan to tinker with someyear.
 
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David Husek

Turbo Buick Performance
#6
Since the dual feed from transgo is installed, you can not go back to standard feed. I have a fix but you only need the transgo bushing for it. Contact me and I can set you up with all the parts needed to get the trans to operate correctly. I have all the clutch packs that you will need for a performance application. Same as used in my Pro Plus Build. Call anytime 516-285-1103
 

INEEDAGN

Seen Your Member
#8
The revised hd2-A kit uses a bushing over top the center support bolt and has you drill out a case partition to be able to dual feed it from the worm casting area and not have to leave off any rings or seals. You can see most of it in the pics above. If the kit comes with a billet servo it's an HD-2 "A" kit with these parts as well as inner springs for the direct drum return springs and other stuff
 

Lil Truck

I spend to much time here....
#9
What is this Trans go dual feed. Have an 85 GN Trans here and putting it back together. It had some pump and vb pump mods, mike
If your trans has the modifications it's easy to identify, look at photo 1 and 4. The bushing with the hole covers on of the black bolts and the case is milled away between two channels. It gives extra pressure to the direct clutch pack, but must be calibrated properly.
 

Steve V

Steve V's Automotive 757 560 2782
#11
Direct clutch pack looks good but has at least 0.126 clearance to the snap ring
Forward clutch pack looks good but has at least 0.075 clearance to the snap ring
I have a BRF valve body and governor and plan to reprogram it along with replacing the thin steel 8 clutch pack with a set up from Bison.
Few thought on my end: Bison uses 6 .100 steels, 6 blue plates, 4140 pressure plate and aluminum apply ring in direct. Go that route, it's living in the 9's

.126 is way to loose in direct I like .030 or so

.075 in forward is a lot, think about it forward is on in every gear except reverse. I like it tight and with drag as well as the wave plate.
 

Lil Truck

I spend to much time here....
#12
Few thought on my end: Bison uses 6 .100 steels, 6 blue plates, 4140 pressure plate and aluminum apply ring in direct. Go that route, it's living in the 9's

.126 is way to loose in direct I like .030 or so

.075 in forward is a lot, think about it forward is on in every gear except reverse. I like it tight and with drag as well as the wave plate.
Thanks Steve, I knew the clearance was way to loose and needed that information!
 

bison

Moderator
Staff member
#13
Thanks Steve, I knew the clearance was way to loose and needed that information!
Adding clutches unless they are thinner will require reduced thickness steel. This is a step in the wrong direction. You need to reduce deflection at the pressure plate and use the thicker steel. This will reduce heat in two ways. The pressure plate being rigid and less prone to coning will reduce slip especially at the clutches closest to the snap ring and the thicker steel has more mass to absorb the heat. The circuit can’t have leakage or direct will never last. Pressure should be 275-300psi hot for a max effort build. If there is a flare it’s usually a timing problem. Band is being knocked of too soon. Reduce 3rd accum orifice and tighten the clutch clearance.


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bison

Moderator
Staff member
#14
Few thought on my end: Bison uses 6 .100 steels, 6 blue plates, 4140 pressure plate and aluminum apply ring in direct. Go that route, it's living in the 9's

.126 is way to loose in direct I like .030 or so

.075 in forward is a lot, think about it forward is on in every gear except reverse. I like it tight and with drag as well as the wave plate.
Yes. This is why you need access to a lathe. If you use a 4140 pressure plate you can turn the plate for additional clearance and it will have minimal effect on the strength of it since you’re only removing material about half way across the plate. Just enough to get the snap ring in. This negates the use of thinner steels to achieve proper clearance.


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Mr.Spool

Well-Known Member
#15
I'm curious to this new clutch pack you guys are talking about.all I Know is dave husek installed the same clutch pack in my trans 7 years ago,my reciept says it consist of 6 blue frictions,6 .100 thousandths
steels,new gm pressure plate,and a billet apply ring.i have thousands of passes on this stuff and I make power than most Stay up a night and dream of:D
 

TexasT

Texas, Where are you from
#16
Yes. This is why you need access to a lathe. If you use a 4140 pressure plate you can turn the plate for additional clearance and it will have minimal effect on the strength of it since you’re only removing material about half way across the plate. Just enough to get the snap ring in. This negates the use of thinner steels to achieve proper clearance.


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This 4140 pressure plate, Is this the $125 unit with the minimum order of five? And the aluminum apply ring, is this a complete piston or just a ring inserted in there? Thanks

I want to thank all who added info, this is the great tech this place is famous for.
 
#18
Not...that I have found. The ones from parts houses when you can find them are now junk. Strangely the forward clutch ones are also now hard to find. I just built another 200R4 for my dad's car and Husek supplied them to me plus convertors. I've not ran this trans yet, but will in the spring.

I don't know what others are doing, but I had to buy a spare 200R4 just to get some basics. That core took me 3 months to find it. Don't lose a snap ring or something.....I misplaced the silly "S" hook on the linkage to the valve body and had to buy a $150 core for it. Water was in the pan so the VB went in the scrap pile. Good luck.
 

Steve V

Steve V's Automotive 757 560 2782
#20
I'm curious to this new clutch pack you guys are talking about.all I Know is dave husek installed the same clutch pack in my trans 7 years ago,my reciept says it consist of 6 blue frictions,6 .100 thousandths
steels,new gm pressure plate,and a billet apply ring.i have thousands of passes on this stuff and I make power than most Stay up a night and dream of:D
The blue plates and .100 steels are not new, the 4140 pressure plate is new and the apply ring is new. Dave has his own plate, it's not 4140. It's stronger than stock as well.