Lan's peformance 4eat transmission

[longassname]

I have a performance 4eat I'm about to sell. This is the first performance 4eat I ever built. If you go to the subiechips website and look at the photo album ( http://www.subiechips.com/photoAlbum.htm ) you can click on the folder icon next to "1st performance 4eat build" and it will expand to show you the five sub folders of pictures from when this transmission was built.

This transmission shifts lightning fast and works better than you can imagine if you haven't at least driven an SVX with one of my valve bodies. Right now, it's still in my pearly.



I'm going to pull it out pretty soon here and "freshen it up" and crate it. Freshening it up will basically entail opening it up, looking at the clutch packs where and when I will find they are all still like new, and then replacing the high clutch pack anyway, and replacing the brake band with a better one I started using later on. I'll post pictures when I do. I'm posting this now so anyone interested can start making plans.

[ShiuludeSVX]

What's the bottom line?????

[longassname]

$3,000 crated.

[longassname]

Ok, keeping things rolling along....


I got this transmission pulled out of my pearly and onto my cart. There's nothing wrong it it but I'm going to take it apart anyway and will be posting pictures here as I go through it. It was working smoothly, holding tight, and shifting lightning fast before I pulled it out. I drained the fluids and they were clean and perfect with no indications of wear.







Again, this transmission happens to be the 1st performance 4eat I ever built. It is the transmission who's rebuild was the subject of the original thread here on these forums 8 years ago when I desperately needed to figure out how to make a transmission that would put the power I was making to the street. I think it's a piece of SVX history.

Before this I had put a 165hp shot of nitrous on my ebony which dyno'd great but on the track spent more time between gears than in gears.

Then I had put a twin screw blower on my ebony which coincidentally dyno'd right around the same power output as the nitrous shot but on the street sheered the transfer clutch off the drive gear the very first time I got on the throttle while turning.

I had put my ebony on the awd dynapack dyno at Mastro Subaru and shown that stock it was reading 165hp at the wheels. I got that up to 176 wheel hp with a z32 air flow meter and ECU chip. I got it up to 280 wheel hp with a nitrous system and ECU chip. I got it up to 269 wheel hp with a twin screw blower.

I had installed a low miles 97 transmission (this transmission) into my ebony between the nitrous system and the blower system. The transfer clutch sheared on the first corner with the blower system. I then developed the through bolted transfer clutch mod which I installed into a 3.9 ratio transmission out of a turbo legacy. The supercharged car smoked that transmission almost instantly. I got stuck shipping out a group buy of half a dozen supercharger systems without a final version of firmware and with my own SVX broken down. Things had gone terribly wrong. This transmission needed to be developed.

So...this transmission was the low miles 97 transmission I had put in my ebony and then sheered the transfer clutch off of. Pictures of the build are in the photo album on the Subeichips website here:
http://www.subiechips.com/album/albu...ce+4eat+build/
http://www.subiechips.com/album/albu...ld%2Fassembly/
http://www.subiechips.com/album/albu...Fdissassembly/
http://www.subiechips.com/album/albu...ild%2Fforward/
http://www.subiechips.com/album/albu...build%2Fvbmod/http://www.subiechips.com/album/albu...d%2Fvbremoval/



You can see in the photo album that every piston seal was replaced, every clutch pack was replaced...it was thoroughly rebuilt. Part of the upgrade of the transmission was just that frictions used had an upgraded friction material. There were a lot of modifications beyond that. I can highlight some of them in specific pictures in the photo album.

This picture is of the low/reverse clutch pack. I forget the year split but Subaru actually downgraded it in later years. Early SVXs had more frictions than later SVXs. You increase the torque carrying capacity of a clutch pack by 1) increasing the apply pressure of the hydraulic fluid pressing the piston against the clutch pack 2) using a friction material with more grab and or 3) increasing the # of frictions in the clutch pack. Any SVX transmission has as many or more frictions in all of its clutch packs as any other model Subaru with a 4eat transmission. Usually more, the SVX transmission was and is the strongest 4eat out there. 92 SVX transmissions had 8 frictions in this clutch pack. Later model SVXs and every other model Subaru out there had 6 frictions in this clutch pack. I bought out Subaru's inventory of 92 style pistons at that time to ensure I would always be able to upgrade this clutch pack. Using the 92 style piston and a pressure plate of appropriate thickness to set the lash where I wanted it I upgraded this clutch pack to hold 8 high energy graphite frictions.http://www.subiechips.com/album/albu...DSC_4002%2Ejpg

The main forward clutch on most Subaru's uses 5 frictions, SVXs use 6, I used 7 high energy graphite frictions.http://www.subiechips.com/album/albu...DSC_4012%2Ejpg


Subaru made many modifications to the high clutch hub over the years. Apparantly they were trying to increase the cooling of the high clutch rather than beefing it up. They've gone through all kinds of patterns of holes. I've seen them looking like swiss cheese. This is the 97 version where they settled on a smaller # of larger holes. I don't consider which version you use to be important. The important thing is to upgrade the high clutch so it doesn't slip and make all that heat to begin with. I only post the picture of the 97 version hub to be informative: http://www.subiechips.com/album/albu...DSC_4034%2Ejpg


I don't seem to have a picture of inside the high clutch pack but that's ok I will be taking a picture of it when I take it apart again. That is where the most important upgrade was made. Other model Subaru's use 4. Some of the higher output models use 5. SVXs use 5. I use 6 high energy graphite frictions and kolene steels. Now, the actual high clutch drum which houses the high clutch is different in different model year SVXs. The frictions of the reverse clutch spline into the high clutch drum so the high clutch drum determines which style reverse clutch frictions you can use. Later model frictions are bigger and better but I've never seen a reverse clutch be bad without the high clutch also being bad. I believe they only go bad when cooked by a bad high clutch. This one obviously has the latter model, better one but I don't consider that important.
http://www.subiechips.com/album/albu...DSC_4036%2Ejpg


I only make this modification to transmissions that will be installed in cars with serious power. I made it to this transmission. There is an arm inside the pump which presses up against the side of the vane pump changing how much fluid the pump outputs. It's a feedback mechanism to decrease pump output as line pressure increases. Very slightly grinding down the end of this arm allows a little more leak down and increases line pressure.
http://www.subiechips.com/album/albu...DSC_4051%2Ejpg


Upgraded sealing rings and stainless sealing ring expanders were used on this transmission as well:
http://www.subiechips.com/album/albu...DSC_4066%2Ejpg

A 2nd spring was added to the 1-2 accumulator piston to stiffen up the shift from 1st to 2nd. It makes the 1 to 2 shift very fast and sharp. I don't usually do this anymore because some of the more luxury oriented drivers found it too sharp and I was able to make the shift fast without it. This transmission was built to the max and I'm going to leave it that way. I don't find it uncomfortable at all and it is very definitely FAST so I'm not going to mess with it.http://www.subiechips.com/album/albu...DSC_4107%2Ejpg

Speaking of being built to the max..this transmission has a through bolted transfer clutch hub so it will not shear off if you have a twin screw blower, a 165hp shot of nitrous, or a Garrett gt series turbo: http://www.subiechips.com/album/albu...DSC_4126%2Ejpg

It's too much to illustrate in pictures but the valve body modifications in this transmission included changing springs for the pressure regulator and pressure modifier to further increase line pressure as well as blocking holes and drilling holes in the plate separating the upper and lower valve bodies to increase the flow in cooling and lubrication circuits. Most of the mods are different than what i do now but they are still highly effective. After all this transmission has proven itself. It's smooth, it shifts lightning fast, and it has held up.

[longassname]

There are a lot of parts in a transmission....so there are going to be a lot of pictures. I've gone through this

transmission now and as expected it shows virtually no signs of wear. It has really held up well. After 6 years every last

friction in it is still like new.

Ok, so out comes the torque converter:



Then I cleaned up the outside with some wd40:



Opened the extension housing and removed the transfer clutch:


Opened the transfer clutch up and inspected the frictions. The transfer frictions are the only "tan" (tan = regular)

frictions I use. The transfer clutch is broken in so it operates smoothly but not at all worn. The original thickness of

the frictions when new was 0.071"...they are still 0.071" thick. You might also note that the fluid in the transmission is

very clean. That's because nothing in it has worn.




Next, I destaked the stake nut which holds the driven gear to the end of the pinion, pulled the through bolted transfer

clutch hub/drive gear/output shaft assembly, pulled the driven gear, pulled the parking lock mechanism, and cleaned the

mating surface.

[longassname]

Next came unsnapping the harnesses so they hung free, removing the fill/dipstick tube, and removing the cooler lines so the

differential could be removed. The differential doesn't show any wear either. I actually have the Subaru specialized tools

for setting up the differential. When you set them up right and use the right fluid they don't wear. You might note that

the contact pattern is large and in the center of the teeth.




With the extension housing and differential off it's time to stand up the transmission. The pump and pinion can be removed

as a unit.



With the pump off the transmission is open and I could start pulling out parts. I pulled the brake band out and inspected

and measured it. Although it was just a regular brake band it wasn't worn. It measured the same as the borg warner band I

favor now and will replace it with.

[longassname]

The brake band wraps around the reverse clutch drum. It comes out next. The guts of a transmission are pretty much a stack

of parts which stack into each other. For a while here you'll just see pictures of disassembled clutch packs but that will

be followed with the lined up parts which will be followed by the stacking them all back together in the transmission. By

the end you'll see what I mean.

Here's the reverse clutch pack opened up. Still looking good.



Next comes the high clutch. This one is the big deal. If something was going to be worn it would have been the high clutch

or the brake band. This is the clutch pack that is usually the culprit in a blown 4eat. It is also usually significantly

worn in a still normally operating 4eat. The stock clutch pack uses 5 frictions. I upgraded it with 6 high energy graphite

frictions and 6 kolene steels. Kolene steels are a hardened steel. They come with a black finish. The black you see on

them is finish that hasn't worn off. The 6 year old frictions are still the exact same thickness as the new ones I'm

replacing them with. There's nothing wrong with them but I'm replacing them anyway so that the next owner knows he has a

new high clutch.






Then there's the high clutch hub and a bunch of gear stuff I'll cover better during reassembly. For now here are the

planetaries, sun gears, bearings, one way clutches, etc etc all lined up:

[longassname]

Next is the forward clutch. The forward clutch drum is big. Most of the guts of the transmission fit inside it. With all

that removed and the forward clutch drum pulled out there's nothing left in the transmission case except the low/reverse

clutch which we will get to shortly. Now, the forward clutch drum houses both the overruning clutch and the forward clutch.

The forward clutch is the big one and it comes out first. The stock clutch pack uses 6 frictions. This clutch pack has 7.





Ok, so first out comes the forward clutch. Again, the frictions look new and measure the same as new. Then out comes the

overrunning clutch. Again the frictions look new and measure the same as new.






Now we can look in the transmission case and see the low reverse clutch which installs into the case itself. This 97 SVX

transmission originally had 6 frictions in this clutch pack. I changed it to the 92 style arrangement that uses 8. Like

every other friction in this thing they looked and measured like new:






Before putting anything and everything back in the transmission case I removed the pan and installed a new OE gasket. I

like the genuine Subaru pan gasket.

[longassname]

The forward clutch drum is the first thing that goes in. For some reason I evidently didn't feel like taking a picture of that.

The next thing that goes in is the overrun clutch hub. You use Vaseline to stick the bearing to its bottom side and Vaseline to stick the plastic spacer to it's top side. Yes, petroleum jelly is the correct goo. It's pretty much impossible to build a transmission correctly without it. Almost every part in the stack has a bearing or a spacer stuck to its underside and you need something to make them stick so they stay where they belong while you are installing the part. Petroleum jelly mixed with atf is also great assembly lube.





Here's the forward clutch hub and a one way clutch. It needs to be taken apart. Just because it came out in one piece doesn't mean everything stayed where it belongs. In fact the spacer between the two is out of place. The tongs that stop it from spinning are not in the holes where they should be. I take it apart, lube up the one way clutch (the part that looks like roller bearings but isn't), install the forward clutch hub, stick the spacer to the rear ring gear, and install the ring gear.







Next I install the rear planetary and sun gear:

[longassname]

Stick the bearing to the front planetary, install it, and stick the next bearing to it.




Stick the bearing to the sun gear, lube it, and install it.





Install the high clutch hub and and the next bearing and then the high clutch. There's a selective thickness washer on the high clutch. If I had changed anything I would have to break out my precision depth micrometer set and some specialized tools to take a bunch of very accurate measurements to select the correct thickness washer to put here which adjusts the end play of the whole stack. There are also selective shims for the pinion and reverse clutch drum. I have all of these things but I don't need to change them in this instance.





Next, the reverse clutch goes in and then the brake band. At this point you need to tighten the band up enough that it doesn't fall apart but leave it loose enough that it doesn't make it difficult to install the pump.

[longassname]

We're ready to install the pump now so it's time to install the pump gasket to the case. There are two nuts that hold the pump to the case. After I torque them I torque the pan bolts. When I installed the pan earlier I installed the bolts with a screw driver so they were loose enough to let it be nudged by the pump if necessary.





Now it's time to install the differential. I always use a new seal pipe. This is what keeps your atf and gear oil separate. You need your mating surfaces chemically clean so you get a good bond. Prep solve is the best solvent to use but others would work acceptably too. Ultra-grey is really the only acceptable sealant to use. You don't want to forget the rubber bushing for the fluid pass through and you should lube the ends of the seal pipe with petroleum jelly.





One of the bolts attaching the differential to the transmission also holds the fill tube. It's best to install the fill tube now. You want to put all the differential bolts in finger tight, then torque the little bolt at the bottom of the fill tube down, then torque the differential bolts.

[longassname]

Now's a good time to change the crush washer on the pan. You always want to use a new crush washer.



The transmission is pretty heavy now and it's time to lay it down before it falls over and hurts somebody then we can install the driven gear, parking lock, drive gear, transfer clutch, and extension housing.



Speaking of new crush washers it's time to install the cooler pipes. You need new crush washers for these too. And look at that: we're done.

[longassname]

This transmission is ready to go now. It's available for sale here for $3000 crated..for now. After I actually have it crated and start advertising it on Ebay the price will go up to $3500.

[ShiuludeSVX]

I would do it now, but for the funding problem.

I will be looking at you again, when I can approach that.

Thanks

[longassname]

I hear ya. Just FYI, I don't plan on getting into the transmission rebuilding business again. I'm just selling the driveline out of my pearly because I'm getting it ready for different goodies.