Performance transmission build

longassname · #1 02-10-2007, 04:35 PM

Ok, time to prove the rumors right and start unveiling the performance 4eat build. I've been working on the ultimate 4eat rebuild for the svx. There's a lot involved in this so documenting and illustrating what I'm doing is difficult. Expect the thread and organization of pictures to be sloppy. There will be a a huge # of pictures posted; even still a lot won't be in pictures because no one was around to take a picture while I had my hands in that particular part.

The original plan was put together the ultimate rebuild kit consisting of the parts I am using to build the transmission for the sub 10 second car I'm putting together. It turned out more practical to offer the compete built transmissions (and I came back and edited this line to say that). The build is a job and a half and I found several critical points of failures that most transmission shops will probably just ignore even given the correct parts. I'll try to point them out as they pop up in pictures.

The build parts start with a complete set of super quality seals and gaskets. Most of these seals are from the same manufacturer as OEM but there are also some that are improved to prevent the leaks that create the pressure drops that are partly responsible for clutch pack burn outs and planetary over heating.

On to that are added parts to modify the fluid pressures of the various circuits. These are mostly springs and plungers in the valve body and accumulators but we also modify some fluid paths. What we are doing here is increasing the apply pressures on the clutch packs to increase their holding power, increasing the fluid flow to the planetary to improve lubrication, and modifying some shift pressures to quicken shifts.

The next major group of parts are the friction sets. Here we are replacing the frictions with graphite frictions which both last longer under daily driving conditions and have a higher friction coefficient under higher power levels. We use some special retaining plates to let us fit in more clutches for even higher power levels.

This is most of the parts originally planned to be used in the kit. Some more have been added during the course of the project. On the transmissions that I'm building I also replace the solenoids and torque converter.

longassname · #2 02-10-2007, 04:42 PM

Here are some photos of the valve body removal.

pan off

bolts reatining valve body off

valve body pulled up and flipped over
here you can see the accumulators in the transmission body..more on them later

valve body removed
now you can see the planetary set..on it later

longassname · #3 02-10-2007, 04:49 PM

With the valve body removed we clean the parts with kerosene and make the modifications to it modify the line pressure and various circuit pressures. Most of the modifications involve replacing the springs on the plungers which maintain the pressure for their particular circuit. We also replace a couple plungers and enlarge a fluid path in the plate between the upper and lower valve body halves and block off another.

longassname · #4 02-10-2007, 04:51 PM

continued....

longassname · #5 02-10-2007, 05:01 PM

Here are some sparse pictures of dissassembling the transmission.

gear case with extension housing and differential case removed

Staked nut on drive gear on back end of pinion.

drive gear being pulled off pinion

pinion unbolted from pump and being pulled out of case
note the tube around the input shaft..this tube has bonded rubber seals on each side and is a special order part most rebuilders don't replace...that's the cause of contamination between the gear oil and atf. It should always be replaced.

pump being pulled off of gear case
note the lathe cut seals on the pump..they shrink and are another point of failure..these are replaced with better versions

gear case with planetary removed and the accumulator for the band apply in my hands
note the seals on the band apply accumulator..another point of failure..they wear and cause poor apply pressure and brake band burn out

longassname · #6 02-10-2007, 05:17 PM

I'll have a lot more planetary pictures soon. For now I just have some of the forward clutch drum to illustrate how they work and why most transmission rebuilds done on the 4eat skip right by a couple importan points of failure.

the forward clutch drum houses both the forward clutch and over running clutch.
Each is a stack of frictions, alternating steel plates and friction plates, plus dish plates, retaining plates, circlips, and pistons which under hydraulic pressure engage the clutches. The friction sets are easy enough remove and are what the transmission shops usually remove and replace in a rebuild. The pistons are more difficult to remove only because you have to either have the special tools from the factory or just the right set up to be able to press the spring loaded pistons in order to remove and install the circlips that retain them. The truth is you can pretty much count on your average transmission shop skipping right past this step and there are several piston seals in this trans that are prone to failure. We of course replace those seals with improved seals.

empty forward clutch drum in the press to remove the circlip retaining the forward and overrunning clutch pistons.

forward and over running clutch pistons removed and with new seals installed
note each piston has seals on both it's inner and outer
seals and grooves are covered with trans gel

forward clutch drum reassembled with new improved friction sets installed.
graphite frictions are used for both the over running clutch and forward clutch
A special retaining plate is used and the # of frictions for the forward clutch are increased.

Crazy_pilot · #7 02-11-2007, 03:04 AM

Quote:

Originally Posted by longassname

.... the sub 10 second car I'm putting together...

This is the part that makes me all happy. A 10 second 4EAT SVX? Sweeeeeet.

SSSVX · #8 02-11-2007, 09:39 PM

Cool, lot of technical pictures.

Are you going to improve the gear ratios and the differential too?

If you want to buy an used SVX stock ratio tranny, let me know. I have one sitting in the storage. The front differential was bad but the tranny itself was still shifting fine, was told it was rebuilt 20k before I bought the car. But I replaced 4.44 tranny on my yellow.

svxstarship · #9 02-11-2007, 10:02 PM

Wow. Can't wait to hear about the results. Might want to enlarge the casting slightly where the brake band outside bolt is. That way a gear wrench will fit on the 17mm bolt and make adjustments easier. The wall of my gear wrench was to thick and the casting was in the way.

SVXRide · #10 02-12-2007, 07:59 AM

Michael,
Nice! I like the idea of the two Toms doing the build-up/install. Shipping transmissions around is going to add cost that may put the mod out of the reach of many.
10 second SVX? Gonna have to take some weight out of that bad boy first!

-Bill

TomsSVX · #11 02-12-2007, 10:48 AM

I have a couple transmissions here. One I know lost 3rd and 4th. The other was completely fine(looking at the friction materials and steels). If someone is in the area looking for a rebuilt trans... I have no problem building it LAN's new kit. Him and I have been speaking about this for a little while now and I am glad it is finally out in the open

Tom

longassname · #12 02-12-2007, 06:58 PM

Eh, you're imagining freight at the rates you get quoted though. Freight would be at the rates I get.

I don't imagine the built transmission will be put in as a mod by those who don't have money either. They will be bought by those with the money to put together nice cars and those who may not have money but have blown transmissions in which case they may really need to put the major expense on a credit card.

Don't forget, while you live next to the two Toms not everyone here does.

Quote:

Originally Posted by SVXRide

Michael,
Nice! I like the idea of the two Toms doing the build-up/install. Shipping transmissions around is going to add cost that may put the mod out of the reach of many.
10 second SVX? Gonna have to take some weight out of that bad boy first!

-Bill

AJ4U2 · #13 03-16-2007, 10:05 AM

Whatever happen to this project? Would like to hear about if anyone has install one or in the process and the results if anyone has...
Aj.

TomsSVX · #14 05-16-2007, 08:57 PM

u mean .2 seconds right?

Tom

longassname · #15 05-16-2007, 09:01 PM

NO, definitely way more than .2 seconds. You seem to have forgotten already how slow stock svx's are. I wouldn't be suprised to see them pull high 16's. You'll definitely improve quarters by more than a second on a stock svx......An svx with nitrous, easily more than 2 seconds. Man I remember doing runs with my 150 shot and I was spending more time in the shifts than in the gears.

Quote:

Originally Posted by TomsSVX

u mean .2 seconds right?

Tom