Re: '94 FWD transmission non conversion swap questions
 

The TC has a hydromechanical clutch in it for the lock up function. The operation is controlled by the TCU. Based on gear (only fourth), fluid temp, vehicle speed and throttle position. This is a separate function from the torque converter itself. See the manual for explanation.

I have a 3.70 JDM transmission. I used to have a 4.444 4ACT from a 2.2 n/a 1996 Outback.

The (stock) SVX is an old skool relaxed gentlemans grand tourer. Keep it that way :D. And do not forget the heat generation issue.

/T

Re: '94 FWD transmission non conversion swap questions
 

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Re: '94 FWD transmission non conversion swap questions
 

Not quite sure what you meant Huck.....

Re: '94 FWD transmission non conversion swap questions
 

When you inlarge Hucks post you get 43 squares, so obviously what Huck meant was 43 X 43 = 1849 as in 43 squared!
If you take the number 1849 and subtract the world standard performance number, 1320, as in how many feet in the 1/4 mile you are left with 529.
From this number you must OBVIOUSLY subtract 230 as in the flat 6 HP, leaving 299, and from that subtract 228 as our stock torque! :)
Now left with the number 71 you have to go back to Subaru roots, as in the SEVEN Sisters, DUH!
Leaving the numbet 64!
6 - 4.
Another way of saying TEN!
And as we all know the SVX stands for Safety Vehicle X or 10.
Good show Huck,
Good, show!

Re: '94 FWD transmission non conversion swap questions
 

Update:
I have purchased the '93 Legacy turbo Touring wagon 4EAT tranny, and have ordered a tranny filter and gasket kit, and new input and axle seals. The transmission number and model are: 479801 TZ102ZJ3AA-N8

Issue #1:
I am still mulling over the issue of the impact of the higher stall speed of the Turbo donor TC on driveability. I value and am taking Tapani's opinions into account -- but haven't heard anything definitive from the rest of you folks (other than to avoid 4.44 final ratio). Tom says it will work, but hasn't offered an opinion on what the impact to driveability will be. Huck just put a post out with a bunch of periods. Doesn't anyone else have any experience to share on this -- either agreeing with or disagreeing with Tapani????? :confused:

So y'all don't have to dig to get them, here are the specs on this '94 FWD SVX -- the stock tranny had a 3.7 final ratio in the integrated front differential, and a TC stall speed of 2350-2750 RPM. The replacement tranny from the '93 legacy turbo donor has a 3.9 final ratio, and it's TC has a stall speed of 2800-3200. Should I be looking for a lower stall speed TC because the Turbo TC will make the SVX feel really sluggish at lower RPMs, or will the donor TC just make the SVX feel more "sporty" and "aggressive" like some of the Turbo models do? How about sharing some experience and opinions here?

Issue #2:
On to the next topic -- as part of this tranny swap, I am raising the transmission cooling question again....

I've read a bunch of threads on this forum, and haven't seen anything resembling a consensus being formed.

Here are the issues that seem to surface in the threads:
1. What I have read seems to indicate that extra cooling is a good thing for the most part -- especially in stop-n-go driving.
2. I've also read that flow restriction is a major problem -- especially when incorporating the stock radiator cooler in series with an external cooler. Tom favors bypassing the radiator cooler altogether. Others say to put it in series with the external cooler 1st to reduce the temp, and the stock cooler 2nd acting as a temperature regulator to keep the fluid warm but not too hot.
3. I've also read that in cooler ambient temperatures too much cooling is not a good thing as it prevents the TC lockup clutch from engaging (fluid must be at 150 degrees F or better). If the fluid temp is really low, it might not shift into 4th gear.
4. A number of folks have worried about 3/8" connectors reducing flow.
5. Some folks are using automatic t-stat valves to divert the flow to an external cooler from either the stock cooler or from simply recirculating it back into the tranny. The t-stat valves open when the fluid temp is raised up to about 160-170 degrees F). Others have expressed concern about fluid restriction using these valves, and a concern that their likely potential failure mode is to be "closed", meaning that the fluid could overheat if the valve fails and the external cooler fluid path is left out.
6. I have only seen one mention of running an external cooler in parallel with the stock radiator cooling fluid circuit. This was by Tom, stating that a customer had requested it. How did that work out?

Given all that I have read, I am leaning towards installing a smaller (10000 GVW rated) external tubing-and-fin type cooler in parallel with the stock radiator cooling fluid circuit, and mounting it in between the condenser and radiator as Tom has suggested. It seems to me that this would eliminate the need for an additional cooling fan and would also provide some (hopefully enough) heating from the coolant in the radiator to allow the TC lockup to function in colder temps. I live in the Pacific NW (Oregon), so the temps seldom go lower than freezing -- most of the winter they stay in the high 30's to low 40's F. In the summer the daytime temps vary between the high 70's to the upper 90's, so I think additional cooling would be helpful -- especially for in-town driving. I might install a ball-valve inline in the external cooler's fluid circuit for the odd sub-freezing temperature weather that sometimes hits in the winters here.

Sooooo, what do you "experts" think about the parallel installation? Is the 10000GVW external cooler a correct size, or do you recommend something else?

Let the opinions fly!

Issue #3:
I understand that the early 4-EAT pump seals were problematic and could leak reducing the fluid flow and pressure. How hard is it to get to and change the 4-EAT pump seal? Would I need to disassemble the tranny, or is it something that can be done by just taking off the pan?

Thanks again for all your recommendations....

Philip

Re: '94 FWD transmission non conversion swap questions
 

Oregon winters are "real" - yes?

I commute 20 miles each morning. Now that the ambient has dropped to below 10C in the morning the tranny pan temp reaches only app 120-130 F, so no TCC lock up. My cooling set up right now is an external cooler between the rad and the AC condenser, I have disconnected the bypass valve. I also have a valve body from ECUtune which is supposed to increase the cooling circuit flow rate. This is for the occational track days.

I will go back to the rad bottom cooler alone for the approaching winter. I may try the bypass valve during the coldest months....

If you want to monitor the fluid temp a gauge is very easy to install. I have my sensor in the drain plug.

You have all the basics correct - you just need to decide what you want. One approach is to try :). Install the tranny as it is, with the TC and all and have a taste. Just drive it !

I think you have done a good job and dug into all this quite deep - why not repair your own tranny yourself? Not much harder than swapping the pump gasket.....

Or go all the way, convert to VTD four wheel drive :eek:. JDM trannies are available as are 3.7 rear diffs. You just need to sort out the TCU with a chip burned with the correct firmware.

Good luck,

/T

Re: '94 FWD transmission non conversion swap questions
 

Hi Tapani,

First off, thanks for your thoughtful, helpful and encouraging responses!

Although we are above the 45th parallel in the Pacific NW in Oregon and Washington (include western BC, Canada too), the winters are surprisingly mild -- nothing like you are used to in Finland. This is due to a warm Pacific current that comes across from Japan, and keeps the temperatures on the west side of the Cascade mountain range warmer in the winters. As I mentioned in the previous post, the normal winter temperatures are in the mid 40's F (about 8-10 C). We get a lot of rain in the winter, which is why the area is home to a temperate rain forest. Every 5 years or so the arctic jet stream pushes south and we get a week or two of hard freezing temperatures, and a snow storm with 3-4 inches of snow -- but it's a rarity. The summers are quite dry and warm though (which is why I am installing a tranny cooler).

I am still hoping to hear from some of the other "experts" on the forum with their opinions and experiences on the 3 issues I raised below.

Philip

Re: '94 FWD transmission non conversion swap questions
 

1) Stall speed is not cast in stone.
If you put a 230HP engine in front of a trans designed for 160HP the stall speed will be forced up.
BTW stall speed is only reached if you power block an engine as in drag racing.
If you are worried about it then just use an SVX torque converter.

2) My automatic SVXi have a transmission cooler run in series with the factory radiator IF that car has a factory radiator.
If it has a factory radiator the aftermarket cooler is before the factory cooler so that in the winter the radiator reheats the transmission fluid back up to a workable temperature.

3) you have to dissassemble the trans to do a pump seal.

BTW, The 4.44 does not hurt gas milage in an area with hills or mountains!
Even with the crappy ethenol gasoline I still get over 20mpg in The Mountain State.

Re: '94 FWD transmission non conversion swap questions
 

Here's another update....

First off many thanks to all the experts that replied and shared their experience and opinions. It's been very helpful and enlightening!

In the last update, I shared that I had acquired a transmission from a '93 turbo legacy wagon that had a 3.9 final differential gear ratio. Since then, I came across a local SVX owner who was selling an AWD SVX transmission that had a bad transfer case solenoid at a reduced price of $180. Since my SVX is a FWD -- not AWD, I can simply remove the transfer case (and it's solenoid), and replace it with the bad transmission's rear case plate. By doing this, I'll have a FWD SVX with a 3.5 final differential gear ratio. This should hopefully improve highway mileage by keeping the RPMs lower at highway speed.

Thanks to Tom for suggesting putting the aftermarket tranny cooler in SERIES and BEFORE the stock radiator instead of my original plan to put it in parallel. This solves the potential for the transmission fluid never getting warm enough in the winter time -- because the stock radiator will heat the fluid back up to operating temperatures before it returns to the tranny.

I hope to have this done in the next couple of weeks and get this SVX back on the road again.

I'll either keep and use the '93 AWD turbo Legacy wagon 4EAT tranny elsewhere, or sell it.

Philip