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Old 09-02-2014, 08:02 PM
phreich phreich is offline
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Join Date: Mar 2013
Location: Milwaukie, OR
Posts: 12
'94 FWD transmission non conversion swap questions

Hi,

I've read a lot of stuff on this forum regarding SVX tranny swaps, but most seems to deal with MT conversions, or FWD to AWD conversions. There are a lot of posts out there dealing with AWD transmission replacements, but not much on FWD swaps, so I have started this post to try and get some expert opinions on issues related to doing a FWD to FWD automatic tranny swap from a non-svx Subaru donor vehicle.

Background on my situation:
I've got a '94 FWD SVX with a blown automatic tranny.

Getting the transmission rebuilt is very expensive, so I am looking to get a good used one. However, as you all know, the used FWD SVX tranny's are rare and go for a premium.

I am not interested in doing a FWD to AWD conversion, nor am I interested in doing an AT to MT conversion. I just want to stick with a FWD 4EAT 4spd automatic.

Here are some questions that would be very helpful to get addressed by you knowledgable folks:
  1. First off, I'd like to verify some assumptions based on the research I've done so far:
    • a. Is it true that since 1989, just about all the 4spd automatic transmissions subaru used are basically the same 4eat tranny -- the main difference is the gear ratio in the differential. Of course the FWD and AWD trannys are different because the FWD does not have a built in transfer case and rear output shaft.
    • b. I understand the gear ratio for the FWD is a bit higher -- the FWD is 3.7 instead of the 3.5 used in the AWD SVXs.
    • c. Subaru stopped making FWD cars after 1995, and few were made in 1995.

  2. I have talked to a couple of people who have said that the 4.44 ratio trannys may last longer due to the increased ratio, but the fuel use will increase dramatically. Soooo, I was wondering what ratio you folks would suggest to get the best of both worlds -- better longevity and okay fuel economy? 3.9 possibly?

  3. Is there a particular model, trim and year of non-svx FWD Subaru donor car I should be looking for?

  4. Do I need to be concerned about the TCU with the ratio change?

  5. How do I get the speedometer re-regulated to work with the changed ratio?

  6. Any particular years to avoid? Any that would be better?

  7. What about turbo vs non-turbo trannys? I think there were a few FWD turbo subarus made.

  8. Any worries about stub shafts matching, or TCU issues?

  9. Any concerns about wiring harness issues?

  10. I understand that there was a change in the transmission fluid filter and screen? Does this really make a difference in the longevity of the tranny? If it does, is there a recommended type and a range of years when it was used?

  11. Any reasonably inexpensive upgrades that I can do to help preserve the replacement tranny besides running synthetic fluid and using a tranny cooler? Is there a "shift-kit" that would be a good idea that doesn't cost too much?

  12. I plan to install a transmission cooler when I replace the tranny to help keep it cooler. Any suggestions on location for the cooler?

  13. I am thinking that it might be helpful to post an update with the results of the swap, along with any notes and issues that surfaced during the swap. Do you think I should add those posts to this thread, or start a new thread and have a link in this thread pointing to it?

Thanks for your opinions and thoughts!

Philip
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