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Swap manual for automatic

I have a 2005 Subaru Impreza with an automatic transmission. I do mostly city driving which means a lot of shifting. My arthritic left knee is not handling this well. I’m not ready to buy a new/used car with an automatic transmission and asked my dealer’s mechanic if it was possible to swap the manual for an automatic. He said no because of the computer settings. Somehow he didn’t sound credible. Anyone know if this can be done? Anyone do it?

It would cost you way more than it’s worth.

Your best bet is to look for a replacement with an automatic.

You really need to sell the manual and buy an automatic, switching is unrealistic.

I agree. Yes, it can be done, but the cost involved is just not worth the probable results. The cost of the parts, the labor, and the possibility that everything may not work particularly well after the conversion all add up to a bad idea.

If you really need a car with an automatic transmission, your best bet is to trade in your current vehicle for one with an automatic trans.

Trade it in or find someone who wants to swap. Post an add in the classified’s of your local chapter of

You really need to find someone that has done it. It is more practical to do it with some cars than with others. Dealers never do this kind of stuff, but hobbyists do. Find a Subaru board and ask there unless someone here has personal experience. That said, the others are probably correct in that it would not be cost effective. I would modify that by saying that it might be cost effective if you find an inexpensive, suitable donor car that has most of the parts you need intact, and do the work yourself.

I helped a friend of mine go from automatic to manual on a Mercedes 240 once and it wasn’t too bad. There was a scrapyard that sold a kit for going from automatic to manual on 123 bodies which included everything from the transmission to the clutch pedal to the driveshaft. I think it cost something like 1000 bucks including new clutch parts-- a lot cheaper than replacing the automatic! Since all the holes are drilled for both versions, it was a pretty easy install too. It probably all told took about a weekend’s worth of work. So sometimes it’s not as bad as you’d think.

Of course, with that car there’s no computer to worry about and it’s a simple rear-wheel drive drive train. The Subaru drive-trains are very complicated, and I’d guess in order to do this you’d need a new everything from the flywheel to the drive axles in addition to whatever engine computer issues there are. I think Andrew’s got a good idea offering it as a trade on that site or you could also try craigslist or even your local newspaper classified. Since this is a sort of sporty car, I’d guess you’ll have no problem finding someone who’ll trade you for an automatic or buy it off you outright.

It’s doable but it’s not cost effective as others have mentioned. Wire harness, ECM, etc., etc. are all things that must be changed. It’s best to sell or trade it.

A word of caution if you’re looking for an automatic transaxle version. I would advise inspecting the transaxle very closely (or having a trans shop do it) in regards to the ATF fluid and the final drive hypoid oil. Sometimes the automatics are prone to gear oil loss through internal seals. The gear oil mixes with the ATF and over time this can knock the automatic transaxle out or blow up the ring/pinion gear assembly.

The hypoid oil level should be inspected. If it’s low (even a little) and there are no visible signs of leaks externally there could be an expensive problem brewing with the transaxle.

If you can’t afford to trade, you can’t afford the $5.000 it could cost to swap transmissions, computers, driveshafts, trans cooling lines and all the other hardware. Then the differentials will be the wrong gear ratio for an automatic. Then, after all that, you will have a car that you can’t sell and probably won’t run right. It sounded like a good idea at first, but when the advice comes out, the idea falls apart.

I will add on a Subaru it is much involved than a simple transmission swap. Your vehicle has the elegantly simple pure mechanical AWD system(the item I love about my 2004 Subaru WRX). An automatic uses an electronic AWD system with a solenoid clutch pack that you need in addition to the automatic transmission.

Andrew makes a good point. What would normally be a complicated, fairly expensive conversion would actually be a VERY complicated and VERY expensive conversion on this model. The OP should avoid this project that would leave him without a car for an extended period of time during the conversion, and could well result in a vehicle that is barely driveable, given the complexity of the project.