$2500 is really cheap but like DT said try other less costly things first before jumping to a trans rebuild, i would expect to see some P0730 (incorrect gear ratio) and other P073* codes if the trans is at fault,

 

Hi guys, many thanks for all your input so far. These are the error code:

P0741
P0783
P0730
Is the best course of auction a rebuild?

 

P0741 - at face vale, not good. Indicates torque convertor issue. Either failing or not locking up as it should. Basically the trans is not spinning as fast as it should. I guess REALLY bad/wrong/contaminated fluid could cause this too.
P0783 - 3rd to 4th gear shift issue.
P0730 - gear ratio issues.

First, simply check fluid level and top off if needed. Then I would do a trans flush, a proper flush, with the correct fluid. That is still the least expensive thing to try and probably the only thing to try. Needs to be done correctly with correct filling procedure. If that is of no help, then it is time to rebuild/replace the trans. There is always a chance its the Medtronic wiring sleeve contaminated with fluid, but with those particular codes I doubt it. I would not hesitate to gamble on installing a used transmission, these are generally pretty tough if taken care of. Used may be cheaper than a rebuild.

 

Hi. The car has lead a pretty priviliged life so far. First owner meticulous with full main dealer history and I've always used what I hope to be a trustworthy, knowledgable indy mechanic to look after it.
It had a flush and new oil last year, our first attempt at curing the issue. I can purchase a replacement box locally for around $1400 or a full rebuild for $2000. Rebuild sounds like the way to go?

 

I would still at least check fluid level if its not been done. If the rebuild has a warranty, then given the price difference I would probably go that route myself.

 

If the rebuild price includes a new/rebuilt torque converter then its a bargain, if not i would still be replacing it.