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Jeckyll-Hyde tranny... please help me, soobie sleuths!


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Please help me solve the Strange Case of my Jeckyll and Hyde Tranny...

 

here's hoping my Holm(i)es got my (out)back! :)

 

(If you read this, THANK YOU SO MUCH! I will try to be concise.)
 

PROBLEM: 99 LegOB/2.5/Phase II AT with 98 engine (seems to be, based on coolant sensor, recently replaced) has intermittent periods of very hard shifting (at around 3500 rpm, enough to "squeek" the wheels) following recent install of tranny from 04 Forester.
 

BACKGROUND: I bought this OB a year ago, had head gaskets done, water pump, etc. and it worked great for about 6 months after which began a strange shift pattern where after starting out it repeatedly flipped between 3rd and 4th until hanging up in 3rd for a couple minutes or so before finally shifting into 4th (on a straight run), after which it was OK. I tried to fix this by replacing the TPS (cheap aftermarket, but tests OK), adding Trans-X, replacing trans filter, and even solenoids from another valve body (!) but nothing worked. It finally slipped and banged itself to death.
 

So I replaced it with a tranny from a Forester with 55k miles on it. IT was fine for about 30 miles but then started going through VERY HARD SHIFTS mentioned above. I WIGGLED WIRES TO THE DROPPING RESISTOR (which I never changed) and everything seemed to be right as rain again, so I thought maybe it was a WIRE HARNESS PROBLEM and indeed found multiple splices leading to the dropping resistor and elsewhere but only the ground wire showed questionable continuity. (I should tell you that I also got "Jeckyll" back once after sitting in neutral at a light, so I maybe wasn't only saved from "Hyde" by wiggling wires. Who knows... maybe all this is COINCIDENTAL.)
 

YESTERDAY FOR THE FIRST TIME I PULLED TRANNY CODES and was rewarded with #s 31, 75 and 76 ("handshake" method) which indicate shorts or deficient electrical involving the TPS and two different solenoids!!!.

 

I now have $3000 in this car, and the body, tires, engine, and interior are good. What I want to know is DO I QUIT and CUT MY LOSSES or SHOULD I CARRY ON on this Dark Parade? Are there too many "unknowns" here? Seems I have have been on one goose chase after another, and here "Hyde" is re-awakened again in yet another transmission to mock me.


Much of the time the few days I've driven it since the tranny replacement it works JUST FINE... but eventually the "bang" shifts with their high revs surface, ultimately hanging up at around 2500 rpm at 60 mph after hitting 4th. Furthermore, that Mr. Hyde isTERRIBLE ON GAS I have no need to say.

 

If it is just re-splicing a couple of wires, I guess I could keep on keeping on...


...yet this car also needs a CV joint and new pads and rotors!


 

 



 



 

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when I say it is experiencing very hard shifts "like above" I don't mean like the previous tranny (although it gave out some pretty hard bang-shifting towards the end)... I mean like stated in the problem...banging through every gear shift only after attaining higher than usual rpms... Sorry for confusion.

 

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I will try the shop again... they were nice enough to try to evaluate the problem from the first tranny (kept it for two days) and didn't charge me because they couldn't figure it out... then I took to Subaru and they wanted to replace the harness, the tps with throttle, and tranny...(plus axle) for about 7500!!!
 Since this was such a "shotgun" approach from subaru, I figured they weren't able to pinpoint the problem either!

BUT... since finding all these splices, I will try again with the transmission shop, for perhaps they can indeed figure something from those wires now.

 

THANKS!

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The TPS has an adjustment range. Adjusted too far one way and the shifts occur at higher rpms and are hard. Too far the other way and the shifts are mushy. I think the TPS is either loose or out of adjustment or both. 

Thanks... I will check that out. I am considering buying a used throttle body with TPS attached. Plenty for sale on Ebay but don't know how close they have to be to year/model to work... seems since I have a Forester tranny and there is crossover reference to one throttle for both models, I might risk it. First, though, I'll let a shop check it out. It's just that I don't trust shops to know all the details on the model like a Subie nerd would.

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