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Shift Correction Kit for Auto Transmission

951 Views 3 Replies 3 Participants Last post by  DangerRanger
Does anyone have any experience with the kit that is advertised at this link: I also attached a picture.

Ford Transmission Shift Correction Kit 5R55S 5R55N 5R55W Superior Valve Body | eBay

I have a transmission on order and I was looking to see if there was anything I wanted to do to it before I installed it. It only has about 30K miles on it so I don't think its ready for a rebuild. However, this kit, which claims to correct a flow deficiency, seems ok. I would have thought that if there was a serious flow problem, Ford would have issued a recall for it to be fixed the next time you turn your car in for service. Does anyone know anything about this kit or the problem? Thanks.


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There isn't a serious flow problem. For everyday driving (and assuming the fluid level is maintained) the 5R55S works just fine. Some people have had servo issues with the 5R55 transmissions, but by far the most common problem is overheating, and poor fluid levels. (That, and crappy fluid change cycles/practices...100k miles between changes? Screw that noise, change it after at least 50, and if you drive hard or do any racing, sooner.)

Our autos come with a decent trans cooler, but there's no way to easily check the fluid (no dip stick, you have to crawl under the car while it's running and do a drip test). The transmission is VERY sensitive to fluid level, and without being able to easily see if you're down, you can guess what causes the most problems.

Also, these things (like most automatics) do two things...change gears, and change cold oil into hot oil. There's no transmission temperature gauge, and a lot of folks are going around thinking everything's fine, when they're not. If you run around zippy, or do any kind of racing, even if it's 10 degrees out, they heat up fast. This is compounded incredibly by wrong fluid levels.

So one, do yourself a favor and get that fluid level checked. If you want, have the fluid changed and the filter changed (DON'T have it flushed, there's no reason to flush an automatic's not a radiator).

Two, if you want nice firm shifts and responses, go get a real dyno tune (not a canned tune, a real on-a-dyno tune). It'll knock your socks off how much slop there is to lose (remember, it's a mass-market consumer transmission...they're made soft for that reason).

Three, get a gauge and keep an eye on that temperature.

I'd leave that kit alone unless you actually have one of those components fail. There's just so much you can do to have a better time with your transmission without tearing into the guts of it.
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Thanks for all the information. You are the second person today to inform me that this transmission doesn't have a dipstick and tube. I didn't know that until today. One of the advantages that an auto has always had over a manual is the ease of checking the fluid level (with the dipstick). Looks like that's gone now. Since there's no tube, I'll have to learn how to refill this one and how to check on the fluid level. I just got this 2008 GT in August. The last Mustang I had was a 97 GT convertible. I've got some catchin' up to do.
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I've got some catchin' up to do.
welcome back! hope ya get it figured it out
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