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5r55s transmission

Old 10-03-2018, 01:43 AM
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Default 5r55s transmission

Well my transmission on my 08 mustang gt just went out. I was thinking about having it rebuilt but was looking at putting a shift kit in it. can anyone recommend what i should use and the best place to buy it?
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Old 10-03-2018, 04:59 AM
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There are tons of options. eBay has plenty shift kits. If you are going to rebuild it,
then get the updated Servos, better clutch packs and bands. Yes, these have
three bands, leave it to ford to continue to use bands when everyone else is using
brakes. This also leads to people not adjusting them, which wears them out
faster; they slip when loose. There is an updated solenoid pack, and look for
an updated valve body.

I fit is too much, look for one that was already rebuilt, with updated stuff, and stronger
parts. Any that is advertised as "bullet proof" and so on, are good builds that will
probably out last the car.

You need a 2007+ trans, the 05-06 are different, the parts inside the bell-housing.

Raybestos sells a stage 1 rebuild kit, and shift technology plus has a shift kit, with
all new springs and a no stick line pressure relief valve, TCC lockup upgrade, and
other parts that increase flow through the trans.

Last edited by 08'MustangDude; 10-03-2018 at 06:00 AM.
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Old 10-03-2018, 05:45 AM
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You are not in the correct section, as the explanation at the top says, this is for:
Forum Issues and Feedback Discuss any issues you are having with using Mustang Forums here.
In other words, issues related to using the forum not issues related to your car.

As a new member you need to take time to look at the forum structure. There is a section for the 2005-14 S197 models which your 2008 falls under.
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Old 10-03-2018, 07:38 AM
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Moved to tech.
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Old 10-03-2018, 02:03 PM
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Originally Posted by Preech40 View Post
Well my transmission on my 08 mustang gt just went out. I was thinking about having it rebuilt but was looking at putting a shift kit in it. can anyone recommend what i should use and the best place to buy it?
How many miles are on yours? What exactly went out on it? Mine was a blown input shaft which grenaded the TC and Trans Pump at 85K.

Anyways, as far as shift kits, lets make sure we're talking about the same thing. Shift kits for automatics usually means modifying the Valve Body to improve or enhance the shifting characteristics to either get rid of laginess and/or to shift more firmly (not slam into gear, but to signficantly decrease the slipping).

A ShiftER is external to the tranny and does not impact transmission behavior.

If you're talking about a Shift Kit for the valve body to improve shifting characteristics and improve life expectancy, I'd suggest a combination of components from Shift Technology Products and Sonnax. That's what I have. There's Transgo as well but I don't have any experience with them and they seemed to leave out some important updates/upgrades that the other two have.

Shift technologies has a done a great job of improving two things that kill the 5r55s, heat and lack of lubrication. More than half of their updates are for improving fluid circulation and thus cooling. Sonnax has done a great job of firming things up so the shifts are snappy but not harsh (Slamming into gears). Sonnax doesn't have a kit for the 5r55s so you need to go through their site and determine what individual items you want to upgrade.

The only downside with just doing a shift kit is that certain mods cannot be done by you unless you have the necessary equipment to do valve body rebuilding. They require precision boring and reaming and vacuum testing after the upgrades are done to make certain you didn't just ruin your valve body.

A second option is to contact Level 10 transmission. They have a bolt in valve body that is custom tailored to your driving style (Street, strip, track). A bit pricey at $500 but it's a drop-in solution. They would provide the types of upgrades that require reaming/boring of the valve body to improve shift feel even more. They also have a transmission only tune which addresses specific transmission parameters that most engine tuners like Brenspeed, American muscle, Lund, etc just don't do.

Also, if you're doing the tranny rebuild yourself, from what I've heard, Ford's clutches and bands are actually better than most aftermarket. Stay away from any kits that have red clutches. They are put put out by Eagle brand I believe and they disintegrate fairly quickly.

Level 10 may actually have their own kit available.

If you buy their kit and their Valve body, maybe you can get the tune for free?

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