As I mentioned briefly in another post, my daughter's 02 Liberty developed a REALLY hard shift from 2nd to 3rd after changing out the fluid. I used ATF +4 of course.

So doing some searching here, I found this thread amongst a few others, talking about Dr. Tranny Instant Shudder Fix:

viewtopic.php?f=5&t=49879&p=552944&hilit=dr+tranny+dr+tranny+instant#p552944

Huge thanks to FLMAN for posting that.

I added the 2 oz to the tranny in the Carquest parking lot. Drove away and noticed the first series of shifts was already smoother, the 2nd series was even smoother. By the 3rd series of shifts, there was NO hard shift at all. It now shifts buttery smooth, I'm amazed.



Wow, I never would have believed it.
http://www.lubegard.com/~/C-230/Dr.+Tra ... udder+Fixx

I also picked up their Lubegard and intend to use that too, in both of my vehicles.

That's great. I'm curious what this does to the life of the transmission though. Please report back on this in six months or a year and let us know how the transmission is doing.

My concern would be that it's allowing more slippage in the transmission making it shift smoother. In turn, it may shorten the life of the transmission.

According to a transmission rebuilding book I read YEARS ago, most transmissions in luxury cars have clutch overlap between gears making shifts nice and smooth. The down side of this is increased wear and tear on the friction parts, excess heat produced, poorer efficiency.

"Shift kits" actually accomplish just the opposite. They extend transmission life by making shifts quick and firm, making them more efficient. This also produces less heat within the transmission, which is the number one enemy of automatic transmissions.

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2003 Liberty Limited Edition

2006 Liberty Sport

You would be very correct,hard shifts are better for a auto trans and produce less heat.


A trans relearn would have helped without adding chemicals that may harm your trans.

If you don't have the relearn done when changing fluid, will the trans relearn eventually anyway?

Not really,not like it's supposed to.

It is a good thing i am i stumbled across this post because i now know who to ask how to do a relearn on a transmission. Is there a post on here somewhere telling how to do it ? And is there any difference on how to do it on a CRD vs. the gasser.

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My CRD Build Thread
Soon to Come:more lights

The correct way to have a trans relearn is via a high end scanner with the correct updates,talking in the $3000+ range type scanners.Any Chrysler dealership can do it,takes 5mins to do,and no just unhooking the battery is not the correct way as it wipes the whole RAM of the TCM and PCM and you don't want to do that.

I presume a dealer can do the relearn? If so, wonder what the cost of that is.

I agree, a relearn is a better way to go. I put in the additive ONLY after doing a lot of reading here and on other sites about this product, especially waiting to see what people said after months of use. Based on what I read, I found only positive experiences with this product.

Also to restate, I don't mind a firm shift but prior to this product, the shift was jarring, not just firm.

So I now have hard shifts and trans light came on... changing the fluids tonight.
does the filter need to be change too?
will a relearn fix my issue?

Just an update a year later and the tranny is still shifting smooth. I'm amazed how well that stuff worked.

Thanks for the update. You need to post more often, lol.

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2015 Ram Ecodiesel/Big Horn/4x4/Quad Cab
2016 Arctic Fox 22G/Onboard 2500 LP Cummins Onan Generator/160 Watt Solar Panel

I took the road less traveled. Now I'm LOST.

Hah yeah, I know. Since I gave the Jeep to my daughter, I don't do much with it except change the oil and look in disgust at all the bumper stickers she's put on there!