info please - transmission jerk while towing

barnez224 · **Joined:** Fri Jan 19, 2007 11:28 am **Posts:** 130

Can anybody help point me in the right direction of what be the cause of this issue? First off, let me say that I'm not going to go running to the dealer because I can count the number of times on my hand this has happened in the 6 years I have owned the jeep, but when it does happen at 55-60 mph...it's a little scary. It's more for my own piece of mind because I would really like to know if others have had this issue, and perhaps this has been discussed on another post and someone can point me in the right direction.

The jeep:
2005 CRD
Currently 92K

The scenario:
Towing a load when weather is hot outside (talking 95-100 degree temps) seems to be when it really happens. Can't recall if it does it during cooler temps or not, but distinctly remember it's always hot when it happens.

The problem:
When towing, sometimes (not always) during the shift from 4th to 5th while accelerating and applying about only half throttle, the Liberty seems to jerk into gear like it went back to 3rd and RPM's shoot up immediately followed by a slam of the transmission that jerks you in your seat. Immediately, I let off the gas and everything seems to go back to normal. But...when I say jerks you in your seat, I mean it does an actual bucking motion one time. This whole event only lasts for a couple seconds.

Just wondering...has anyone had this or know if this is something I really need to be worried about?

Thanks!

warp2diesel · **Posted:** Sat Jun 30, 2012 11:29 am

Your Smart TCM does quickly learn to shift more crisp due to increasing the line pressure when towing. After you quit towing it will relearn to shift softer.

One good move is to install a Magnifine filter ~$20 and place it in the trans cooler return line.
The Magnifine will absorb the fine steel particles that can screw up the solenoid shift valves in the valve body. Removing the steel particles from the transmission fluid insures they are not accumulating in the valve body shift solenoids. After installing my Magnifine a couple years ago, I noticed smoother shifting with fewer shift hiccups. When I tow the shifting gets more crisp and less crisp when I unhook the trailer. Shifting hiccups may be due to the steel particles in your valve body building up. The Magnifine will remove them if and when they flush their way out of the solenoid valves.

Ford has been installing Magnifine inline filters on their Reman transmissions for years to reduce warranty costs. Trans shops swear at them instead of for them because they cut into their rebuild business. Bean Counter Engineers don't like them because they cost money and cut into parts sales. The ~$20 investment is cheaper than what a dealer or trans shop charges.

For those who trust the Bean Counter magnet in the trans pan :ROTFL:

Hydraulic Jack · **Posted:** Sat Jun 30, 2012 6:24 pm

what size Magnifine inline filter do you have? HJ

DOC4444 · **Posted:** Sat Jun 30, 2012 10:28 pm

Are you running any type of electronics that connect to the OBDII?

DOC

Joe Romas · **Posted:** Sun Jul 01, 2012 8:57 am

Your transmission is going into limp mode :furious:

Have you ever changed the transmission fluid and BOTH filters? They were due at 62k miles. The inline filter Warp mentions is a good prevention but at 92k you might be beyond that kind of help :dead:

When towing when very hot turning OD off will keep the transmission in 3rd gear and the TC will lock up and stop causing a lot of extra heat but you'll be going about 60 moh.

You don't mention how much your trailer weights or what kind of roads.

barnez224 · **Joined:** Fri Jan 19, 2007 11:28 am **Posts:** 130

No...I have not changed tranny fluid as I do not tow often - hence the reason I can count on my hands the number of times this has occurred. My decision for not changing the fluid at interval was based off of my uncle who's a mechanic and told me since it's a sealed system, not changing should be OK since I'm not submerging the jeep frequently in mud or sand. I was definitely planning to do this at 100K however. Maybe I should have done sooner?

As far as the trailer weight...this most recent event was when towing a 6x12 loaded, 2 trips, for about a 20 min distance while moving a friend. Like 15 mins. hwy and 5 mins combined side streets.

sota · **Joined:** Fri Aug 07, 2009 7:44 pm **Posts:** 379

I forget, which gear has a "twin" in that trans? was it 4th?
if so could it be that it's making the change to that extra gear?

ATXKJ · **Posted:** Sun Jul 01, 2012 1:00 pm

also a scangauge or similar code reader - hooked up as a gauge - can kick the tranny out of Overdrive.
overloads the data bus and confuses the computer (and it's fairly random).

info please - transmission jerk while towing

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