Torque Converter Interogation

FormerlyBankNote4x4 · **Posted:** Thu Oct 22, 2009 4:29 pm

As many of you know I've been struggling to diagnos a vibration issue.
Almost everyday I've been checking possible causes as I commute a little ways and need this thing running right!
Last night I decided to remove some of the ATF+4 from the Transmission as it's been overfilled for a couple years.
After checking it hot today it's half way in between the cold and hot hashes.

Maybe I just need to add a little ATF but, here's my issue:

I am down on power and getting vibration from under the shifter area.
I pushed the accelerater down more to compensate and as it's rev'ing up it surges like something is holding it back and then lets go for a second and the Jeep accelerates quickly.
This makes me wonder if I have a TC problem!!!

What would be symptoms of a TC issue???
(I had AAMCO put in the Suncoast and revised DC pump and bits about 3 years ago).

Can a TC be loose?
Can a pump go bad to cause this?

The last thing I want to do is take it to someone, but at this point I would be willing if it's needed. I just don't know how to go about figuring this out!

Josh

NJCRD · **Posted:** Fri Oct 23, 2009 1:45 pm

Problem is you took it to aamco

danoid · **Posted:** Mon Oct 26, 2009 10:02 pm

If you're slipping the torque converter clutch or any of the transmission clutches you should see a check engine light, with a P0700(?) + whatever clutch slipped. Also you'd be stuck in 3rd gear and the torque converter would never lock (transmission limp in). Since you didn't report any of these symptoms, this can probably be ruled out.

I'm not sure if the trans is over/under filled. If it's between the lines it should be good. Make sure you are checking the fluid level in Park or Neutral on a flat surface. Sounds like that can be ruled out also. Usually you have to be quite a bit low for the trans to slip, and often it's shows up first going uphill/downhill/freeway on ramps, etc when the fluid is sloshing around. If you are overfilled, there will be a significant amount of bubbles in the ATF when you check it. Overfilling is just as bad as the ATF then gets frothy and you can't compress air bubbles.

Check the mounts. I had a car once that had a broken engine mount bracket. Everything was fine until you hit the pedal a little too much, then the whole front end of the car jumped up as the engine tried to literally flip out of the car. Check for loose bolts, broken metal, sheared rubber (the transmission mount) etc.

Next check the transmission crossmember that the trans mount attaches to. I had several of the rivnuts (the female thread on the 'frame' that the crossmember bolted to) strip out and they were barely holding on. This was discovered while installing torque converter #3 and the mechanic was none too happy about the extra time.

Lastly, check the rear suspension. If a control arm or that funky triangle thing that attaches to the top of the axle (real scientific yes I know) has a broken attachment your axle could be winding up and binding the u-joints. When the torque in the driveline relaxes, the driveshaft can turn again, then the car accelerates.

Just some thoughts.

nursecosmo · **Posted:** Tue Oct 27, 2009 11:34 am

Plugged fuel filter? Is your fuel gage before or after the filter?

FormerlyBankNote4x4 · **Posted:** Fri Oct 30, 2009 8:21 pm

Thanks for the reply's!! I checked the rear suspension parts, all looks ok. I got the tranny fluid dead on, and that really made a difference, that may have been all it was, hopefully. But still vibrating up front. I think it might be the brakes- I'll put up a topic about it. The fuel pressure gage is after the filter I think, it's attached to the racor fuel head. I copied RetMil46's set up and he mentioned being able to messure you filter effeciency when it pulls below 4 psi etc... I did just change the filter ~2 mo.'s ago, yes I know it can be 1 bad load of fuel.
And AAMCO, yaaa, they were to bring in a specialist overnight to do the tc install etc...(this was at the milwaukee location over 2 years ago, not really any trouble with it, but last month I took it over to the Madison location and discovered the young guy working there was the one that did it. Well I guess he's good enough but what a snow job.
Also I had Firestone balance my tires/wheels with the hunter gsp 9700, and when they tested it and it still vibrated they told me the engine was shutting down 2 pistons, they knew because the engine light was on(orm) and the way it felt. Well lets hope they can get the road force machine right so they at least have some purpose in life. They told me it was a diesel like they were expecting me not be suprised :roll:

hahaha

Joe Romas · **Posted:** Sat Oct 31, 2009 9:11 am

You seem to be having trouble finding good shops :shock:

I have found Discount Tire does the best job on tire and wheel work for me. The first thing I look for is how they raise the vehicle up. I tend to go ballistic when a high school drop out raises my car by the pinch welds and bends them up :shock:

I've been satisfied with their ballancing too.

FormerlyBankNote4x4 · **Posted:** Wed Nov 04, 2009 3:32 pm

So I managed to tighten the Flex plat to Torque Converter bolts in an effort to address the continuing vibration. I did it with a 1/2" regular socket driver since my torque wrench wouldn't work in that area, so hopefully I don't have a torque issue.
This seemed to address the rough idle and very losse vibration at 27mph and above 50 mph. However I still get some vibration in the lower rpms, especially when colder and shifting into 4th- almost grinding as the tc fully engages.

Do you guys get some vibration and noise when shifting into 4th at a liesure acceleration?

It's been so long I don't remember if it always did this.

danoid · **Posted:** Wed Nov 04, 2009 9:28 pm

Does anyone know how Suncoast balances the torque converters? The OEM's are balanced as an assembly with fluid in them.

Ripple · **Posted:** Sat Nov 07, 2009 9:40 am

if its any help, maybe reading some of this 114 page 545RFE will uncover some detail.

http://hotrodlane.cc/New%20HEMI%20Tech/ ... 0trans.pdf

Torque Converter Interogation

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