This is slightly off topic- but not by much. The oil pan on my transmission is sitting on top of a jack in the garage. After a bite to eat I will separate trans. and engine for the SECOND time in two weeks to remove a brand new performance torque converter. It has livened up the car, but it was not balanced properly and it vibrates. In all of the three positions it can be attached…Then the OE converter (which is ok) goes back in. Then I get to put the car back together. The oil pan and I are becoming well acquainted, but not in a good way. Then I guess I will drive to Summit and visit their “Returns” dept- probably spend less on gas than UPS’ing the darn thing.
Dave:
The “balance” on the converter may be in conflict with the “balance” on the flex plate. In an ideal world, the converter and flex plate should be ‘balanced’ as a unit. But, the ideal world is not here…
At times, 'clocking" converter in situ can get the “matched”.
Carl
There should be six positions it can be attached. Probably won’t help, though.
Have you considered adding a washer under one bolt head? Try all possible positions. If things get better in one particular position, vary the size washer at that site and see how good you can get it. If you can’t get it perfect, try adding a second smaller washer under an adjacent bolt head. Try either of the two adjacent bolt heads, and vary the washer weight there.
I always have my flywheels and clutch assemblies balanced as a unit by my machine shop. They mark things so I know how to clock them when I reassemble.
Is that not a thing for torque converters and flex plates?
Bob
just curious, how are you removing such a large and heavy TH400 by yourself? Do you have a lift and transmission jack?
Well, if by “clutch assemblies” you include the disk, I would think that’d be a bad idea. The disk can get relocated while running. It definitely needs to be balanced separately. In general, I would think balancing all of these parts separately would be a better idea, if for no other reason than you don’t have to remove the flywheel/flex plate from the engine for balancing.
Kirbert, this converter has a dual bolt pattern for 11 and a half and 10 and 3/4 bolt circles, so only three positions to work with.I spent a lot of time on a creeper yesterday bolting and unbolting and changing the position of the converter relative to the flexplate. Yes, I played around with washers, too, but all I managed to do was move the vibration to different rpm points. I finally unbolted the converter, and pushed it away from the flexplate, and started the engine.Vibration gone.
The converter is supposed to be “balanced” so that just about anyone can buy one and bolt it up and job done, but not this one!
I always “clock” things before taking rotating pieces apart, so my OE converter is back in the car, in its original position, and there is no more vibration.I guess I should learn to drive like others my age- Left hand lane, with LH turn signal going!
No lift, Greg. Just four jack stands . When I had to work for a living, I worked by myself, mostly on heavy equipment. That was a good teacher. I just use a floor jack with a home made platform secured to it.And I’m careful- I still have all my fingers, and would like to keep it that way! Second time in and out was much faster than the first- there’s just so much “stuff” that has to be removed first! Road test tomorrow weather permitting. I’ll post something on this experience later- it has been interesting!
Carl, yes I tried moving things around but had no luck. -Should not have to go to such lengths, IMHO! If I take a balanced wheel and tire off my Cherokee, and put it on my wife’s Cherokee, it doesn’t shake the steering wheel!
I feel for you…it’s terrible doing a difficult job…twice.
So you don’t want to exchange the TC in case you got a bad one? Horrible to do the job a 3rd (or 4th) time, but sounded like it improved a lot having a higher stall speed?
When my fingers have recovered for a few days, I’ll post the differences between stock and “performance”. Then you can decide. Another go-around? We’re running out of Summer around here!
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I don’t see what difference that makes. There is a circle of six mounting holes in the flex plate. One particular mounting hole on the torque converter could line up with any of the six, hence six possible mounting positions. Still, if there is no vibration with it unbolted, the flex plate is clearly balanced and the torque converter is not, which means it doesn’t matter where you put it, it’ll shake.
Never heard of anyone balancing the disc. I am refereeing to the pressure plate and flywheel. They are balanced together and clocked for two reasons.
- heavy side one one can offset heavy side on the other, meaning minimum material needs to be added or removed to achieve best balance.
- minimum error. If balanced separately to say within 5 grams (depends on tolerance of balancer. Nothing is perfect) each and not clocked, you can get 10 grams out of balance if you happen to get the heavy sides together when you assemble. If balanced as a unit and clocked, you are within 5 grams (or whatever the tolerance of the balancer is.)
Yes you should be able to bolt on a new torque converter or clutch and be fine. I always go to the extra effort to balance because it can help expose a bad part, and I Like things to be as close to perfect as possible. I’ve done it both ways, my results have been better when I balance.
Changing these parts is work enough without doing it multiple times chasing a vibration.
This should help. Based on info from the converter manufacturer, they advised enlarging three of the holes in the flex-plate for ease of assembly. When I actually saw the converter and its hardware, I could see that I could use the original, undrilled holes. All three of them. FWIW, I’ve changed converters in several of my vehicles, and never had a balance problem like this. Rotors too, and brake drums, etc, etc,
The bolt set that I bought with the converter is going back, too!
Agree!! But, at times, things stack up. The Cherokee to Cherokee wheel swap is an example Almost always OK, but not always!! Lottsa weight and the wheel balanced on he car. May e just fine there. but not on another carl.
I like my venerable 94 Jeep Grand Cherokee. Lottsa miles, still tight and shiny!!! It’s old tech + some noew tech AMC origined straight OHV six is tough… needs a wash job, though!!!
Carl
I got my transmission mount off, thanks Bernard, if you’re out there, for your excellent write-up! My mount bushing was still there, but not by much! Looking forward to trying the poly one. See photo.
I also think the filter wasn’t hooked up to the pickup tube! I hope not. That could explain the rattling I hear from the trans pan area when it idles? Although I may have pulled filter off pickup tube when I dropped pan?
Good news, no shavings at all. A lot of black gunk on magnet and bottom of pan though.
Are you keeping original setup only with poly bushing? If so I’m sure you will have a lot of “fun” squeezing bushing into place 
Yes I am. Won’t torquing the single big nut do the trick? If not, I’ll just use floor jack to push it up so I can start nut.
You have to squeeze bushing into metal mounting plate before assembly. There was a drawing in the book how everything should look like when assembled.
