I saw that LET has a High Stall TC. Is it worth the extra $$$?

How do I order one, and how much should I pay a technician to install it? Trying not to break the banks here...

PJ

How did you know that your torque converter was broken? What were the sympthoms? I don't how much less money the stock one is, but if its broken, i would go for the LET one as an upgrade if i was going to buy a new one. Good luck.

I have had the 1500 RPM Tranny Jerk problem for some time now, and it is getting on my nerves. Want to fix it once and for all, and everything I have researched points to the Torque Converter (after replacing the Radiator, trans filter, and flushing the trans fluid of course). I was hopeful those things would fix it, but nada... I checked around and it looks like the LET TC is $1000 (worth it?) The dealer wants around $1500 fro an OEM TC!!!

Q: Is our Tranny a 722.6? I found a site that sells warrantied rebuilt TCs for under $400 (Europeantransmissions) I'm going to call them in the morning and see if the sell TC's for the C32.

I have a new torque converter, transmission, tcu, and radiator, and still have the 1500 rpm jerk in w mode only. When i took my car to the MB dealer after all the parts were replaced, i told them that my car still jerks at 1500 rpms. They told me that there is nothing else they can do the car and that i have to live with it. The original torque converter in our cars sucks, and if you have the money, might as well upgrade to the LET one. Yes, our cars do have the 722.6 transmission. Good luck with your fix, but if the car drives fine (aside from the jerk) , i would maybe look for a software upgrade instead. I feel you on the whole rpm jerk issue, it makes the car feel cheap and uncomfortable to drive.

please let us know if the LET HSTC fixes the jerk for you. my '02 has the annoying jerk too. fresh fluid, never glycol contamination.

if i give my car about 3 WOT's, i get no more jerking about 15 mins into driving... you don't even have to accelerate, just push the pedal into the kickdown switch and then let off right away. the rpm's will jump up to ~4k and you can use the shifter to bring them back down again.

Some questions, and I would try try this first...

The only time you're at 1500rpm is after start up IIRC?

Is the trans cold when this happens?

Note: Even though the motor may be warmed up from just driving. The trans takes longer to get to its ideal operating temp.

STAR diagnostics says... (Not verbatim just memory recall..So i hope I get this right)..... When conducting a shifting test via STAR DAS the trans must be at 60 degrees celceus . Thats 140 degrees Fahrenheit. Your motor will heat up to operating temp much sooner than the trans. If there isnt any slipping of the clutch packs going on it could take a bit, as the friction from slipping will cause heat. Thus heating up the trans faster.

I was driving around doing this test not to long ago.. It took forever for my trans temp to get to that 140f/60c temp. However my car was piping hot. Just noting you cant judge your trans temp on your engine temp

So.. I would get with someone who has STAR DAS. Hook it up Go under "Transmission" and then go to "Performing Adaptations" run though the steps STAR asks for like acceleration 1st to 2nd, 3rd to 4th, then do the deceleration from 5th to 4th and so on... See what info is given, or adjustments can be made based on that test results...

Also think about clearing the adaptations in the transmission

A few other things..

The torque converter in these cars is crazy stout/heavy i would even say its about half the weight of the transmission itself. For such a robust piece. I would maybe thing about looking into the valve body as the problem.

Sometimes a simple fluid change is not enough to free up overly clogged valves/solenoids. Thats when maybe you should flush the trans..

Also a jerk could be from not adding enough fluid during the last change. Without draining the torque converter its kind of a guessing game as to how much fluid you need to put back in... 75 bucks you can get the dipstick from the dealer.

Side Bar: I almost always use some of the old fluid when i do a trans oil change. I hear so many stories about people flushing their transmission only to have it poop the bed a month later. I don't want to be one of those guys. Strangely enough i just rebuilt my trans. For other reason though.

adaptation at its finest...

So just to clarify, a high stall torque converter, if i'm not mistaken, only lets you stall up to a higher RPM before you launch right?

Which is good for cars with drag slicks/lsd or AWD cars.

Now, for regular street cars like mine thats modded and have a hard time launching it in 1st anyways, I can only imagine that a HSTC would only amplify the problem.

For instance, when I launch my car in 1st gear, I can only give it maybe 20% power initially and then give it about 60% gas near the end of first (with ESP off) and then finally can go WOT after engaging second gear.

If i torque-brake to load the transmission up I spin out even more in 1st. It seems like if I just increase the stall speed on my car it would just amplify the problem.

Wouldn't it be more cost effective to put on a pair of drag slicks to hook up and reduce the ET of a drag run?

OR

Do HSTC also affect how much power the tranny is putting to the ground in addition to raising the stall speed because it is a superior torque converter to the OEM piece?

I think I would have to get an LSD over a HSTC because my 1st gear is essentially useless now after my mods

Well, All I want at this point is to get rid of this freeking jerking. If I can get better perf. from a high stall, great, but is it worth $1000? I only have K&N and a Code3 Pulley. After the dealer changed my fluid, the jerk was even worse than before. I called European Transmissions, and they sell rebuilt TC's for our cars for $365. The MB service manager stated that "most" of the time the TC replacement is all that is needed to fix this issue, but not 100% (For that price, I am willing to have a local shop put it in and then have MB program the adjustments necessary to get it just right (does that make sense?). They want $143 to hook it up to Star Diag and run "tranny wear" tests to determine if the trans needs replacement. unbelievable...

as far as i know, there are only two POTENTIAL solutions to getting rid of the jerk. either the LET TC, or a '03 TCU. i dont know which, or if any will fix the jerk. for sure you will be wasting your money on that rebuilt TC for 365, since it has factory settings.