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722.6 transmission slip

A

amazighman

Active Member
Joined
Apr 22, 2016
Messages
747
Car
CLK 430
<div class="bbWrapper">Hi fellas.<br /> <br /> I have this old 2004 W211 with 722.6 transmission.<br /> <br /> The issue is it has a slight slip when going from 1st to 2nd , worse when cold ,less noticeable when warm.<br /> <br /> Basically as you pull away the RPMs go up as they should till 1800 then they drop suddenly to 1600 with a slight jerk , then pick up again and then gear change happens into 2nd .<br /> <br /> Changed fluid few times ,its red and clean..<br /> Changed valve body with good 2nd hand<br /> Changed transmission filter.<br /> Pan was clean no metal shavings or sludge<br /> Fluid level is spot on.<br /> No faults on diagnostic <br /> <br /> I ran out of ideas<img class="smilie smilie--emoji" alt="😭" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f62d.png" title="Loudly crying face :sob:" data-shortname=":sob:" loading="lazy" width="64" height="64" /></div>
 
<div class="bbWrapper">You could try readapting the shift points?<br /> <br /> You could maybe lock the torque converter with the diag see if that stops the fault?<br /> <br /> What sort of miles is it on?<br /> Could just be clutch pack wear?</div>
 
<div class="bbWrapper"><blockquote data-attributes="member: 145033" data-quote="Dodipops" data-source="post: 3254580" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=3254580" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-3254580">Dodipops said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> You could try readapting the shift points?<br /> <br /> You could maybe lock the torque converter with the diag see if that stops the fault?<br /> <br /> What sort of miles is it on?<br /> Could just be clutch pack wear? </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote>Its 180k<br /> <br /> Clutch pack wear maybe , but pretty much goes away when warm.</div>
 
<div class="bbWrapper">I only have Icarsoft , doubt it can lock anything</div>
 
<div class="bbWrapper">Goes away when warm because the clutches expand, when setting these up you get shims to adjust the play in the pack and we are talking fractions of mm difference. That can make the difference between slipping and not</div>
 
<div class="bbWrapper"><blockquote data-attributes="member: 145033" data-quote="Dodipops" data-source="post: 3254596" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=3254596" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-3254596">Dodipops said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Goes away when warm because the clutches expand, when setting these up you get shims to adjust the play in the pack and we are talking fractions of mm difference. That can make the difference between slipping and not </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote>To be honest I dont know.<br /> <br /> The blip in Rpm happens way before the new gear engages , somewhere in middle , me think maybe pressure is lost somewhere</div>
 
<div class="bbWrapper">Sounds like the clutches are worn. One option is to add one of the many liquid 'snake oil' products out there that are a supposed 'fix' this . Never had to do it myself , but might be a last chance alternative before having the box re built <img class="smilie smilie--emoji" alt="🤷‍♂️" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f937-2642.png" title="Man shrugging :man_shrugging:" data-shortname=":man_shrugging:" loading="lazy" width="64" height="64" />. All the best with it <img class="smilie smilie--emoji" alt="👍" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f44d.png" title="Thumbs up :thumbsup:" data-shortname=":thumbsup:" loading="lazy" width="64" height="64" /><br /> <br /> Here is an insight into the clutches. <br /> <br /> <form action="/misc/cookies?update=1&amp;add=1" method="post" class="bbMediaJustifier" data-xf-init="cookie-consent-form ajax-submit" data-redirect="off" data-media-site-id="youtube" data-media-key="5RyqGYrvpP4" > <input type="hidden" name="_xfToken" value="1741898107,4afd0f2f0afc6fd6392adbca487fa777" /> <div class="block-rowMessage block-rowMessage--alt"> <div class="u-dimmed u-smaller"> To view this content we will need your consent to set third party cookies.<br> For more detailed information, see our <a href="/help/cookies">cookies page</a>. </div> <div class="u-inputSpacer"> <button type="submit" class="button button--small"><span class="button-text">Accept third party cookies</span></button> </div> <input type="hidden" name="consent[_third_party]" value="1" /> <input type="hidden" name="_xfRedirect" value="" /> </div> <template class="js-embedHtml"><span data-s9e-mediaembed="youtube"><span><iframe allowfullscreen="" scrolling="no" style="background:url(https://i.ytimg.com/vi/5RyqGYrvpP4/hqdefault.jpg) 50% 50% / cover" src="https://www.youtube.com/embed/5RyqGYrvpP4"></iframe></span></span></template> </form></div>
 
<div class="bbWrapper">The gearbox will need to be stripped to see the issue. No amount of fluid changes or a valve body replacement will fix this.</div>
 
<div class="bbWrapper">Could well be the case.<br /> If i drive it in Sport mode obviously starts 1st gear then struggles to engage second under light throttle.<br /> However if I accelerate harder then the problem doesn't happen.<br /> In comfort mode starts on second gear absolutely silky smooth no issues</div>
 
<div class="bbWrapper">Found an old thread exactly.same symptoms as my transmission. This is from 2010 so a while ago <img class="smilie smilie--emoji" alt="🙈" src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f648.png" title="See-no-evil monkey :see_no_evil:" data-shortname=":see_no_evil:" loading="lazy" width="64" height="64" /><br /> <br /> <div class="bbCodeBlock bbCodeBlock--unfurl js-unfurl fauxBlockLink" data-unfurl="true" data-result-id="27386" data-url="https://forums.mercedesclub.org.uk/index.php?threads/w211-gearbox-kick-fake-gearchange.60195/" data-host="forums.mercedesclub.org.uk" data-pending="false"> <div class="contentRow"> <div class="contentRow-main"> <h3 class="contentRow-header js-unfurl-title"> <a href="https://forums.mercedesclub.org.uk/index.php?threads/w211-gearbox-kick-fake-gearchange.60195/" class="link link--external fauxBlockLink-blockLink" target="_blank" rel="nofollow ugc noopener" data-proxy-href=""> W211 gearbox kick / fake gearchange </a> </h3> <div class="contentRow-snippet js-unfurl-desc">Hi guys and gals, Since buying my car, I have pretty much been exclusively driving in &quot;C&quot; mode. When starting to use &quot;S&quot; mode I noticed what may be a problem? In &quot;S&quot; when accellerating gently from a standstill, the engine revs to about 2000rpm, then you feel a kick and the revs drop...</div> <div class="contentRow-minor contentRow-minor--hideLinks"> <span class="js-unfurl-favicon"> </span> forums.mercedesclub.org.uk </div> </div> </div> </div></div>
 
<div class="bbWrapper">It sounds like the torque converter lock up clutch to me. It’s controlled by a PWM signal to the solenoid, but they do get bumpy with age. Changing the solenoid may be a good first step. It’s not massively expensive</div>
 
<div class="bbWrapper"><blockquote data-attributes="member: 140904" data-quote="Jobsworth" data-source="post: 3254948" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=3254948" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-3254948">Jobsworth said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> It sounds like the torque converter lock up clutch to me. It’s controlled by a PWM signal to the solenoid, but they do get bumpy with age. Changing the solenoid may be a good first step. It’s not massively expensive </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote>I changed the whole valve body with a second hand one.<br /> Would a lock up clutch affect only one particular gear?</div>
 
<div class="bbWrapper">It doesn’t affect all gears no, it’s designed to allow a certain amount of slip, especially in lower gears at low revs, floor it and it allows less slip. That’s why you need to have it locked via the diagnostic to prove the fault goes away.<br /> <br /> Using a suitable diagnostic you can also get lots of info on the clutches K1 K2 and K3 that during a slip condition will be noticeable in the data.</div>
 
<div class="bbWrapper"><blockquote data-attributes="member: 145033" data-quote="Dodipops" data-source="post: 3255000" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=3255000" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-3255000">Dodipops said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> It doesn’t affect all gears no, it’s designed to allow a certain amount of slip, especially in lower gears at low revs, floor it and it allows less slip. That’s why you need to have it locked via the diagnostic to prove the fault goes away.<br /> <br /> Using a suitable diagnostic you can also get lots of info on the clutches K1 K2 and K3 that during a slip condition will be noticeable in the data. </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote>Lockup clutch is part of the torque converter right?<br /> I can understand that my torque converter is on its way out</div>
 
<div class="bbWrapper">Yeah when we say lock up clutch that means locking the torque converter so no slip from that, it’ll give direct drive to the clutches and if the symptoms disappear you’ve found your fault, if not then the slip is happening in the clutches themselves.</div>
 
<div class="bbWrapper"><blockquote data-attributes="member: 145033" data-quote="Dodipops" data-source="post: 3255099" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=3255099" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-3255099">Dodipops said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Yeah when we say lock up clutch that means locking the torque converter so no slip from that, it’ll give direct drive to the clutches and if the symptoms disappear you’ve found your fault, if not then the slip is happening in the clutches themselves. </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote>Need star for that...<br /> Doubt it can be done using Icarsoft V2.0</div>
 
<div class="bbWrapper">Not sure I’ve never used it. <br /> I have autel maxis and it has the function.</div>
 
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