New issue with 5-speed manual in W201 - difficult shifting - PeachParts Mercedes-Benz Forum

Greg in Oz · #1 06-09-2006, 04:33 AM

If those of you out there with manual (stick shift) transmission cars are anything like me, you will tend to remember who on the forum own manuals and some of the issues they have had with them. You may then remember that I have had a few issues with the clutch on my '90 190E-2.3 Sportline 5-speed. A pity really as I purchased this car due to its rarity and the fact it is a manual, and I really enjoy driving it. Apart from the clutch issues it has been reliable over the 3 plus years I have owned it.

For those who can't remember the issues I've had (and who have plenty of time to read and follow the story!) the threads (in order) are:
http://www.peachparts.com/shopforum/showthread.php?t=62898
http://www.peachparts.com/shopforum/showthread.php?t=68950
http://www.peachparts.com/shopforum/showthread.php?t=79274
http://www.peachparts.com/shopforum/showthread.php?t=79447
http://www.peachparts.com/shopforum/showthread.php?t=94692
http://www.peachparts.com/shopforum/showthread.php?t=106387
http://www.peachparts.com/shopforum/showthread.php?t=114385
http://www.peachparts.com/shopforum/showthread.php?t=147948

Anyway, to get back to the reason for this thread, I now have a new issue that has started over the last few days. The shift from 1st to 2nd has become difficult and to a lesser extent so has the shift from 2nd to 3rd. The problem is mainly difficulty getting it out of gear rather than into gear, although the shift into 2nd is a bit baulky on the move. At higher engine speeds the problem is most noticeable whereas shifting through the gears with the engine idling while stationary is not a problem at all. This tends to rule out the possibility of clutch drag (which I believe would make it difficult to get into gear whilst stationary). I should also mention that I replaced the clutch slave cylinder a few months back (something I don't think I mentioned in previous threads) at the same time I changed the gearbox fluid (and found the mystery part mentioned in the last thread above). Earlier threads mention that I have also replaced the clutch master cylinder.

My concern now is what may be causing the new problem, especially having found the mystery part whilst changing the gearbox fluid. On the weekend I will get underneath and check things like the shift linkage bushes and the gearbox fluid level. I don't believe the fluid level could be down much considering I only changed it a short time ago, however I know there is a slight gearbox fluid leak. To rule out the clutch hydraulics I will also bleed the system again.

I did a search but could not find anything quite like this. Any of you helpful folk want to offer suggestions?

Thanks,
Greg

#2 06-09-2006, 06:53 AM

In most cases this is a clutch release issue meaning hydraulics, but make SURE that you keep the trans full of lube. Poorly releasing clutches or poor driving style, moving the lever before the clutch is released, leads to worn brass which will cause shifting problems.

Good luck,

kidMoBile · #3 06-09-2006, 10:46 AM

Greg:
I'm going to guess it's the synchro ring shared by first and second gear. If the 3 to 4 and 4 to 5 shifts are okay, then that gives more credibility to the bad synchro hypothesis. Plus that wire you fished out of the fluid (posted a while back) looked like part of a synchro assembly to me.
There are two main synchro ring assemblies in the trans. One is shared by gears 1 and 2, and the other is shared by gears 3 and 4. When shifting into and out of gears one or two, you are using that synchro to do it. If the assembly is screwed up, you may still be able to shift but it would be atypical, just as you describe. If so, then it's rebuild time.
Good luck.
Brian

kidMoBile · #4 06-09-2006, 10:57 AM

Greg:
Also, a synchro problem tends to show itself at higher engine RPM. The synchro's job is to try and get a fast spinning part (the engine) together with a slower spinning part (the gears in the gearbox). If the two spinning objects are nearly matched in rotational speed relative to eachother (low RPM or especially idle...no work to do there) then the synchro's job is easy. Large delta between rotational speeds means more work for the synchro, thus the problem you are experiencing.
Brian

Greg in Oz · #5 06-12-2006, 10:48 PM

Thanks Larry and Brian for your replies. They both sound plausible given the symptoms however I am now in a position to give you some more information as on the weekend I explored the problem further.

Selector linkage bushes all look and feel fine. Gearbox fluid level is full. I did notice that the gearbox input shaft seal must be leaking slightly though as there is evidence of transmission fluid (red) drips from the bell housing area. Previously drips from this area were clutch hydraulic fluid however the replacement slave cylinder has rectified that.

A test drive in a quiet area allowed me to investigate the problem further. I earlier stated that I believed it was not a clutch dragging (ie. disengagement/release) issue. Well I now believe it is. Strangely, it only occurs when the engine is at higher speeds. As I mentioned, gear selection is not a problem with the engine at idle. As the engine speed increases so does the difficultly in shifting gears. I have also determined that the problem occurs in any gear, not just 1st and 2nd. It is more noticeable in 1st and 2nd because these are the gears where higher engine speeds are used when accelerating from a standstill. If the car is driven to higher speeds then the same difficulty is experienced with selection of 3rd, 4th and 5th.

The problem, put simply, is that the clutch with not release with the engine spinning at higher speeds. If the engine is taken as high as say 4000 to 5000 RPM it is not possible to release the clutch to shift gears. If the car is allowed to slow such the that the engine speed decreases sufficiently then eventually the clutch will release. In fact, engine braking can still be achieved at higher engine speeds even though the clutch pedal is depressed!

Likewise, if the engine is revved above say 2000 to 3000 RPM in neutral, it is not possible to disengage the clutch to allow any gear to be selected until such time as the engine speed is allowed to drop back to idle speed. I appreciate this is not something someone would normally do, I simply use it as a means of demonstrating the problem. The clutch is behaving almost like a centrifugal clutch or the torque convertor on an automatic except for the fact that once released the clutch will remain that way.

I will next try bleeding the clutch hydraulics again to confirm that is not the cause, however I would have thought that a hydraulic issue would exist irrespective of engine speed. As I mentioned, with the engine idling gear selection is fine without any suggestion of baulkiness. Any clutch drag at idle would certainly show up with a crunch when selecting reverse however this is not the case. Rev the engine much above idle and selection of reverse is met with a crunch and selection of any other gear gets more difficult as the engine speed increases. The clutch pedal "feel" is perfectly normal.

Just something else that may be worth mentioning is that previously the clutch had a shudder problem that could only be avoided by getting the revs just right when moving off from a standstill. This problem was always worse when cold, when the car had sat unused for a few days, and in very humid or wet weather. The problem improved somewhat following replacement of the slave cylinder which I attributed possibly to the bell housing no longer being contaminated with hydraulic fluid. Since this latest problem suddenly appeared, the clutch shudder problem has completely disappeared.

The sudden apperance of one one problem and disappearance of another, and the engine speed sensitive nature of the problem makes me wonder if it is a mechanical issue with the clutch (rather than say a hydraulic one). For what it's worth I should also mention that being a 1990 model the car runs the "newer" version of the W124/201 gearbox and clutch with the dual mass flywheel.

Keep the helpful suggestions coming!

Thanks,
Greg

Greg in Oz · #6 06-13-2006, 07:51 PM

I am paying careful attention to the behaviour of the clutch and shift action at the moment (I need to as it really is not very easy to drive with this problem). Shifts (between any gear) below 2000 RPM are fine. From 2000 to 3000 RPM they are difficult. Above 3000 RPM, don't even bother trying! One thing I must comment on though, is that from a standstill the clutch is the smoothest it has been since I have owned the car. No shudder at all.

I also spent some time studying the WIS in the hope it offer some clues. I captured the most useful information in the attached screen shot.

t walgamuth · #7 06-13-2006, 08:19 PM

it sounds like a pressure plate problem.

some times the centrifugal force will not allow it to release. beyond this i cannot explain.

some old drag racers probably can do so in detail.

tom w

Greg in Oz · #8 06-15-2006, 01:51 AM

Thanks Tom,

Thinking about it some more, I am more inclined to suggest it may be a driven plate (clutch friction plate) problem rather than a pressure plate problem. As I mentioned, it is engine speed sensitive, but only whilst the driven plate is engaged. With the car stationary, if the clutch is released at idle and then the engine is revved there is no difficulty in selecting a gear (reverse is a good one as it will make it quite clear audibly whether the gearbox input shaft is still spinning or not). If the engine is revved before attempting to release the clutch, then attempting to release the clutch and selecting a gear is impossible.

I am wondering if if the cause could be that some of the friction material on the driven plate is breaking away such that at higher rotational speeds the centrifugal force causes it to fly out and make contact with either the flywheel or pressure plate. Even when the clutch should be released this fault keeps the driven plate spinning. This allows sufficient drive to prevent gear selection and shifting. At lower speeds the centrifugal force is insuffient to keep the friction material in contact with the pressure plate or flywheel and therefore the drive to the driven plate ceases which allows for gear selection.

Just an idea anyway. Anyone got any other ideas?

Thanks,
Greg

Greg in Oz · #9 06-19-2006, 10:13 PM

I dropped the gearbox out on the weekend and my thoughts proved correct. The friction material on the pressure plate side of the clutch disc had broken away from the rivets allowing it to fly out and contact the rim of the flywheel. Despite being the original clutch (dated 4/90), it had not worn out over the almost 240,000km it has travelled. Pressumably it was just fatigue which had taken its toll on the friction material. Neither the pressure plate nor flywheel were scored and I was thinking this would not be such a costly job.

Everything was a bit greasy (although the clutch friction surfaces were dry) so I figured a new crankshaft rear main oil seal and gearbox input shaft seal would be in order. This meant removing the flywheel and it was then that I realised all was not well. The secondary mass of the dual mass flywheel was not sitting parallel to the primary mass. A check revealed that the secondary mass was actually free to come away as the eight pins that should hold the flywheel together had sheared. Twisting the secondary mass revealed that there was noticeable lash due to the broken pins before the pressure of the springs between the two masses took effect. In use all that was holding the flywheel together was the release bearing pushing against the pressure plate. A bit of a worry considering that the flywheel and clutch as an assembly weighs in at over 22kg (around 50 pounds) and can spin at up to 6000rpm. Also amazing that the car remained as driveable as it did for as long as it did. This probably explains the clutch shudder I have experienced in the three and a half years I have owned the car.

I am now waiting for prices and availability of all the parts and I am not looking forward to what it might cost. Thankyou to those who offered suggestions and I will keep you informed of progress.

Greg

Greg in Oz · #10 06-19-2006, 10:15 PM

Photos of the damaged clutch...

Greg in Oz · #11 06-19-2006, 10:18 PM

Photos of the damaged flywheel with both the two masses together as it should appear and with the masses separated as it shouldn't appear...

Greg in Oz · #12 06-20-2006, 08:59 PM

Well, I got replacement parts prices from my local dealership and I think I'm still in shock!

The list prices (before tax) in Australian dollars ($1.00 AU is approx. $0.75 US) for the major parts are as follows:

Flywheel $2516.23
Clutch disc $445.30
Pressure plate $495.80
Release bearing $70.59

Are these parts machined from solid blocks of pure unobtainium?! How can they possibly justify such exorbitant prices for what should almost be considered routine service items. Even though the flywheel has suffered an abnormal failure, had it simply been scored due to a worn out clutch it would still have to be replaced since the dual mass flywheel cannot be repaired by machining the way a conventional flywheel can.

Based on these prices, the clutch job would run to around $4000 including tax but excluding labour! You can buy a complete cheaper 190E here for that sort of money. It's only that mine is a rare (in Oz) 2.3 Sportline 5-speed that puts its value somewhat higher. Too bad if it needed the gearbox rebuilt as well. Mind you, I still have not determined for sure what the mystery broken wire spring was from the gearbox, but while it is working OK I'm leaving it alone. I don't need the expense of a gearbox re-build now as well. All this makes re-building an auto transmission look cheap! I guess that's what I get for buying a rare manual version (although manuals are common in some other countries which makes it difficult to understand the high prices for the clutch parts).

I considered the possibility of reverting to the conventional flywheel and clutch assembly of the earlier W201 models. The prices for these parts would be substantially less. Unfortunately, the different thickness of the flywheels meant that the gearbox input shaft was a different length. Obviously it would get all too complicated to perform this modification. A pity as the car would probably be somewhat more sporty to drive with a flywheel of around half the weight, albeit with a little loss of low speed smoothness (the reason for the dual mass flywheel).

Fortunately, another supplier thinks he can get me a flywheel and all the clutch parts for probably less than half those prices. I will keep you informed of progress as it occurs.

Greg

wbain5280 · #13 06-21-2006, 01:21 AM

Greg, you are very luck the flywheel didn't shear your leg(s) off.

As for the prices, sticker shock to say the least. Can you order from overseas and have them shipped or would that be too expensive? Can you get your existing flywheel fixed locally?

Good luck.

Greg in Oz · #14 06-21-2006, 04:40 AM

Warren,

Fortunately, I don't think there was sufficient space between the primary flywheel and the clutch release bearing for the secondary flywheel and clutch assembly to come away from the primary flywheel enough to cause anything as serious as breaking apart and smashing its way through the bell housing and floor. At least I would like to believe as much! Keep in mind that the gearbox input shaft passes through the centre of it all and locates in the bearing in the centre of the primary flywheel.

Regarding sourcing parts, it appears that I can have a flywheel sent from Germany at a competitive price including freight costs. A clutch kit is apparently available locally at a better price than the dealer's.

Thanks,
Greg

Greg in Oz · #15 07-16-2006, 10:04 PM

I am pleased to report that after a wait for the new dual mass flywheel from Germany, I put my 190E back together on the weekend and it is back on the road again. I am also pleased to be able to report that there is no longer any clutch shudder (nor the rattle when stopping the engine I had previously mentioned in another thread). Obviously these minor issues were due to the broken flywheel and the situation had existed for at least the three and a half I have owned the car.

The new flywheel which I had sourced directly from Germany for around half the price the local MB dealer wanted for one here is still from OE manufacturer "LUK". Likewise the clutch, pressure plate and release bearing were sourced for around half price and they are OEM "Sachs". The rest of the parts (rear main crankshaft seal, gearbox input shaft seal and output seal) were sourced from the dealer. Whilst only the gearbox front cover and output seal were leaking (not the gearbox input seal or rear crankshaft seal), I believed it sensible to replace them all while I had everything accessible.

All up the job set me back about AU $2200 (about US $1650) and a total of around a day or day and a half of my own labour. Imagine what it would have cost had the dealer done the job!

Hopefully this will finally be the end of all my clutch problems. It should be since I have now replaced everything associated with the clutch.