Manual Transmission experts - PeachParts Mercedes-Benz Forum

ah-kay · #1 02-25-2020, 01:13 AM

Need some idea on what is the problem on a 190D 5 speed. Clutch seems to be OK, not slipping. Transmission is not making any funny noises. Car shifts/drives OK in town or freeway at all speeds with the following issues.

Symptoms:

1) When I put car in reverse, car reverses good then I stop to try to go forwards. Then sometimes I cannot put the tranny back to neutral to go to first. It is kind of STUCK. The only thing I can do is to turn off the car then I can move the gear stick to neutral.

2) Sometimes it is hard to put into first, may be push it a couple of times then it will shift to first.

Throwing out bearing used to be noisy but lately it seems to have gone away. Not sure. I am concern about (1) as I don't know whether it is the clutch or internal to the transmission. I can shift and drive so the clutch must be OK-ish. Any idea?

dieselbenz1 · #2 02-25-2020, 03:47 AM

Clutch is not fully disengaging could be hydraulic, throw bearing or pressure plate. Pump the clutch several times to see if it's hydraulic.

benzguy300 · #3 02-25-2020, 08:36 AM

Have you checked the shifting rods ? Check the ends of the rods and on the transmission check the rubber bushing on arms some times the shifter goes bad and it needs to be rebuild. At the 190rev website there’s a member that sells nylon bushings and he also rebuild shifters

t walgamuth · #4 02-25-2020, 08:54 AM

Quote:

Originally Posted by dieselbenz1

Clutch is not fully disengaging could be hydraulic, throw bearing or pressure plate. Pump the clutch several times to see if it's hydraulic.

This.

TwoMuchBoost · #5 02-26-2020, 08:42 AM

Sounds like the synchro's are fighting to slow the gearset down as they're still in motion from a dragging clutch; hence the shift block. The fact that it drops into gear when you shut the car down makes it pretty likely. A clutch bleed would be the first place I'd start. The fact that you said the throwout bearing was noisy though makes me suspect... it could've worn so badly that it's shorter that you're not getting full extension of the clutch no matter how many times you bleed it. I've seen a stuck throwout bearing eat the tips of the fingers off the pressure plate only disengaging part of the pressure plate also causing a really bad dragging/lurching clutch.

I'd recommend driving the car as little as possible to avoid synchronizer wear in the trans. Esp to first gear.

t walgamuth · #6 02-26-2020, 09:03 AM

Quote:

Originally Posted by TwoMuchBoost

Sounds like the synchro's are fighting to slow the gearset down as they're still in motion from a dragging clutch; hence the shift block. The fact that it drops into gear when you shut the car down makes it pretty likely. A clutch bleed would be the first place I'd start. The fact that you said the throwout bearing was noisy though makes me suspect... it could've worn so badly that it's shorter that you're not getting full extension of the clutch no matter how many times you bleed it. I've seen a stuck throwout bearing eat the tips of the fingers off the pressure plate only disengaging part of the pressure plate also causing a really bad dragging/lurching clutch.

I'd recommend driving the car as little as possible to avoid synchronizer wear in the trans. Esp to first gear.

This too.

ah-kay · #7 02-26-2020, 04:07 PM

Thanks for the info. I suspect the clutch is binding and not fully disengaged on occasions due to the pressure plate fingers/throw-out bearing etc. The clutch and master cylinders are relatively new ( I replaced them both 4-5 years ago. ). I take a look and they seems to be OK. It looks like the tranny has to come out to inspect. Something I do not like to do.

ah-kay · #8 03-22-2020, 03:33 AM

I am in lockdown so I have nothing to do but to fix old cars. I removed the transmission to take a look. The throw out bearing seems to be in bad shape. I don't know what a new one looks like but I find it noisy and have a lot of wear. I am going to replace the clutch kit which include the clutch, the throw out bearing and the pilot bearing.

Questions:

1) Anything I should do with the transmission is out? Any seal to replace?
2) The 3rd gear pops out sometimes. I am not a transmission guy and may farm it out to a shop. The part # is 124 260 00 01. Do you think there is parts available for this 36 years old transmission, say the synchromesh and gears? I have the Haynes manual which has a section on overhauling this manual transmission. It looks very detailed with pictures. Is it a DIY job? Shall I have a go before talking to a shop?

t walgamuth · #9 03-22-2020, 09:39 AM

The throw out bearing should feel smooth while rotating. Getting a transmission apart and back together is a bit tricky.

C.Doner · #10 03-22-2020, 03:06 PM

The third gear thing could be a shifter linkage issue. It is needed to rule out all other possibilities before rebuilding. The best way to rule out the possibilities is with the transmission in the car with a good clutch system, and linkage correctly adjusted. At that point if you still have the issue bring the vehicle to the specialist and have them drive it to verify. That way the the gearbox person will have first hand experience. When rebuilding that will come in handy. Popping out of gear is definitely a good reason for overhauling. It would indicate bearing wear from what I have gathered.
Als, it should be known, the 4 speed 716.2 and has a plethora of parts that are shared with the 717.411 to .413 and possibly others. It is necessary to check the EPC for each for verification on each part. This can save some serious $$$. Gearbox parts from MB are astronomical. Available here is a MB CDbook that would be useful for the rebuilder, Much more than the Haynes.

ah-kay · #11 03-22-2020, 03:57 PM

124 260 00 01 717 410 00 006018

The transmission is stamped above, I presume it is 717.410. The third gear pops out if it is on load, like driving uphill. If I press the shifter to hold it in place then it drives ok and climb up the hill with no issues. No strange noise nor need to 'fight' the transmission so to speak.

What is linkage djustment means? Any specs on the length and which connecting rod is for third gear? 3 rods are of different lengths.

C.Doner · #12 03-22-2020, 03:59 PM

The third gear thing could be a shifter linkage issue. It is needed to rule out all other possibilities before rebuilding. The best way to rule out the possibilities is with the transmission in the car with a good clutch system, and linkage correctly adjusted. At that point if you still have the issue bring the vehicle to the specialist and have them drive it to verify the issue. That way the the gearbox person will have first hand experience. When rebuilding that will come in handy. Popping out of gear is definitely a good reason to look at it if the issue is the transmission. It would indicate bearing wear from what I have gathered.
Also, it should be known, the 4 speed 716.2 and has a plethora of parts that are shared with the 717.411 to .413 and possibly others. It is necessary to check the EPC for for verification on each part. For the most part, major assembly parts from gear one to four are identical. Each unit may have some variation as far as bushings and clips bur that is it. This can save some serious $$$. Gearbox parts from MB are astronomical. Available here is a CDbook that would be useful for the rebuilder, Much more than the Haynes.
Hopefully it's just the linkage.

C.Doner · #13 03-22-2020, 04:17 PM

The third gear thing could be a shifter linkage issue. It is needed to rule out all other possibilities before rebuilding. The best way to rule out the possibilities is with the transmission in the car with a good clutch system, and linkage correctly adjusted. At that point if you still have the issue bring the vehicle to the specialist and have them drive it to verify the issue. That way the the gearbox person will have first hand experience. When rebuilding that will come in handy. Popping out of gear is definitely a good reason to look at it if the issue is the transmission. It would indicate bearing wear from what I have gathered.
Als, it should be known, the 4 speed 716.2 and has a plethora of parts that are shared with the 717.411 to .413 and possibly others. It is necessary to check the EPC for each for verification on each part. This can save some serious $$$. Gearbox parts from MB are astronomical. Available here is a CDbook that would be useful for the rebuilder, Much more than the Haynes.

C.Doner · #14 03-22-2020, 04:27 PM

Obviously having a not so smart phone issue with the multiple repost.
Tried to delete but no avail.
The 717.410 is also the same designation. So it is included I stated incorrectly. You will need a helper to shift while you look at and adjust the shift rods. It also could be a loose lever on the gearbox. I'm pretty sure gear 2-3 is the center lever. It would be the same as a four speed 1 piece transmission. That info is likely in the Haynes. It is gear 3 to 4 not 2 to 3.

ah-kay · #15 04-12-2020, 08:31 PM

We are in lockdown so fixing car is a good pass time. This is what I have done but the problem still persists.

1) Changed out the clutch set which includes throw out bearing, pilot bearing, clutch enclosure and clutch plate. The original clutch plate looks very good but I changed it anyway.

2) The slave cylinder. The push rod seems to have worn. See picture. I thought that was the culprit but it does not seem to be.

This is what I think, the clutch is too low. I press down the clutch and release it a little bit and car moves. Is it possible that the clutch does not disengage sometime because it is too low? I think it used to be higher.

Questions.

1) Is there any adjustment on clutch to make it higher?
2) Clutch not bled properly? I bled it using the front brake from below. It feels positive and OK, not spongy.
3) Shall I replace the master cylinder also? This is the only part I have not changed. Thanks.