Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-09-2004, 04:40 PM
Registered User
 
Join Date: Aug 2003
Posts: 133
Grinds when shifting into reverse...

I searched with no luck...

When I shift my car (83 240D manual 4 speed), into reverse, it grinds slightly. (The car is stopped and my foot is off of the accelerator).

So, I can do one of three things to engage reverse:
1) Push it through the grind (I did this before, if I push the shifter very slowly into Reverse, I can ease through the grind.

2) Push the gear shifer into reverse just to the point it starts to grind, then I ease off and try to engage again. This works most of the time.

3) Fail safe method: I shift in to 3rd, then into reverse (clutch depressed the whole time).

The following were replaces 25K miles ago:
Clutch and Pressure Plate
Throw out Bearings
New Clutch Slave Cyl


Any ideas?

Is it possible that my idle is fast, therefore the revs are up and not allowing me to engage Reverse? I do not have a problem with 1st or any other forward gears. If I had a tach, I could check this easily. Would a fast idle cause the gind anyway?

AC

__________________
'83 240D (W123) 321K miles
250KM Mileage Award
500KM Mileage Award

'84 300TD (W123) 215k miles
250K mileage award pending
Reply With Quote
  #2  
Old 03-09-2004, 04:45 PM
Registered User
 
Join Date: Aug 2001
Location: Evansville, Indiana
Posts: 8,150
More likely the clutch is dragging from air in the slave cylinder or the pilot shaft bearing is dragging.

The reverse gears are turning when they shouldn't, and there is no synchornizer on reverse as a general rule -- it's VERY unlikely you would want to engage reverse while moving!

Also possible the pressure plate spring is bad, causing the clutch to fail to release completely.

Peter
__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
Reply With Quote
  #3  
Old 03-09-2004, 04:45 PM
junior member
 
Join Date: Oct 2001
Posts: 592
did you replace the shift linkage bushings?
Reply With Quote
  #4  
Old 03-09-2004, 05:25 PM
Rick Miley's Avatar
Spark Free
 
Join Date: Jun 1999
Location: Land O Lakes, FL
Posts: 3,086
As psfred said, there is no syncromesh on the reverse gear in this transmission. If it's already sitting still in neutral, press the clutch and shift into any forward gear. They all have syncros, so any will do to stop the transmission input shaft from spinning. Then shift into reverse. Nothing is spinning, so no grinding. For more detailed information about how it works, search for "syncromesh".
__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References
Reply With Quote
  #5  
Old 03-09-2004, 07:18 PM
Registered User
 
Join Date: Aug 2003
Posts: 133
Any fix?

Thanks for the reply(s)....

Rick, this is what I now do 100% of the time. I have no problems doing this as it only takes 1-2 seconds out of my life each time I shift into Reverse. That said:

1) Is there any negative effect from letting this conditon persist?

2) Am I hurting anything by using forward gears to stop the tranny to allow me to shift into Reverse?

If no negative effect other than the added steps for the driver, then I will scratch this one off the list

AC
__________________
'83 240D (W123) 321K miles
250KM Mileage Award
500KM Mileage Award

'84 300TD (W123) 215k miles
250K mileage award pending
Reply With Quote
  #6  
Old 03-09-2004, 07:36 PM
Registered User
 
Join Date: Aug 2001
Location: Evansville, Indiana
Posts: 8,150
So long as you don't grind the gears, it's OK, but you are working the synchros pretty hard.

I'd bleed the clutch master cylinder again, it's difficult sometimes to get all the air out, and it's also possible the clutch master cylinder is bad -- after all, the slave was! If it won't hold pressure properly, the clutch isn't fully disengageing, and this will eat up the synchronizers eventually.

You should also check all the bushings in the shifter linkage, particularly the top set. If you are moving more than one lever at a time, it will grind.

Peter
__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
Reply With Quote
  #7  
Old 03-10-2004, 07:09 AM
Registered User
 
Join Date: Apr 2002
Location: eastern ND
Posts: 657
Remember to bleed clutch system backwards by running a line from a brake to the slave. Bubbles like to go up. At this age you should really consider changing the clutch master. If it's "loose" at all the new slave makes it worse.
__________________
daBenz - 1970 220D
Reply With Quote
  #8  
Old 03-10-2004, 10:50 AM
Registered User
 
Join Date: Jan 2000
Location: PA
Posts: 5,440
Acastell,

I think there is an adjustment screw on the slave cylinder so the clutch can be released further. Not sure though because its been a long time since I worked on manual transmission cars. But you might take a look.


One other thing, is the clutch resoirvoir full?


P E H
Reply With Quote
  #9  
Old 03-10-2004, 10:59 AM
Jim B+
Guest
 
Posts: n/a
ARRRGH! You may be doing it WRONG!

There's a special trick to engaging reverse on these cars...you grab the shift lever and LIFT IT UP and push it into where "first" should be.

Evidently a lot of people, even those who had these cars from new, never were informed they had to "lift", and a lot of trannys were worn out prematurely.

If you don't know this already, try it. Good luck!

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 06:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page