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 > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 01-02-2005, 11:47 PM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Need advice on separating engine/transmission

I bought a 1990 3.0 300E (144k) three years ago that has been leaking oil for the past two years. I have pulled the powertrain from the vehicle (engine and transmission) so that I can refurbish the block and cylinder head (the prime source of the leaks). I know this is overkill, but I want to solve all the present and future oil leaks at once and insure the car runs well for my son for the next four or five years. Besides, I wasn't sure the rear main seal wasn't also leaking so why not go all the way. It only took another couple hour after I removed the cylinder head before I was ready to hoist the powertrain out.
But I now need to separate the engine from the trans so I can have the block cleaned and checked out.

I purchased the twin CD set for the car (W124) from mercedeshop.com but it doesn't contain the sections (26 or 27) that detail separating the engine from the transmission. I'm worried there are some components in the transmission that must not be allowed to become dis-engaged when I separate them. Anyone know where I can go to find this out?

I'd also like advice on how best to refurbish the engine and cylinder head.
I know where all the oil leaks are and already did the easy job of first replacing the valve cover gasket but there were two other leaks - the first I could easily see - the upper timing cover seal .

My mechanic visually surveyed the engine (externally) and also said the head gasket was leaking. I agreed since I also found small quantity of oil in the antifreeze when I drained the radiator. I don't mind doing the mechanical diassembly and re-assembly of major components to save the labor dollars but I'm unsure at what point I should start using a qualified mechanic. Can a do-it-yourselfer do a valve job? How about replacing bearing sets and pistons rings in the block itself? I would of course still have to send the block and head out to have them, cleaned and checked for straightness.

I don't want to dump too much money in the car since it is only used during the summer for my son to drive back and forth to his summer camp job. What is a reasonable set of tasks to do?

The car has been driving well - I didn't do a compression test before I started because I assumed I wouldn't get a good reading because of the head gasket.
Don't know for sure about rear main seal yet. Chances are all the oil I've found around the engine/transmission junction has simply been weeping down and then spraying all over the place.

Reply With Quote
  #2  
Old 01-03-2005, 12:39 AM
Registered User
 
Join Date: May 2003
Location: Huntington Beach
Posts: 329
You'll need to disconnect the Bowden cable and the vacuum line at the engine; since they're out of the car, I'm assuming the shift rod/speedo cable/engine ground/oil cooler lines are already taken care of.

Since the assembly is out, it'll be easiest (IMO) to unbolt the tranny from the engine (17mm), pull it off, then unbolt the torque converter from the flywheel (forgot the size). Access the torque converter bolts by removing the dust cap at the bottom of the engine block, where it meets the tranny. You'll have to unbolt two at a time; there are six total.
Reply With Quote
  #3  
Old 01-03-2005, 08:53 AM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Thanks for the advice - Yes I think it was the torque converter that someone in my office mentioned to me should not be dis-lodged from the transmission itself. What is the best means of keeping it from coming out?
Reply With Quote
  #4  
Old 01-03-2005, 11:12 AM
Registered User
 
Join Date: Jul 2003
Location: Norfolk VA
Posts: 142
I've been contemplating work on my daughter's '87 300E with 270,000 mi. and read this post with interest.... comments...

With "only* 144k (IF serviced properly!) the bottom end should be in fine shape. My compression was almost perfect down the line.

Since you have the drive train already out...

Bottom end: Rings and bearings should be fine (see above). Go ahead and replace the crank seals and possibly the timing chain, tensioner and guides.

Head: Clean, check. Valves and seats should only need a "touch up". Go ahead and replace valve guides (a weak point) and, of course, seals.

Also, this would be a good time to replace water pump if not done recently (hard to get to assembled / in car).

If you had oil getting into coolant, this is a common problem. It wouldn't have effected compression. There are oil and coolant passages from the block to head near #5 that are in close proximity to each other. The leak is between the two. You should see that when you pull the head.

Trans: No leaks?? Gotta be kidding!! At the very least, while it's out replace all the seals at the front near the pump. If it is not leaking now, it will soon!! The trans must be pulled to fix this common leak area. It would also be a good idea to replace all the external trans seals at this time if you don't want to go into it internally.

Unless the car hasn't had proper maintenance or other problems are present, the above should get you in great condition for some time with minimal cost and time.

Further comments anyone?? I'd be interested in experienced opinions since I'm contemplating a similar venture this spring, mainly head and trans rebuild.
Reply With Quote
  #5  
Old 01-03-2005, 01:14 PM
Registered User
 
Join Date: May 2003
Location: Boonville Indiana
Posts: 2,342
Drain Torque Convertor

You can either unbolt the torque convertor and remove with the transmission or leave it connected to the engine and remove the transmission first. You take a chance on the converter falling off the shaft when you pull it with the transmission. Sometimes you don't have a choice because the converter can be temporarily hung up on the transmission. There are 2 tangs on the convertor and over time their will be slots wore into the tangs...I usually remove the transmission and leave the torque convertor bolted to the engine. Then I drain the torque convertor(small allen head bolt drain) and then I remove it from the engine. Their is a small removable door at the bottom of the bell housing. Then as you rotate the engine clockwise you will see a pair of bolts, remove them and rotate the engine and complete the removal of the other bolts. Good luck Jim
__________________
James A. Harris
Reply With Quote
  #6  
Old 01-03-2005, 11:21 PM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Thanks to those who have posted on this - I really appreciate the help.

Maybe things went ok - hopefully someone can tell me whether I goofed. I wasn't sure what a torque converter looks so try not to laugh when so you read further.

My son and I removed the 6 bolts holding the engine drive plate to the starter ring. This appears to have been all that was holding the ring but I could not actually dislodge the ring even at the completion of my work. We then unbolted the starter (which uses two of the engine/trans bolts) and all of the other engine/transmission bolts. I had the engine and transmission independently supported and we separated the two. As we struggled with the starter ring, I eventually found the object next to it (which I thought was a flyweel mass) had coming away from the transmission shaft. This item is a heavy metal doughnut - capped on the engine-side cavity and with a spline recessed in the center of the transmission-side cavity. The spline cavity is filled with transmission fluid and mates to the transmission shaft (The transmission shaft has a ring onto which mate the two tangs (I think 'jim16671836' described) on the end of the doughnut spline.
I've heard it is a big deal (near impossible) to re-assemble a torque converter back into a already assembled transmission. It doesn't look hard at all to put this doughnut back onto the transmission shaft.
Is this doughnut the torque converter or the flywheel? Is there anything special I need to know to re-install it in the future?

Last edited by Jgood12006; 01-03-2005 at 11:56 PM. Reason: More to say
Reply With Quote
  #7  
Old 01-04-2005, 01:34 AM
Registered User
 
Join Date: May 2003
Location: Boonville Indiana
Posts: 2,342
Torque Converter

Yes the donut is the torque converter. If you look on the converter you should find a allen head bolt(on the outer edge)...maybe 6 mm and you need to remove that bolt and let the converter drain...Yes it will be easy for you to reassemble the torque converter on a completely assembled transmission. You just slide the torque converter back on the transmission and make sure the 2 tangs go into their slots(the torque converter when it is all the way on the shaft should be back behind the outer edge of the transmission...you can see the slots next to the shaft by looking in the transmission before you slide the converter on.. then when you slide the transmission back up against the engine and install the bolts don't tighten them...leave them loose and install the 6 bolts by turning over the engine(always turn the top of the engine toward the driver's side of the car) and line up the plate with the torque converter. After you get those 6 bolts in then you can tighten up the other bolts...Good Luck Jim
__________________
James A. Harris
Reply With Quote
  #8  
Old 01-04-2005, 07:42 PM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Thanks for the advice - Glad to know I've not created a major headache for myself.
Appreciate the time you've taken to help me.
BTW - after draining the torque converter, does it need to be re-fillled before installing?
Jim G.

Last edited by Jgood12006; 01-04-2005 at 07:52 PM.
Reply With Quote
  #9  
Old 01-04-2005, 11:54 PM
Registered User
 
Join Date: Jan 2002
Location: NY
Posts: 500
Read this:
http://www.mbwholesaleparts.com/StarTuned/pdfs/Trans.pdf
Reply With Quote
  #10  
Old 01-05-2005, 12:17 AM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Quote:
Originally Posted by myarmar
Yes - this article will definitely help when I re-assemble everything. Thanks.
Reply With Quote
  #11  
Old 02-21-2005, 11:02 PM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
Cool Question on transmission refurbishment

So... time has marched on and I have word back from the machine shop that the cylinder head for my 300E is in reasonable shape - just needs new valve seals and maybe valve guides. He is still checking the bottom end but doesn't believe anything will be found.

Since I have the transmission out of the car, I am contemplating some service on it. It has two problems. First, since I bough the car at 135k it has always stuck in first gear for the first few blocks of driving in the morning before making it out to second. It has become noticably longer now at 144k. Once it unsticks from first, it drives well for the remainder of the day.
Second problem is that if I accelerate hard to pull out from a stop, it slips badly (lots of noise but little acceleration). My normal driving habits make this a rare occurence but I always have it in the back of my mid that the car is not to be put to the test when pulling-out on a busy road.

The transmission shop I've always used (one of the largest on the east coast) said they wouldn't work the transmission until I had the car re-assembled so they could diagnose if the problem was internal or not. Seems reasonable but at the same time I would be eager to replace items either related to the issues above or just those that are normally wearing out at this stage. For example, I've seen comments about B2 piston replacement.
What is considered preventative maintenance at 144K? I suppose I could at least do the filter and pan gasket. Is that a DYI job?
Any thoughts? Is it better to leave well enought alone? I mentioned resealing the transmission and they felt that if it wasn't leaking already they wouldn't recommend a reseal (what isn't broke, doesn't need fixing...)

Last edited by Jgood12006; 02-22-2005 at 10:58 PM.
Reply With Quote
  #12  
Old 02-21-2005, 11:53 PM
Registered User
 
Join Date: May 2003
Location: Huntington Beach
Posts: 329
Quote:
Originally Posted by Jgood12006
First, since I bough the car at 135k it has always stuck in first gear for the first few blocks of driving in the morning before making it out to second. It has become noticably longer now at 144k. Once it unsticks from first, it drives well for the remainder of the day.
Second problem is that if I accelerate hard to pull out from a stop, it slips badly (lots of noise but little acceleration). My normal driving habits make this a rare occurence but I always have it in the back of my mid that the car is not to be put to the test when pulling-out on a busy road.
As far as the morning shifts, it sounds like it just needs to warm up. The auto in my 190 did that as well. I'd be more worried about the trans slipping. When was the last fluid and filter change? If it's been within the last year or two, then you should think about having the trans shop work on that problem; the slipping will only get worse, and the trans is out anyway.
__________________
1990 190e 2.6 - The only one I can really call "My Car".

1987 190e 2.3 - The donor car's up and running, only mods are Euros and a Sony headunit. My Dad's runabout now.

1990 300e 2.6 - The parents' ride.
Reply With Quote
  #13  
Old 02-22-2005, 07:22 PM
Registered User
 
Join Date: Jan 2005
Location: Maryland
Posts: 21
In the process of separating the engine and transmission I drained (and discarded) the fluid - little did I know the cost of that fluid... Still, I have regularly changed the transmission fluid/filter in my other autos (all domestics) every 40k miles so I figured I do the same with this car. I don't think a 1990 300E has a 'sealed-for-life' transmission does it?
Reply With Quote
  #14  
Old 02-22-2005, 08:11 PM
Registered User
 
Join Date: Jan 2005
Posts: 91
The late shift into second in the mornings is completely normal. This is done intentionally and allows the catalytic converter to heat up.

__________________
1992 190E 2.3
150,000 Miles
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 09:09 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page