Author Topic: Restoration Difficulty Level (Read 948958 times)

rutger kohler · « **Reply #1025 on:** July 21, 2014, 22:01:59 »

Hi Andy. I think you have figured the problem out re packing the oil seal with grease, as you say no need to do this as long as you put a smear on the inner seal area. I will be homenext week (thursday) if you want a hand or any machining.

cheers

Rodger

andyburns · « **Reply #1026 on:** July 22, 2014, 05:42:05 »

Have taken a closer look at the front seal housing this afternoon and discovered that there is a slight offset from the block to the upper pan. This manifests itself in two very slight lips. Am wondering if I could have perfected this when installing the sump pan. Am picking there is a few thou of slop between the securing cap screws and the holes in the pan that would allow you to move the pan left to right on the block.

I went to the end of earth to seal the rear and dont wont to pull this off to trial the theory if you guys think its wasted breath. Take a look at the pictures and see what you think.

rutger kohler · « **Reply #1027 on:** July 22, 2014, 07:30:48 »

Hi Andy, if it is only 0.002" or so I wouldnt think it a problem, how about running a slip stone or something similar around both the sump and block front edges to make sure you don't have a bump or something else that needs honing off. The hardest part is starting the oil seal entering as you probably know. I put mine on some time ago with the engine assembled. Is the oil seal pictured undamaged enough to have a practice? I guess you have used some sort of sealant between the gasket and the block between the sump and block, otherwise you could slack it off a bit but I still think you could get the seal in if you don't pack it with grease this time without doing this. Further to this the seal size is quite a common one although it has special features like the stop lugs. You could buy a standard seal locally and have a practice run if you wanted to. Just pull the practice one out when the new seal arrives.

cheers

Rodger K

tel76 · « **Reply #1028 on:** July 22, 2014, 07:45:25 »

If you have used a non hardening gasket cement, slightly loosen all the bolts and tap it into position.
Looking at the first picture the sleeve seems to be too far in the recess, where is the polished part (seal rubbing mark) is it a little off centre, on the other hand it could be the picture.

andyburns · « **Reply #1029 on:** July 22, 2014, 08:52:32 »

Thanks guys appreciate your responses. Its really good just to chew the fat before I attack it again. Keeps me sane.

There is no paper gasket between the block and pan so all I down is time to redo it. I would love to avoid it but want this aspect correct. What I would love to know out of interest is if getting the two halves perfectly aligned before you tighten up the cap screws is factory procedure. I have used threebond sealant. I dont know if it sets hard or not. If I get it wrong what are the ramifications. Can you remove the upper pan without lifting the engine when its back in the car?

Eric have you ever encountered this issue before. Am sure you would have cracked hundreds of these pan.

tel76 · « **Reply #1030 on:** July 22, 2014, 19:01:33 »

Andy,
I do not want to state the obvious but when I offer the pan up I ensure that there is no discrepancy, when you do the job next time niether will you.
If it was me I would redo it, there is no cost involved and you will feel happier knowing that it is correct.

andyburns · « **Reply #1031 on:** July 22, 2014, 20:06:16 »

Cheers Eric, I will redo it from scratch then. I dont think this is that obvious for first timers and think its valuable to put up here in case anyone else runs into the same issue.

stickandrudderman · « **Reply #1032 on:** July 22, 2014, 22:34:35 »

I was going to say:
When would you rather do this job? When the engine is out of the car or when it is in it?
Because you will be doing it again!

andyburns · « **Reply #1033 on:** July 22, 2014, 23:19:55 »

Hey guys, that is fantastic. Thanks for all your input. Having only ever seen one of these pans close up I was unsure if this very slight offset was 'normal' or not. And if such a small imperfection would cause significant issues with the seal.

It is entirely within the realms of possibility here that the seal, which does slip in ok with some extra lubrication on the lip, would seal with the aid of addional sealant.

What I think is valuable to the formum is guys like Eric, Stick, Dr Benz and JA comment on if they have hit the specific issue, ignored it and then bore the consequences when it leaked like a sieve or if the are aware of certain factory procedures to avoid the problem. At this point no one has offered up an admission.

Tonight I am going to dig into the BBB to see if there is a factory reference to this alignment.

andyburns · « **Reply #1034 on:** July 23, 2014, 05:41:34 »

After taking on board all the comments made in here over the last couple of days I have gone back out this afternoon and taken another good hard look at everything. I think Eric may have picked the the problem. I found an old sleeve off a W108 crank I had lying about and used it to expand the seal. It worked well and let me install the seal with a much better control. If you dont have this you are fighting trying to roll the lip of the seal over quite a prominent step risking damage to the seal.

With the seal seating back in I checked on a point that Eric made a few posts back regarding the sleeve being too far recessed on the crank. At the time he made the comment I didn't fully understand exactly what the sleeve was.

To my horror the outer lip of the seal was hanging in mid air. I initially thought that I may have driven the sleeve back on the crank in my first attempt to install the seal. Departing the garage angry with myself I decided to check back on the photos I took while the engine was coming apart.

Clearly you can see the same issue with the old seal. I am almost certain the last time the engine was rebuilt the sleeve was replaced so I am picking the mechanic either didn't pick up the issue or ignored it.

All this is based on my assumption that the outer lip should be riding on the sleeve. If I am wrong please feel free to point out the error of my ways.

If indeed only half the seal was operational to begin with it could explain all the oil present.

I have spent a good hour pawing through the BBB for clues on the installation of the upper sump pan and the crank sleeve. I have drawn a blank on both. If anyone knows which section to look in I would appreciate a point in the right direction.

drmb · « **Reply #1035 on:** July 23, 2014, 07:01:04 »

Why not do it the easy way,while the upper sump pan is off put the front crank seal in place with sealer,bolt up the upper pan which will align the seal hole as it is being bolted up.
The outer lip on the front seal is a dust seal and seals on the flange of the front pulley.

andyburns · « **Reply #1036 on:** July 23, 2014, 07:15:28 »

Thanks Llloyd, that approach does sound sensible. I like the idea of the pan aligning itself front and rear on the two seals.

I have been reading up in the BBB about the three types of seals, one of them being designed to be installed in the manner your describing.

I am still in the dark how the sleeve is aligned on the crank. I would have imagined that it would be driven onto a hard stop shoulder on the crank so all this alignment milarcy talked about could be avoided. ie no guesswork.

I also dont quite understand how the outer seal lip seals on the flange of the front pulley. As per the photo the lip is incredibly close to the shoulder of the sleeve. Even if the pulley crushed right up onto the sleeve the seal would be bearing down right on the boundary between the two which wouldn't be a good thing.

When I pulled the seal out it wasn't quite pushed all the way into the block. I assumed at the time this was due to the last guy not wanting to run the seals in old historic worn groves. But when I pulled the seal out the sleeve was in excellent condition.

All in all I am still a bit perplexed as to how to proceed.

Bare minimum I will be removing the sump again. Just not sure what to do with the sleeve. Do I pull it off and reinstall in another position? If so how do you gauge that position?

tel76 · « **Reply #1037 on:** July 23, 2014, 07:39:24 »

Andy,
The sleeve is pressed onto the end of the crank (all the way in) and the seal runs on this sleeve, it should run about 1/3 in, this is what allows you to turn the sleeve over if you do not want to buy a new sleeve.
A picture of the sleeve in situ would help, it may be that your sleeve is incorrect ( not long enough) is it a genuine part or has someone made a replacement ?
I have an old one( the one I use to install the new seals) I will today measure it and come back to you later today.

andyburns · « **Reply #1038 on:** July 23, 2014, 08:47:55 »

Thanks Eric, I went out and did another measure up to confirm what Lloyd was saying. It all seems to be spot on. The spacer gets pushed onto to the crank and butts up against a hard shoulder on the crank. The heavy timing wheel is then put on after and rides hard up against the shoulder of the sleeve. The large bolt with large washers bolts into the end of the crank and cranks the timing wheel hard up against the sleeve and the shoulder on the crank holding everything tightly together.

It is possible that my sleeve is some sort of nasty after market part and is shorter than it should be. I wont know until I take it off and measure. I don't want to do this if I can help it.

Think I am starting to get a handle on it all now. Without considering all of the parts this setup is hard to understand.

Note the sleeve in the photo is from my W108 spare part stash. The two grooves cut in it are incredibly deep to the point where I thought they couldn't have been done with a rubber seal.

tel76 · « **Reply #1039 on:** July 23, 2014, 20:38:39 »

Andy,
The sleeve is 17mm long and the OD is 45mm, when you remove the pan post a picture of the sleeve in situ, with the pan removed you will easily measure the sleeve you could also fit ( temporarily )your damaged seal to see where the oil seal runs.
Also be aware that when you fit the large pulley wheel it will only go on in one position, it may take a few attempts to get it correctly aligned with the dowel pins.

andyburns · « **Reply #1040 on:** July 24, 2014, 04:27:31 »

New seal kit arrived today so just have to figure out the exact placement for the front seal and I am off running again. Pulled the upper pan and took further measurements and photos highlighting what drmb pointing out regarding the position of the outer dust seal lip.

My initial gut feeling seems correct that if the seal was pushed all the way up flush with the block would result in the outer lip of the seal sitting in a valley between the sleeve and the boss of the timing wheel. I am almost certain that this why the previous mechanic didn't home the seal all the way to the block.

I am going to hang off installing until I have got some confirmation that all my thoughts on the position are spot on.

andyburns · « **Reply #1041 on:** July 24, 2014, 04:28:46 »

I am proposing that this is the correct position for reinstalling the seal. What say you all?

I would be interested in your thoughts about why Mercedes would have designed a seal which sealed partially across two different parts ie the sleeve and the timing wheel. Why did they not increase the length of the sleeve by 5mm and have the seals two lip mating to the one part. I would have thought that would have created a more reliable seal which was easier to intall.

tel76 · « **Reply #1042 on:** July 24, 2014, 07:23:53 »

The seal is pressed in all the way until the raised portion is flush with the block, the forward lip is only to keep the important inner seal clean.
Did you measure the length of the sleeve and when you removed your temporarily fitted seal how far on the sleeve was the rubbing mark left by the seal ?

mbzse · « **Reply #1043 on:** July 24, 2014, 08:07:50 »

Quote from: tel76

The seal is pressed in all the way until the raised portion is flush with the block, the forward lip is only to keep the important inner seal clean

Perhaps discussed - but did you look carefully at the drawing in the workshop manual?

The lip of the seal (7) runs on the wear ring (8 ) on the crankshaft, but also the forward lip seals lightly onto the balancing disc (6). The wear ring [as well as the chain sprocket No9] are clamped in position by the Bellevue springs (13) and the big M18x1,5 bolt (14) at the front.

The seal must be put on absolutely perpendicular to the crankshaft - I use a special sleeve with a flange to push the seal in, by means of the big bolt. I use sealant, so I leave the special sleeve on for some hours, until sealant has cured. I then torque the pan/block bolts at the forward part, these were loose when seal was pressed in
/Hans in Sweden

andyburns · « **Reply #1044 on:** July 24, 2014, 08:50:18 »

Hi Hans, thanks for that diagram. I missed it in the manual. I wasn't really looking for this rather than details of assembly of the upper pan. I have also been back to work this week so very limited time to do research.

I did read your thread a few days ago regarding using the tool to push the seal back in. Its an excellent way to do it in a controlled manner and as always with your posts I was impressed with the clear way in which you explained the problem and solution. Superb effort! I actually went out to see if I could find some bits I could weld together to replicate the tool.

After a few comments on this thread I moved away from trying to push the seal on as the general consensus seems to be that I have to split my upper pan to get its alignment correct.

drmb's suggestion of assembling the pan with the seal in place seemed to make sense and after reading that it was done this way at the factory sealed my decision to follow suit. I also think you can get a better coverage of sealant in place using this technique.

Hans I am interested how far in you pushed the seal on your car, how long ago you did it, how many k's the car has done since and if its showing any signs of weeping.

Whatever technique I decide to use on mine I am happy to report back and let other know if its been successful or not. Whats the point of this forum otherwise.

mbzse · « **Reply #1045 on:** July 24, 2014, 09:48:29 »

Quote from: andyburns

.../...I did read your thread a few days ago regarding using the tool to push the seal back in. Its an excellent way to do it in a controlled manner and as always with your posts I was impressed with the clear way in which you explained the problem and solution. Superb effort! I actually went out to see if I could find some bits I could weld together to replicate the tool.../...

Ah, yes, I suppose you refer to this old posting: http://www.sl113.org/forums/index.php?topic=7282.msg46106#msg46106
The wear ring removal tool Frank K made is elegant
/Hans in Sweden
.

rutger kohler · « **Reply #1046 on:** July 24, 2014, 10:48:44 »

Hi Andy, posts from Lloyd and the sectioned view supplied by Hans clearly show the outer oil seal lip running on the back of the front pulley. Have you checked that the sleeve length is correct for a 230sl, is a 280sl sleeve longer? If it is then either the crankshaft sprocket is not sitting hard back on the crankshaft shoulder or the crankshaft is too far forward? Something is preventing the crankshaft pulley from going back far enough to engage the oilseal front lip.

cheers

Rodger K

GGR · « **Reply #1047 on:** July 24, 2014, 11:10:43 »

Quote from: rutger kohler on July 24, 2014, 10:48:44

Hi Andy, posts from Lloyd and the sectioned view supplied by Hans clearly show the outer oil seal lip running on the back of the front pulley. Have you checked that the sleeve length is correct for a 230sl, is a 280sl sleeve longer? If it is then either the crankshaft sprocket is not sitting hard back on the crankshaft shoulder or the crankshaft is too far forward? Something is preventing the crankshaft pulley from going back far enough to engage the oilseal front lip.

cheers

Rodger K

I would second that. The last picture on your post #1040 shows that the pulley is not flush with the crankshaft where the big washers and bolt go (it looks to be flush on the sectioned view). Also check if your sprocket on the crankshaft is properly aligned with the other timing sprockets, as you don't want the chain to be working "sideways", as it will end up failing (got the case on a 230 single row chain that broke due to a misaligned intermediate gear). Something seems to be wrong, better find it now than after a potential catastrophic failure.

andyburns · « **Reply #1048 on:** July 25, 2014, 06:05:52 »

Guys I measured the distance delta between the face of the crank and the face of the timing wheel at only 1.5mm. I would have thought that this would have been normal as some preloading would be necessary to clamp everything down on the shaft?

I cant see from the factory diagram if there should be any offset here. Let me know what you think. Would love to put all this back together this weekend.

rutger kohler · « **Reply #1049 on:** July 25, 2014, 08:26:03 »

Hi Andy, if you are sure the sprocket can't go any further back, and the crankshaft is in the right place longitudinally, it seems to me the seal wear ring is too long? Have you checked how long a 230SL wear ring should be? If the collar was shorter it would allow the crankshaft pulley to move further back and engage the oil seal front lip? Could a longer wear ring off another model have been used in earlier engine rebuild?

cheers

Rodger K

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Author Topic: Restoration Difficulty Level (Read 948958 times)