My Leaky Tranny. I'm Screwed, Part II - NOW UNSCREWED - YEAH!
12-23-2011, 02:53 AM
#31
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Gonna be done a day late..was hoping to leave today, but will be complete mid-am Friday.
So..the phone aint ringing, so the fill it up, and drive it around this evening part of the job went ok.
Just alignment in the AM, then outta here.
But how they work...watching a little the other day, it makes sense to me now.
The valve body part..thats pretty wicket, but the clutch/drum/band bit..is pretty stone knives & bearskins.
12-23-2011, 03:00 PM
#32
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OK, I got the pump off. No more metal pieces inside that I could see.
One concern is that every part inside has an 89MY part number (there were changes between 88 and 89), except for the one he changed - the B3 piston. He used 88MY. He doesn't have access to PET, so he went off Mercedes 722 parts sheets. Perhaps that is of no consequence, but I just don't know.
Here's some pics. I think the rear bushing on the primary pump (pic 3) is burned too.
One concern is that every part inside has an 89MY part number (there were changes between 88 and 89), except for the one he changed - the B3 piston. He used 88MY. He doesn't have access to PET, so he went off Mercedes 722 parts sheets. Perhaps that is of no consequence, but I just don't know.
Here's some pics. I think the rear bushing on the primary pump (pic 3) is burned too.
Things look fairly normal. On the sideview picture of the pump with the B-3 piston attached, there is a small spec of what appears to be brass...but that could just be a piece of something that got there when the pump was removed.
Also tough to imagine the B-3 piston having much to do with all of this. If the piston was the wrong dimension, it seems like this would affect only reverse...reverse would either be engaged all the time or never work.
If somehow things got "bound up" from something not seating all the way, when the transmisson was re-assembled, it would be possible for the transmission to not have enough endplay....essentially "squishing" the entire assembly when the pump got bolted on.
This would "kill" the rear thrust bearing (which is brass, BTW) very quickly, and would make lots of the type of noises that Bill has described.
I think that I'd remove the pan and see what kind of "goodies" are in the pan/filter.
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greg brown
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Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
12-23-2011, 03:47 PM
#33
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12-23-2011, 04:06 PM
#34
Drifting
Like Greg said, it's hard to tell by the photos. But I see scoring inside the end of the main pump cover (part that the B-1 piston fits into) and on the K-1 clutch (both inside and outside). The cover needs to be replaced, while the clutch might be reusable.
Do you have a photo of the metal piece you found inside the front seal? It looks like the shaft got flexed to cause the off center rotation that is apparent by the additional scoring of parts.
Since you don't have the special tools to take them apart, you'll need some assistance by a mechanic that has.
Do you have a photo of the metal piece you found inside the front seal? It looks like the shaft got flexed to cause the off center rotation that is apparent by the additional scoring of parts.
Since you don't have the special tools to take them apart, you'll need some assistance by a mechanic that has.
12-23-2011, 04:11 PM
#36
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They are easy to rebuild, I did one three times before I got another one, a remaned one, once a long time ago.
There is a reason that most general mechanic shops do not do in house trans builds.
I will on my own cars, but it is only because I have no money to pay some one else to do it for me.
There is a reason that most general mechanic shops do not do in house trans builds.
I will on my own cars, but it is only because I have no money to pay some one else to do it for me.
12-23-2011, 04:39 PM
#37
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Like Greg said, it's hard to tell by the photos. But I see scoring inside the end of the main pump cover (part that the B-1 piston fits into) and on the K-1 clutch (both inside and outside). The cover needs to be replaced, while the clutch might be reusable.
Do you have a photo of the metal piece you found inside the front seal? It looks like the shaft got flexed to cause the off center rotation that is apparent by the additional scoring of parts.
Since you don't have the special tools to take them apart, you'll need some assistance by a mechanic that has.
Do you have a photo of the metal piece you found inside the front seal? It looks like the shaft got flexed to cause the off center rotation that is apparent by the additional scoring of parts.
Since you don't have the special tools to take them apart, you'll need some assistance by a mechanic that has.
As to K-1, I don't see anything other that some brake band impressions on the outside of K-1. I will look again regarding off-center rotation and scoring. I'm not recognizing that in the pictures.
The metal flake is visible in the 2nd picture in the first post, but it is very hard to photograph with my camera due to the offset of the lens versus the flash. It ends up being in shadow in most shots. The shaft is in the way and even sunlit shots are difficult. I'll try once more.
12-23-2011, 04:54 PM
#39
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Hard to see much wrong, in these pictures. This kind of stuff is hard to diagnosis from pictures.
Things look fairly normal. On the sideview picture of the pump with the B-3 piston attached, there is a small spec of what appears to be brass...but that could just be a piece of something that got there when the pump was removed.
Things look fairly normal. On the sideview picture of the pump with the B-3 piston attached, there is a small spec of what appears to be brass...but that could just be a piece of something that got there when the pump was removed.
Also tough to imagine the B-3 piston having much to do with all of this. If the piston was the wrong dimension, it seems like this would affect only reverse...reverse would either be engaged all the time or never work.
If somehow things got "bound up" from something not seating all the way, when the transmisson was re-assembled, it would be possible for the transmission to not have enough endplay....essentially "squishing" the entire assembly when the pump got bolted on.
This would "kill" the rear thrust bearing (which is brass, BTW) very quickly, and would make lots of the type of noises that Bill has described.
I think that I'd remove the pan and see what kind of "goodies" are in the pan/filter.
This would "kill" the rear thrust bearing (which is brass, BTW) very quickly, and would make lots of the type of noises that Bill has described.
I think that I'd remove the pan and see what kind of "goodies" are in the pan/filter.
When I was reinstalling the primary pump on my earlier attempt to fix the leak myself, I noticed that the center shaft would not spin when I started to position the pump cover. It was the seating issue you mention. I recentered and seated the shaft as I pushed the cover on and all was good. It never was run that way, and as far as i can tell, since I could spin the TC easily after getting the tranny back from the rebuilder, he got it right too. If not seated, the shaft binds and nothing turns very well. I'm banking that that is OK. I'll look for brass, but so far I see nothing beside the single large flake of what looks like steel and the brass-looking bit that I will re-check.
12-23-2011, 04:57 PM
#40
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They are easy to rebuild, I did one three times before I got another one, a remaned one, once a long time ago.
There is a reason that most general mechanic shops do not do in house trans builds.
I will on my own cars, but it is only because I have no money to pay some one else to do it for me.
There is a reason that most general mechanic shops do not do in house trans builds.
I will on my own cars, but it is only because I have no money to pay some one else to do it for me.
When I rebuild something, I rebuild it. There's a huge difference between "repairing" something and "rebuilding" something, in my mind. I know how to do both and I do both, on a regular basis, but there is a huge difference!
If there's a part in there that is worn, shows wear, has hot spots....it's going to get replaced....period. End of story. That's what "rebuilt" means to me.
Well, when you go to order a part and you find out that there is no stock anywhere in the US from either Mercedes, Porsche, or even from the aftermarket....and there isn't any recent sales history...you've got to know that "marginal pieces" are being left inside transmissions on a daily basis.
When I can't buy the parts (at my cost) for what a "rebuilt" transmission cost to buy, from one of the 928 suppliers, there is something really wrong....and it's not what I'm doing that is wrong! Think about what most of the people that are rebuilding these transmissions are doing....they are paid a "flat rate" to fix them (not paid materials and time). The less pieces they put in, the more money they make!
You think you are geting quality when this happens?
Yeah, not so much.
My rebuilts are made to last for another 100,000+ miles....not just to "get down the road" past some warranty period.
When I first read this thread and Bill was talking about his "rebuilt" transmission that had just the front pump resealed and the B-3 piston replaced....I had to just laugh and shake my head at that naive statement.
That's not a "rebuild"....that's a pump reseal, in my world.
You get back what you signed up for....sometimes.
12-23-2011, 04:59 PM
#41
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Yes, the second shot shows the rear primary pump bushing is burned/scored. Does that mean more than I need to replace the primary pump assembly? What does it sit against that I need to examine? You know, I think the metal flake may have come from this bushing.
I did not make much out of the outer marks on the K1. I thought that could be normal. Am I wrong? I mean, I have no real idea, but I assumed the brake bands will leave some evidence of contact. Or could that be a result of the wrong B3? I did not see the inside score. I will look at that more closely.
This stuff is what scares me. The tranny could be total toast for all I know and I could be completely wasting my time trying to do the simple fix (replace the primary pump/B3 assembly and the TC). This has turned a relatively simple repair into a possible un-ending nightmare.
I did not make much out of the outer marks on the K1. I thought that could be normal. Am I wrong? I mean, I have no real idea, but I assumed the brake bands will leave some evidence of contact. Or could that be a result of the wrong B3? I did not see the inside score. I will look at that more closely.
This stuff is what scares me. The tranny could be total toast for all I know and I could be completely wasting my time trying to do the simple fix (replace the primary pump/B3 assembly and the TC). This has turned a relatively simple repair into a possible un-ending nightmare.
12-23-2011, 05:04 PM
#42
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As you know, we both have the same outlook on that.
I swear the lengths that some folks will go to try and use parts that are pretty obvious not correct for these cars is incredible at times.
I know that when you do a 928 transmission you also rebuild the diff and if applicable the LSD, other trans folks do not.
So in that case you do get what you pay for at times.
Also, what is seems to have been done to this trans is what we do to them when we reseal them when doing a TT, but I do not call it a trans rebuild by any means.
I swear the lengths that some folks will go to try and use parts that are pretty obvious not correct for these cars is incredible at times.
I know that when you do a 928 transmission you also rebuild the diff and if applicable the LSD, other trans folks do not.
So in that case you do get what you pay for at times.
Also, what is seems to have been done to this trans is what we do to them when we reseal them when doing a TT, but I do not call it a trans rebuild by any means.
I finally had to figure them out, just to better serve my customers....I ddin't want to and resisted as long as I could, but I got tired of installing transmissions that didn't work as good as they should work. I'll tell you this: I learned a whole bunch about what things are done and what isn't done, inside these transmissions, just by ordering parts!
When I rebuild something, I rebuild it. There's a huge difference between "repairing" something and "rebuilding" something, in my mind. I know how to do both and I do both, on a regular basis, but there is a huge difference!
If there's a part in there that is worn, shows wear, has hot spots....it's going to get replaced....period. End of story. That's what "rebuilt" means to me.
Well, when you go to order a part and you find out that there is no stock anywhere in the US from either Mercedes, Porsche, or even from the aftermarket....and there isn't any recent sales history...you've got to know that "marginal pieces" are being left inside transmissions on a daily basis.
When I can't buy the parts (at my cost) for what a "rebuilt" transmission cost to buy, from one of the 928 suppliers, there is something really wrong....and it's not what I'm doing that is wrong! Think about what most of the people that are rebuilding these transmissions are doing....they are paid a "flat rate" to fix them (not paid materials and time). The less pieces they put in, the more money they make!
You think you are geting quality when this happens?
Yeah, not so much.
My rebuilts are made to last for another 100,000+ miles....not just to "get down the road" past some warranty period.
When I first read this thread and Bill was talking about his "rebuilt" transmission that had just the front pump resealed and the B-3 piston replaced....I had to just laugh and shake my head at that naive statement.
That's not a "rebuild"....that's a pump reseal, in my world.
You get back what you signed up for....sometimes.
When I rebuild something, I rebuild it. There's a huge difference between "repairing" something and "rebuilding" something, in my mind. I know how to do both and I do both, on a regular basis, but there is a huge difference!
If there's a part in there that is worn, shows wear, has hot spots....it's going to get replaced....period. End of story. That's what "rebuilt" means to me.
Well, when you go to order a part and you find out that there is no stock anywhere in the US from either Mercedes, Porsche, or even from the aftermarket....and there isn't any recent sales history...you've got to know that "marginal pieces" are being left inside transmissions on a daily basis.
When I can't buy the parts (at my cost) for what a "rebuilt" transmission cost to buy, from one of the 928 suppliers, there is something really wrong....and it's not what I'm doing that is wrong! Think about what most of the people that are rebuilding these transmissions are doing....they are paid a "flat rate" to fix them (not paid materials and time). The less pieces they put in, the more money they make!
You think you are geting quality when this happens?
Yeah, not so much.
My rebuilts are made to last for another 100,000+ miles....not just to "get down the road" past some warranty period.
When I first read this thread and Bill was talking about his "rebuilt" transmission that had just the front pump resealed and the B-3 piston replaced....I had to just laugh and shake my head at that naive statement.
That's not a "rebuild"....that's a pump reseal, in my world.
You get back what you signed up for....sometimes.
12-23-2011, 05:16 PM
#43
Drifting
Best put the pieces back in place and observe what could be rubbing (it take two to tango). You might find Greg's concern about the brass thrust bearing is not likely a problem. I can't tell by your photos, so you need to be the judge.
It's not rocket science, but you do need take your time and follow the manual and work in a clean environment. The repair manual won't tell you everything, but the important stuff is there. You do need some special tools which you could make from commonly available hardware. If you do a full teardown, there are so many parts, that you need to keep them segregated by subassemblies so you don't get overwhelmed.
It's not rocket science, but you do need take your time and follow the manual and work in a clean environment. The repair manual won't tell you everything, but the important stuff is there. You do need some special tools which you could make from commonly available hardware. If you do a full teardown, there are so many parts, that you need to keep them segregated by subassemblies so you don't get overwhelmed.
12-23-2011, 05:38 PM
#44
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Yes, Greg & Greg, this was not a "rebuild". I actually never wanted a rebuild. I had a perfectly good working tranny with a leak. But I thought since it was out, at least have a professional take a look at the internals, as well as find and fix the leak. He showed me the clutch friction discs. He chose to replace them even though he said they were still very good. He said everything else looked fine and did not warrant replacing other than a bunch of seals. I trusted that. The wrong model year B3 bothered me a lot, but he said he matched what was in there based on the PN cast into it. I inadvertently forgot to take the used parts he had saved for me, and they subsequently got tossed, so we can't re-check that, but it seems odd that every other part I can see has 89 MY part numbers, not 88.
Anyway, I'll stare at these parts a bit longer.
Something definitely wore the rear bushing on the primary pump. So, is that evidence of improper assembly with low clearance? It wasn't burned when I removed it myself 6 weeks earlier. What do I need to check? Stan and others have said many times that if you don't lube this bushing prior to assembly, it will seize, even if everything is otherwise normal, so I concluded the assembler just didn't lube it. And further that only the bushing (or the entire pump assembly) was all that needed replacement in that case. When I removed it previously, I slathered it and other parts with vaseline, recommended here because of its solubility in tranny fluid.
You guys have gone out of your way to look at this as much as you have. You just as well could have told me to quit fooling around and take it to someone who really knows what they are looking at. The shop in Burlingame that others have recommended is a good possibility. Perhaps they will give me an honest opinion of these parts and whether I need a "total rebuild" or just reassembly with good replacement parts as I had planned/hoped.
Anyway, I'll stare at these parts a bit longer.
Something definitely wore the rear bushing on the primary pump. So, is that evidence of improper assembly with low clearance? It wasn't burned when I removed it myself 6 weeks earlier. What do I need to check? Stan and others have said many times that if you don't lube this bushing prior to assembly, it will seize, even if everything is otherwise normal, so I concluded the assembler just didn't lube it. And further that only the bushing (or the entire pump assembly) was all that needed replacement in that case. When I removed it previously, I slathered it and other parts with vaseline, recommended here because of its solubility in tranny fluid.
You guys have gone out of your way to look at this as much as you have. You just as well could have told me to quit fooling around and take it to someone who really knows what they are looking at. The shop in Burlingame that others have recommended is a good possibility. Perhaps they will give me an honest opinion of these parts and whether I need a "total rebuild" or just reassembly with good replacement parts as I had planned/hoped.
12-23-2011, 06:45 PM
#45
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Bill:
Since you have the later bearing and not the "troublesome" bushing, I don't think that was your problem. I guess the bearing could have been completely dry, but I'd think it would have gotten lubrication very quickly.
My cell number is 714 305 0828. My personal email is GregBBRD@aol.com. Lots of people, on Rennlist, have that information, but you might not.
Anybody else that might need help, please try my email first, unless it is an emergency and you are stuck somewhere. Call my cell, if that is the case.
Call me anytime, Bill, if you need some help. I'm around the house all weekend. I'm going to have every single little piece that is inside that transmission, in stock. I got so tired of not being able to get pieces from Mercedes or Porsche that I ordered multiples of replacement parts and adjusting parts just to be able to rebuild these things without waiting for pieces to come from Germany.
The input shaft, when the front pump is installed, will have endplay when you move it back and forth. That is the endplay of the entire completed assembly of gears and pieces inside the cases. If you don't feel that, something is wrong. That shaft also has to turn freely, when the entire transmission is assembled. If the endplay is not present, you can plan on the rear thrust bearing turning to trash almost instantly, if the transmisson is installed and the engine started. That is what concerns me. However, I think those pieces would make it into the oil pan, very quickly and hopefully you should see those pieces.
If you get really concerned that you don't know what has happened, I'd be glad to help you take it apart, look inside, and put it back together. Throw it and the core transmission into the luggage compartment on your Norton and bring them down....
If you decide to take it apart, go for it! I'll "have your bacK" from here and help as much as required. Between me, the workshop manual, and pictures, we can certainly get it apart and back together properly. The only problem will be the spring pressure on the front piston...but we can figure out a way to get it apart and I can send you up the proper tool to re-assemble it.
If required, I could drive up and help put it back together. My son still lives in Berkeley and although he is down for Christmas, I could come up the following weekend to visit him and help put your transmission back together.
Sorry I can't help more, today.
Since you have the later bearing and not the "troublesome" bushing, I don't think that was your problem. I guess the bearing could have been completely dry, but I'd think it would have gotten lubrication very quickly.
My cell number is 714 305 0828. My personal email is GregBBRD@aol.com. Lots of people, on Rennlist, have that information, but you might not.
Anybody else that might need help, please try my email first, unless it is an emergency and you are stuck somewhere. Call my cell, if that is the case.
Call me anytime, Bill, if you need some help. I'm around the house all weekend. I'm going to have every single little piece that is inside that transmission, in stock. I got so tired of not being able to get pieces from Mercedes or Porsche that I ordered multiples of replacement parts and adjusting parts just to be able to rebuild these things without waiting for pieces to come from Germany.
The input shaft, when the front pump is installed, will have endplay when you move it back and forth. That is the endplay of the entire completed assembly of gears and pieces inside the cases. If you don't feel that, something is wrong. That shaft also has to turn freely, when the entire transmission is assembled. If the endplay is not present, you can plan on the rear thrust bearing turning to trash almost instantly, if the transmisson is installed and the engine started. That is what concerns me. However, I think those pieces would make it into the oil pan, very quickly and hopefully you should see those pieces.
If you get really concerned that you don't know what has happened, I'd be glad to help you take it apart, look inside, and put it back together. Throw it and the core transmission into the luggage compartment on your Norton and bring them down....
If you decide to take it apart, go for it! I'll "have your bacK" from here and help as much as required. Between me, the workshop manual, and pictures, we can certainly get it apart and back together properly. The only problem will be the spring pressure on the front piston...but we can figure out a way to get it apart and I can send you up the proper tool to re-assemble it.
If required, I could drive up and help put it back together. My son still lives in Berkeley and although he is down for Christmas, I could come up the following weekend to visit him and help put your transmission back together.
Sorry I can't help more, today.