Need help diagnosing a possible RMS leak on the 90 GT
12-15-2007, 10:39 PM
#31
Nordschleife Master
Thread Starter
I'm back home now and back under the car trying to put this new seal in.
Ive noticed a light ring around the crank snout which i am pretty sure is from the inner spring coming off its lip and was riding on the crank as it turned. This would explain why the seal was leaking. I am confident that is the issue, so I am now trying to get the new seal on.
However, I know this job takes patience but i am having a bear trying to get the new seal to seat where i can get it into place. Ive replaced 928 RMS's twice but both times the engine was out of the car. So this is my first attempt at doing this while the engine is in the car. So my techniques may need to change somewhat.
I am curious about the notch in the lower crank girdle around the seal. Why is this hear? Is this here to help with old seal removal, or with new seal install? It has to be there for a reason right? I am annoyed after spending 40 minutes trying to knock this seal in but only finding that everytime i think i am there, that one last tap ends up knocking the end 180 degrees away out of its spot.
I dont have space to use a seal installer with a mallet, although perhaps if i get a seal installer that comes out far enough, I can use it to pry against somewhere on the bell housing.
Any suggestions by those that have done this with the engine in the car. I know i need to just keep trying but i figured i would ask away, maybe there is a ninja 928 trick to this job.
Thanks
Ive noticed a light ring around the crank snout which i am pretty sure is from the inner spring coming off its lip and was riding on the crank as it turned. This would explain why the seal was leaking. I am confident that is the issue, so I am now trying to get the new seal on.
However, I know this job takes patience but i am having a bear trying to get the new seal to seat where i can get it into place. Ive replaced 928 RMS's twice but both times the engine was out of the car. So this is my first attempt at doing this while the engine is in the car. So my techniques may need to change somewhat.
I am curious about the notch in the lower crank girdle around the seal. Why is this hear? Is this here to help with old seal removal, or with new seal install? It has to be there for a reason right? I am annoyed after spending 40 minutes trying to knock this seal in but only finding that everytime i think i am there, that one last tap ends up knocking the end 180 degrees away out of its spot.
I dont have space to use a seal installer with a mallet, although perhaps if i get a seal installer that comes out far enough, I can use it to pry against somewhere on the bell housing.
Any suggestions by those that have done this with the engine in the car. I know i need to just keep trying but i figured i would ask away, maybe there is a ninja 928 trick to this job.
Thanks
12-16-2007, 04:22 AM
#32
Nordschleife Master
Thread Starter
well Ive decided to try and throw the seal in the freezer and try again in the morning, hoping that the steel will have shrunk slightly to make the install possible.
Otherwise i will try and find some bolts longer then the flywheel bolts but of the same size and pitch and place the seal on and put the flywheel on and then try and bolt the flywheel on which should keep the seal from moving out the opposite side when you try and put pressure to one side of it.
If anyone has a home built tool they made with dimensions and materials they care to share i'm all eyes.
Otherwise i will try and find some bolts longer then the flywheel bolts but of the same size and pitch and place the seal on and put the flywheel on and then try and bolt the flywheel on which should keep the seal from moving out the opposite side when you try and put pressure to one side of it.
If anyone has a home built tool they made with dimensions and materials they care to share i'm all eyes.
12-16-2007, 05:42 AM
#33
Drifting
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When I did my front seal it was very hard to get in straight, eventually I gave it a good spray of WD40 & then I was able to push it most of the way in with my thumbs; used a light hammer to tidy it up.
As I had left the radiator in place I did not want to use a plastic pipe & a big mallet
marton
As I had left the radiator in place I did not want to use a plastic pipe & a big mallet
marton
12-16-2007, 01:33 PM
#34
Rennlist Member
Ryan..........haven't done a RMS on a 928 but plenty of seals on other vehicles.
To ensure the crank is smooth use some crocuss cloth on it. Do same to cases.
As Bob and Stan state the seal has to be straight and true so if space doesn't permit usage of normal seal tools I'd fashion a socket type of the same outer seal diameter with holes drilled aligned to the crank holes. With the new seal position for install use the tool and 4 bolts with nuts to push the seal squarely home. I'd start the equally spaced bolts by several threads then use the nuts to push against the backside of the socket/tool.
If I can figure out how to draw and post I shall.
To ensure the crank is smooth use some crocuss cloth on it. Do same to cases.
As Bob and Stan state the seal has to be straight and true so if space doesn't permit usage of normal seal tools I'd fashion a socket type of the same outer seal diameter with holes drilled aligned to the crank holes. With the new seal position for install use the tool and 4 bolts with nuts to push the seal squarely home. I'd start the equally spaced bolts by several threads then use the nuts to push against the backside of the socket/tool.
If I can figure out how to draw and post I shall.
12-16-2007, 03:02 PM
#35
Nordschleife Master
Thread Starter
Malcolm,
I know exactly what your talking about doing. I am just trying to figure out if there is something I already have that i could use to do what your suggesting without having to make some custom part out of a flat piece of steel or allow.
I know exactly what your talking about doing. I am just trying to figure out if there is something I already have that i could use to do what your suggesting without having to make some custom part out of a flat piece of steel or allow.
12-16-2007, 03:42 PM
#36
Under the Lift
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Lifetime Rennlist
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I'm back home now and back under the car trying to put this new seal in.
Ive noticed a light ring around the crank snout which i am pretty sure is from the inner spring coming off its lip and was riding on the crank as it turned. This would explain why the seal was leaking. I am confident that is the issue, so I am now trying to get the new seal on.
However, I know this job takes patience but i am having a bear trying to get the new seal to seat where i can get it into place. Ive replaced 928 RMS's twice but both times the engine was out of the car. So this is my first attempt at doing this while the engine is in the car. So my techniques may need to change somewhat.
I am curious about the notch in the lower crank girdle around the seal. Why is this hear? Is this here to help with old seal removal, or with new seal install? It has to be there for a reason right? I am annoyed after spending 40 minutes trying to knock this seal in but only finding that everytime i think i am there, that one last tap ends up knocking the end 180 degrees away out of its spot.
I dont have space to use a seal installer with a mallet, although perhaps if i get a seal installer that comes out far enough, I can use it to pry against somewhere on the bell housing.
Any suggestions by those that have done this with the engine in the car. I know i need to just keep trying but i figured i would ask away, maybe there is a ninja 928 trick to this job.
Thanks
Ive noticed a light ring around the crank snout which i am pretty sure is from the inner spring coming off its lip and was riding on the crank as it turned. This would explain why the seal was leaking. I am confident that is the issue, so I am now trying to get the new seal on.
However, I know this job takes patience but i am having a bear trying to get the new seal to seat where i can get it into place. Ive replaced 928 RMS's twice but both times the engine was out of the car. So this is my first attempt at doing this while the engine is in the car. So my techniques may need to change somewhat.
I am curious about the notch in the lower crank girdle around the seal. Why is this hear? Is this here to help with old seal removal, or with new seal install? It has to be there for a reason right? I am annoyed after spending 40 minutes trying to knock this seal in but only finding that everytime i think i am there, that one last tap ends up knocking the end 180 degrees away out of its spot.
I dont have space to use a seal installer with a mallet, although perhaps if i get a seal installer that comes out far enough, I can use it to pry against somewhere on the bell housing.
Any suggestions by those that have done this with the engine in the car. I know i need to just keep trying but i figured i would ask away, maybe there is a ninja 928 trick to this job.
Thanks
This is a pain in the butt. You know I did it the same way you are doing. In an AT car it is much harder as the AT flywheel is trapped by the bellhousing.
http://www.billsworkshop.com/P928S4/seal/seal.htm
Yes, the notch is there for removal.
My leaking seal looked perfectly OK on removal. No obvious defects.
Driving the new seal in is a challenge with the limited space. Getting it started squarely is trial and error. it will tend to **** out wherever you are not pushing. I used perseverance in my case, tapping around it, holding it, restarting over and over with a variety of improvised tools until it started in squarely. I made a driver from a piece of thin wood (you could use plastic or metal) with holes drilled in it for the flywheel bolts and the crank to clear and used the bolts to draw the seal in. That was about 4 years ago. The new seal is doing fine.
01-26-2008, 03:23 AM
#37
Archive Gatekeeper
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Rennlist Member
When I did my RMS about a month ago, I had a hell of a time getting the original RMS out, and the new RMS in. I used the trick of putting in the flywheel and tighenting down 4 bolts in order to seat the new seal. I lubed the heck out of it with motor oil beforehand. The flywheel trick seated it nice and square, about half way in, and I ended up using a 4" plastic pipe to seat it just below flush.
I did make a small ding in the crank (at 7o'clock) while digging out the old RMS, which I polished smooth with emery paper (this is the 'before' picture):
Fast forward one month, and I got under the car tonight to find:
I cleaned everything with brake cleaner and will check it again in the morning, but I think it's gonna be the RMS. During reassembly I left the rear-most two bellhousing cover bolts out just in case, looks like I gotta go in again. Or perhaps this is a take-it-to-Greg sort of thing....
CRAP!
I did make a small ding in the crank (at 7o'clock) while digging out the old RMS, which I polished smooth with emery paper (this is the 'before' picture):
Fast forward one month, and I got under the car tonight to find:
I cleaned everything with brake cleaner and will check it again in the morning, but I think it's gonna be the RMS. During reassembly I left the rear-most two bellhousing cover bolts out just in case, looks like I gotta go in again. Or perhaps this is a take-it-to-Greg sort of thing....
CRAP!
I swear if my car leaks when I'm done, I'll **** a cow!
01-26-2008, 04:40 PM
#39
Nordschleife Master
Thread Starter
OH MY GOD ROB!
I dont feel so bad anymore! WTF happened! Seriously, I havent touched the car in 3 weeks, I have the new seal in about 99% of the way. I made a seal press that i will document on here out of 3" or so sewage pipe cap. I used the old seal which oddly fits in perfectly into the end of the cap so that i get direct perfect seal to seal pressure, then i use 4 bolts to press it in. The bolt holes arent perfectly aligned so i have to tighten it, then remove it and reclock the tool which is why its not totally sealed where i want it. So i need to get my *** under the car again and finish the job. But i am still somewhat hesitant because i dont want to do all this crap and have it leak again, so i am avoiding the problem by not finishing the job.
I was reading an article about a guy who rebuilt his 964 engine and when he was done he had an RMS issue as well. I thought it was odd to have this problem with a new seal, but apparently it happens. Now we need to figure out why. This i do not understand. I hope this new seal Ver 2.0 stays dry.
I will try and take some pics of the seal and create a parts list for them or perhaps make some to sell.
I dont feel so bad anymore! WTF happened! Seriously, I havent touched the car in 3 weeks, I have the new seal in about 99% of the way. I made a seal press that i will document on here out of 3" or so sewage pipe cap. I used the old seal which oddly fits in perfectly into the end of the cap so that i get direct perfect seal to seal pressure, then i use 4 bolts to press it in. The bolt holes arent perfectly aligned so i have to tighten it, then remove it and reclock the tool which is why its not totally sealed where i want it. So i need to get my *** under the car again and finish the job. But i am still somewhat hesitant because i dont want to do all this crap and have it leak again, so i am avoiding the problem by not finishing the job.
I was reading an article about a guy who rebuilt his 964 engine and when he was done he had an RMS issue as well. I thought it was odd to have this problem with a new seal, but apparently it happens. Now we need to figure out why. This i do not understand. I hope this new seal Ver 2.0 stays dry.
I will try and take some pics of the seal and create a parts list for them or perhaps make some to sell.
01-26-2008, 04:57 PM
#40
I think there were some issues with Porsche supplied RMS in the recent past. A local up here got a new one and it leaked after putting it in...May want to double check with your parts supplier to see if that's the case..
Good luck,
Tom
89GT
82 Track Car
Good luck,
Tom
89GT
82 Track Car
01-26-2008, 05:33 PM
#41
Addict
Rennlist Member
Rennlist Member
You might try my method. I have been doing it this way for more than 50 years with no leaks.
Always lube the new seal and the shaft with oil or assembly lube. With no lube, a new seal will be destroyed in a few revolutions.
Use #3 Permatex on the outside of the seal. It will somewhat lubricate the seal during installation and then harden enough to eliminate leaks. Use sparingly.
Install with a 16oz hammer. Keep moving the hammer and slowly pound until flush or pound until you have a new surface on the shaft. Sometimes it is better to install almost flush to get a new surface on the shaft.
I have never been successful using a big piece of pipe that installs the whole seal at one time.
One other caution with 928 crankshaft seals. When you remove the old seal using the notch, be careful that you don't nick the housing as well as the shaft. That notch is sharp may need dressing to eliminate leaks in the new seal.
Always lube the new seal and the shaft with oil or assembly lube. With no lube, a new seal will be destroyed in a few revolutions.
Use #3 Permatex on the outside of the seal. It will somewhat lubricate the seal during installation and then harden enough to eliminate leaks. Use sparingly.
Install with a 16oz hammer. Keep moving the hammer and slowly pound until flush or pound until you have a new surface on the shaft. Sometimes it is better to install almost flush to get a new surface on the shaft.
I have never been successful using a big piece of pipe that installs the whole seal at one time.
One other caution with 928 crankshaft seals. When you remove the old seal using the notch, be careful that you don't nick the housing as well as the shaft. That notch is sharp may need dressing to eliminate leaks in the new seal.
