Starter Question - The agony continues
12-03-2005, 08:44 PM
#1
Legend Killer
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Starter Question - The agony continues
Let me give some background info that is leading up to the starter question.
My clutch went out and I have had a mechanic working on it for a couple weeks. During the install he found that the bell housing was bad ( i think stripped threads and something else). Therefore I bought another used bell housing. After placing the new bell housing back on and trying to start the car he heard some scraping noise. He remmoved the bell housing and found that the ring gear was scraping on the inside of the bell housing. He decided that the ring gear was warped and so we got another 951 ring gear. Now after a couple of weeks he finally placed everything back together and when we went to start the car the starter was not engaging. He removed the starter and bench tested it and founf that the ring was spinning but the gear was not popping up and. So the next day I got a used starter. I placed the starter in and when we turned the car on it wouldnt start and I could here the gear on the starter just spinning. So after some trial and error we gave up and decided to push start the car with the starter still in. Once the car started there was a terrible scaping noise.....smoke.....
Turned off the car, removed the starter and found that the pressure plate had scraped the end of the starter (please see pic). This was been done at a shop and the shop mechanic stated that the bell housing must be wrong and that is why the starter doesnt fit correctly. He guessed that the first mechanic probably put on a 944 bell housing instead of a 951.
So I called the first mechanic and told him the shop said the wrong bell housing was put in....but this mechanic said it was very unlikely siince the 944 bell housing would not have bolted in easily and there would have alignment issues. He believes that I got the wrong starter and instead of getting a 951 starter I got a 944 starter.
So which is it??? Do i have the wrong bell housing on? Can a 944 bell housing have even fit around the clutch of a 951? Is there a 944 and a 951 starter? Or is all this trouble based on some other problem?
Please help.
First pic is of scratched new starter and second pic has the original starter on the left and the new starter on the right.
My clutch went out and I have had a mechanic working on it for a couple weeks. During the install he found that the bell housing was bad ( i think stripped threads and something else). Therefore I bought another used bell housing. After placing the new bell housing back on and trying to start the car he heard some scraping noise. He remmoved the bell housing and found that the ring gear was scraping on the inside of the bell housing. He decided that the ring gear was warped and so we got another 951 ring gear. Now after a couple of weeks he finally placed everything back together and when we went to start the car the starter was not engaging. He removed the starter and bench tested it and founf that the ring was spinning but the gear was not popping up and. So the next day I got a used starter. I placed the starter in and when we turned the car on it wouldnt start and I could here the gear on the starter just spinning. So after some trial and error we gave up and decided to push start the car with the starter still in. Once the car started there was a terrible scaping noise.....smoke.....
Turned off the car, removed the starter and found that the pressure plate had scraped the end of the starter (please see pic). This was been done at a shop and the shop mechanic stated that the bell housing must be wrong and that is why the starter doesnt fit correctly. He guessed that the first mechanic probably put on a 944 bell housing instead of a 951.
So I called the first mechanic and told him the shop said the wrong bell housing was put in....but this mechanic said it was very unlikely siince the 944 bell housing would not have bolted in easily and there would have alignment issues. He believes that I got the wrong starter and instead of getting a 951 starter I got a 944 starter.
So which is it??? Do i have the wrong bell housing on? Can a 944 bell housing have even fit around the clutch of a 951? Is there a 944 and a 951 starter? Or is all this trouble based on some other problem?
Please help.
First pic is of scratched new starter and second pic has the original starter on the left and the new starter on the right.
Last edited by Andial951; 12-04-2005 at 01:14 PM.
12-03-2005, 08:50 PM
#2
Racer
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The starter motor burned out in my 83 so I ordered a new one from my local Porsche dealer and when I went in to hand in the stinky fried original core motor I was handed a much smaller diameter starter motor with a 951 prefix part number. Works fine. I understand the 951 starter motors are smaller to clear the turbo?
Mike
Mike
12-04-2005, 11:37 AM
#3
Three Wheelin'
Depends on the year. As I understand the situation, '87 and later starters have some internal wiring changes to give the motor a stronger magnetic field, and hence more torque. The down side is some '87 cars have a problem with magnetic cross coupling between the starter, flywheel and the speed and reference sensors. This cross coupling confuses the DME into firing the spark plugs, resulting in a real nasty "kick back" that can break starter ring gear teeth and starter housings.
The "fix" for this problem was Porsche modified the speed and reference sensor bracket and installed magnetic shields on the sensors.
I got my '87 for a measley $1800.00 because it had a broken starter ring gear and broken starter.
The "fix" for this problem was Porsche modified the speed and reference sensor bracket and installed magnetic shields on the sensors.
I got my '87 for a measley $1800.00 because it had a broken starter ring gear and broken starter.
12-04-2005, 02:24 PM
#4
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Here's what PET says about the starter, and the different models it fits. Not all these cars came with a 944 starter, but they were suppreceded by the 951 starter.
Last edited by Dmitry S.; 12-04-2005 at 02:40 PM.
12-04-2005, 03:40 PM
#5
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Dimitry,
I dont think I fully understand your post. Does this show that there is a 951 starter AND a 944 starter? Does this prove that a 944 starter should not be used on a 951? when I look at the starters side by side I see no difference. Do you think this problem is been caused by the bell housing, starter or something else?
I dont think I fully understand your post. Does this show that there is a 951 starter AND a 944 starter? Does this prove that a 944 starter should not be used on a 951? when I look at the starters side by side I see no difference. Do you think this problem is been caused by the bell housing, starter or something else?
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12-04-2005, 06:15 PM
#9
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Somebody correct me if I'm wrong on this....
The bellhousing on a 944 is different on the inside than a bellhousing for a 951. The 951 clutch and starter ring is larger. The smaller type starter from a 944 or 951 would work if you had a 951 bellhousing. The 944 bellhousing went on, and the torque tube lined up, but the starter ring was way to tight up against the starter. Probley bent the shaft inside it. Also, the 944 bellhousing went over the 951 clutch, but I doubt very much it went on too easy. The bolts that hold the bellhousing on, are in the same spot on both bellhousing, but like I said, the 951 bellhousing is a little fatter to allow for the larger clutch.
I know the bellhousing are different from the wrecked cars that I have parted out. Also..... IF.. I remember correct, the 951 bellhousing, has a 951 part#
The bellhousing on a 944 is different on the inside than a bellhousing for a 951. The 951 clutch and starter ring is larger. The smaller type starter from a 944 or 951 would work if you had a 951 bellhousing. The 944 bellhousing went on, and the torque tube lined up, but the starter ring was way to tight up against the starter. Probley bent the shaft inside it. Also, the 944 bellhousing went over the 951 clutch, but I doubt very much it went on too easy. The bolts that hold the bellhousing on, are in the same spot on both bellhousing, but like I said, the 951 bellhousing is a little fatter to allow for the larger clutch.
I know the bellhousing are different from the wrecked cars that I have parted out. Also..... IF.. I remember correct, the 951 bellhousing, has a 951 part#
12-04-2005, 06:19 PM
#10
Burning Brakes
This is from memory - but doesn't the 951 have a different number of teeth on the flywheel than the NA cars - or at least the early cars? I believe Porsche increased the # of teeth on the later models to get more signal pulses to the DME - though I'm parapphrasing the FR wilke site, I believe
12-04-2005, 07:28 PM
#11
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Originally Posted by mbonner
The starter motor burned out in my 83 so I ordered a new one from my local Porsche dealer and when I went in to hand in the stinky fried original core motor I was handed a much smaller diameter starter motor with a 951 prefix part number. Works fine.
Mike
Mike
http://www.allzim.com/acatalog/924_944_Starters.html
Bosch has surperceded the large starter used on the early 944to this smaller, gear reduction type starter. They are completely interchangeable.
12-04-2005, 08:01 PM
#12
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Originally Posted by tod84944
Somebody correct me if I'm wrong on this....
The bellhousing on a 944 is different on the inside than a bellhousing for a 951. The 951 clutch and starter ring is larger. The smaller type starter from a 944 or 951 would work if you had a 951 bellhousing. The 944 bellhousing went on, and the torque tube lined up, but the starter ring was way to tight up against the starter. Probley bent the shaft inside it. Also, the 944 bellhousing went over the 951 clutch, but I doubt very much it went on too easy. The bolts that hold the bellhousing on, are in the same spot on both bellhousing, but like I said, the 951 bellhousing is a little fatter to allow for the larger clutch.
I know the bellhousing are different from the wrecked cars that I have parted out. Also..... IF.. I remember correct, the 951 bellhousing, has a 951 part#
The bellhousing on a 944 is different on the inside than a bellhousing for a 951. The 951 clutch and starter ring is larger. The smaller type starter from a 944 or 951 would work if you had a 951 bellhousing. The 944 bellhousing went on, and the torque tube lined up, but the starter ring was way to tight up against the starter. Probley bent the shaft inside it. Also, the 944 bellhousing went over the 951 clutch, but I doubt very much it went on too easy. The bolts that hold the bellhousing on, are in the same spot on both bellhousing, but like I said, the 951 bellhousing is a little fatter to allow for the larger clutch.
I know the bellhousing are different from the wrecked cars that I have parted out. Also..... IF.. I remember correct, the 951 bellhousing, has a 951 part#
The starters will interchange in the 944/951 series. The 968 has the two-piece bellhousing, so it has a different starter.
Andial's bellhousing had a a casting number that started with 944, not 951 on it.
If we can confirm that a bellhousing from a 944 n/a will fit over the 951 clutch/flywheel assembly, then I think it will prove that Andial has the wrong bellhousing.
12-04-2005, 09:06 PM
#13
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Yes if we can confirm that a 944 bell housing will fit over a 951 clutch or if we can prove that the casting number for a 951 bell housing does begin with a 951 then maybe we can prove that I have the wrong bell housing on. BUT......I went out to the garage and took a look at the bell housing that was priginally on the car and the casting number is 944-116-401-2R. I dont recall the exact number of the new bell housing but i do recall that it also started with a 944.....so perhaps the bell housing is correct.
I wonder if the answer to this problem is a simple one....such as perhaps the starter was installed incorrectly....it seems if the pressure plate was scraping the end of the starter that would mean that the starter was in too far....correct? Perhaps all it needs is a couple washers so that the starter does not go so deep into the housing? Could it be that simple?....probably not since its a Porsche right?
My mechanic said that he measured the new bell hosuing before putting it on making sure it matched the one he was taking off. He said everything measured correctly and the housing went on without any problems or alignment issues and therefore is pretty sure its not the housing.....but then what else could it be?
And assuming that a 944 bell housing would fit on the 951 why wouldnt the starter work? Assuming that there is no difference between a 944/951 starter.
That said the mechanic says he will come out this week and measure the original housing and the new one and see if there is any difference. I hope we can get to the bottom of this. Any advice from Rennlisters is appreciated.
I wonder if the answer to this problem is a simple one....such as perhaps the starter was installed incorrectly....it seems if the pressure plate was scraping the end of the starter that would mean that the starter was in too far....correct? Perhaps all it needs is a couple washers so that the starter does not go so deep into the housing? Could it be that simple?....probably not since its a Porsche right?
My mechanic said that he measured the new bell hosuing before putting it on making sure it matched the one he was taking off. He said everything measured correctly and the housing went on without any problems or alignment issues and therefore is pretty sure its not the housing.....but then what else could it be?
And assuming that a 944 bell housing would fit on the 951 why wouldnt the starter work? Assuming that there is no difference between a 944/951 starter.
That said the mechanic says he will come out this week and measure the original housing and the new one and see if there is any difference. I hope we can get to the bottom of this. Any advice from Rennlisters is appreciated.
