Ring gear and starter problem
11-03-2018, 12:00 AM
#1
6th Gear
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Ring gear and starter problem
Bought this 85.5 car a few months ago and it needed work. Made a grinding noise when starting and PO said it needed a new starter (and I believed him). Realized ring gear was worn after replacing the starter so took it to a shop to have it changed. Ring gear changed grinding still there, Porsche mechanic had no idea what it could be. So I trawled forums and it seems the bell housing may have been changed and is incorrect.
So so here is my question as I have not found the answer yet. Is there a fix other than changing the bell housing? Is there an alternate starter? Can starter be shimmed or machined to fit? Would a different bendix gear with more/less splines work?
the ring gear wore on the tips of the splines so the starter gear appears to be too close and not getting into the depth of the spline.
So so here is my question as I have not found the answer yet. Is there a fix other than changing the bell housing? Is there an alternate starter? Can starter be shimmed or machined to fit? Would a different bendix gear with more/less splines work?
the ring gear wore on the tips of the splines so the starter gear appears to be too close and not getting into the depth of the spline.
11-03-2018, 12:13 AM
#2
Rainman
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you might have a 944 turbo bellhousing on your non-turbo car, that puts the starter in a slightly different spot to accomodate a larger diameter flywheel/ring gear.
944 ring gears aren't something that normally ever wear out, that was a lot of work...
944 ring gears aren't something that normally ever wear out, that was a lot of work...
11-03-2018, 12:40 AM
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i believe that is exactly what it’s is. There were signs that a PO had tried to work around it by grinding part of a starter away where it sits in the BH. So is there an easy fix?
11-03-2018, 09:33 PM
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so I have located a 944 NA bell housing for 30 bucks. Checked part number and it’s correct, checked my bell housing and it is from a turbo. I read somewhere on this forum that the bell housing can be changed without pulling out the transmission, but that does not sound possible. Can anyone confirm?
11-03-2018, 11:38 PM
#5
Instructor
You usually remove there are exhaust and transaxle in order to slide back the torque tube. Only often that can you remove the bellhousing. Not bad on an n/a car on a lift but a bit of a pain in the garage on jack stands. Best of luck in your repairs.
11-03-2018, 11:49 PM
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got it thanks. Will get a quote from my Porsche guy first, if it’s a few hundred bucks I will let him do it. He just fitted a new clutch kit, starter, ring gear and repaired an oil leak on the transmission so I must be his best customer!
11-04-2018, 02:46 PM
#7
Rainman
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you might live in rust country or have stuck bolts but...
recently i pulled the drivetrain out of my 944.
i had the exhaust and trans on the floor and the torque tube pulled out from the bellhousing in an hour....this is in my garage on jack stands.
recently i pulled the drivetrain out of my 944.
i had the exhaust and trans on the floor and the torque tube pulled out from the bellhousing in an hour....this is in my garage on jack stands.
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11-08-2018, 08:07 AM
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So...using a Turbo bell housing on an NA block results in a mis-aligned starter with respect to the ring gear/flywheel.
Would the replacement of the ring gear/flywheel with a turbo unit resolve this alignment issue?
Would the replacement of the ring gear/flywheel with a turbo unit resolve this alignment issue?
11-08-2018, 04:50 PM
#11
Nordschleife Master
Turbo and na blocks are the same, it’s only the bellhousings that are different, so you have to match the bellhousing to the clutch/flywheel/pressure plate assembly you are using. A turbo assembly requires a turbo bellhousing and an na assembly requires an na bellhousing. Basically a turbo bellhousing pushes the starter further out so that it meshes with the ring gear on the larger turbo flywheel. Also iirc a turbo ring gear/ flywheel will not fit inside an na bellhousing.
Last edited by MAGK944; 11-08-2018 at 09:25 PM.
11-08-2018, 08:35 PM
#12
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Yes but it would add a new issue. The turbo ring gear has more teeth than the NA, so if you're using the stock sensors you'll have problems.
11-08-2018, 11:05 PM
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Thanks guys for confirming the bellhousing and flywheel are matched depending on application as well as sensors used in each model. Makes perfect sense.
IIRC the 968 manual starters also work with the 951 bell housing and have little more 'grunt' to them.
IIRC the 968 manual starters also work with the 951 bell housing and have little more 'grunt' to them.