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torque spec for bolts in the bell housing

Old 12-28-2017, 03:02 PM
  #16  
Slakker
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I think autozone has triple square in stock. For the two top bolts, I've used a 16mm box wrench if they are torque'd to spec while basically hugging the tranny. I've also used a series 3/8 extensions with u-joint adapters.
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Old 12-28-2017, 03:38 PM
  #17  
Kris Murphy
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Also, once you get the tranny out, you can replace the AOS without having to take anything off the top of the motor. It still sucks, but 100% possible, and worth doing whenever you are near it.
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Old 12-30-2017, 08:58 PM
  #18  
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Originally Posted by cds72911 View Post
Get a transmission jack first. You'll use it to remove the bolts. I have a cheap harbor freight version, with the typical coupon it was well under $100 shipped.

Put your transmission jack under the transmission, remove the bolts on the front mount and lower the transmission end down, then go at the top mounting bolts with a 1/2" ratchet and lots (several feet) of extensions, you'll be doing yourself a big favor.
My second attempt at loosening the top two bellhousing bolts didn┤t work, so I think I┤ll do what you suggest which is to get a harbor freight transmission jack, disconnect the front transmission mount and
lower the front of the tranny to get a better angle to remove the top bolts. Question: Will I damage the two engine mounts when dropping the front of the tranny so the engine/tranny combo points downward, or do I need to loosen
the engine mount to prevent damage. If I loosen the engine mount, by how much ? I don┤t want to lower the engine too much and stress out the various coolant, fuel, and brake hoses that are connected between the engine and the chassis.

Thanks!
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Old 12-31-2017, 12:25 AM
  #19  
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I┤m gonna declare partial victory. After dropping the engine at the engine mount for about half an inch, and disconnect the front transmission mount, I was
able to loosen the top bell housing bolt. So the only bolt left is the triple square, so once I get a triple square bit the bell housing should be done.
I also took out the hydraulic clutch slave cylinder, the shift cables, and the backup light switch, so they tranny is ready to come out once I get a triple square bit
and a harbor freight tranny jack.

Anything else I need to worry before trying to pull the tranny out?
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Old 12-31-2017, 11:01 AM
  #20  
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Nice work!

I had the sway bar, diagonal support bars and aluminum crossmember out. Not sure you need to, but I prefer having space to work.

Two other things come to mind:
1) make sure the engine is supported from below - once you take out the transmission, it isn’t supported from the front - so it would be hanging from just the motor mounts at the back of you don’t support it. There is a special engine support tool that mounts in the sway bar mounting holes, but if you can cut, weld and drill, you can make one pretty easily. I do my work on a lift, so having a jack under it doesn’t work for me when I change heights.
2) make sure the car is lifted high enough that you can roll the transmission out. Easy enough to change later when on a lift with the engine support bar in place but not so easy if you are on jack stands and your engine is supported by a floor jack...
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Old 01-08-2018, 03:22 AM
  #21  
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the IMSB flange says 99602406

Fedex delivered my HarborFreight high rise transmission jack Saturday afternoon, just so that I have something to do on
Sunday :-)

So the tranny is out after an hour or so after removing the bell housing bolts. The inside look really clean, not much brake/clutch
dust. I stopped after dropping the tranny, I will start removing the clutch and flywheel in the next few nights.

I can see that the IMSB flange has part number 99602406, with a large nut. Do I have the large single row bearing?

Last edited by mayday1; 01-08-2018 at 01:22 PM.
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Old 01-09-2018, 01:22 AM
  #22  
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Originally Posted by Slakker View Post
I don't know of any reason why you couldn't reuse the clutch. I know Jake hates the LWFW but almost all of the SP996 racers use them and don't have any issues with them. That being said, on the street, it's something you either like or you don't.
Slakker, do SP996 racers use the stock clutch plate with LWFW? I have the AASCO LWFW, and what looks like a stock clutch plate (without springs), so there is no damping between the engine and the tranny at all.

Do you know if LWFW should be mated to clutches with springs so that there is at least some damping/decoupling?

My tranny has rattling noises at idle when fully warmed, which I┤ve read is normal for LWFW, but it also makes funny roars when slightly lugging the engine at 5th or 6th gear (2-3k RPM, slight load), as well as in
2nd and 3rd gear when engine braking. It is possible that the tranny has problem, but I wonder if the noises are due to LWFW with springless clutch, and can be alleviated either with going back to dualmass FW, or
switch to a clutch with springs.
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Old 01-09-2018, 01:02 PM
  #23  
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Unless it is a dedicated race car, I don't see the point in having an driveline without some sort of dampening. Either the DMF or a clutch disk with springs can work acceptably. In my limited experience (race car with lightweight flywheel, four puck ceramic clutch with no springs) driving without some sort of dampener is a PITA. It is like an on/off switch, which has its merits while racing, but takes away any civility in starting from a stop in daily driving situations or easing shifts. I don't suspect it is all that healthy for the drivetrain, but that is intuition, not engineering speaking.
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Old 01-09-2018, 02:49 PM
  #24  
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I agree that it is almost pointless for a street car to have LWFW given all the noise and vibration that it transmit to the transmission and rattling of the gears.
Even though my car is just an occasional weekend autocrosser (I think I've only driven it a handful of times non-autocross in my 18 months of ownership), I'm going
to switch back to the DMFW.

Now my next move is to select a DMFW. Looking at pelican parts, partsgeek, ..etc. It seems like LUK makes several flywheels for 1999 Carrera, I don't know
which one is correct, I'm leaning towards DMF-024 but it doesn't seem to come with a pilot bearing and I don't know what pilot bearing to go with it. I couldn't find
any useful info from the LUK website.

From googling around I'm pretty sure I have the large single row IMS bearing similar to the ones in M97 engines, should I open up the IMSB flange and remove the bearing seal as Jake Raby recommends, or just leave it alone and not risk screwing up a working bearing since the failure rate of M97 IMS bearing is low?

Thanks
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Old 01-09-2018, 03:08 PM
  #25  
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Not sure about your car, but my 2000 C2 six speed used the DMF024. The pilot bearing was pre-installed in the new flywheel as delivered.

The Sachs clutch kit I used (K70246-01) includes the clutch disk, pressure plate, throwout bearing, packet of grease and a centering tool.

Don't forget new bolts for attaching the flywheel to the crank, and bolts for attaching the pressure plate to the flywheel. They are one time use.

I don't have any useful advice about your IMSB. Opinions seem to vary. I googled the part number you posted earlier, and it looks like you have the larger model bearing that requires the case to be split to R&R. if it were me, I'd also be torn between leaving it alone/not risking leaks, and pulling the flange and removing the grease seal. Sorry, but I'm no help.
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Old 01-09-2018, 07:21 PM
  #26  
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Sorry for the slow response. I know you are going back to a DMFW but to answer your question, no, the SP996s I know of do not use the spring plate with LWFW. And yes, I've also read someplace that you should, but it seems to work fine without it.
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Old 01-10-2018, 03:40 PM
  #27  
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I strapped down the crankshaft with a couple of nylon tiewraps and that was enough to allow me
to undo the flywheel bolts.

The aasco flywheel is a work of art, too bad I don't like the way it made my gears rattle. Perhaps if
I had springs in the clutch plate things would have been better.

Ordered a LUK DMF024 this morning. I've never driven a watercooled 911 except mine with the aasco
flywheel. I hope the DMFW will not turn the rev happy engine into a slug.
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Old 01-11-2018, 11:19 AM
  #28  
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Mayday1, thanks for the great thread. I need to pull my transmission for a rebuild and this has been very helpful.
Did you end up using an engine support bar to hold up the back of the engine when you pulled the transmission? Or did you use a jack? I'm debating which way to go on this.
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Old 01-11-2018, 01:46 PM
  #29  
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Originally Posted by sjg1138 View Post
Mayday1, thanks for the great thread. I need to pull my transmission for a rebuild and this has been very helpful.
Did you end up using an engine support bar to hold up the back of the engine when you pulled the transmission? Or did you use a jack? I'm debating which way to go on this.
I am using a scissor jack to support the engine. I wish I have an engine support bar though. While I'm swapping the flywheel, I may want to remove the IMSB grease seal and replace the
AOS. To remove the IMSB grease seal requires me to drain the engine of oil before opening up the IMSB flange and removing the chain tensioners. Currently with the engine supported
by a jack it is hard to drain the engine oil without make a big mess since the jack is in the way.

Do you have a simple design for an engine support bar?
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Old 01-11-2018, 04:40 PM
  #30  
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If you google it, there are engine support bars available for purchase, and some pictures of them marked up with dimensions.

https://www.google.com/search?q=pors...w=1680&bih=862

The Part number is Sir tools P254 or 9624/1.

It mounts to the four threaded holes where the swaybar normally mounts.

I made one myself with some angle iron, square tubing and some nuts and bolts. If you can measure, cut, drill and weld, it's easy.




Picture in the middle of fabrication (after this, I drilled a hole in the middle, welded a nut to it, and used a bolt to adjust to the bottom of the engine).
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