RngTrtl

Dear All, (1985, 5.0, 32v, 4C, Auto)

The progress so far is this. I have the exhaust out, heat shields out, lower bellhousing cover off, 4 front TT bolts out, lower 2 rear TT bolts out, the 2 bottom tranny bolts out, the front TT flange clamp bolt out (1-1.5 mm of flexplate movement after loosening). Now I am ready to remove the front of the TT from the front of the bell housing. After looking into the TT spline clamp it appears as though it slides in at least 2.5-3.0 inches into the flange. Am I supposed to unbolts the 6 bolts that connect the TT clamp flange to the flexplate and then slide the TT and tranny rearward? Or am I supposed to just slide the TT and tranny rearward out of the clamp flange with the clamp flange still bolted to the flexplate? If the latter is the case, I see no way to have enough clearence to lower the TT from the front of the motor. So I am guessing that I need to unbolt the clamp flange from the flexplate to lower the TT from the front of the motor. Just for kicks, I tried to remove one of the bolts from the flange to the flexplate and it began to turn the motor. How can I safely lock the motor in order to remove the bolts that go from the flange to the flexplate. Thanks in advance to any assistance and advice from other more learned than I?

TAREK

You need to take the flange out and unbolt the flexplate. You will need a helper to hold the motor at the crank bolt, but if you dont' have a helper, you can do what I do:

get a big screw driver and hold it flat across the bottom of the car on the passenger side while stuck into the teeth of the starter ring. It works well for unbolting. You will have to do it at the driver side for tightening. Either way you will have to make a few trips to the front to turn the engine over for exposing the bolts.

RngTrtl

I got it all figured out. Many thanks to TAREK for the advice of locking the flywheel. I got everything loose and tomorrow i shall finish dropping the tube. Thanks to all for the help (Bill Ball you Rock bro!)

Bill Ball

Excellent. I PM'd you about the flexplate and flange. For others here, I leave the flexplate and flange together as I slide the tranny back. As you drop the TT out of the bellhousing (you are leaving the bellhousing on as the rear cross piece was already cut), you should have room to again slide the flexplate back so it will clear the flywheel. However, if this is not so in your case, you can separate the flexplate from the flange NOTING THEIR RELATIVE POSITIONS, as the flexplate-flange-clamp combo is a balanced unit (note scallops ground out of some of the flexplate arms).

RngTrtl

I sure am glad that I have a fear of putting stuff back together wrong, or am lucky. I am one of those guys that indexs every thing, hell I even make sure to put the same bolts back into the same holes. I had a bad experience on my Bronco II one time (don't ask, it was bad ). So now I am overly cautious about removing stuff! Thanks to all again, hopefully I will have the TT out in a few hours.

TAREK

Just curious if one loses the relative positions, how could one re-balance? wheel shop?

Bill Ball

Good question. It surprised me when I noticed that different flexplate assemblies had differing number and placement of the ground scallops in the arms. And, if you check the PET, the flexplate and clamp flange are partnumbered as a unit with only the bolts are sold separately. I have no good ideas on a balancing technique.

SharkSkin

Any shop that balances engine parts could probably put the collar and plate in a jig and find which of the 6 possible positions is the most balanced. You could make a jig for this yourself, just support the assembly perfectly on the axis of rotation, on bearings that have very little resistance to rotation. The heavy side will end up at the bottom, and if the assembly is perfectly balanced it will stay in any position.

TAREK

there are 3 possible positions...so I'm guessing one should try all 3 and pick the most "balanced" position at a certain max rpm. What would that be by the way? Sorry for all the questions but I think it's important to do this right after all the work involved in removing tranny/TT/suspension, etc

TAREK

oops. I guess there are 6 possible positions

Bill Ball

I don't think you would notice an out of balance flexplate right away. The vibration would probably just work the front TT bearing until it migrated back - THEN you would feel the vibration, but it would be too late.

So, someone must have an idea of how Porsche balanced these unit in the first place. They are probably too small for any tire balancing machine, but machine shops must have something for balancing small rotating masses. I'm just not familiar with this.

Might need to buy one of these!
http://www.hinesindustries.com/indus...flexplate.html

Anyway, googling "flexplate balancing" led to lots of comments that machine shops can spin balance flexplates.

Also, from googling I saw lots of comments that flexplates on a number of engines (e.g., Chevy, MB Unimog) are not zero balanced. These engines are referred to as externally balanced. Egad! I've never seen any mention that this would apply to the 928. I think it is internmally balanced. I index everything too, but I saw no factory marks for flexplate to flywheel position or flywheel to crank.

RngTrtl

My (hopefully) last stupid question about getting this TT done. As it stands now I have everything off and the good news is that I think the TT bearings are fine. I spun it with a few yards of rope (like one would do an old gyroscope) and the bearings sound like normal bearings (just a slight whurr as I would expect from any bearings). The TC cover bearings are another matter though. Turning the tranny input shaft by hand makes a horrible grinding/popping noise that makes ones blood freeze cold. So I am gonna just replace the TC cover bearings and hope for the best. I already have the TC cover bolts out, but the cover does not seem to wanna come off. Do I need to remove the C-clip at the base of the shaft in order to slide the cover over the shaft? I am assuming that I do, but just wanted to check. Thanks to all.

borland

First remove one of the rubber plugs on the TC housing.

Remove the six bolts that attach the torque converter to the internal flex plate.

The housing is a tight fit with two alignment pins. With all bolts removed, the housing should come off with some minor persuasion.

RngTrtl

ahhhhh. Now I see how this thing attaches. Thanks alot Borland, i really appreciate it.

Mrmerlin

Hi, if your going to replace the bearings for the torque converter it would be a good time to replace the front pump O ring and the torque converter seal, if you do remove the torque converter from the front of the transmission then it would be a good idea to drain the torque converter and the transmission . There is a drain plug on the torque converter you can see it from the bottom of the transmission grating, if you do remove the torque converter put a dab of grease on the the bushing just inside of the torque converter seal this will prevent the torque converter from seizing on the front pump bushing, These seals can be replaced with the trans in the car and you can also install the torque converter back into position , Ahh one side note measure the depth distance from the torque converter to the edge of the transmission housing before you remove the torque converter, so you can make sure it is fully seated , to seat the converter spin gently while pushing it into the trans.