AO

I'm about to tackle a rattling rear flex plate on an 87 auto. I saw the post from Steve Catano where he lists the parts I need which I'll get ordered up, but I'd like to know:

1. is there a write up on this? Bill Ball eluded in one of his posts that you can slide the tranny back, but it sure looks like it needs to come down.

2. what are the other WYAIT's? I'll do a filter and gasket change, but was wondering what other things should be done at this most opportune time?

I did go through the search, but didn't see anything specific to this procedure unless it was combined with TT replacement or other major tranny service.

Thanks to all in advance for their replies.

Mrmerlin

check the trans fluid lines any that are weeping should be replaced, you can get new hose and cut off the factory crimps and secure them with screw type hose clamps.
OR remove the lines and take them to a hose shop and have them put on crimped lines (more desirable)

blown 87

I have got the TSB at the shop, I can send it to you Monday if that will help, or do you need it sooner?

I can tell you this much, when I did nine the bolts I got from Porsche were a little short and I have seen better quality nuts and bolts on swing sets.

Use Wurth ones if you can get them, if not I can send you a set if you can give me the grip length and number you need, I can not remember how many and what size.

Greg

Z

How long of a list do you want?

Torque tube rebuild?
New torque converter bearings?
Rebuilding the transmission cooler lines?
Replace several of those seals behind the torque converter and at the pump in the front of the transmission?
Constantine Clamp?
Replace that brake band piston that Mercedes has an updated part for?

AO

Thanks Greg. Bu I think I saw it posted on a previous thread. I thnk I can probably source the fasteners here if the Porsche ones are marginal.

I prefer a short list. Maybe the torque converter bearings.

So do I have to drop the trans to do this job?

Bill Ball

You can pull the torque tube (TT) and the torque converter (TC) cover to get to the rear flex plate with the rear suspension left untouched. Here is an incomplete draft of the process, but it shows the key steps in detail.
http://billsworkshop.com/P928S4/TT/torquetube.htm

Black Sea RD

Hi Andrew,

When I did this to my rear flexplate for the 86.5 track car before it was converted to a 5 speed, I had a local machine shop do the work for me. The bolts chosen had threads that started above the point where the flexplates would hit the bolt when they were installed. This way it would be less likely for the plates to work against the threads and loosen, instead they would be working against the solid shaft of the bolt. The shop also trimmed the bolts so they did not protrude too much after they were tightened and I used both loctite and split washers to ensure there would not be any chance of them loosening.

As far as the short list on WYITs, Z provided you with a great short list. You didn't mention how many miles the 1987 has but even with low miles the age of some of the seals would need replacing. I did not replace the O-rings in the primary pump of our 1989 928S4 and sure enough within a year it was leaking through the front grate of the transmission. While you have everything apart you might as well tackle most on that list, not trying to be self serving though about the Super Clamp or TT rebuild parts. If you are doing this to a 928 that you want to fix and move on, then it is understandable to do the least amount needed.

Cheers,
Constantine

AO

Thanks Bill. I'll check it out and maybe see if I can't help round out the proceedure.

Thanks Constantine. I appreciate your candid, BTDT, feedback. For the record the trans has 100k. Oh... and this is not my car. It's a local Detroiter's car who's throwing me a bone and letting me do some wrenching for him for some pocket money. I'll reevaluate Z's list and suggest it to my client.

AO

Well, me and boys (Dennis and Dave) dropped the suspension and trans yesterday. Maybe we didn't have to pull it out, but I feel better working on it out of the car than in. It makes it a lot easier to get things done.

So, I'm going to replace the torque converter bearings, flex plate rivets (already drilled them out), probably replace a few of the various seals and clean, clean clean. The cooler lines look to be in good shape, so I think I'll leave those.

It appears that some white thread locker was used on the flex plate. Can anyone confirm what should be use on re-install?

Mrmerlin

that white thread locker was probably blue loctite, it turns white after its dried out and then removed

AO

Thanks Stan. I'll use Blue.

Mrmerlin

Ahh sorry I misread your post.
IIRC you should use Red loctite on the flex plate connector bolts.
That said blue will work but Red is better in this case as its a hi strength fastener that wont be getting removed.
Sorry