Want to be

Dropped exhaust 3-5 inches to remove bolts.

Removed the housing.

Verified the flex with a straight ruler. .03 inch per spark plug tool.

Loosen flex bolt after cracking to correct position

With dial indicator and vice grip attachment arranged, I pushed the flex plate over towards the rear (exhaust side) of the car.

Dial indicator moved to (I think) .05 inch, ( I did her the ka-clinch) then I accidentally hit the indicator with arm. Lost exact measurement.

I've tried to push the back to (towards the engine) reset the play test. I have only been able to possibly push it back once. The flex plate keeps pushing it back. The second measurement was .05 inch.

I've retighten the flex bolt and rotated the engine several times and then redid the flex play check with the dial indicator Still can't get it to reset back.

Any experience on how to push the plate back towards the engine?

Should I just give up and get my red loctite out and tighten the clamp and call it a day?

I'm installing a PKclamp too.

Any thoughts would be appreciated. I've read a few right ups ( fantastic help) and made a quick video to share soon.

My car has over~ 240k with a broken OD. I just can't believe the bottom end is this solid with a recent top end rebuild.

Thanks for any help.

FredR

Your post has me a bit confused as to what you have measured but I will try to give you a simple summary of actions.

1. You should check the pinch bolts at both the front and the rear couplings and install new bolts at each end.
2. With the front pinch bolt loose the clamp should be free to slide along the splines but it will not move freely because of the stiffness of the flex plate but you should be able to see it moving unless someone has loctited the clamp splines previously.
3. With the pinch bolt on the flex plate loose check the crank end float- it should be about 0.2mm. To measure end float you have to pry the crank to both extremes of its float- I typically use the flywheel and the front pulley as pry points.
4. If all seems well you fasten the rear bolt first after making sure the bolt is engaging the detente on the shaft correctly and all looks clean as it should. The pinch bolts can be tightened to 110% of the WSM spec.
5. Finally torque the front flexplate clamp. If you are using the PKlamp you should not need to use any Loctite anywhere. The leaves of the flex plate should be pretty much square unless they have taken a permanent set due to overstressing.

Trust the above helps.

docmirror

I'm hoping you meant you had 0.005" or 5 thousands play, because 0.050 or 50 thousands is a lot of movement. I think the spec is 0.2mm which is around 8 thousands (0.008").

What I did on the last one was replace both pinch bolts. Put the rear one in first and torque to 62 ft/lb. Because the flex plate takes somewhat of a set, I wrapped a few loops of bailing wire around the back of the flex plate, then connected the bailing wire to a ratcheting tie strap, and put some modest tension backward on it. You can hook the other end of the tie strap to one of the exh pinch bolts, just don't put a lot of strain on it.

Once you have the flex plate drawn rearward on the splines, install the front pinch bolt, and torque to 60 ft/lb.

YMMV

Want to be

Ok, I'm now confused other than posting the wrong measurement. I miss read my gauge, its .001 per notch. So, .005 if I measured it correctly.

Replace both bolts? You mean for the PKclamp?

I only loosen the flex bolt and the pkclamp is off.

What other bolts need loosen or replaced?

FredR

The pinch bolt that holds the rear clamp adjacent to the torque converter.

You do not need this loose to measure the end float but it is an accepted practice to replace this bolt from time to time as it has also been known to let go.

We are not talking about the PKlamp bolting

Want to be

Can someone post a picture of the two other bolts I need loosen? Sorry, I've not seen a write up of loosening anything other than the one bolt on the clamp.

I'm getting more consumed and hope to get this clarified. Appreciate all the help.

Thanks

FredR

There are two clamps on the torque tube- one either end and both use a pinch bolt to lock them up. The rear clamp bolts into a fixed position thus why it has to be bolted first. After that the front clamp is bolted up such that there is no pre-load on the thrust bearing.

I do not have any pics of when I did the bolts but plenty have been posted in other threads. To get at the rear clamp I dropped the exhaust and then removed the heat shields to expose rear of the torque tube. There is a rubber grommet that you remove and then you have to turn the engine so that the head of the Allen bolt is correctly oriented for access. I use an long 1/2 inch drive impact socket which if I remember correctly is an 8mm item. The bolts are identical both ends of the torque tube.

docmirror

Drop your rear exhaust, unbolt from the front pinch clamps, unbolt from the back near the muffs, and any hangers back there. Pull the rear exh off. There is a heat shield held on by some machine screws, remove the screws and the heat shield. (first pic)

Above the heat shield you will see an access hole in the outer torque tube(seen in the pic near the hose). Put the trans in N, and rotate the inner shaft so you can see the allen head pinch bolt.

Remove the pinch bolt. Replace and torque. Draw the front flex plate back as I stated before. install your Pklamp. Release the tension on the flex plate, install your heat shield and rear exhaust.

daveo90s4

To the OP

You don't say what year your car is. If it is about 86 for earlier it will probably have the 25mm central shaft with the circlip on the front. If so you will very probably need to rethink your approach.

Dave

daveo90s4

... and with the circlip arrangement Porsche specified a certain amount to rearward static thrust on the crank. Not sure why this same thrust would not be applied with the PKlamp option.

Dave

Want to be

My car is 87, was on my footer. I didn't realize it disappeared.

Near project is to replace the two bolts on the torque converter. I'd assume I need to purchase a screw with a certain hardness.

I made a video and will post my results on Monday.

Thanks everyone!

FredR

If your car is an 87 S4 then you need to check which torque tube is fitted as some of the very early models had the earlier smaller diameter shaft that is installed a bit differently- I suspect the pinch bolt is the same but I do nor know that for a fact.

As I have alluded to several times, there are two pinch bolts, one at each end of the torque tube. As I am aware both these bolts are identical, they are high strength bolts and you need to order them from one of our specialists parts suppliers [or Porsche] and they are not screws!

Want to be

Thanks for the help.

Regretfully I wasn't aware of the need to replace the bolts.

So, my next creep check I'll replace both bolts.

I made this flex plate video to show the basics of performing the one measurement check with a dial indicator.

FredR

A good video!

The not so good is the number you came out with. As I understand your gauge units of measurement must be in thou's of an inch and 11 thou translates to 0.43mm. Did you record how much the flexplate clamp jumped when you undid the pinch bolt?

A normally healthy motor typically sits in the range 0.2mm to 0.25mm. As per Porsche the bearing service life is over at 0.4mm. Now the question is why is your thrust bearing at this level of wear [presumably it has been over pressured] and this in turn begs the question as to whether more extensive damage has been done.

By the time most owners find out what has happened it is way too late and the engine is totally shot with end float values in excess of 1mm. If you have old oil in the motor you could try sending a sample off for analysis. You could also pull the sump plug and see if there are signs of excess metal and you could also split the oil filter if it is an oldish one to examine for signs of excessive metal pick up.

I would not start fearing the worst yet but it seems to me further investigation is warranted. It will be interesting to see how the "brains trust" reacts to your situation.

Trust I have not misunderstood anything in your video. You should also repeat your dial gauge measure several times until you get several consistent readings within a thou or so of each other.

Want to be

Thanks for your input. Regretfully I had to get the car back together because my wife wanted her car spot back.

Regarding your question on if I did more measurements in the opposite direction. Not very well, when I have more time I'll do another video of both measurements soon.

Regarding the flywheel play, I'm near or at the end of the porsche specifications.

I asked a 911 mechanic, and he said to cut open the oil filter. He doubted anything would be there because the thrust bearing debris most likely came off many many oil changes ago.

In his experience, .011 inch was not the end of the world just yet.

So, anyways. More investigation to come