JE928Sx4.

I'm pepping a car to go to SITM next Friday. I'm going to do the timing belt check, but figured that It might be a good Idea to check the coupling and do the "Locktite procedure" that Capt'n Earl recommends. I was rinning around at Frenzy 5 and didn't get to see this done. Anyone have some BTDT to share?

<a href="http://boards.rennlist.com/upload/928Sx5-4.jpg" target="_blank">http://boards.rennlist.com/upload/928Sx5-4.jpg</a>

<img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />

Greg86andahalf

Are you speaking of the pinch collar bolt/flexplate procedure?

Mike Schmidt

The loctite procedure is pretty easy and does seem to keep the hub from moving. I'd suggest giving the area a good cleaning with something like brake parts cleaner and blowing it good and dry before applying the loctite. Ideally you'd want to give the loctite a good while to dry before driving the car.

shaaark89

use a new pinch bolt if you can and torque to 66 ftlbs with loctite on the threads. use penetrating loctite on the splines of the driveshaft (the green stuff.) if you can, wait 24 hours before driving it.
also check the rear pinch bolt and torque to 66 ftlbs. (mine was very loose)
i've done 4 cars (s4) and takes about 2 to 3 hours.
tom

Randy V

What model years are prone to TBF?

My understanding is that there are no documented cases on the 16V cars. True?

Greg86andahalf

I did it a couple of months ago on my 86.5. I posted results here:
http://forums.rennlist.com/forums/ul...&f=14&t=001411
It's a good idea to leave a paint mark or other reference point which can be viewed from the inspection hole in the housing to check hub migration.

Greg

Snowball the 81 white 928

cite your authority randy. i am now slightly concerned about this problem. to be frank with you, i thought there was only one pinch bolt as well.

Mike Schmidt

There's a pinch bolt in the rear too, but it's a different setup back there. There's a groove in the shaft that the bolt fits into. That prevents the rear hub from moving along the shaft at all.

johnb

Randy V:

TBF - mine failed on my 1984 euro S.

4.7L 16V twin dizzie.

cronic failure of both crank and block. crank lost about 40 thou inch off of thrust face. block badly damaged at all journals, block also cracked from each journal up towards centre V.

the flex plate was forced up into flywheel, moved back about 2 tenths inch when pinch bolt released.

all good fun.............NOT!

johnb

Snowball the 81 white 928

is the rear pinch bolt located in the front area accessed by the triangular inspection plate or is it at the rear of the torque tube somewhere? growing more concerned.

JE928Sx4.

Excellent! Thanks Greg and Tom. Just a couple clarifications. The pinch bolt is a hex head correct. The procedure is done to the end of the clamping sleeve at the flex plate end because the trans side bolt fits into a notch in the drive shaft? Is that correct?

The 86's in the school:
<a href="http://boards.rennlist.com/upload/928Sx5-4.jpg" target="_blank">http://boards.rennlist.com/upload/928Sx5-4.jpg</a>
<a href="http://boards.rennlist.com/upload/928Sx5-5.jpg" target="_blank">http://boards.rennlist.com/upload/928Sx5-5.jpg</a>

Thanks! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Mike Schmidt

The rear pinch bolt is located at the back end of the drive shaft, by the transmission. The pinch bolts are allen head. The procedure is done to the end of the clamping sleeve at the flex plate, but you might want to check to make sure the rear bolt is tight as long as you're down there. That rear pinch bolt does fit through a notch in the drive shaft.

JE928Sx4.

Excellent! Thanks Mike.

JE

shaaark89

what mike said.
also, if you have access to a dial gauge or other fine measuring device, check your end play in the crank. actually, thats a very important part of doing this because it will tell you if the thrust bearing is ok. just pry the flywheel fore and aft with a prybar and measure from a set point (edge of bell housing is good.) as i recall 16/1000s of an inch play is wear limit. all the cars i've checked/seen checked have been in the 5 to 9/1000s range.
good luck
ps if you want some help i'm just down the raod in fredericksburg. let me know.