Tampa 928s

Any feedback what is causing this, and what is the solution to fix it?
86 928s 5-speed.
Mark

Tampa 928s

http://picasaweb.google.com/tampapix...ey=bNuktNkIATg

John Veninger

That is normal machining of the block. If the cank is rotating freely, then no worry.
Just check the thrust bearing/ crank end play.

heinrich

Oh dear. CHECK END PLAY!

Fabio421

I didn't know you went to Sebring. Did we meet?

John Veninger

I was rushing around with the car. Parked right next to Anderson's ride under the tent.
Sorry I didn't get to hang with a few more people.

MarkRobinson

That looks completely normal to me. I agree, machining of the block before it was assembled. If your drain plug is not accumulating metal scrap, I wouldn't even check for end-play. Of course, you'd have to spend considerable more time to check the end-play, but you can always cut-open your oil filter & check your drain plug. I don't think I've ever found metal on the drain plug before. The most I've ever seen on an abused engine couldn't be smelted to make even a BB. I've re-sealed/rebuilt a few engines: all had circular machining marks like that.

Your crank could NOT touch the block unless that thrust bearing is toast, for which your drain plug would have little triangular-ish flat pieces of bearing material: should be very obvious. Course, turn the engine over (1/2 breaker bar & a deep 27mm socket, clockwise from the front), & listen for scraping/grinding, take an LED Flashlight & a dentist mirror & you'll see it's probably no where close.


Mark

Tampa 928s

What is the procedure to check end play I assume you need a dial gauge with the motor out?

ROG100

Dial Guage on the flywheel - use a mag base on the steering rack plate.
Pry the flywheel forward and back.
Looks fine to me - but best to check the end play.

Stan.Shaw@Excell.Net

Thanks Roger, that looks like the answer I was asking in the other topic:

What if a 928 had an incorrect adjustment for a period of time, but was then adjusted properly. The thrust bearing could be worn allowing too much axial crankshaft play, correct? If so, is there any way to determine this without dropping the pan?

AO

Looks like mine did a few months ago. Here's my pic to ease your mind. You have to look closely, but you'll see he same type of machining marks.

Tampa 928s

I hope your correct I guess I could turn the crank and see if there are marks on the counter balancer

Kevin in Atlanta

Normal. Every 928 engine I have looked at has that. I know of no 5 speeds that have ever had TBF. And I have a 88 block with TBF at the shop for comparison purposes. Not very pretty.

Mike Frye

Tampa,

I learned a trick from an old guru about checking for tolerances. Scribble a little on the block with a sharpee, then while it's stilll wet, turn the crank. If it's smudged it's rubbing, if it's not, you're good.

Rob Edwards

Piling on:

90 GT, 109K miles. ('Scuse the grime.....)


FWIW, I just about had a heart attack when I saw this, but then realized that all the machining is on the wrong side of the webbing to be TBF....