Thread: Engine Balancing? - Broken Flexplate

That flex plate looks conical. That shouldn't be. It looks like the torque converter has been pushing the flex plate forward.

Is it now conical and no longer flat?

Scoob, has the mount boss to the crankshaft got a bronze bush in it? The piccie seems to indicate a step in the boss which may foul the correct seating of the TC, causing the "coning" that p38a has noted. If there is a bush there, remove it. The TC may then fit correctly. It would be there for a manual gearbox installation, indicating a possible change when the engine was done over.

Pete

looks to me like the last person that put it back together didnt get both internal splines of the torque converter lined up on the input shaft. after spending 2 hours fighting with mine when the engine was done its a complete pain to get it right. if they are not lined up correctly you are left with bout 4mm gap between bellhousing and block this can be seen as just tight dowels and pulled up with the bolts causing warping of the flex plate.
with the converter installed correctly the bellhousing and block will mate and then you bring the converter forward to meet the flex plate after you have a couple of bolts tight. the converter should have a small gap to the flex plate with the bellhousing bolts done up which you then close by pulling on the converter before tightening the flex plate bolts.
good luck

Yes to all of the above!!

I have since removed the puzzle that was once a flex plate (13 pieces ). As ron said, it appears conical on the floor. That sounds like a possibility about the Torque Converter.

The question is how do i prove it? I guess i ring them up on monday and say "Hi.... broken flex plate... appears flexed in the wrong direction, you guys were last to bolt it up", or the question is were they? Because the engine builder has had the car since them to replace the camshaft that stripped itself, but i am unsure whether they removed the motor or not!.

*slaps forehead*

I see no specific reference in any of this conversation to the "drive plate setting height" specified for particular engine numbers when bolting the flex plate to the torque converter. RAVE makes specific mention of this and when/where it applies.

There's a 3 digit code on the plate affixed to the auto transmission box which specifies the shim stack required. This is critical to preventing cracked flex plates... Ashcroft transmissions has a Table on their website Ashcroft Transmissions - ZF4HP22

Check your engine number to see if the depth calculation is a requirement (see RAVE) for your vehicle. If it applies and if when reassembling the job, whomever didn't take account this, then it may be one of the significant factors contributing your problems... perhaps you could ask them a leading question like:" Can you remember what size shim pack you used between the TC and flex plate...etc and how did you calculate it? see how much they know/understand...

Good luck with it

I cant find any reference to these shims in my rave, and the Ashcroft website just talks about them not where they go. My box ends in 909 and that doesnt even list in there table.

There were no shims on the original engine when i first removed it years ago. I'm just wondering if the shims are there to adjust the flex plate spacing from the flywheel... hmmm.

Scoob, is there a bronze bush in the end of the crankshaft?

Pete

FWIW: Here's what's in my version of RAVE:

Up to engine (4.6L) number 46D00450A, and (4.0L) engine 42D00593A : setting height is 7.69mm-7.81mm

From 46D00451A, and from 42DD00594A and all petrol V8 engines with serial number prefixes 47D-51D: these do not require a setting height

cheers