Auto box strange noises

#1
Just come back from a show in my mates P6 2000 auto. Noticed on roundabouts and when setting off, a strange rattling scraping racket coming from the box we assume? Not had a look yet. Does it on start up as well. Sounds like the starter not returning, but don't think so. Low on oil? or is it cream crackered? Still drives and changes up and down the box ok, just this nasty noise. Any ideas welcome.
 

harveyp6

Well-Known Member
#5
They can crack around where it's bolted to the crank, particularly if it's a pattern solid plate, and if the plate is OE then they can crack on the struts. OE are double thickness so one side can break while the other remains intact. (Untill that breaks as well). You can't see the former through the starter hole, but you may see the latter, or some evidence of cracking.
 
#7
Thanks for that. Will take the starter out anyway and check the return spring on the solenoid while it's out. Our car did make a similar noise when our starter was less than perfect. He did have trouble when he first fit a new starter, with it not clearing the ring gear. He had a spacer plate made and it seemed to sort that problem. I don't suppose it would need much flex in the said flex plate to contact the teeth on the starter motor while on power out of junctions, or a roundabout if it still too close to the ring gear, or the return spring is broken, or the gear not returning. Will have a look this week and report back. Worth a go before ripping the box out. Thanks again.
 

SydneyRoverP6B

Well-Known Member
Staff member
#8
They can crack around where it's bolted to the crank, particularly if it's a pattern solid plate, and if the plate is OE then they can crack on the struts. OE are double thickness so one side can break while the other remains intact. (Untill that breaks as well). You can't see the former through the starter hole, but you may see the latter, or some evidence of cracking.
Hi Harvey,

Are the cracks in your opinion the result of the bolts being incorrectly torqued when it was attached to the crankshaft, or is it likely something else?

Ron.
 

harveyp6

Well-Known Member
#9
Are the cracks in your opinion the result of the bolts being incorrectly torqued when it was attached to the crankshaft, or is it likely something else?
There are about 10 reasons why they can fail. A combination of any of them can cause failure, as the plates are so weak in the first place.
 

harveyp6

Well-Known Member
#11
When I used to dismantle after the plates had broken I would always want to find a reason for the failure, then when reassembling I would rectify all the problems that were there on the way back in.

When dismantling, make sure that the 2 dowel bellhousing bolts are fitted, and fitted correctly. Slacken all the bellhousing bolts below the engine sumpline, leaving the bottom 2 till last. If when you slacken them a gap opens up between the bellhousing and engine bearer plate, the engine sump needs to be moved backwards. Do this on reassembly.

When removing the crank bolts and washer, note which way round the washer is, it needs to have the curved edge next to the flexplate, not the flat edge.

Check the converter spigot, they can get worn, bent or even ripped out completely, but if that's the case you will have been swamped in ATF while doing the job, so it's hard to miss.

Renew the spigot bush.

Clamp the ring gear in the vice by the area where the timing marks are. Remove the old plate and refit the new with a dab of loctite on the bolts. Doing it this way saves any confusion getting the plate in the right position.

Refit the plate getting the crank washer the correct way around. Reassemble with new, or old converter if OK. Fit bellhousing, then refit gearbox.

Once the eng/trans is back in and level, I always slackened all the engine sump bolts and forced the sump fully backwards before retightening all the sump bolts.

If you can get the strengthener assembly that was fitted to the 2200 auto, then fit it.

Once assembled, get the fluid level correct, set the kickdown cable correctly, set the ignition timing correctly, set the idle speed correctly.

Roadtest, return car to customer, taking copious amouts of cash from him as you do so.
 
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#12
Got the car sorted. On getting it on the lift, immediately noticed the starter was loose on its bolts. The 3 mil plastic sheet spacers he had made for the starter had squashed a bit and the starter gear was contacting the ring gear sometimes, making the noise. Laser cut him a proper metal spacer and no more problem. It must have had a wrong starter fitted at some time in it's life and the previous owner had just made it fit. All's well now, thankfully I don't have to drag the box out. Many thanks to all who posted regarding this. cheers, Rob
 
#16
Can do without the work right now anyway. Don't know where I would go to get a plate? Lucky for him though as he's booked in to a car rally thingy on Sunday. The design and laser cutting however was not cheap, but a quick and easy fix. Happy customer too, even on Friday 13th!! Bet if ours starts making the same noise we won't be so lucky!
 
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