Pulled a stupid + need diagnostic help

[UK PONY]

Ok so lets get my stupidity out of the way first - after giving the battery from the "new" '90 a good charge I placed it carefully on the battery tray & didn't realise I had it in backwards. Net result, lots of sparks, some smouldering wires and a very shameful look on my face. In the words of the great Homer J Simpson - DOH!!

Now for the diagnostic help. After putting the battery in the correct way around the daytime running lights came on & stayed on the whole time the battery was connected - probably as a result of the earlier DOH moment. But when I came to start the car the starter spun (maybe a little too freely) but the car wouldn't fire up. THe previous owner did say he thought the tranny had gone but before I fork out $300 for a used tranny I thought I'd seek the collective knowledge available on here.

Any thoughts guys & girls?

[TheAnnihilator]

When you went too start the car it cranked over like normal but wouldn't fire? If this is the case check too see if you have spark. I know a common problem is the ignition modules.

[Savier]

if the starter is spinning but the car isnt cranking, its the starter. Bendix isnt engaging. You could try tapping on it while someone tries to start the car...or replace it, gunna have to eventually

[Arbour88]

Originally Posted by Savier

if the starter is spinning but the car isnt cranking, its the starter. Bendix isnt engaging. You could try tapping on it while someone tries to start the car...or replace it, gunna have to eventually

UK PONY, what he said.

John

[UK PONY]

Thanks for the input guys - the starter is, alledgedly, quite new (I know this doesn't rule it out as faulty though). I wondered if the bendix isn't engaging with the ring gear on the tranny - maybe a faulty starter or worn / stripped ring gear?

Maybe this weekend I'll have time to pull the starter off & see what's what - hopefully I'll be able to get a look at the ring gear through the starter's mounting hole.

[Savier]

just so you know, few weeks ago i baught a brand new starter, and it was faulty...had me stumped for a while why this brand new starter was making noises, but not working...

[UK PONY]

^^^ had that happen to me before as well, of course I checked everything else before realising the cause of the problem

[UK PONY]

Ok so it took me a little longer than expected to get to this but...

I removed the starter today & sure enough it does look very new, a remanufactured Champion unit. There is a starter & alternator place just a stones throw away from me so I'll ask them to check that it works as it should & that it is the correct unit.

Now that I can see the ring gear I can tell that the teeth are in good order but.........and it's a big but.........I can turn the ring gear by hand, very easily.

I had a friend turn the motor by hand whilst I looked in through the starter opening - the ring gear does not turn with the motor!! There is a small amount of play in the fore & aft movement of the ring gear piece as well.

My friend & I think that the pressure plate / ring gear piece has somehow come loose from the crankshaft (either the bolts have sheared or fallen out) meaning that the starter spins the tranny but not the motor.

I'm going to move the car to another friends place with more equipment on hand & we'll pull the tranny away from the motor to see what we can see but any thoughts on this folks?

[UK PONY]

Oh yeah, one other thing......if the bolts sheared, what caused this to happen?

Thanks again folks.

[5.0 Fugitive]

The crank bolts may not have sheared it maybe the ring gear seperated from the flywheel.

You shouldn't be able to turn the ring gear/flywheel by hand unless you are using something to pry on it. A quick test to see if the ring gear is fubared, is to put the trans in neutral and put a socket wrench on the crank snout bolt and turn the motor by hand. If you can hold the ring gear still and turn the motor by the wrench, it's time to pull the transmission and inspect it closer to see what has gone wrong.

[UK PONY]

Thanks for the info 5.0, I forgot to mention the car is an automatic.

The ring gear, if it is a seperate piece, is very firmly attached to the pressure plate / flywheel.

The tranny was in park at the time - I'll check again in Neutral to see if it's any different.

[UK PONY]

I had chance to go to the starter / alternator place after work today - good news the starter is fine & is the correct one (apparently there is no difference between manual & automatic as far as the starter goes)....of course this means the bad news is there is still something broken & it's more expensive :-0. Plus I still don't know what caused whatever it is to break in the first place.

[notstockstang]

if I remember correctly, the flexplate is bolted to the crank, and the torque converter is bolted to the flexplate. if the motor is staying still and you can turn the flexplate, then the crank could be broken,. or it isnt bolted to the crank.

[4648]

Flex plate is likely broken. Not an unheard of failure. What's supposed to be wrong with tranny. Could it be ok and the broken flex plate, be the only problem?

[UK PONY]

I'm hoping it's just the flexplate that's broken. I'd never heard of this happening before but on asking around a couple of examples have come up so fingers crossed it's that simple. If it is I may be able to get the car on the road for under $500 in total.

nonstock, you're correct in the way that the three parts are linked. the motor cranked over by hand with enough resistance to indicate compression - hopefully that puts the crank in the clear.