Loud thunk, then nothing

[Pablo]

Hi all,
Writing from Okinawa, Japan. I'm here for a couple months for work. I left the car with the wife and I told her to feel free to drive it. Yes I'm sure some of you think I am crazy but I want her to enjoy it too, and if she breaks something well then it needed upgrading anyway.

So she broke something She said she took it for a ride and at some point in the ride she punched it. The car took off and after a little ways she heard a loud thunk and lost all gears. Like neutral. She had it towed home and that's where it sits till I get home.

She said there were no parts or fluids that came out, no grinding noises, nothing... just the thunk and nothing else.

I've been sitting here trying to come up with what went wrong. Any ideas? Kind of seems odd to have a sudden catastrophic failure like that with no grinding sounds or slipping gears, etc.
Yeah kind of a vague question but sitting here on the other side of the earth thinking about it has me really curious as to what broke.

Up till then, the tranny shifted like a champ.

The only concern I had was what I thought was massive torque converter slippage.
I ran an 11.2@118 with a 1.54 60ft
I crossed the line at 5200 rpm in OVERDRIVE

I also wonder how much I will gain without the slippage.

 

[Thumper]

forward drum broke would be my first thought. Time for a trans rebuild with upgrades.

Thanks
Bill

 

[matt69olds]

That is my bet also

 

[Quick6'n'-K.C.]

I have to agree, if the car has no reverse also... then its the drum that broke.

If it has first gear, then slides, its the second gear band that has broken... most common


Good sushi there?

BW

 

[Pablo]

Yeah, she says it's like the car is in neutral.

If it is in fact pretty catastrophic I will probably go 4L80. With my limited tranny knowledge I thought the drum might be suspect but didn't really know what a failure like that would be like.

I have a buddy who is offering me a good factory 4L80 for 500 bucks. I will have to research this option further.

Yes the sushi here is phenomenal though I haven't had any yet on this trip
I was here back in 02-03 for a year with the Marine Corps and ate plenty of it then

 

[rmar]

4-0 drum....

 

[TurboBuRick]

I put my money on the drum.

 

[TURBOPOWERED68]

I broke a stator support and it went just like that.
Life was good then a thump and it was blank no gears at all.
Good luck

 

[Clark6]

what about the ears(tangs) on the front pump drive going into the converter snout? Well thats what happened to me, no d no rev no nothing,,,,, but i didnt hear the thunk though..... so scratch that.

 

[2QUICK2B6]

I got down on my car after putting larger 28 inch tires on the rear right before i let out i heard a loud thud like metal to metal. I lost all forward gears like it was in neutral the car would just rev but it still had reverse. I had a built tranny on the floor so i havent torn the broken 1 apart yet

 

[charlief1]

where's Chris718 when you need him? LOL Bison (Brian) or one of the tranny guys needs to answer you.

 

[mikestertwo]

Forward Drum

 

[David Husek]

From what you have described, the forward drum has broken. When they break though, they break clean; make no noise and there is no movement. It is a simple fix if the Transmission needs no other work. They usually break from the Trans shift timing being off and having a hard (not positive) shift to be vague on the subject. I stock quality billet drums and also the Art Carr drum. Both are great pieces and neither will break in your application again.
<O

 

[chris718]

May also be pump rotor.Have to disconnect a cooler line and start it up to see if there is oil moving.If your car is close to Oakland/bay area I suggest going to Mizzis automotive.If you need a phone # let me know.