MTFCA Forum

Some of you have seen it happen on video - it's way worse now. I have an issue with the green thunderbolt - I thought it was akin to slamming a modern car into park but after watching the video I shot yesterday (bcking the car out to bring in another trans to rebuild on camera as requested) - it is definitely throwing the car forward when it happens and I would guess it is hitting in high gear, not a band by the violence of it. Pretty much as if you where holding the pedal and your foot slipped off into high gear - engine stalls.

I had the inspection cover open recently (filmed that too - oil change video), didn't see anything wrong. It still rolls free immediately after this happens as you can see in the link below. All I can think is "clutch disks" but I believe I put a turbo400 in it and you'd think it would have torn the lining off by now (happened 7-8 times) and I'd have no high gear left. I can't envision how something could grab that hard "sometimes" when there are no hands on the lever, one foot on R and the other on the gas pedal. Any thoughts?

If you want to see what it's doing - 1:54 mark in this video where it looks like I stalled it. Backing up and BAM, then it rolls before I can get my foot onto the brake. https://www.youtube.com/watch?v=pY7sUr8ZvsU

A loose clutch plate lining might do that. Could a cracked drum cause it by snagging the band and pulling it tight?

You have asked this exact question before in November in your thread: Speculation on the lurching...?

Got lots of answers...and some good ones, at that.

seems like you really want "views" rather than answers?

The only likely way you're going to really know what's going on is to pull that transmission, so whatever you're really seeking, I sincerely hope you get it.

So the T400 (I think that's what I put in it) clutch disc lining maybe?

TXGOAT2 wrote: ↑

Wed Mar 22, 2023 9:10 pm

A loose clutch plate lining might do that. Could a cracked drum cause it by snagging the band and pulling it tight?

I am looking forward to pulling this engine about as much as a root canal or lobotomy. I forgot about the other thread - I'll try to find it again.

Scott_Conger wrote: ↑

Wed Mar 22, 2023 9:20 pm

You have asked this exact question before in November in your thread: Speculation on the lurching...?

Got lots of answers...and some good ones, at that.

seems like you really want "views" rather than answers?

The only likely way you're going to really know what's going on is to pull that transmission, so whatever you're really seeking, I sincerely hope you get it.

I'm guessing as to what might be causing your issue.

You're risking severe damage to the vehicle or an ugly accident, or both, if you continue running it as-is.

You might start by pulling the hogshead, if you havent already, and looking for any signs of failure.

The problem is likely in the transmission/clutch, but it could be anywhere in the driveline.

Have you sampled the rear end lube and any auxilliary gear box lube?

TheSpeedsterProject wrote: ↑

Wed Mar 22, 2023 9:04 pm

......................

I had the inspection cover open recently (filmed that too - oil change video), didn't see anything wrong. It still rolls free ................

I posted this in the "other" discussion ion the same issue
You'd better ID what you found in the oil screen and drop the the inspection pan to see if there is more of that!

Only You know what You put in this motor You rebuilt. Do confess, so no one else makes a similar mistake.
Thats some nasty goo.

Root canal time!

I wouldnt do any less than than a complete disassembly & cleaning. (including oil control rings)
That goo looks thick enough to plug & restrict any & all internal oil entry points.

Tripple gear bushings are prone to locking up, so extra clearance is a good idea during a rebuild.
Even with extra clearance, they cant be run dry.
That goo will not lube those bushings or the drum bushings either for that matter.
Lurching problem solved.
I hope you will be able to disassemble the transmission without destroying it.
There is bound to be some galling @ the least.

speedytinc wrote: ↑

Thu Mar 23, 2023 1:59 pm

Tripple gear bushings are prone to locking up, so extra clearance is a good idea during a rebuild.
Even with extra clearance, they cant be run dry.
That goo will not lube those bushings or the drum bushings either for that matter.
Lurching problem solved.
I hope you will be able to disassemble the transmission without destroying it.
There is bound to be some galling @ the least.

Doesn't that goo look like anti-seize, they way it sticks to fingers etc

TRDxB2 wrote: ↑

Thu Mar 23, 2023 2:12 pm

speedytinc wrote: ↑

Thu Mar 23, 2023 1:59 pm

Tripple gear bushings are prone to locking up, so extra clearance is a good idea during a rebuild.
Even with extra clearance, they cant be run dry.
That goo will not lube those bushings or the drum bushings either for that matter.
Lurching problem solved.
I hope you will be able to disassemble the transmission without destroying it.
There is bound to be some galling @ the least.

Doesn't that goo look like anti-seize, they way it sticks to fingers etc
PERMA SEIZ.png

It does, but, Why would there be 2 tubes worth in a motor??

The grey color is commonly indicative of iron shavings from the cylinders. Chrome molly rings? or just the lack of lubrication.
Some is expected to be caught on the transmission screen magnet in a new motor, but decreases to negligible over time.