Lost all gears...whats the most likely suspect

Okay here is the gist:

I have a trans built by Brian Hofer about 2.5 years ago. It has about 1500 miles on it. It sat for almost a year waiting on an engine rebuild. After the rebuild I realized I didn't have 4th gear. A friend familiar with both Turbo Buicks and the 200-4r took it apart and found that a retaining clip was missing allowing the clutches enough movement to burn up. Fixed that then promptly got in an accident a month later. Car sat for another 5 months waiting on a worthless "body man" (read hack) to fix it (my own fault for trying to save a buck).

Here are the details on the trans: built by Hofer (or whoever built them for him) with billet super-servo, external cooler and filter, deep aluminum pan, 3200 PTC 10" L/U converter.

Here is what happened: I took it out for an easy cruise just to get the old fuel out of the tank and fill up a fresh tank of 93. I noticed as soon as I left the neighborhood it seemed like the down-shifts were very harsh and jarring. Kinda thought it had just been a long time since I drove the car and forgot how it shifted. It did seem to get a bit worse, not terrible, but pretty harsh downshifts for sure. I was almost home and found a bit of open road and toe'd in to about half throttle just to see how it was running with fresh fuel. I ran it up to about 70 and let off the throttle...then a loud sound, not a boom but definitely not a normal sound and then no power.

The engine continued to run but would just free rev when you applied throttle. I coasted to a stop and visually checked the underside...everything seems normal in drive shaft etc but I have no gears, not 1st, not 2nd not D, not O/D, not reverse. Feels like the trans is shifting into gear but it just revs like its in neutral. Fluid level is good and smells fine.

So I'm thinking it could be: broken converter, wiped stator shaft splines, broken band, or something internal. Based on the hard down-shifts is there a "most likely" culprit? Between converter, trans, and fixing trans I already have a $hit-ton of money in the trans and just want this ordeal to be over.

Most likely issue is the typical busted shaft on the input drum.

Very typical failure if you didn't have it replaced with a billet part when the initial work was done.

Don't you still have reverse if you break the forward drum?

Sounds like you might have broken the rotor in the pump. Just a possibility. Try taking a pressure reading on the transmission.

No, you have 6 neutrals and park.

6 neutrals and park? Kool!

That's funny!

Forward drum seal?

The piston seal in the forward drum can blow out if there is too much clutch pack clearance under hard acceleration, it will make an unsettling sound and act as if you pushed in the clutch on a standard trans. Both forward drum problems though. Let us know what the problem turns out to be. Good luck, John.

Wasn't really hard acceleration...just 1/4 throttle to about 70mph from about 45...it really is going to be a while before I even get the chance to address the problem. Work is going to balls to the wall until late Aug. I'm just trying to get an idea of what I'm looking for before I go looking.

That and its looking expensive...

It doesn't take much! I broke 3 of them in two years way back when. Then got smart and got a billet shaft installed. Can't break it now.

But mine always broke on fairlly light accerlation from a stop sign. Of course this followed some racing the previous week.

I broke 3 in one car, 2 in another and 1 in my sons car before someone came out with a billet shaft forward drum. Same scenario, day or two after some abuse, pulling away from a stop light under slow acceleration, boom! when it shifted into 2nd.

I can do ya one better! I busted two of those three at one time. The female part of the planet busted open and broke the shaft off the input drum at the same time!!

That's what convinced me it was time for some billet parts.

Well, after almost 10 months I've got off my ass and we have an answer:



So, ignoring the the obvious answer that there is dog hair all over the trans...hey you go tell a German Sheppard not to shed in and tell me how it works out for you...what do we see wrong with this image?


Scroll down for answer if you don't know!























Honestly it was broken so clean I didn't even notice it at first. I guess maybe I haven't broke a lot of transmission input shafts but I would have expected to see more gnarliness on the broken edge. The break is so clean it looks like it could have been machined like that on purpose. It's so clean I'm wondering if it was a metallurgical problem.

Hey, at least the dog does guard the car pretty well....




You can tell how old this picture is by how clean and lacking various Buick parts jammed into every possible open location...must be a few days after I bought the car honestly cause the garage is a hell of a lot fuller now!

Very clean break! that's one input shaft down.

I have a nearly identical story to you. Brian H. Trans that was shifting firmer than I remember. I have been taking it real easy on it all day and as I turned on to my block I laid the wood to it in first gear and heard a light pop and then I had no directional power. I hear a very light tapping noise when the car is idling and I am almost positive I have a broken input shaft, I have been down this road with my old truck before... Looks like it is going away for the season.

,Dan

An input speed sensor on this trans would save all this trouble! Anyone have an idea?

I wish they had input speed sensors... then you wouldn't need to calculate TQ converter slip, or guess if the clutches are slipping. I guess it's time to figure out a 4L80E swap...

,Dan