Blew up my transmission - not sure what let go on it yet - was a B&M upgraded unit from Ligenfelter circa early 90's - apparently one of their "stage" packages that was done to a 92 Camaro and it didn't have a ton of miles (~50k and was "gone through" after it was pulled). Worked GREAT till it just lost every gear suddenly one day about 3 weeks ago on a run to the post office. It had a B&M 3000 stall non-locking converter in it. I put quite a bit of power through it though - around 325 RWHP and I have a Procharger kit sitting here so it clearly wasn't going to survive that. I'm going to do a tear down and find out what failed. Might put it in my Jimmy.

I have a huge Dewitt aluminum radiator with the 87+ dual fan setup. And I could keep the temps down to 220 or so even in 100 degree weather on the highway - but it just wasn't enough to run AC. The temp would climb and pretty soon it would be 230 or 240 and I would have to shut it down.

I suspect that running down the highway without the converter locked and since the Firebird front end has pretty terrible airflow (yes I have all of the air dam in place)..... that was contributing to the engine temps. I have two trans coolers so the trans would rarely get above 180-190. I think I might have saw close to 200 once after a lot of driving on a hot day.

Anyway - blew that trans and just received and installed a Performabuilt level 3 rated for 900 HP, So far I like it and I'm working on tuning with the lockup converter but I suspect it will result in lower cooling system temps as the lockup results in significant reduction in RPM at highway cruise speeds.

I suspect that non-locking converters are contra-indicated on the 3rd gen chassis Firebird body if AC is desired, etc. Mostly due to the lackluster airflow.

Experiences?

GD

 

Not sure but I was driving once on my 87' IROC (stock) and OD went out, then 3rd, then 2nd, then 1st until I had to pull over and call a tow truck. I was on a long trip home and figured the closer I got to the house the less the tow truck was going to cost. Had the transmission rebuilt and it was fine.

 

Mine lost all gears including reverse instantly and without warning. Was working perfectly right up to the point of failure. No noises or fluid leaks. Pulled the pan during the trans swap - only some very light metal flake. I'll tear it down at some point and see what let go.

GD

 

Sounds like a valve body issue, I can ask my brother in law who owns a transmission shop, but generally losing all gears is valve body from my past experience.

 

Forward clutch or sprag

If there's not abuncha clutch mud everywhere, probably the sprag

 

Im not sure how much heat is added to the cooling system thru the factory trans cooler in the rad.

Also not sure how much heat load is added thru non lock up additional rpm load on the engine
In a sense, you may have more power with higher rpm and less overall load on motor at cruise. Locking in od could increase load on engine and produce more heat. But usually more rpm even if slightly less Kpa on the map sensor is still using more fuel than lower rpm higher kpa, but i guess it could depend on how much variance there is. More fuel is more fire so probably more strain on the cooling system

i know since my th400 swap in my turbo cars, it still runs good with factory style ls1 fans. I had two different rad setups, and i was able to keep it cool enough with both setups on the highway with higher rpm. It def got hotter the longer i ran it on the highway for sustained high rpm vs a cruise at lower speeds on backroads for similar amounts of time

so probably something to the idea keep rpms low as possible to keep heat load down. These cars including birds have been bottom feeders so nose area shouldnt matter. The air is suppose to stack up in front of the air dam and go into the rad.

 

A little bit of metal flake. No clutch material. Fluid looked bright red.

That a common failure? Perhaps I could just go in there and clean everything out, replace the sprag and add the input drum reinforcing ring.

GD

 

Sounds like the pump may have failed. It is easy to damage them during an engine swap.

 

I've done that. When I lost/damaged the C4 in my Mustang during installation (didn't seat the tq converter correctly when bolting it up to the motor), within 5 miles during the test drive the tranny locked up immediately, bogged the engine to the point it stalled, and I had to pull over to the side of the road and get towed home. I had no gears and the car would turn over but not start. I also heard a big whoosh noise when it happened. If it lost the pump I don't think it would lose each gear one at a time, normally it's trash in the valve body that works its way through everything.

 

A friend has a loooose non lockup NOS converter in his car. It really heats up like that due to the serious miss match of cam and converter

 

I know how to install a converter without breaking a trans pump.

Apparently I have a real problem with wrecking things in mysterious ways though.




GD

 

Nice one! Did the same thing to a 4L65E once.

 

Nice work!