Engine/transmission failures and fixes
 

Over the years we have all experienced a variety of issues we worked through. Figured I would make a blanket thread to share these issues and what corrected them.

Low oil around turns, or generally suprised by low oil: add the idiot pressure switch and run the wite to a decent lamp like a reverse bulb at the dash.

I cracked a iron sealing ring on T 400 pump. The trans seemed to work well, until I did my first burnout with it. Melted down everything in 1st drum. On tear down I found a 1/4" piece of a ring was gone and went though the pump.
Solution, changed the pump after cleaning trans and replacing everything in 1st gear.
Then I went to Teflon seals used in 480LE transmissions. They are thinner but work great. Pack then in with Vaseline and install.

Back in the day 1980s i built a rubber rod 455 and intentionally drove it to about 7000 rpm in 1st gear as an experiment, just to see and hear how it would play. Then a month or so later i tore it down and found a rod or 2 bent (Z'd i would say) but did not break, and that was the experiment. Oh heck i pitched the rubber rods and put SD-455 Rods in.

Later on, after 9 1/4 mile runs with late-shift over-revs for High-12s at best, i would spin a SD Rod bearing on the way home from Island Dragway, and chunk that engine. Think I rebuilt it and sold it!

From that i learned that high-RPM is only warranted if the Heads continue to flow. We all got to know our "choked-flow limitation" in the inhale path. Usually is the Pushrod bulge, then the bowl, then well the whole path CSA being some reasonable value. The next project ran 12.0s at 4950 rpm at the big end. 3.31:1 gear with 28" tires, yet needed 94+ -to- 110 LL fuels.

Now the 68 GTO does those 12.0s with 89 Octane, SD-455 rods, and OVERdRIVE. The HP is in the Heads.

Since getting my first car in 1954... "Engine & transmission failures" would fill a book!
But no point in it, since I'm still experiencing such failures.

Using a transgo shift kit with stock valve body gasket ,direct clutch took a very long time to apply

I have very little experience with the Pontiac engine design pre 1966. It was very easy and inexpensive to make around 500 hp with off the shelf parts and iron heads. Seems to me like every 50 to 100 hp increase is a new batch of issues. It looks to me like there some younger people on here that might benefit from the elders failure's.

I removed the failed Roller Bearing in the crankshaft and rebuilt the Muncie 4 speed trans
(Input Shaft Bearing failure) from Powershifting.

I replaced the Pilot Bearing in the crank with a Bronze Bushing (like the Chebby boys run) (after turning down the bushing to the Pontiac Roller Bearing Diameter).

Never had another failure after that.

Tom V.

When I first put the GTO together (15 years ago) I had thrust bearing issues. I would wipe out the thrust bearing is a few runs. Built the engine 3 times, I ended up limiting the converter feed in the th400 and grooving the parting line on the thrust bearing, never had a problem since. To this day every oil change I cut open the filter and check the thrust with a dial indicator.
The trans was set up with a trans brake and a ATI MRT 8" converter.

Have more but that was the biggest problem and fix.

I did something like that when I put a Ford Top Loader 4 speed in my GTO as a kid. Bought a bronze bushing and had a machine shop turn it down to fit the Ford input shaft.
It worked well.

I will say cheap roller springs last about half as long and decent ones that cost about 50 percent more. Cheap is not always the best Investment. Low spring pressure beating your lifters up and potentially damaging your cam and block isn't good. One of the more informative posts I have read in recent years was from the boss bird group enlarging the oil supply circuit throughout the block to fix their bearing issues.

The Boss Bird fellas just freely putting their information out there, trial and tribulations is what this place should be all about. Pontiac Jack helping them out with smoothing things out inside the oil passages was interesting for sure.