63 Catalina trans

[63catalina]

I have the original 375 roto-hydramatic (slim-jim). It is hesitant to downshift as I come to a stop. Sometimes killing engine. Does anyone know if this is an incurable flaw with this model? I am considering a swap, but would prefer to keep original, if flaws can be fixed. I am looking for reference material or advice. This car is cool, but it's too old for most sources.

[Larry]

I removed the duplicate post that you had and it zapped the photo in this post?????

It is a great looking car, so sure didn't want that to happen. The two must have been linked in some way.... who knows. Please try reposting the photo to your question. Just click onthe "edit" button to the upper right of your message.

Now, about the question. Check in our Technical Advisor section and give Steve Peluso, our automatic transmission Tech Advisor, a call at his shop tomorrow. There isn't anything about Pontiac transmissions he doesn't know!

[Stu Norman]

From what you're saying, my guess would be you need to adjust your TV linkage. Here are the steps for adjusting the TV linkage, from my Chilton manual.

1. Remove carburetor air cleaner.

2. Loosen lock nuts on top of throttle control rod trunion.

3. With engine at normal operating temperture and selector in "drive" adjust idle to 450-500 RPM (540-560 RPM with air conditioning).

4. Stop the engine and install proper diameter pin through holes in throttle control level and bracket.
NOTE: Four-barrel units have a throttle return check. Before installing the pin in these models, it is advisable to remove the throttle return check to prevent interference with linkage adjustment,

5. With throttle valve fully closed, loosen lock nut and adjust length of transmission throttle control rod to carburetor so that the gauge pin is free in the hole. Then tighten the lock nut.

6. Push throttle control rod to transmission (T.V. rod) downward until the outer throttle lever is felt to touch the end of it's travel.
CAUTION: Make sure that, when the lever is in this position, the upper lock nut is not interfering with the trunnion.

7. While holding the throttle rod to transmission in this position, tighten upper and lower trunnion lock nuts finger tight. SHorten throttle control rod to transmission by 2 1/2 turns and tighten upper nut securely. Remove gauge pin.

8. Loosen lock nut on carburetor throttle rod. Adjust carburetor throttle rod to obtain 5-9/64" (5.140") from roller end of pedal rod to body toe biard.

9. Tighten lock nut on carburetor throttle rod.

10. Reinstall air cleaner.

11. To complete throttle linkage adjustment, road test the car. Modify the adjustment as required by shortening or lengthening the throttle control rod to transmission, (T.V. rod) 1/2 turn at a time to obtain the best shift pattern.

A picture would be nice, but they don't have one. You might just try step 11, adjusting it 1/2 turn either way and road testing the car to see if you can eliminate the symptoms.[/i]

[Dualquadpete]

Scott, I went thru the same problem w/my 64 Cat 2+2 & finally swapped the trans to a turbo 350. I had to "massage" the floor tunnel w/ a BIG hammer, but not much, move the cross member ahead [ used short 350] & used a 64 Bonnivile d/shaft. A little modification on shifter linkage [floorshift] change the frt yoke. A long turbo 400 or O/D trans would likely be easyer w/drive shaft. The only problem you are going to hit is the starter mtr. my 64 block was drilled for later apllication of starter to block. where earlier ones were not, but believe there is an adapter made for this??? I used a late 70 to early 80's Olds trans, & a lemans 326 flexplate/flywheel, olds starter. It made such a difference in the car, performs much better, & if you do have trans. problems later, parts & labour are available!!! Dualquad pete Ontario Canada

[63catalina]

I adjusted the linkage this weekend and replaced motor mounts. It really improved the upshift perfomance and kickdown. However, I still have some difficulty with downshifting as I come to a stop. I have not set dwell or timing with instruments, so there may be room for improvement there. I had the most trouble with it when I first got it running. It was tuned for regular gas. I put in 93 octane and bumped up the timing; what a difference. I checked the head numbers listed here and found I have 10.25:1 compression. So much for cheap gas! I am still hoping for a tinkerer's solution. A friend of mine a few years back, built automatics. One thing I remember him doing was removing springs from servos and removing balls from valve bodies. I will probably investigate something like that before I give up. Thanks for your help.

[63catalina]

I adjusted the linkage this weekend and replaced motor mounts. It really improved the upshift perfomance and kickdown. However, I still have some difficulty with downshifting as I come to a stop. I have not set dwell or timing with instruments, so there may be room for improvement there. I had the most trouble with it when I first got it running. It was tuned for regular gas. I put in 93 octane and bumped up the timing; what a difference. I checked the head numbers listed here and found I have 10.25:1 compression. So much for cheap gas! I am still hoping for a tinkerer's solution. A friend of mine a few years back, built automatics. One thing I remember him doing was removing springs from servos and removing balls from valve bodies. I will probably investigate something like that before I give up. Thanks for your help.

[Larry]

Have you caled Steve Peluso yet?

He's "The Man" when it comes to transmissions. And one of the last "Good Guys" around when it comes to helping people too.

[63catalina]

I did not find his number. I am new to this site.

[Larry]

You can reach Steve at his shop: 617-327-2122

[63catalina]

It's been a while since the last post. I have since installed a turbo 400 trans. I used the adapter plate from Butler Performance to mount the starter with no problems, except needing an extra 1/4" of shims to align the starter. Then added headers and dual exhaust with a Lokar cable shifter on the column. I also had to get the Lokar flexible dipstick as there was not enough room for anything close to original. Now I am building a 450" stroker 389 with Edelbrock round port heads. Using flat top pistons and 75cc chambers, it's about 10.8:1 CR. Hughes 2500 stall converter and 3.64 gears. Motor should make about 514 HP and 575 lb/ft torque with the Comp XE268 cam, never going past 5000 rpm.

[Larry]

WOW!
Somebody has been busy!

That should be plenty of engine to move that big Pontiac at a good clip. That converter and those gears will make so smoke (just for show, of course) too.

Any chance of a bunch of photos and a story about you and your '63 for one of our monthly "Cover" Car Features? We have never had a '63 "Cover Car" before and it's one of the favorites for many Pontiac lovers.

[Guest]

The funniest part is how I got to the decision to build another engine. I built the 389 into a 400 in 2009. It had forged pistons on stock rods with ARP bolts, balanced and I added the 4X heads to get lower compression and bigger valves. What I failed to recognize was the 1963 block had two oil galleys that fed oil to the original heads and the 1974 model 4X did not close the gallies when installed. It ran OK for 4 years, since I did not get gears and rag race until recently. The bottom end and the oiling system were sufficient to withstand normal driving, even with the two 5/16" port puking oil constantly. It did however create some "windage" issues. Initially, it would puke oil out the dipstick on wide open throttle. You can only go for short bursts when it fogs oil smoke, so no engine damage was done. I eventually decided to re-ring the motor, believing I had made a serious mistake gapping rings. Upon disassembly, I drilled a vent in the upper section of the dipstick tube to balance the pressure. I installed new rings and putit back together. The cylinders were a little scuffed from the crap carburetor I had for a while. I started with the two barrel setup on a newer intake. This was a poorboy start, but it was all that I could afford immediately. I just wanted it back on the road. I eventually picked up a four barrel intake and carb from Craigslist. Typical of used equipment, the carburetor left me stranded one day when the float sunk. Single exhaust was the big choker now. It's time for duals. I need headers! Nobody made headers for the Catalina. So I bought a set of Summit headers for a 64 GTO. They almost fit. I had to modify the tube for number 7 to clear the steering column shifter bracket. After my first attempt at making mitered cuts and rerouting the tube, I finally got it stitched back together. I soldered up the smallest holes that my welder was too hot for and wrapped it in insulation. On installation, the starter will not fit. I had to buy an aftermarket, small starter. I was surprised to find one available for the 1963 mounting system. Next was mufflers. I bought the cheap Summit turbo mufflers and had them installed. A month later the carb flooded and popped a muffler. More new mufflers installed, but I don't really like the sound. It sounds a little like an old pickup from Bubba country. Sad thing is the new mufflers are welded and durable. I am stuck with them until I just blow some more cash. The rear axle was the last obstacle to drag racing and seeing some hard proof of my car's ability. I ordered a gearset and a spool. There are no other posi units available, that are new. Used posi units for the 9.3" axle are too expensive. I also wanted to build the axle myself. Fabcraft offers everything you need to do it yourself. Their book was a great asset for a successful build. Alright, got gears, got duals, got 4 barrel, let's go race! Fifteen seconds flat at 93 mph. I was disappointed. I thought it might be faster. I raced it about ten or twelve passes. It was fairly consistent. My worst ET was 15.22 @ 92 mph. But iwas not totally satisfied. I eventually found a set of Edelbrock heads on Craigslist. They were about half price of new. I had to get them. They would step me up to the next level! I needed to take my time, though. I had just completed the rear axle and it was not cheap. Parts alone were about $1600. So, no problem, it's a cruiser anyway. Just save money and build it when the time is right. The heads needed new valves and I wanted to do some porting. There were plenty of things to keep me busy. The car began running hot on the freeway after the gear change. It was turning about 3800 rpm at 80 mph. That is more than most cars, but not so exotic as to make me believe the car should not be able to cool adequately. So, I started chasing that problem. Purchasing all the gizmos that should make the problem go away. None of it worked. At 80 mph, it was getting hot, period. It cooled off when you slow down. I thought the pump may be cavitating at high rpm. It all became clear when the engine failed. I left a local carshow and got on the freeway. I stomped the accelerator and it began popping through the carb. I know that is the death pop. I try to limp home one more time. It dies at an intersection, at 250+ degrees. The next day I find a flat cam. Number 3 exhaust lobe is gone. Now I see why it was getting hot. But why did the cam go flat? I pull the motor and inspect, finding five spun rod bearings, also. Then it occurs to me that the gallies were not sealed. I had recently added a zinc additive to see if it would decrease the running temp. It, along with ground up camshaft, left some debris in the oil and made a noticeable patter where oil flowed. This highlighted the open gallies for me. Now I have found the root cause of all weird Pontiac tricks from the last four years. With the American economy in shambles, I had concern about the funds in my 401k. Would they still be there when I retire? Would our elected officials bring about our imminent demise? Maybe there was something I could do? I will take the biggest loan possible on my 401k account. This will remove as much money as possible, without dropping out and facing taxes. I can pay myself back with interest and make more money than the crappy stock markets. Now I have funding. The wife decided not to divorce me as long as this motor was right, this time. It will be off my list after this next build. VICTORY! I will post some pics when I get the motor out of the machine shop.

[Larry]

Sounds like a lot of learning curve along the journey so far. But, it sounds like you've discovered most the problems that should help with the new project.

I agree with the money saved vs. value later. I am re-restoring and resto-rodding my '40 Pontiac and figure if I have to cash out an IRA or two, it will be worth it. If I don't do it now, I may never get to it, and then the only work done will be by the lawyers handling my will.

Still would like to see a story on your car. You sure have a lot to tell.

[63catalina]

I got the 450 complete and installed. It is a beast. Now the transmission has given up. I ordered an upgraded stage 3 replacement from www.transmissioncenter.net rated for 1200 hp. I was looking at parts for a rebuild and decided it was more cost effective to buy the complete unit, assembled.
The motor runs cool, even on the highway. I have an aluminum radiator and two electric fans pushing air through it with the factory mechanical fan behind it and a secondary trans cooler in front of the fans. Too much torque. Not enough traction.

[Larry]

It isn't surprising the 400 pooped out. Strong as they are, that much power is beyond their curve. Guessing too that now traction will be the next issue.

That much power is often a game of "what will break next" until every weak link is found. There's a lot of bulletproof GM rear ends to choose from.