friesjh

There's a couple things going on with the trans in my 71 442. I replaced the kick down switch at the accelerator pedal last year. After that the trans would shift at around 5500 rpm during WOT acceleration. Yes the switch is working properly and is sending 12v to the trans when appropriate. Before replacing the switch it was shifting at about 6000 rpm.

I just received my carburetor back from Cliff at Cliff's High Performance in Mt. Vernon, Ohio. They tuned the carburetor for me (and what a great job they did, I am extremely impressed with the car now!). After changing vacuum hoses and getting everything adjusted, now the the transmission shifts 7000+ rpm during WOT acceleration. Not sure when it shifts as I didn't want to damage the engine so I let up on the accelerator pedal. Following are the questions I have.

Is there any adjustment at the switch mounting at the accelerator pedal as to when the trans shifts? If so, which way and how much to adjust the switch?

Why would tuning the carburetor effect when the trans shifts during WOT acceleration, since the downshift solenoid would be engaged at this time and the only change to the engine was tuning the carb?

I have heard that the appropriate time to shift up a gear would be 10% more rpms than where peak power is produced by the cam. How do I adjust shifting to accommodate this?

Thanks to all,

John

svnt442

Make sure the vacuum line to the modulator is connected correctly.

oldcutlass

Are all gears shifting at high rpm or just the passing gear?

friesjh

@svnt442 - Yes the modulator vacuum line is connected properly. I double checked all vacuum hoses last night.

@oldcutlass - not sure what you mean by "just the passing gear". The information I provided was from a dead stop WOT. So the passing gear (i.e. down shift) was not going to happen.

oldcutlass

Sounds like a governor problem as that is what controls wot shift points. Does the trans shift properly under light load?

friesjh

Yes the trans shifts fine under normal driving.

I always thought that TH400 trans would shift around 5000 rpm with no modifications. The trans was rebuilt with a shift kit many years ago, but not sure how that would affect this.

oldcutlass

To the best of my knowledge the wot shift points are controlled by the weights on the governor. More weight to lower, less weight to raise. The springs control the shift points under light load in conjunction with the modulator.

friesjh

Yeah, something just doesn't seem right since its not shifting to 2nd until very high rpm. Anyone have a spare governor?

droldsmorland

Is the modulator hooked to direct intake vacuum? It should be.
If the modulator line is steel with rubber connectors (hoses) on both ends verify the metal line isn't obstructed. Had that happen before.

Is the modulator the small "Standard Ignition" TM50 or the large nonadjustable stocker?

If its adjustable play around with it. Counterclockwise will reduce the upshift RPMs.

Pull the governor and inspect the feed holes and shaft for burrs and integrity(weights n springs).

The attached pic shows what I did to get fine-tuned adjustability out of my kick down.
The detent switch may be sticking or defective?

Its gets deeper from here starting with pressure checks.

The fact that the carb rebuild changed something means the vacuum signal is seeing something different or something that was on the bitter edge of failing or on its adjustment limit is now showing up.

How much did they charge you for the carb work? I'm getting lazy and thinking of sending mine out. Its been almost 20 years and it's surely time.

matt69olds

The modulator adjust shift points based on engine vacuum, the modulator can be unhooked and it will still shift at the same WOT speed as before. The detent solenoid shouldn’t have any effect, above 60-70mph it should upshift into 3rd. My guess is something is screwed up in the governor. There are 4 bolts that hold the cover in place, once the cover is off the governor slides out. Make sure the plastic gear isn’t “Apple cored”, the springs and weights move free, and the bore isn’t chewed up.

RetroRanger

I am impressed w shifting a a BBO at 7k and living to tell about

OLDSter Ralph

Must be a good solid lifter cam and springs because the hydraulic lifters would have pumped up before 7,000.

OLDSter Ralph

[QUOTE=friesjh;1076428 I have heard that the appropriate time to shift up a gear would be 10% more rpms than where peak power is produced by the cam. How do I adjust shifting to accommodate this?[/QUOTE]
There is also the "theory" that you shift at the peak horsepower, as long as your RPM's don't drop below peak torque. Its all theory and depends on the transmission ratio's, differential ratio and tire size. Experimentation with shift points is what provides the answer to the quickest acceleration.

matt69olds

B&M, TCI, etc offer governor calibration kits, it includes weights, sprints, and the axles/e-clips to make changes. I would get a couple spare governors and cover gaskets, and take detailed notes.

oldcutlass

Get a bunch of cover gaskets as its trial and error. You will have the cover off and on multiple times.

friesjh

Awesome! Thanks to all for the responses. To answer some of the questions posed.

@droldsmorland - Yes vacuum to modulator is direct to the manifold, per the service manual vacuum hose routing diagram. It is the smaller adjustable modulator. I am planning to play around with this, but I was under the impression that at WOT the modulator does not effect shifting?? I have not checked to see if the metal vacuum line for the modulator is obstructed, but I will when I get under there. I'll blow some carb cleaner through it just to make sure. The detent/kick down switch at the accelerator pedal is new mid 2017. Is there any adjustment here without mods? If so, where should this be set?

@matt69olds - I am inclined to agree that something is up with the governor. What do you mean by "the bore" when you said to see if the bore isn't chewed up. I took it as the hole the governor goes into. I will definitely check this when I get the governor out.

@RetroRanger - Me too! The best thing I ever did for that motor was have it balanced. I do not like to get above 6000 rpms, but it is comforting to know that it will hold together. Plus the guy that built the motor is an Olds guy and he really liked the black 442. So hopefully he went the extra mile, so to speak, when building it.

At this point I agree that it is most likely a problem with the governor. I have found and purchased a NOS governor part #8627442 and will be installing it as soon as it arrives. If that doesn't satisfy my expectations for the car I will purchase one of the governor calibration kits. Knowing myself, I will most likely get a kit just to play around with the governor. Who makes the best kit or are they all pretty much the same?

Thanks again for all the help! I'll let everyone know when I get the governor installed and have test driven the car.

John

matt69olds

The bore I’m referring to is the hole in the case the governor rides in. The theory for the plastic gear is hopefully if the governor for whatever reason binds or doesn’t want to turn, the gear will strip off the teeth and save the case. Sometimes things don’t work as planned in real life! If the case is chewed up, you can buy repair sleeves, unfortunately the trans has to come out and be completely disassembled for installation.

The calibration kits are the same, the weights adjust the WOT shift points, the springs will fine tune how far apart the shifts are at part throttle. If your NOS governor doesn’t fix the issue I would suggest replacing the detent solenoid in the pan, it’s possible it could be internally leaking. If that doesn’t help, it’s probably time to remove the valve body for a careful cleaning. Make sure you have a detailed diagram, get a bunch of sandwich backs that can be sealed, put the valves from each bore in a seperate bag, and work carefully. If that is too much tedious work, I am pretty sure CK perfomance in New York offers ready to install pre-tested valve bodies. Valve bodies are precision parts, the valves are very sensitive to dirt, burrs, anything that can cause a valve to stick. Good luck!

friesjh

Great thanks matt69olds! Let's hope the NOS governor does the trick, with maybe just a calibration kit.

I'll let everyone know how it turns out.

Thanks again,
John

friesjh

Ok, so the governor arrived yesterday and I installed it last night. Drove the car to work today and there is a difference. Now the car will shift from 1st to 2nd and from 2nd to 3rd at almost 6500 rpm. Better, but still high. Just for sh**s and giggles I removed the plug from the detent/kick down switch at the accelerator pedal. With that plug disconnected the car will shift, both shifts, at just under 6000 rpm, maybe 5800. I would really like to get it to shift between 5000 and 5500 rpms, so I'm guessing the next step is to purchase a calibration kit.

Does all this sound normal for a stock 71 442? Since the governor I bought is correct for the car it should be close to stock performance. Should disconnecting the detent switch make this much of a difference? Should I leave it unplugged?

Thanks for all the input!

John

matt69olds

How much gear is in this car? The detent regulator is suppose to move the detent valve in the valve body around 70ish mph. What does the fluid look like? At this point I think I would remove the valve body for inspection and through cleaning. If the original governor worked at one time, and doesn’t seem to stick, and the bore it rides in doesn’t appear worn, and a different govemor helped but didn’t solve the issue, I think you need to keep digging. Has the trans been worked on lately? What’s the history? Do you have access to a line pressure gauge? Any oil pressure gauge that will read up to 300psi would work perfectly as long as it has a 1/8 pipe thread fitting

friesjh

The car has a 4.66 gear in it, but I just bought a 3.23. It should have shipped yesterday or maybe it will ship today. It may take me a couple weeks to get the new gear installed. Not sure if I want to tackle that job myself or not. I didn't think the rear end gear had very much to do with when the transmission shifts, please correct me if I'm wrong.

The fluid looks good, bright red, and clean. I have replaced the governor many years ago. At that time at WOT froma dead stop the car would act like it would go into nuetral when shifting from 1st to 2nd. I bought a generic governor from the local parts house and swapping it took care of that issue. The governor I pulled out Monday night seemed to be in good working condition and the bore looked ok. Some wear marks from spinning in the bore, but it didn't look all chewed up. Other than the governor swap this week, as far as I know, the transmission has not been worked on since the mid to late 1980s.

The history of the car is it was a drag car. I am the 2nd and 4th owner. Not really sure what the 3rd owner did to the transmission, if anything. He died so no way of finding out. The car seemed to shift and operate the same as when I owned it previously, so I would guess the 3rd owner did nothing to the transmission.

I'm sure I can come up with the appropriate gauge and piping to check transmission pressures, but I'll be honest, this is new territory for me. That being said I am not afraid of learning to work on my own transmission.

Again, thanks for everyone's help with this!

John

Fun71

Did you get a new carrier as well? The 4.66 gears use a different series carrier than the 3.23 gears.

friesjh

I have been talking to Brian Trick about this rear end and bought the 3.23 gear and kit from him. He is telling me the posi unit I have will work with the gear he sold me. From what I could tell from searching around he is the guy to talk to about differentials.

Fun71

Yep, Brian Trick is one of the go-to guys for differentials. I dunno the details of what you have and what he gave you but if he says it's OK, I would believe him.

matt69olds

With a 4.66 gear it’s going to shift thru the gears pretty quickly! I’m sure you could find some detailed info on how to do a line pressure check, basically put the gauge on, warm up the trans, get a reading in each gear, unplug the vacuum modulator and check it again in each gear, there is a procedure on how to make sure the detent solenoid works hydraulically. However, I wouldn’t be surprised if the 3.23 gears changes the rpm it shifts. You might want to get the rear end gears installed before worrying about the trans now.

friesjh

I was thinking the same thing, get the gear done, see if the shift points change, and go from there. The 4.66 is a lot of fun, but highwy driveability is out the window. I write back after I get the gear in.

Thanks,

John