Transmission problem 1958 Cadillac Series 62 2 door hard top

[myfiat]

Hi

After 20 months of working on my 58 Cadillac I finally drove it, but it never got out of first gear, does any of the experts out there know what is wrong and what can I do to rectify the problem.

I have checked the transmission level while the car was idling and the level is ok.
I have disconnected the kick down rod from the transmission.
I am not aware of the condition of the transmission before I bought it.
The engine was rebuilt and it runs great.

Scott

[Walter Youshock]

Front sprag.  Same thing happened on my '57.  These tannies were prone to problems bit the '58 was far better than the '56 and '57.

Unfortunately, I'd say you are in need of a rebuild.

[wbdeford]

Bad front sprag would not cause this symptom.  It would keep the car in Neutral.

If you have 1st and Reverse, but no other forward speeds, it is most likely a problem with the governor.

[Glen]

I have disconnected the kick down rod from the transmission.

Isn’t that the rod that tells the tranny the throttle position?  It is not the “kick down rod”.  If it is just dangling it could be in a position that tells the tranny the throttle is wide open.  That rod needs to be connected and the adjustment is very critical to the shifting of the tranny.       

I agree with William on the governor, that is what tells the tranny how fast the car is going.  Without that input the tranny thinks the car is sitting still.   

[Dan LeBlanc]

To add to what Glen and Bill have said, driving with the TV rod disconnected will disintegrate the transmission in fairly short order.

Adjusting these following the shop manual is the key to getting the transmission to shift just right.

[wbdeford]

Its official name is Throttle Valve (TV) rod.  These transmissions only have 4 inputs:

1) Engine speed
2) Car speed
3) Shifter position
4) Throttle position

The Throttle Valve has a spring that tries to push the rod back to the closed position, so if the rod is dangling, that probably isn't the problem.  I suppose the throttle valve could be stuck.  Other stuck valves in the valve body is also a possibility, or a blockage in the oil passage to the governor.

The first thing I would do is drain the transmission and remove the pan (not hard at all on these, because they have drain plug, unlike TH400s....).  Unless it is pretty clean in there, I would rebuild the valve bodies, which isn't hard either as long as you keep careful track of parts.  It is also a good idea to drain the torus.

Next, it's an option of whether to try to fill the transmission and see if the problem is solved (risking wasting a few gallons of transmission fluid).  Or, you can rebuild or replace the governor.  The governor is accessed by removing the extension housing, which requires, among other things, the removal of the propeller (a.k.a. drive) shaft.  The governor then pulls straight out of the rear pump.  It is also easy to rebuild.  It may have broken rings, which could be the source of your problem.  (Governor replacement was made much easier on the TH400--just unbolt and pull straight out)

The governor is turned by the rear pump, which turns at the speed of the output shaft.  The faster it turns, the more oil pressure it sends back to the valve bodies, letting the transmission "know" how fast the car is going.  When it can't do that because something is blocked or broken, as Glen said, the transmission "thinks" the car speed is 0 keeping you in 1st Speed.

[fishnjim]

The "kick down rod" (the one that attaches to the carb) being disconnected won't affect anything except not allow it to gear down on full throttle acceleration.   Sometimes when they change to newer carbs there's no linkage for it and is left unattached.   I had to add linkage to mine to hook it back up.   
Mine was shifting shiftily, and one of the clips wore out/broke and caused parts to move plus send pieces in places where they shouldn't be.   
So I'd get in there quickly, cause if you drive it like that much, and something's broke, you're just paying the parts guy more.   I think that why the trans guy told me to drive it like that at first.  But then he made me chase the parts.   I had to replace about half and it was $2.1K for parts alone.   He only charged $300 to rebuild.
ps: I'd also check the brakes thoroughly before i drove it much.   These are notorious for probs.

[Dan LeBlanc]

The "kick down rod" (the one that attaches to the carb) being disconnected won't affect anything except not allow it to gear down on full throttle acceleration.   Sometimes when they change to newer carbs there's no linkage for it and is left unattached.   I had to add linkage to mine to hook it back up.   
Mine was shifting shiftily, and one of the clips wore out/broke and caused parts to move plus send pieces in places where they shouldn't be.   
So I'd get in there quickly, cause if you drive it like that much, and something's broke, you're just paying the parts guy more.   I think that why the trans guy told me to drive it like that at first.  But then he made me chase the parts.   I had to replace about half and it was $2.1K for parts alone.   He only charged $300 to rebuild.
ps: I'd also check the brakes thoroughly before i drove it much.   These are notorious for probs.

Whoever gave you this advice gave you some REALLY bad advice.  It is not just a kick-down on these transmissions.  It is used to control shift firmness, line pressure, etc. 

[wbdeford]

Whoever gave you this advice gave you some REALLY bad advice.  It is not just a kick-down on these transmissions.  It is used to control shift firmness, line pressure, etc.

Dan, I agree that it is not just a kick down rod.  It's function is to delay up shifts based on how far open the throttle is, and also to help facilitate downshifts on hard acceleration.  Without it, the throttle valve will stay closed and the car will behave exactly as it would if you started from a stop on a steep downhill and just let it roll forward.  It would shift at the minimum speeds, which are (with 3.36:1 axle...other axles slightly different).

1->2: 6-9mph
2->3: 13-16mph
3->4: 17-21mph

With throttle still closed, if you apply the brakes to stop the car, again, the car will behave exactly the same as if the TV rod is disconnected, doing its downshifts at:

4->3 12-16mph
3->2 10-18mph
2->1 0-5mph

So, the only consequence I can see of having the rod disconnected is that your upshifts will occur too soon and during hard acceleration or going up a steep hill, the engine will be under extra strain from turning too slowly to efficiently move the car.  I don't see how the transmission itself will care.

What am I missing?

[Dan LeBlanc]

Imagine lumbering up a steep grade in 4th when the car should really be in 3rd and won't downshift based on throttle input.  Then think of the heat that creates.  All the lugging, less fluid going through the cooler.  Heat is the enemy of all things mechanical.

That's just one scenario.

[Jon S]

Dan, I agree that it is not just a kick down rod.  It's function is to delay up shifts based on how far open the throttle is, and also to help facilitate downshifts on hard acceleration.  Without it, the throttle valve will stay closed and the car will behave exactly as it would if you started from a stop on a steep downhill and just let it roll forward.  It would shift at the minimum speeds, which are (with 3.36:1 axle...other axles slightly different).

1->2: 6-9mph
2->3: 13-16mph
3->4: 17-21mph

With throttle still closed, if you apply the brakes to stop the car, again, the car will behave exactly the same as if the TV rod is disconnected, doing its downshifts at:

4->3 12-16mph
3->2 10-18mph
2->1 0-5mph

So, the only consequence I can see of having the rod disconnected is that your upshifts will occur too soon and during hard acceleration or going up a steep hill, the engine will be under extra strain from turning too slowly to efficiently move the car.  I don't see how the transmission itself will care.

What am I missing?

The TV rod adjustment also controls the smoothness or abruptness of the physical shift.  When properly adjusted, the transmission shifts as well (or better) than any computer-controlled transmission I have driven.  There are detailed Factory Recommended adjustment procedures and "fine tuning" the nut 1/4 to 3/4 turns open or closed can make a good shifting transmission into a fantastic shifting transmission.

[wbdeford]

The TV rod adjustment also controls the smoothness or abruptness of the physical shift.  When properly adjusted, the transmission shifts as well (or better) than any computer-controlled transmission I have driven.  There are detailed Factory Recommended adjustment procedures and "fine tuning" the nut 1/4 to 3/4 turns open or closed can make a good shifting transmission into a fantastic shifting transmission.

True.  By "consequence", I was thinking of things that might cause damage/extra wear.  Does a smooth shift mean less wear?

[wbdeford]

Imagine lumbering up a steep grade in 4th when the car should really be in 3rd and won't downshift based on throttle input.  Then think of the heat that creates.  All the lugging, less fluid going through the cooler.  Heat is the enemy of all things mechanical.

That's just one scenario.

I would think the lower input speed to the transmission would mean less heat there rather than more.  How does that create extra heat in the transmission? 

[Jon S]

I would think the lower input speed to the transmission would mean less heat there rather than more.  How does that create extra heat in the transmission?

Lumbering in a higher gear can build excessive heat just as high reving in a lower gear can create excessive heat.  Transmissions run coolest when they are not straining or being abused.

[Jon S]

True.  By "consequence", I was thinking of things that might cause damage/extra wear.  Does a smooth shift mean less wear?

A truly smooth shift creates built in slippage which contributes to wear.  A harsher shift has less slippage and assumeably less wear.

[wbdeford]

A truly smooth shift creates built in slippage which contributes to wear.  A harsher shift has less slippage and assumeably less wear.

Ah, so the rougher the shift you are willing to deal with regarding a particular friction clutch the longer it will last.  Never thought of that!  With a '58 in DR4, the only shift that applies a friction clutch is 2->3 (the rear clutch).  All other shifts are just directing fluid into or out of the fluid coupling (and releasing the friction clutch in the case of 3->2). 

So I can see the smoother application of that clutch (the rear clutch) as causing more wear than a harsh application.  But wouldn't doing that at a lower input speed also contribute to less wear, which would mean there is no actual harm to the transmission in not having the TV rod connected (unless it relates to heat, but I still can't see how the transmission would run hotter)?  The engine would have a harder time turning the transmission, but the transmission wouldn't have a harder time turning the propeller shaft....in my small brain anyway....

[Jon S]

Ah, so the rougher the shift you are willing to deal with regarding a particular friction clutch the longer it will last.  Never thought of that!  With a '58 in DR4, the only shift that applies a friction clutch is 2->3 (the rear clutch).  All other shifts are just directing fluid into or out of the fluid coupling (and releasing the friction clutch in the case of 3->2). 

So I can see the smoother application of that clutch (the rear clutch) as causing more wear than a harsh application.  But wouldn't doing that at a lower input speed also contribute to less wear, which would mean there is no actual harm to the transmission in not having the TV rod connected (unless it relates to heat, but I still can't see how the transmission would run hotter)?  The engine would have a harder time turning the transmission, but the transmission wouldn't have a harder time turning the propeller shaft....in my small brain anyway....

Good question - I was told by the Cadillac transmission guys in the '60's that a disconnected TV rod would burn the transmission up in no time.  They didn't explain why, and I was only a teenager back then.  They did explain how they would set the rod to Specification and then road test the cars turning e trunion nut in 1/4 turns until they found the "sweet spot."

[wbdeford]

They did explain how they would set the rod to Specification and then road test the cars turning e trunion nut in 1/4 turns until they found the "sweet spot."

Right....the 57 shop manual says how to get to the official spec, and then says:

"NOTE: It will be necessary to check and adjust the TV jam nut slightly to obtain smooth shifting.  This should be done after completion of all other carburetor adjustments."