1966 Newport 3 speed trans woes

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Hello all! I am still having hard shifting with my 3 speed trans. It takes some effort to shift out of first and into second. If I take too long to hit second, it grinds. Second to third is ok Third to second downshift is also difficult. This trans is just rebuilt.
My first question is: is it possible to do something wrong when rebuilding to cause this problem? It seems to me that the internal workings are pretty straightforward; either it is broken or it all works well. The trans this one replaced was a dream to shift.
What you can tell me will determine here I go next.
 
As stated, check the linkage first, the rods/neutral position or the neutral position of the levers on the column may not be properly set. If that's good, it may be a synchronizer issue. On a 3spd, the 1st/reverse are one fork, 2nd/3rd the other. Sounds like an issue in the transition.
 
Do you have any trouble shifting from neutral to any gear with the engine running and the car not moving?
 
Is the excess effort needed to shift from first to neutral or neutral to second? Do the gears grind shifting into first or reverse? Does the shifter move easily with the rods discinnected? Does the trans shift well with the rods disconnected? Lindsay
 
Just curious, why was the prior transmission replaced or rebuilt?

I understand the frustration in the current transmission not working as easily as the prior one did. I suspect something internal, rather than external. No reason for the linkage to suddenly stop working smoothly, I suspect. Granted, correct adjustment needs to be checked, but you might not find anything significant there, all things considered.

Rather than the throw-out bearing per se, I would also suggest checking the clutch linkage adjustment, for good measure.

It MIGHT be a minor thing, but what lube did the rebuilder put in the transmission? Reason I ask this is that Chrysler usually used ATF in their 3-speed manual transmissions, rather than the 90W lube everybody else did. Either would work, but the 90W might increase the shift effort a bit, possibly?

Also . . . check the product information to see if Low gear was synchronized or not on those 3-spd manual transmissions.

Is the rebuilder local to you, or otherwise? Did they do the installation?

Happy Holidays!
CBODY67
 
Is the excess effort needed to shift from first to neutral or neutral to second? Do the gears grind shifting into first or reverse? Does the shifter move easily with the rods discinnected? Does the trans shift well with the rods disconnected? Lindsay
Is the excess effort needed to shift from first to neutral or neutral to second?
I would say both. Coming out of first for sure.
Do the gears grind shifting into first or reverse?
Nope; no grinding.
Does the shifter move easily with the rods discinnected?
Yes; I rebuilt the column. Smooth as can be.
Does the trans shift well with the rods disconnected?
Yes I remember that being the case.
 
Just curious, why was the prior transmission replaced or rebuilt?

I understand the frustration in the current transmission not working as easily as the prior one did. I suspect something internal, rather than external. No reason for the linkage to suddenly stop working smoothly, I suspect. Granted, correct adjustment needs to be checked, but you might not find anything significant there, all things considered.

Rather than the throw-out bearing per se, I would also suggest checking the clutch linkage adjustment, for good measure.

It MIGHT be a minor thing, but what lube did the rebuilder put in the transmission? Reason I ask this is that Chrysler usually used ATF in their 3-speed manual transmissions, rather than the 90W lube everybody else did. Either would work, but the 90W might increase the shift effort a bit, possibly?

Also . . . check the product information to see if Low gear was synchronized or not on those 3-spd manual transmissions.

Is the rebuilder local to you, or otherwise? Did they do the installation?

Happy Holidays!
CBODY67
Just curious, why was the prior transmission replaced or rebuilt?
It was slipping out of second on deceleration. I had another 745 from a 66 Newport rebuilt.

I understand the frustration in the current transmission not working as easily as the prior one did. I suspect something internal, rather than external. No reason for the linkage to suddenly stop working smoothly, I suspect. Granted, correct adjustment needs to be checked, but you might not find anything significant there, all things considered.
I adjusted the linkage twice to the procedure in the manual.

Rather than the throw-out bearing per se, I would also suggest checking the clutch linkage adjustment, for good measure.
Clutch adjustment is good. The disc is loose when the pedal is floored.

It MIGHT be a minor thing, but what lube did the rebuilder put in the transmission? Reason I ask this is that Chrysler usually used ATF in their 3-speed manual transmissions, rather than the 90W lube everybody else did. Either would work, but the 90W might increase the shift effort a bit, possibly?
ATF is in there.

Also . . . check the product information to see if Low gear was synchronized or not on those 3-spd manual transmissions.
Non-syncro first.

Is the rebuilder local to you, or otherwise? Did they do the installation?
I installed it a couple of times.
 
I have the same trans in my 66 Fury. If the trans shifts well (easily) at the trans shift levers with the rods disconnected and the shifter operates easily and smoothly with the rods disconnected and the lnkage is adjusted as per FSM, what is left? Do you have the clutch interlock paul which prevents shifting from low or reverse with the clutch engaged? If so, try removing that whole rigging. Could the rods be bent and binding? can you have someone shift the trans while you watch the action from below? Did you check the runout on the bell housing. Mine was out by 0.018" and that gave me problems. I wish I were closer. Lindsay
 
I have the same trans in my 66 Fury. If the trans shifts well (easily) at the trans shift levers with the rods disconnected and the shifter operates easily and smoothly with the rods disconnected and the lnkage is adjusted as per FSM, what is left? Do you have the clutch interlock paul which prevents shifting from low or reverse with the clutch engaged? If so, try removing that whole rigging. Could the rods be bent and binding? can you have someone shift the trans while you watch the action from below? Did you check the runout on the bell housing. Mine was out by 0.018" and that gave me problems. I wish I were closer. Lindsay
Did you check the runout on the bell housing.
Did this cause the shaft to ride hard to one side of the pilot bushing, and keep the input shaft turning?
 
What changed since when you replaced the transmission? Did you replace the clutch, bellhousing, or pilot bushing? Messed around with the column or linkage?

I doubt this is an internal transmission issue. If it shifted properly on the bench or with the linkage removed then I don’t think the transmission is at fault. Rebuilding these things is not rocket science.

The first thing I’d do is verify 100% the input shaft is not being driven with the clutch released. You can check this a few ways. Easiest is to just jack up the rear wheels, run it with the car in gear & the clutch pushed in. If it’s turning the driveshaft/ wheels with any significant force then you have a problem. It may not be the actual clutch adjustment. The disc could be warped or the pilot bushing have too tight clearance. If the bellhousing runout is out of whack the pilot bushing will excessively contact the input shaft.

You might want to check your motor mounts. If one is bad it can twist the whole drivetrain causing the column shift linkage to bind. I had this happen once and it caused the car to stick in gear; a replacement totally cured it.
 
What changed since when you replaced the transmission? Did you replace the clutch, bellhousing, or pilot bushing? Messed around with the column or linkage?

I doubt this is an internal transmission issue. If it shifted properly on the bench or with the linkage removed then I don’t think the transmission is at fault. Rebuilding these things is not rocket science.

The first thing I’d do is verify 100% the input shaft is not being driven with the clutch released. You can check this a few ways. Easiest is to just jack up the rear wheels, run it with the car in gear & the clutch pushed in. If it’s turning the driveshaft/ wheels with any significant force then you have a problem. It may not be the actual clutch adjustment. The disc could be warped or the pilot bushing have too tight clearance. If the bellhousing runout is out of whack the pilot bushing will excessively contact the input shaft.

You might want to check your motor mounts. If one is bad it can twist the whole drivetrain causing the column shift linkage to bind. I had this happen once and it caused the car to stick in gear; a replacement totally cured it.
If it shifted properly on the bench or with the linkage removed then I don’t think the transmission is at fault. Rebuilding these things is not rocket science.
That is the statement I was looking for. So now I can chase what I am suspecting.
When I bought this car, the engine was done. I replaced it with a 68 383 from a 727 car. That required a pilot bushing adapter and a needle bearing type pilot. The drilling in the crank appeared deep enough. The original trans shifted just fine.
When I installed the rebuilt trans, which came from a different 66 Newport 383, I had a problem right away that I could not shift it. It would grind every gear. So I spaced the transmission back with washers between the trans and the bellhousing. Now I could shift without grinding but the shifting was difficult as I described.
This past spring I pulled the trans, bellhousing, and clutch out. I compared the input shaft length to the original trans and it was a little longer. I don't recall shortening the original one, but who knows? It was a long time ago.... So I cut a piece off the input shaft, replaced the pilot bushing, clutch disc (it was handy). I checked and rechecked dimensions. Put it all together. Checked the clutch disc that it was free to move with the pedal pushed in. Adjusted clutch and linkages to the book. It was still difficult shifting, but now I didn't need the spacers. AS the summer faded away, I installed the spacers again, but no change.
Something is still grabbing the input shaft. I'll pull everything again and measure. It may be that the end of the shaft is rubbing the the crankshaft bore.
 
In my case the runout on the bellhousing caused clutch chatter and may have contributed to the trans dropping out of second. I can't be sure of the latter as I made acouple other changes in the trans at the same time.
 
Putting spacers between the trans & bellhousing is not a good idea. You want full insertion of the input bearing housing into the bellhousing register. Personally I don’t care for those retrofit pilot bearings. The original bronze oilite bushings work best. You can have an automatic crank machined to fit the bushing but it’s more costly & the crank has to be removed. Whenever you mix & match engines/ bellhousings it’s a good idea to check the runout. It is tedious but sometimes offset dowels are needed to correct. Procedure is in service manual. If it’s way out it could cause various trans wear issues & also to pop out of gear.

After reading your posts again you say you have no problem shifting into the non-syncho 1st without grinding. This should be all but impossible if the input shaft is turning with the engine leading me to think that is not the issue? Leaves me scratching my head.

Although I don’t think the problem is with the trans, it’s not an impossibility. If it’s rebuilt, who did it? Are they competent? One nice thing about the 745 is that you can change the input shaft without disassembling the whole transmission. If the crankshaft was hitting the input shaft it could have damaged the bearings. Also, Redline MT-90 works well in these. I think the ATF is too thin, especially in hot weather.
 
As for the pilot bushing, they are normally a bronze bushing, BUT the needle bearing types can replace them with no issues . . . when the crank originally had a bushing in it. BUT the needle bearing types might not be as forgiving of mis-alignment as the bronze bushings might be, I suspect.

Some cranks were machined for the pilot bushings, even if the car was an automatic transmission car. That made things a lot easier for doing manual transmission conversions and as one part number crankshaft covered both types of transmissions. Some crankshafts might have been poured with the thought of being machined for a pilot bushing, but had a shallower hole that could be machined as needed. A variable situation, by observation.

Just some thoughts,
CBODY67
 
The transmission is out and I measured the bellhousing runout to be 0.008" I have the offset dowels. But, how do I remove the old dowels? Any method that worked well for anyone?
 
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