Hard downshift from 2nd gear to first. A-833 4-speed.

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So I parked my 68 Barracuda last fall but before I did, I was experiencing difficulty getting the transmission to shift back to first gear from 2nd gear.

New Brewer Transmission purchased as part of their 4-speed conversion kit.

Mcleod dual diaphragm clutch , over center spring removed.

I initially had synthetic fluid in it but removed it and replaced with regular gear oil. 75/90 oil in both cases.

No difference.

Transmission has 7000 miles on it since install.

What adjustments would correct this or are there any?

I've read about mixing synthetics and regular petroleum products but that doesn't explain why the trans worked perfectly before with synthetic oil.

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Just finished cleaning up the Wife's '67 383 x 4 gear for the same deal. 3/4 shift rod was about 2 turns too short. Get under it and check your shifter linkages for slop and set up. I don't know what fluid is in hers, I run 20W50 engine oil in my Bee. I wouldn't run synthetic in anything 50+ years old, but that's banter for another thread...
 
did you:
check the bellhousing alignment to the crank?
use the roller bearing vs a pilot bushing?

typically the problem described is caused by too much centerline crank to transmission offset and using a pilot bushing vs the roller bearing, no lubricant fixes that.

As far a lubricants, do not use atf, use GL4 whatever, preferably a synthetic as the trans runs cooler, shifts better. Do not use GL5 lubricants. Sure motor oil works but so does atf.....btw atf is band aid for cold cold temps in manual transmission, it does not have enough lubricity for manual transmission and over time there will be worn parts. Passon used to make his own lube-if that is avail i would use that over anything else. I tried all sorts of lubricants as i had a very wicked 4sp car...

Manual trans cars should have the lubricant changed on a regular basis.
 
did you:
check the bellhousing alignment to the crank?
use the roller bearing vs a pilot bushing?

typically the problem described is caused by too much centerline crank to transmission offset and using a pilot bushing vs the roller bearing, no lubricant fixes that.

As far a lubricants, do not use atf, use GL4 whatever, preferably a synthetic as the trans runs cooler, shifts better. Do not use GL5 lubricants. Sure motor oil works but so does atf.....btw atf is band aid for cold cold temps in manual transmission, it does not have enough lubricity for manual transmission and over time there will be worn parts. Passon used to make his own lube-if that is avail i would use that over anything else. I tried all sorts of lubricants as i had a very wicked 4sp car...

Manual trans cars should have the lubricant changed on a regular basis.
Bell housing alignment done when first installed.

Roller bearing as well when first installed.

I'm hoping its a rod adjustment but wanted some ideas before trying anything.

Thanks!!
 
Hang on boys
we , or maybe just me, needs more information. To whit;
You said;
"So I parked my 68 Barracuda last fall but before I did, I was experiencing difficulty getting the transmission to shift back to first gear from 2nd gear."

So I ask;
1) is this with the car moving?
Now it's a backshift problem or
2) is this with the car stopped?
now it's an engagement issue.
3) since first and second are "in-line" the gate is not involved, and the rod adjustment should be moot. but
4) if the levers have come loose from the studs on the cover, yur stick is gonna have a real hard time of it

Numbers 3 and 4 above are an easy fix
number 2 above is sometimes normal.
number 1 is NOT normal and has more than one cause.

So which is it?

BTW
I will NEVER AGAIN try to run synthetic Manual Transmission fluid. I had to take my trans down, and apart, to wash it all out, and then it finally shifted, again. I mean I really really tried to make synthetic work.
 
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Hang on boys
we , or maybe just me, needs more information. To whit;
You said;
"So I parked my 68 Barracuda last fall but before I did, I was experiencing difficulty getting the transmission to shift back to first gear from 2nd gear."

So I ask;
1) is this with the car moving?
Now it's a backshift problem or
2) is this with the car stopped?
now it's an engagement issue.
3) since first and second are "in-line" the gate is not involved, and the rod adjustment should be moot. but
4) if the levers have come loose from the studs on the cover, yur stick is gonna have a real hard time of it

Numbers 3 and 4 above are an easy fix
number 2 above is sometimes normal.
number 1 is NOT normal and has more than one cause.

So which is it?

BTW
I will NEVER AGAIN try to run synthetic Manual Transmission fluid. I had to take my trans down, and apart, to wash it all out, and then it finally shifted, again. I mean I really really tried to make synthetic work.

1. Car moving , rolling to a stop , downshifting when coming to a stop sign for instance.

2. car moving

3, 4, I will be under the car this weekend. I'll definitely check this out. Also going to recheck shift rod adjustments.

I remember your post about this in a previous topic. I changed back to regular dinosaur oil after reading that but didn't see any difference.

Thanks for the reply!
 
Ok so with the car moving.
I assume you know how synchronizers work, but humor me.
The two FOUR working parts of the Synchronizers are;
the Brass rings
the Brake cones
the three struts, and
the Energizer springs.
If any of those parts fail to do their jobs, You have problems, and a couple of different ones at that.
In your case, you do not mention any gear-clash or grinding noises.
Now, consider this:
When the car is stopped and your foot is OFF the clutch, and the engine is idling:
1) The driveshaft is Not turning so neither is the output shaft, nor the two synchronizer assemblies that are mounted on it.
2) the engine is at around 750 rpm, and so are the clutch and, the trans input gear. The cluster and all three gears are spinning at various speeds.
If you tried to engage a gear, by NOT first clutching it, the brass ring would have to try to slow the engine down, to zero rpm so that the big slider could engage the clutch teeth of whatever gear you were trying to engage. Obviously the relatively small brass-ring could not do that, so some smart guy invented the De-clutching mechanism.
>>With the Clutch pedal down, and sufficient clutch departure, the input gear is allowed to be slowed to a crawl by the thick gear-oil until the brass ring is able to grab the brake cone, synchronize the gear to it's speed, and BadaBoom the slider slips over.

Every upshift gear change works the same. Except, the designer of the trans expects the driver to learn to to keep the rpm difference in a realistic operating window. For instance, if a particular gear is synchronized at 30 mph @3000 rpm, then there's no good reason to try and select that gear with the tach at 6000. Any little friction in the clutch will make impossible.
So then, while you are accelerating thru the gears, the driver is expected to allow the rpm to come down, into the window. If you miss it and the rpm drops too low, again, any clutch drag is gonna make it hard for the brass to synchronize.
Now, for downshifts, the Brass ring works in the same way, But in this case, the operator is expected to bring the rpm UP, into the window of synchronization, to give the brass a chance to do it's thing.
Most of us just blip the throttle and hesitate the shift, waiting for synchronization to happen. If you miss the window, you just bring the rpm back up.
So, what I'm saying is that a great deal of shifting is on the operator. Eventually, this becomes automatic.
So far, I have talked about technique and clutch departure.

Now we'll talk about the parts.
First how it's supposed to work.
Synchronization is 100% dependent on the brass, which by friction, lock onto the brake cones. So the first order is to squeeze the oil out. Synthetic oil is very difficult to squeeze out, and even when it's out, it leaves a micro-film of slippery molecules stuck on the brake cones that is as good as impossible to remove. Even when you try to wash it out with solvent. That is some slipperychit. But say you got it all out, and the brass has squeezed out whatever oil you installed. Now the brass is in intimate contact with the brake; and it's inner dimensions exactly match the brake cones, and they are not egg-shaped nor out of round. So then, by friction, they bring the rotational speed of the gear attached to the brake, up or down, to match the speed of the brass. As soon as it is within a few rpm, the slider jumps forward to engage the clutch teeth, and synchronization has occurred.
Ok now, what pushes the brass ahead onto the brake?
That would be the struts. but there are two other parts involved in this process, namely, the matching notches in the slider and the energizer springs.
The springs keep the struts jammed into the slider notches making it act as one unit, spinning at driveshaft speed. The faster the driveshaft spins, the harder the struts are flung into the notches, but in the grand scheme of things, this is not so big a deal, BUT, the springs gotta be doing their jobs, cuz if they are weak, the slider will move ahead too soon, causing the teeth to butt and grinding is the result.

Now, you did not mention grinding. So then everything seems to be working as designed and the only hick-ups can be lack of friction, or technique.
As to friction, When I rebuild one of these, I chuck the gears in a lathe and deglaze the cones with 100>120 emery cloth, just a couple of swipes. and I bias the swipes so that the brass rings screw onto the brakes in the upshift direction. and I make sure the brass works by dry-fitting them onto their intended brakes, always giving special attention and priority to Second gear. Cuz I know,
Second is the single-most-used gear in that box.
Fourth is only used for cruising, and
Third is mostly just used to get to fourth.
and First is mostly just downshifted into, so I bias that brake for down-shifting. When I get done, my brakes shift like lightning for a long time. But, I have been driving the A833 almost continuously since 1970, so, I got pretty good technique, lol.
And finally is oil.
I find that All my A833's have loved Dextron II.
and all have tolerated 85/90 EP oil. But none have liked 140 EP, and the one I currently drive, absolutely hates full-synthetics.
but
With Dextron,
you gotta have adequate clutch-disc departure, cuz you'll get no help from it, to slow the gears. Whereas;
the 140 will slow the gears real fast, and it's real easy to miss the synchronization window. and
85/90 works pretty good.
So my recipe is half Dextron/half 85-90, cuz the EP oil slows wear on the cluster pin.

Now in your case, down-shifting into First from Second with the car moving;
This is likely the most difficult shift to make work right.
Here's what all has to happen;
1) The Rpm has to be increased to get into the synchronization window
2) the clutch departure has to be adequate, so that the disc does not drag.
3) the engine rpm must NOT come down too fast after the blip
4) the trans-oil has got to get out of the way, and
5) the brass has got to bite on the brake, and
6) the struts have to not want to come out of the notches until it is time.
7) and the wild card is that the 3-4 internal shift lever on the older covers, has to properly detent so that the interlock-pin is not being tickled. This is what @dadsbee was mentioning in post #2.

That's a lottachit going on right there.
Since you say that you have a Brewers Transmission, Ima thinking he has done his part in making that unit work. He knows his stuff.
So then, if I had to guess;

I am confident that the problem is Not #6, and
reasonably confident Not #3 nor #7.
Had you never installed synthetic, I would have put #5 with #3 as reasonably confident, but like I said earlier, I had to disassemble my trans to wash that slipperychit out of my box.

Therefore, I'm leaning towards numbers 1, and/or, 4>5, in that order; with numbers 2 and 7 as possibilities.

Happy HotRodding

PS
I almost forgot
The notches in the sliders, and the struts are a matched set, AND the old style is different from the new. The old style struts have a large drive hump on them, and a matching deep notch. Whereas the notches in the new-style slider is pretty shallow. Otherwise, those sliders are physically interchangeable, while the struts go with the hubs. IDK what would happen with old style struts in new style sliders. However Your symptoms do not point to a mix up, so I wouldn't think about it. I just thought you might like to know, lol.
 
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Ok so with the car moving.
I assume you know how synchronizers work, but humor me.
I'm no expert but I have a general idea of how speed matching different gears work in a manual trans by using syncros .

I am open to any advice but to add to my problem's description, I am not getting any gear grinding. It just feels like I am forcing the transmission into first gear when downshifting from 2nd. Also upshifting under speed is no problem going through the gears from first to fourth.
 
Yeah, Ima thinking technique.
Here's something you can try .
drive the car in first gear, up to a speed that makes 2500 rpm on the tach , look at the speedometer and make a mental note of the speed. I'm just guessing but say it 20 mph. Now, you will forever know that for zero speed difference of the input and output shafts that 20 mph (or whatever it is in your car) is 2500rpm. So then you know that to downshift into first at 20 mph, the rpm will need to be around 2500, to rule out problems with clutch departure. So go out and practice it.
In second gear at say 22 mph, press the clutch pedal down, bring the engine to 2500 rpm, then wait for the car to slow to 20, then ram that stick right into First. See how easy that was!
Oh yeah, about declutching ; how far do you have to press the pedal? That's easy to figure out.
Start the engine, push the clutch down, put it into fourth, then while slowly bringing the pedal up, watching the tach. as soon as you see the tach dropping, or feel the car moving. that is already not enough pedal for to shift at, so press it back down a bit, and make a mental note of where the pedal is, relative to the floor.
Now, adjust your seat to make that position, the default position, with your leg comfortable enough to hold it there. Now try again, this position needs to feel natural. If your leg is uncomfortably bent to limit your leg power, this will not be natural. If your seat is too high this is gonna be a problem. I put the ball of my foot on the pedal and slam it down until my heel touches the carpet and so, I have a repeatable declutched position that I never have to concentrate on. I re-engineered my seat tracks so that this occurs with my seat all the way to the front. And I changed out my steering wheel until I found the perfect combination of dish and diameter, so that this is comfortable for like 90% of the time. On long trips I move the seat back some more. Thus all my muscles have memorized the constant seat position, and so the clutch is always pushed down to the same position.
Now, after finding that position, with the car stopped and engine idling, push down the clutch and attempt to engage reverse. I bet it grinds, Wait 5 seconds and try again, if it still grinds, wait 5 more, and try one last time. Then rest your leg.
It grinds because the cluster is still spinning, and there are only two reasons for that;
1) the clutch is dragging for lack of departure, or
2) the clutch is dragging for lack of the pedal being pushed down far enough.
3) at most, I might expect the gears to have stopped spinning by 5 seconds.

Therefore repeat the test but this time depress the pedal another inch, and wait 5 seconds, then try it. If it still grinds, I would bet money that the disc is not coming to a stop. To engage reverse, with the vehicle not moving, the disc has to stop! So if you get into this situation, figure out why the disc won't stop, and fix it.
Here are some of the reasons; in order that I would suspect;
1) insufficient departure
2) a bent disc. that is to say, disc not perpendicular to the hub. This only happens if during installation the trans was hung in the crank before the retainer was fully inside the bellhouse. The only cure I know of is to replace it.
3) a warped disc, which is to say cupped. You measure the departure as ok but towards the center, the disc is dragging. Gotta replace it.
4) clutch fingers not all adjusted to the same height. . You measure the departure in one spot and it's fine. then you find out, it is less/more in a second spot and worse in another. Only cure is to take it to a clutch shop and have it readjusted.
5) packed up organic linings.
6) BH severely out of alignment with the crank and/or flywheel. Ok so bedtime for this cowboy.
 
are you off the gas when changing?
come off completely see how you go and provided you are not free wheeling at 90 i.e you are somewhere in the 20 mph range all should be well.

Or come off to reduce engine rpm to where you think it should be for first, see how you go

OR

double declutch before going into first

clutch down out of second engine spins independent of trans, you are in neutral the road is driving the trans output, and main shaft, but no gear is locked, just idling. Input and counter gear should be near standstill

clutch up engine and input spin the same counter gear spins along as a consequence, but in neutral so no locked speed gear, just idling along on the spinning main shaft
if engine rpm is sensible for first, clutch down and into first

this doesn't provide perfect synchronisation but you help it on its way

still a problem id suggest linkage adjustment

no problem id suggest synchro i.e you managed a shift OK with closer alignment of rpm between input and gears
but you can't when you expect the synchro to do that work for you.

MMMmmmm

one last thing
does this just happen when its cold? if so its a feature not a problem :) my t5 does it and my single rail BW 4 speed does it.

once warmed no problem. the synchros work when the oil is at the right temperature but not so great when its like treacle.

in my admittedly limited "hobby centric experience" Most transmission issues are to do with the shifter or clutch or in remote shift applications worn out transmission mountings. they only progress to be a transmission issue if nothing is done about the initial issue.


one other last thing

it sounds like a new unit so doubt anyone punched it into first so hard as to bend the shift forks

Dave
 
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in your first post you mentioned that you put in a dual diaphragm clutch in the car.
Did you mean a dual disk diaphragm clutch?
If so check the departure on the second clutch disk(closes to the trans). On sum of these dual disk clutches the disk will hang on the input shaft and keep spinning with the pressure ring. The cure for this, is to set the clutch up with a little more departure and to grease the input shaft with a special grease thats helps to keep the disks sliding on the input shaft.
The new Challengers with the 6 spd. all seem to have this same problem.
 
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