dhowlan
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I just realized I have an endoscope. If it comes to it, I can have it all assembled and look through the fill hole. Wish that had occurred to me earlier. C'est la vie. 
833 OD sticking in 4th, chipped synchro
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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If the new struts are dimensionaly the same as the old, and you install them; I can almost guarantee you that you will end up having the same problem ....... down the road.
The struts are captured by the brass, and limited in travel by the distance between the bottoms of the slots. As the brass wears, they creep up the brake cones, and the inter-slot dimension grows. This allows more space for the struts to come out and eventually they are able to pop out the back.
New struts will not solve this. You have to reduce the inter-slot dimension, by one of the following three ways;
1) install new brass that sits higher up away from the clutch teeth, or
2) move the mainshaft forward, or
3) move the Input gear deeper into the case.
Since all A833s that I have worked on, have this design problem, I just move the input gears back in the first place.
I should mention that if your box runs too hot, the brass will expand and climb down the brake towards the clutch teeth, opening up the inter-slot dimension; leading to strut pop-out.
However, the over-heated brass turns color, and yours are still bright yellow, so this is not your problem.
But Since you have it apart, check the faces of the brass for signs of having run that deep and throw those away.
Another thing I do is attempt to stretch the brass,, looking for broken ones.
The struts are captured by the brass, and limited in travel by the distance between the bottoms of the slots. As the brass wears, they creep up the brake cones, and the inter-slot dimension grows. This allows more space for the struts to come out and eventually they are able to pop out the back.
New struts will not solve this. You have to reduce the inter-slot dimension, by one of the following three ways;
1) install new brass that sits higher up away from the clutch teeth, or
2) move the mainshaft forward, or
3) move the Input gear deeper into the case.
Since all A833s that I have worked on, have this design problem, I just move the input gears back in the first place.
I should mention that if your box runs too hot, the brass will expand and climb down the brake towards the clutch teeth, opening up the inter-slot dimension; leading to strut pop-out.
However, the over-heated brass turns color, and yours are still bright yellow, so this is not your problem.
But Since you have it apart, check the faces of the brass for signs of having run that deep and throw those away.
Another thing I do is attempt to stretch the brass,, looking for broken ones.
dhowlan
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Understood.
The front bearing (308) snap ring on the input shaft is 0.0640". You are suggesting a thicker snap ring to move that rearward? Or shim the mainshaft forward?
The front bearing (308) snap ring on the input shaft is 0.0640". You are suggesting a thicker snap ring to move that rearward? Or shim the mainshaft forward?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I do not think moving the M/S forward is an option in that trans.
>As to the front snapring; I do not recall the thickness of the factory ring. .064 sounds a lil thin, but I just don't remember. So;
lay the gasket onto the retainer and slip the big snap ring into the receiver-step. Make sure it sits below the gasket. It has to sit below the gasket, else either the retainer will break when you tighten it up, or it will leak.
>By the same token;
If after you mount the input gear into the case and bolt the retainer on, the whole thing moves back and forth, something is wrong. and most likely would be that the wrong thickness gasket is being used, but could also be a too-thin outter snapring. So figure that out first.
Your goal is to move only the input gear back. Once the correct relationship is restored as to the large snapring, then you can see about the small one. Here your only choice is to put the thinnest snapring that you can find into the groove, and move the bearing up tight to it, then measure between the input and the bearing, and install whatever shims you can get, into there. I used to use rear-end shims, left over from the days I was a rebuilder, some 40 years ago..
Now, before you spend a lotta time on this, consider that you're not gonna get much. It is usually much more advantageous to just install a new hi-riding brass on both of those gears, which will instantly restore the inter-brass distance, to the factory measurement.
>And once again I highly recommend NOT to install any synthetic oil into that box. It is too slippery, and will either delay your shifts or else you will get impatient and ram it into gear, which will chip off your clutch teeth. I use 50/50 Dextron-II and EP 85/90. You can use whatever EP oil you have; just make sure it does NOT contain any additives for any type of Limited Slip Differential. This EP oil is only in there to protect the Cluster pin.
>Finally, that od box has very-wide ratios, same as any Mopar 3-speed, so it's NOT a hi-perf box, and so; don't try to get hi-perf out of it. If your engine is slow to rev or more importantly the revs don't fall in a hurry, either fix that, or go easy on the trans.
>The ratios are; 3.09-1.67-1.00-.73od with splits of; .54-.60-.73.. The regular
4-speed is .... 2.66-1.92-1.40-1.00 with splits of; .72-.73-.71
What the splits mean, is that at whatever rpm you out-shift at, the in-shift rpm of the next gear will be at those percents.
Say you outshift yours at 5000 rpm;
54% of 5000 is an in-shift rpm into Second of 2700 for a drop of 2300. Now with the regular 4-spd, still outshifting First
at 5000, your inshift into Second will be to ... 3600 a drop of just 1400.
So like said, yur gonna have to wait for the Rs to come down.
The picture is only a tiny bit better at 3000, the Rs still have to come down to those percents.... so you still gotta wait, just not quite as long.
>After reassembly, keep after your clutch-departure, so the brass doesn't have to work so hard, trying to slow the engine down. This means; keep your hand OFF the shifter, except to shift, and don't bother downshifting into direct, unless circumstances require it. Be nice to that brass and it will last a really long time. Another thing to keep in mind is if the car is slowing down too fast. This could be due to; dragging brakes, very low tire pressure, excess baggage/towing, terrain, or road surfaces.
If your engine is slow on the deceleration, my guesses are;
A heavy flywheel
lack of cylinder pressure,
insufficient clutch-departure
throttle open too far
running too rich
lack of timing advance.
Lord help you if she has all of those problems, lol.
>As to the front snapring; I do not recall the thickness of the factory ring. .064 sounds a lil thin, but I just don't remember. So;
lay the gasket onto the retainer and slip the big snap ring into the receiver-step. Make sure it sits below the gasket. It has to sit below the gasket, else either the retainer will break when you tighten it up, or it will leak.
>By the same token;
If after you mount the input gear into the case and bolt the retainer on, the whole thing moves back and forth, something is wrong. and most likely would be that the wrong thickness gasket is being used, but could also be a too-thin outter snapring. So figure that out first.
Your goal is to move only the input gear back. Once the correct relationship is restored as to the large snapring, then you can see about the small one. Here your only choice is to put the thinnest snapring that you can find into the groove, and move the bearing up tight to it, then measure between the input and the bearing, and install whatever shims you can get, into there. I used to use rear-end shims, left over from the days I was a rebuilder, some 40 years ago..
Now, before you spend a lotta time on this, consider that you're not gonna get much. It is usually much more advantageous to just install a new hi-riding brass on both of those gears, which will instantly restore the inter-brass distance, to the factory measurement.
>And once again I highly recommend NOT to install any synthetic oil into that box. It is too slippery, and will either delay your shifts or else you will get impatient and ram it into gear, which will chip off your clutch teeth. I use 50/50 Dextron-II and EP 85/90. You can use whatever EP oil you have; just make sure it does NOT contain any additives for any type of Limited Slip Differential. This EP oil is only in there to protect the Cluster pin.
>Finally, that od box has very-wide ratios, same as any Mopar 3-speed, so it's NOT a hi-perf box, and so; don't try to get hi-perf out of it. If your engine is slow to rev or more importantly the revs don't fall in a hurry, either fix that, or go easy on the trans.
>The ratios are; 3.09-1.67-1.00-.73od with splits of; .54-.60-.73.. The regular
4-speed is .... 2.66-1.92-1.40-1.00 with splits of; .72-.73-.71
What the splits mean, is that at whatever rpm you out-shift at, the in-shift rpm of the next gear will be at those percents.
Say you outshift yours at 5000 rpm;
54% of 5000 is an in-shift rpm into Second of 2700 for a drop of 2300. Now with the regular 4-spd, still outshifting First
at 5000, your inshift into Second will be to ... 3600 a drop of just 1400.
So like said, yur gonna have to wait for the Rs to come down.
The picture is only a tiny bit better at 3000, the Rs still have to come down to those percents.... so you still gotta wait, just not quite as long.
>After reassembly, keep after your clutch-departure, so the brass doesn't have to work so hard, trying to slow the engine down. This means; keep your hand OFF the shifter, except to shift, and don't bother downshifting into direct, unless circumstances require it. Be nice to that brass and it will last a really long time. Another thing to keep in mind is if the car is slowing down too fast. This could be due to; dragging brakes, very low tire pressure, excess baggage/towing, terrain, or road surfaces.
If your engine is slow on the deceleration, my guesses are;
A heavy flywheel
lack of cylinder pressure,
insufficient clutch-departure
throttle open too far
running too rich
lack of timing advance.
Lord help you if she has all of those problems, lol.
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dhowlan
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Brewers has that snap ring listed at .065 so I think it's fine. I'll check the play with the new gasket etc. when I get there.
I'm aware of the limitations of this flavor of a833. I had a long time to stew on swapping to another option. It's fine for the slant.
I'm guessing I will subconsciously be more gentle in the 3-4 shift in the future regardless.
Thanks for the input. Parts are supposed to arrive Friday.
I'm aware of the limitations of this flavor of a833. I had a long time to stew on swapping to another option. It's fine for the slant.
I'm guessing I will subconsciously be more gentle in the 3-4 shift in the future regardless.
Thanks for the input. Parts are supposed to arrive Friday.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I wasn't knocking your transmission selection.
I myself ran that trans for a couple of years behind a stout 367.
to make it a high-rpm runner, I know what to do
But in the end, I let it go.
BTW;
I want to give you some food for thought:
I am currently using the Commando with ratios of 3.09-1.92-1.40-1.00 / With 3.23s (no longer in the car) the Road gears were;
-------9.98--6.20-4.52-3.23-- if you ran 3.73s with that od box, your roadgears would be
11.53------6.23----3.73---2.72 ; and 65=2475 with a 24" tire. This is actually a pretty good set-up for a slanty
Notice Second gears are the same.
To cruise any slower and still get better fuel-economy would be difficult because of the near impossibility to provide enough ignition advance with the factory type distributor. So that's two gears in your favor.
As for the 11.53 starter gear, while being pretty doggone low, it's a really good parade gear, and a dump-it-and-go starter gear. But Second gear comes along pretty fast. First gears this high are hard to rate, with the small 24" tires. The 3.73 roadgear is pretty good because with it 40 mph is ~2100, a good place to be cruising at in the city. So that's 3 out of 4 not too bad.
You may have other ideas, and that's fine, the real point I'm trying to make is that down below about 2400 it is no longer possible to meet the engines timing requirement, and fuel-economy will begin to suffer because of that. To find out how much timing your engine wants at any cruise rpm, just rev it up to the chosen rpm and read the current advance.
Then, keep giving it advance while simultaneously keeping the rpm at the set point. When the rpm no longer rises with additional advance, read the timing and subtract about 2 or 3 degrees for the load, and that is your magic number. Now put the timing back and return the engine to idle. Finally, compare what the engine wants to what your distributor is currently giving, then figure out if she can be modified to supply the difference.
Don't be surprised to see a requirement of over 50* at 2400rpm.
If you cruise below the magic number, you can expect that whatever savings that the lower rpm might be worth, is lost to the lack of efficiency due to not enough timing. They sorta run neck and neck but in opposite directions.
You can try this at say 200 rpm intervals from 1600 to 2800, then modify your distributor as best as you can, and plot the two sets of numbers on a graph to see where they intersect, and badaboom, there is your optimum cruising rpm.
Now you just have the carb to deal with, lol.
If you really want to cruise below 2200 and simultaneously get optimum fuel economy, then, you will need a stand-alone, aftermarket, dash-mounted, dial-back , timing module. Mine has a range of 15 degrees. or a timing computer.
Happy HotRodding.
I myself ran that trans for a couple of years behind a stout 367.
to make it a high-rpm runner, I know what to do
But in the end, I let it go.
BTW;
I want to give you some food for thought:
I am currently using the Commando with ratios of 3.09-1.92-1.40-1.00 / With 3.23s (no longer in the car) the Road gears were;
-------9.98--6.20-4.52-3.23-- if you ran 3.73s with that od box, your roadgears would be
11.53------6.23----3.73---2.72 ; and 65=2475 with a 24" tire. This is actually a pretty good set-up for a slanty
Notice Second gears are the same.
To cruise any slower and still get better fuel-economy would be difficult because of the near impossibility to provide enough ignition advance with the factory type distributor. So that's two gears in your favor.
As for the 11.53 starter gear, while being pretty doggone low, it's a really good parade gear, and a dump-it-and-go starter gear. But Second gear comes along pretty fast. First gears this high are hard to rate, with the small 24" tires. The 3.73 roadgear is pretty good because with it 40 mph is ~2100, a good place to be cruising at in the city. So that's 3 out of 4 not too bad.
You may have other ideas, and that's fine, the real point I'm trying to make is that down below about 2400 it is no longer possible to meet the engines timing requirement, and fuel-economy will begin to suffer because of that. To find out how much timing your engine wants at any cruise rpm, just rev it up to the chosen rpm and read the current advance.
Then, keep giving it advance while simultaneously keeping the rpm at the set point. When the rpm no longer rises with additional advance, read the timing and subtract about 2 or 3 degrees for the load, and that is your magic number. Now put the timing back and return the engine to idle. Finally, compare what the engine wants to what your distributor is currently giving, then figure out if she can be modified to supply the difference.
Don't be surprised to see a requirement of over 50* at 2400rpm.
If you cruise below the magic number, you can expect that whatever savings that the lower rpm might be worth, is lost to the lack of efficiency due to not enough timing. They sorta run neck and neck but in opposite directions.
You can try this at say 200 rpm intervals from 1600 to 2800, then modify your distributor as best as you can, and plot the two sets of numbers on a graph to see where they intersect, and badaboom, there is your optimum cruising rpm.
Now you just have the carb to deal with, lol.
If you really want to cruise below 2200 and simultaneously get optimum fuel economy, then, you will need a stand-alone, aftermarket, dash-mounted, dial-back , timing module. Mine has a range of 15 degrees. or a timing computer.
Happy HotRodding.
dhowlan
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To follow up, it's back together and back in the car. All 4 gears plus reverse work in and out (at least for the 5 miles it's done so far). Reverse was a nuisance until I realised I had flipped the lever over. Doesn't work that way. Fingers crossed it lasts another 20 years before I have to redo this.
I appreciate all the assistance.
I appreciate all the assistance.
I've been reading your post with great interest as I have the exact transmission and problem as you describe. After 20 years of trouble free driving yesterday my transmission locked up in 4th gear after cruising on the highway. It freed up and worked normal until I got back on the freeway and it locked up again. I haven't torn into my transmission yet but would really like to know what you replaced and the results. Where did you purchase parts Brewers / Passon or ? Can you advise if the new Keys and synchro solved your problems?
DionR
Well-Known Member
I too read this post with great interest as I was having a similar problem. I pulled the trans and popped the side cover off and sure enough I had a strut sticking up when in 4th similar to the OP.
In the end, my issue was the strut springs, they were oddly shaped and not making good radial contact with the struts. The spring popped off the strut in the middle of the spring on the 4th gear side allowing the spring on the input side of the syncro to rock the strut up when in 4th and make it a pain to get out of 4th.
I had a parts trans so I grabbed all the strut springs from it, plus 3 struts. The other 3 struts I replaced with new parts from Brewers. I also got my gaskets and countershaft seal plug from them. All my syncro's looked brand new, the trans had been rebuilt and had less than 8-10K on it, so I left those as is.
Trans works great now, no issues since putting it back together.
In the end, my issue was the strut springs, they were oddly shaped and not making good radial contact with the struts. The spring popped off the strut in the middle of the spring on the 4th gear side allowing the spring on the input side of the syncro to rock the strut up when in 4th and make it a pain to get out of 4th.
I had a parts trans so I grabbed all the strut springs from it, plus 3 struts. The other 3 struts I replaced with new parts from Brewers. I also got my gaskets and countershaft seal plug from them. All my syncro's looked brand new, the trans had been rebuilt and had less than 8-10K on it, so I left those as is.
Trans works great now, no issues since putting it back together.
Thanks DionR thats very helpful. Since I'm going to have to take the Tranny apart I'm just going to get a rebuild kit, but most don't include the struts and spring so I'll add that to the build. Any good hints for getting the tranny to seal up. I always seem to have some leaking around shift arms and tail shaft?
DionR
Well-Known Member
I don't really have any hints for sealing. I know the shift arms have o-rings, so maybe replace those? The gaskets I bought from Brewers were the "high quality" ones and they say to to not use sealer, just bolt them down, so that's all I did. I had a leak on the side cover prior to pulling it and discovered mine had been put back together using aluminum OD case gaskets, which are different then the iron case stuff even though mine is an OD box. So maybe watch for that. I know there is a vent shield that if missing will cause the vent to puke gear fluid. Seems like the slip yoke bearing has groves and a hole that should be pointed down so any fluid that gets back there can drain into the case instead of getting to the seal. Maybe look at that.
Can't think of anything else. But my knowledge is pretty limited, just what I picked up messing with mine a couple of months ago.
dhowlan
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Hi,
I just saw your question. So far, it is still functioning. I have to say, every time I shift out of fourth, I pause, let everything come back to as slow as possible, and then say a small prayer before sliding it out of fourth. I also don't use fourth unless it's really necessary. I'm a bit paranoid about it. But it's still working.
I just saw your question. So far, it is still functioning. I have to say, every time I shift out of fourth, I pause, let everything come back to as slow as possible, and then say a small prayer before sliding it out of fourth. I also don't use fourth unless it's really necessary. I'm a bit paranoid about it. But it's still working.
DionR
Well-Known Member
Only other thing I would add is that my shift arms were getting wallered out and coming loose and @AJ/FormS had a post somewhere that detailed a fix. So while I had my side cover off, I used a punch on the lever to bring the corners of the slot in and then filled it with thread locker and let it sit with the levers down over night. Haven't checked to see if they are still tight, but feel pretty confident. And this is the best time to do it, so just pointing it out as something to think about.
DionR
Well-Known Member
Hi,
I just saw your question. So far, it is still functioning. I have to say, every time I shift out of fourth, I pause, let everything come back to as slow as possible, and then say a small prayer before sliding it out of fourth. I also don't use fourth unless it's really necessary. I'm a bit paranoid about it. But it's still working.
If you are worried about overshifting or something, you could swap in a Comp+ shifter with the stops. Maybe that would easy your minds some?
That's what I have and I set it up on the bench before I put the trans back in.
Can you provide an update? Did rebuild cure the problem? I have the same problem with identical transmission. Only happened twice after prolonged highway travel. Transmission locked in 4th gear as I tried to exit freeway. First time it just popped out after about 15 minutes of me trying different ways to free up and second time It worked out after a few minutes. Its been almost 20 year since I rebuilt it but only 6,000 miles. I've been driving around town and had no repeat. Before I commit to a rebuild I'd like to know your results! Thanks
DionR
Well-Known Member
Not sure if that is pointed at me but I can give an update.
Trans has been great, no issues. I haven't been looking for leaks but I haven't noticed any either. Been in and out of 4th multiple times, probably 10 times almost every time it leaves the garage.
I would pull the trans and then the side cover, put it in 4th and then roll it around and look for a strut that seems to be loose or popping up just to confirm that it isn't some other problem. I wouldn't plan on a full rebuild if you find an issue there, just replace the all the strut springs and struts and re-gasket it. Just me though, certainly less chance of a problem for another 20 years if you do bearings and such.
Note that it could be the strut spring is popping in and out and if so you might not see the problem without taking the trans all the way down to the syncro's.
I'm a bit late to the thread but after 20 years of flawless operation my 4 speed overdrive, aluminum case, started to stick in fourth gear, as described at the start of this thread. I removed the tranny from the car and found that for some reason 4th gear was traveling over the normal stop position and causing the slider block to **** upward preventing the gear to move back into neutral. After following this thread and similar I got fed up with trying to identify the problem and moved on to correcting the situation. I build up the backside of the interlock lever (welded a bead about an 1/8 inch) and relieved the front side ( ground out a equal amount of material in front) effectively moving the gear forward. This allowed the slider gear to move into fourth but prevented it from going to far. I bench tested until I got it correct. I installed in the car and have many hours and miles on the car with perfect operation - no issues, works great. I figured 4th gear is the least pounded on gear in the tranny so I had nothing to loose. I know the purest won't like this fix but it works and lets you move on to enjoying the car versus trying to figure out where you lost that fraction of an inch. It allows the car to work the way it should. Before this fix I tried, a new fork and new interlock lever with no success.
Inertia
Well-Known Member
You hotrodder you ! ! - LOL
Good job, understanding what was needed, making it work, - congrats .
Last edited:
6PakBee
Well-Known Member
I had a '76 Volare` that I bought new with the same problem that started just out of warranty. I was younger and more ignorant but I was able to determine that overshifting 4th was the problem. This may have been a backyard fix but I fabricated a 4th gear stop on the shifter and that took care of it until I sold it in about '83.I just realized I have an endoscope. If it comes to it, I can have it all assembled and look through the fill hole. Wish that had occurred to me earlier. C'est la vie.
Dartswinger70
Well-Known Member
Get a really low set of rear gears then you'll never have to shift out of 4th...
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