Randiego

36 Plymouth P2 Transmission Issue

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Plymouth heads,

I am in a quandary regarding my transmission.  I bought the car back in October 2016 and have been getting it roadworthy over the last year.  I removed the trans, clutch, pressure plate and flywheel.  I had the flywheel surfaced, put in a new clutch and pressure plate.  The throw out bearing was in excellent shape (love Chrysler engineers who put an umbilical flex tube to a cap that you turn to grease the bearing.  Ingenious).  I had my friend, Gary who owns a local trans shop go through the tranny.  The bearings were fine but the synchro hub was worn out.  I got a N O S  hub (last on on the shelf) and new seals and gaskets.  We inspected the components and all looked fine.  I re installed everything back in the car and was sad that when I warmed up the car, it would "grind" when shifting between 2nd and 3rd, or downshifting.  And after a short time, it would lock up going into two gears.  I would have to "work" the gear shift to get it out of gear(s) and it would be fine as long as I was shifting "gingerly".  

 

This last two times, I had to remove the shifter/top cover off the transmission to manually slide the selector bar to unlock the transmission.  Gary and I took the two top brackets off of the top (under the cover) that holds the slider bars in place. He looked at the assembly and we could not see anything out of the ordinary.  He could only deduce that there may be something missing in the transmission that needs to be in place to keep the shifter from moving the two bars at once.  Note;  the shifter is tight in the top cover and the spring is in place.  Nothing worn out there or out of place.  I have attached a picture of the to of the transmission with the gear selector bars exposed.  There is a gap between the two bars (towards the bell housing)  that he thought might take another check "ball" or some other part that keeps the gear shifter from moving the other bar when it is not supposed to be moving. We have the two retainer "straps" off and checked the two balls and the detents (on the bottom of the shifter bars) and they are all in place and not worn.  I don't have a transmission manual showing if there is a part(s) missing or not.  Your help will be appreciated in this quandary.

 

Randy

 

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On the '33 transmission which has a similar set of shifting bars, there is a ball that does under bars at the location of the front hold down strap that only allows one bar to be moved at a time. Basically a lock out that keeps you from moving both bars at the same time. Looks like your transmission is supposed have the same type of lock out and it looks like the ball (I think it might be spring loaded from below) is missing.

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This is a '38 overdrive with '39 shifter forks. Pretty much the same though, ply33 is correct, you're missing this ball. It just drops in and isn't spring loaded.

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Edited by Plyroadking (see edit history)

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Rebuilt the trans on my 36 Dodge last year, everything is identical in your photo except for the two little balls. If these balls fall down into the tranny, things lock up when you move the shifter. (I found this out the hard way) 

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To Steve;  The two balls are in place (under the shifter bars and perform correctly.  That was my first thought that they had "fallen out" but that was not the problem.   

 

To Plyroadking;  Your transmission shows the two indents in the shifter bars towards the rear of the transmission.  Mine is in the front.  Don't know if that is an issue but I certainly am missing the ball.  I will try to measure the size of the gap and get a ball that will fit.  I am sure that this is the problem after seeing your transmission.  Funny how for a different year that they move the indent to the rear of the transmission.  Probably due to the overdrive unit?  

Anyway, thanks to you both for responding to my dilemma.   Now I can fix the issue.

 

Randy 

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Plym 33;  Thank you for your post.  Your transmission is like mine.  Definitely need the ball but does any one know if, indeed, there is a spring below the ball to engage it into the slot?  I can get the ball but I don't have a clue as to what spring or other device is below the ball to actuate it.  If anyone knows, please help.  

 

Plus;  I can only think that the issue with the synchro hub could be caused by the oil being too thin?  One individual said to remove a cup of the oil and add a light oil.  That did not do the trick.  Now I am thinking of going the other way with the heaviest oil I can get (120 weight?)  Since the tranny only grinds when it is warm, I am thinking that when it is cold, the oil is thicker and therefore allowing the gears to mesh without grinding. 

 

Any one have an answer for this or a schematic for the ball and check spring or what goes below the ball?  Does any one know of a source for the parts I am missing?   Your help will be appreciated.

 

Randy

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My indents are towards the front. In my picture the transmission is pointing south and yours is pointing North. They should be pretty much identical as I robbed parts from a '36 transmission to put one of mine together. I can measure the diameter of the ball for you this evening. It just sits there and has no spring or other hardware. The top strap keeps it captured when everything is assembled.

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Sounds like the synchro hub is not working. Assuming you have it all in correctly and have the right synchro ring, perhaps the oil is too slippery?

 

Are the synchro rings made of bronze? If so, remember to ensure the oil passes the Copper Strip Corrosion test with a 1a result. Or use an oil with no EP additives.

 

Presumably you have the clearances and end floats set up correctly too.

 

One more thing, does the bell housing need to be dialed in to make sure the opening for the gearbox is coaxial with the crankshaft?

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Don't know if there is a spring under the ball bearing or not on my '33. Just guessing to cover up my faulty memory (been decades since I've had the transmission apart). Thinking about the lock out mechanism, there does not seem to be a need for a spring under the ball so there probably isn't.

 

The '33 and '34 are unsynchronized, just sliding dog clutches for 2nd and 3rd. I believe syncros were added for '35. On my '33 if the lubricant is on the light side it definitely makes it harder to do a quiet shift. I'd start with the summer weight recommendation from the owner's manual on any experimenting on lubricant weight as you will be doing most of your driving in summer weather.

Edited by ply33 (see edit history)

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There are springs under the detent balls for the shift rails. There is also a small detent ball and spring located inside the gear sleeve (synchronizer) and there is also a second gear thrust washer pin and spring which prevents the second speed gear thrust washer from rotating. If it does move , it will interfere with the alignment of the gears. You'll have to remove the gear set to check those parts. Also, did the person who reassembled the gears check the end play to make sure that the thrust washers were not overly worn? I would also use 140 wt. gear lube and nothing lighter unless you are driving the car in very cold conditions. 

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3 hours ago, hwellens said:

Attached is a view of a 36 Dodge transmission parts view which I assume is the same if that helps.

 

 

36 transmission.pdf

 

Very much a similar design on the shifting mechanism to my '33 Plymouth. I see that item 16, the balls that give the center feel when in neutral, are spring loaded. While item 14, the ball that locks the shift rails so only one can move at a time, is not spring loaded.

 

I can also see that those who have told me that a later transmission will bolt on to my '33 bell housing if you swap top covers and shift rails are probably correct.

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TO all that responded;  THANK YOU !  ! !   Love the AACA Forum as the help you need is just an inquiry away.

 

My friend, Gary, who owns Well Built Transmissions here in Oceanside, CA took the tranny apart, he missed replacing the detente ball that goes between the gear selector slider bars.  I don't fault him as it is not everyday that someone walks into his shop with an older transmission.   Any way , we deduced that there was a detente ball missing as there was a grove and  "cupped" openings in the sliders.  Plyroadking  supplied a picture of a 38 overdrive transmission.  In that picture, it shows the ball arrangement but in a different location.  His was at the rear of the transmission where as mine is towards the bell housing.  

 

I went to my ball bearing supply drawer and found a ball that was the right size.  I installed the ball.  No spring, just the ball was needed and re assembled the transmission.  VOILA ! !  Works like a champ.   Amazing how a little part can give you all that grief.  Never too young, er old,  to learn about my Plymouth.

 

Now on to the next problem.  In the 36 model, there are no synchro rings.  There is a synchro hub that has the teeth machined into the brass insert.  I got the last NOS part from Northern Transmission.  The next guy that needs one, they are going to have to send him theirs and he will refurbish the part.

 

All the gears and bearing in my transmission are in great shape (71,000 miles on the car) but the hub was worn excessively.  Installing the new synchro hub did not take care of the grinding issue.  In the morning, when the car is cold, the gears don't grind going into gear.  When it warms up, they do not sync properly.  Now I do not "grind" the gears.  I put in the clutch, wait till the engine decelerates, and gently shift into the next gear with minimal or no "grinding" sounds.  

 

I have 70-90 weight trans oil in there right now.  Would going to the 90-140 multi weight oil do the trick?

 

Any help with this would be appreciated.

 

Thank you all for your responses.

 

Randy 

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Plym33,

 

I downloaded the PDF File and lo and behold, item #14 is the detente ball !  Thank you for your help.  Is the page out of a Motor Manual  or a specific Plymouth book?  I would like to get a copy of the book if possible.

 

Randy

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19 minutes ago, Randiego said:

 

I have 70-90 weight trans oil in there right now.  Would going to the 90-140 multi weight oil do the trick?

 

Is this really some transmission-specific oil you have in there now or just gear oil?

 

Synchronizers are a brake. Most gear oil available in the USA is far too slippery. If the synchronizer cant stop the gear, it is going to grind.

 

To make things worse, we have an idiotic rating system (gl4/gl5) that really tells you nothing about whether the oil is suitable for a transmission. There is also the separate issue that the oil might eat the brass over time... or not.

 

If it were mine, I might try Redline MT-90 in it, or motor oil.

 

If you try motor oil, keep in mind that it is rated on a different viscosity scale.  SAE 30 motor oil is about the same 85W gear oil, SAE 50 motor oil is more like 90 weight. (in viscosity)

 

I don't know if heavier weight will help. Heavy oil is usually a detriment on most cars, causing the synchronizers to work worse until the oil warms. On the other hand, heavy oil creates more drag. This would help you get into the unsynchronized first gear quicker at a light.

 

I did hear of one situation where heavier oil helped a lot. The pre-1937 Chevrolet transmission has a weak synchronizer on high gear. One user over on the VCCA discovered that by using heavier oil shifting was improved. The original oil was SAE160, not a standard weight anymore, so most use SAE140 these days. By going heavier instead of lighter, he found the transmission shifted better hot. I suspect the drag of the oil may have been slowing things down faster so the synchronizer had less to do. Nevertheless, it worked!

 

Whatever you try, let us know how it turns out.

 

192300d1308489008-50w-eng-oil-and-90w-ge

.

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Bloo,

 

Thank you for your reply.  Question is;  What the hell did they use back in the thirties?   All our oil today is formulated for the transmissions (and rear ends) of today.  Old cars used the oil that they formulated for then.  What ever they put in the oils or blended them, the oils were different that today.  I will drain my oil and go with the heaviest gear oil that is available.  I hope that works.  I will let you know what I find out.

 

Randy

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Try GL1  (mineral oil) not supposed to attack yellow metals (brass). Used this in my Airstream this summer with no negative results. This was used in many older tractors, etc.

Good luck

 

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I don't have period literature showing what was recommended for your year. For my '33 the recommendations were:

 

Summer (above +40°F) use "Free wheeling lubricant No. 110"

Winter (above +10°F) use "Free wheeling lubricant No. 90"

Extreme Winter (below 0°F) use "Free wheeling lubricant No. 80"

 

Below +10°F if easier shifting is desired there are instructions on mixing in "low cold test motor oil" to the gear lube.

 

I've never found confirmation that the weights given for "free wheeling lubricant" are on based on the same scale or test as for modern gear lubricant. I've assume they are close but  that is just an assumption.

 

For the last 10 or 20 years I have been using SAE 140 hypoid gear lube in my transmission with reasonably good results with respect to ease of shifting. The stuff on the shelf in my garage is Sta-Lube and it claims to be safe for yellow metals even though it is a hypoid lubricant. In my case that does not much matter as there is no brass in my transmission (all roller or ball bearings and no synchronizers). Years ago I used lighter weight gear lube and it was a bit trickier to get the double clutch shifting to be quiet. 

 

Edit:

Neither San Clemente nor Oceanside see low temperatures below +40°F and certainly the average daytime temperatures are nearly always above that all year,  so for my car a 110 weight gear lube is called for. But near as I can tell that does not exist nowadays. At least not at my local auto supply stores. I was more inclined to go heavier than specified rather than lighter, thus my choice of SAE 140. And having the heavier weight is probably an advantage in summer when touring "over the hills" into the much hotter inland areas.

 

Been a while since I've gotten the old car out for more than around town. The weather forecast for next week does not look too bad, is there a coffee shop in Oceanside that would be worth braving I-5 to visit?

Edited by ply33 (see edit history)

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Mineral oil, and is still available, in large quantities, from NAPA. I'm just going from memory, but sure if you can get the information from past posts on the forum. Defiantly don't want to use the modern stuff like GL 5, it's supposed to eat up the brass parts in your trans and OD. Not sure but I think that you want GL1.

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1 hour ago, Randiego said:

Question is;  What the hell did they use back in the thirties?   All our oil today is formulated for the transmissions (and rear ends) of today.

 

 

They didnt have gear oil as slippery as we have now in the 30s. That is the problem (as far as the transmission is concerned). Most oil formulated for transmissions today is synthetic.

 

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You are on the right track. The 1935 Motors manual calls for 160 weight for summer use, 90W for winter use in both the transmission and rear  end. Probably the new 140 weight would work best but you need to make certain that it is compatible with brass parts. Try a marina as many boat drives use brass - they should be aware of the problem. When I was looking I remember reading that some of the brands state on the label or product sheet that they are safe for use with brass.

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Again,

 

Thanks to all.  I have a local boat shop owner who is my friend and expert on outdrives.  I will ask him what product that is available for my needs.  To Plym 33;  I recall talking to you back when I removed the transmission last year.  I did not note the exact location(s) of the linkages and different apparatus that goes onto and around a Plymouth transmission.  Invincible I wasn't !  You were kind enough to help me with that.  As far as venturing South, there are some nice places down here to grab a cup of coffee and a nice lunch if you want to drive down here.  We can meet up and create a "stir" with our old Plymouths.  I use to live in San Clemente  back in the early 80's.  I lived on Capistrano Lane (a block up from the pier) and there are a nice array of restaurants there too.  I use to do oyster shooters at the Fisherman on a regular basis.  Send me an email and we can discuss meeting and grabbing a bite.  I can also drive up to San Clemente too.,   randy@americanarbortreeservice.com    To the rest of you, again, thank you.  I will post which product that I find works best and gets rid of the annoying "grinding" of the gears.  

 

And Plym33 outlined the fact that we do not have weather below 55-60 degrees (during the day) ANY time.  Unlike what is going on back East with sub zero weather.  And in the summer, we generally hover around 75 to 80 degrees with some spells getting up in the 90s.  So a thicker lubricant is called for.

 

Randy  

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To find out if your chosen oil is suitable for brass parts (i.e. that contain copper), look for the Copper Strip Corrosion Test ASTM D130 test results. They should be 1A (or maybe 1B).  If they are not available for your chosen oil, find one for which they are. I have seen them in the oil's SDS. Gary W gave a good description of it in his thread on the restoration of his 1937 Buick in the Buick Pre War forum.

 

PS. see post #322 on p. 13 and above and below it.

 

Edited by Spinneyhill (see edit history)

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And that should keep the brass from corroding. It is a little hard to ignore the crunching that occurs because hypoid gear oils are so slippery they cause synchromesh not to work.

 

As I understand it, in other parts of the world you can buy gear oil labeled "EP" or "NON-EP", I have seen bottles like this pictured in service manuals. This would make it real easy to decide what to put in a hypoid differential (EP) and what to put in a transmission (NON-EP). In the US, the gear oil kept getting slipperier and slipperier for decades, and no such distinction was ever made. In the 1980s and early 1990s nearly every manual transmission car sold here used either ATF or motor oil in the transmission. There were few exceptions. Today synchromesh fluid is available in any parts store here, though probably not in a thick enough viscosity for a 1930s transmission.

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