How should I be shifting

[JSabah]

I don’t drive the ‘49 too often but when I do I get a little gear grind when shifting. I can minimize it by putting in the clutch, taking it out of gear and counting to 2 or 3 before putting it in gear. It now occurs to me that I should be double clutching... am I correct? This is for a ‘49 Plymouth Woody P18 with the original Flathead 6 and transmissions (3 on the column). Thanks 

[BobT-47P15]

I don't believe there was ever any "double clutching" required to shift a correctly working clutch/transmission in a 40s or 50s MoPar.    

 

But - I don't know what the problem is.    So---not much actual help here.   Perhaps someone with much more knowledge

than me will join in.....

[Dodgeb4ya]

No double clutching should be needed.

Maybe worn syncro's?

Try changing the trans oil.

Make sure clutch and shift linkage is adjusted right too.

[TodFitch]

Is that grinding going into first or reverse? Those aren’t synchronized. You should be at a stop to shift into those and maybe a little delay after depressing the clutch pedal to allow the gears to stop moving.

 

Second and third are synchronized so any grinding there indicates a problem.

 

For what it’s worth, 1935 is the first year for synchros for Plymouth.

[keithb7]

Just in case, don't use modern GL4 or GL5 oil in the tranny.

[Worden18]

Like TodFitch said, 1st and reverse aren't synchronized.  I always quickly shift to 2nd then down to first (without releasing the clutch pedal) if I'm coming to a rolling stop, or even if I'm completely stopped.  Keeps it from grinding.  If already in 2nd gear I'll shift to neutral, then back to 2nd, then down to first.  Any time I shift to reverse I'll quickly shift partially into 2nd, then reverse.  As far as upshifting normally from 1st to 2nd to 3rd, after depressing the clutch I take my time shifting to the next gear, then it is smooth.  If one hastily jams it into the next gear, it'll grind.

[Sniper]

Speed shifting these transmissions is tough, that's for sure.  Others have pretty much nailed how to do it.  If that is already how you are going it then maybe it's time for a gear oil change and linkage adjustment.  Check and correct and linkage bushing wear issues as well.  If that all fails it might be worn synchros.

 

Napa can get the GL-1 the book calls for

 

https://www.napaonline.com/en/p/FHQ65201?impressionRank=1&keywordInput=65+201

Edited April 3, 2021 by Sniper
Napa pn

[Sam Buchanan]

A lubricant that works great in our trannys is Redline MTL or MT-90. These oils will make a cold transmission shift as nicely as one that is warmed up. My P-15 had a persistent crunch going from first to second until I went with Redline, now it is smooth all the time.

 

Don't let the price spook you, after driving with Redline you will consider it a bargain. 

 

Edited April 3, 2021 by Sam Buchanan

[DJK]

I second the Redline gear oil. Good stuff.

[JSabah]

Great info. Thank you. I think I’ll drain and refill the oil as a first step as I don’t recall doing so before. What is the difference (or what is better to use in a non rebuilt/original trans) - Redline MTL or 90wt ? Also, how much does the trans hold (sorry I don’t have the manual with me)?

[greg g]

Does your trans grind a bit shifting into first or reverse upon start up from neutral?  If so that indicates your clutch is not disengaging completely allowing the input shaft to turn in neutral which will also translate to grinding on the first second shift going down the road and also grinding on the downshift from third to second.  You need to get under the car and adjust the clutch rod to increase it's length by about a quarter inch or so. You might need to back it off a bit if you detect slipping in third while accelerating of going up grades.

[maok]

Also, check the level of the oil in the trans, it maybe very low.

[DJK]

18 hours ago, JSabah said:

Great info. Thank you. I think I’ll drain and refill the oil as a first step as I don’t recall doing so before. What is the difference (or what is better to use in a non rebuilt/original trans) - Redline MTL or 90wt ? Also, how much does the trans hold (sorry I don’t have the manual with me)?

My 52 holds 2 1/4 pts. I use the 90wt

[greg g]

Just make sure it's comparable with gl1 specs.  Syncro pieces are brass and bronze and modern oils dont play well with those metals.

[Sam Buchanan]

Redline MTL is formulated and intended for trannys like ours with brass components.

Edited April 5, 2021 by Sam Buchanan

[JSabah]

Thank you all. Just drained what was in the Trans. Supposed to have 2.25 pints or 36 oz. only about 19 brown (muddy looking) smelly oil came out. Refilling with the MTL as advised and hopeful that will do the trick. 

[JSabah]

Took her for a test drive. No grind between 1st and 2nd, but still a little grind between 2nd and 3rd.  Didn't fix it all, but 80% - maybe its an old car ?  .Also, glad I changed that old smelly oil and added the correct amount of fresh oil anyway.

[RobertKB]

One of my old cars does the same. I eliminate the 2nd to 3rd grinding by shifting a bit slowly and just giving it a few extra rpm as It passes neutral on the way to third. I don’t actually double clutch. 

[Sam Buchanan]

18 hours ago, JSabah said:

Took her for a test drive. No grind between 1st and 2nd, but still a little grind between 2nd and 3rd.  Didn't fix it all, but 80% - maybe its an old car ?  .Also, glad I changed that old smelly oil and added the correct amount of fresh oil anyway.

 

Yep, just give the old tranny a little extra time between shifts. Also, after you put some more miles on the new oil you may find the shifting improves.