marcapra Posted August 24 Share Posted August 24 (edited) My gearshift was working OK for awhile although there was some grinding when shifting into reverse. After I did an adjustmnet on the shift controls according to directions in the MTSC booklets, I can't shift into reverse anymore. I've tinkered with the adjustment nuts many times on the control rod and the selector rod, but nothing seems to work. Edited August 24 by marcapra (see edit history) Link to comment Share on other sites More sharing options...
Oldtech Posted August 24 Share Posted August 24 On this type of linkage the pull rod - the one operated by pulling back on the shift lever(selector rod) has to toggle the lever on the transmission all the way when the shifter is pulled back. Check to see if this is happening. (Needs 2 people) It also needs to come all the way forward when the lever is in the 2-3 position. 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 What's happening now is I totally loosened the control rod nut. It has a slot where you can slide the control rod up or down to center the gear shift lever so it is horizontal. When I loosen the nut I can sometimes get into a gear. Right now I can check into reverse again, but not into low or high range. This is with the engine off. I am afraid try this with the engine on for fear of breaking gear teeth. I'm following the directions in the booklet, but the transmission is not cooperating. A couple of days ago the transmission was shifting fine, except there was a little grinding when shifting into reverse. A buddy said you might have too much play on your clutch, so I've reducing the free play there, but the clutch pedal still is floppy for about an inch. There is a stiff return spring on the trans. selector rod. The rod can go forward but not back. Is that correct? Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 2 hours ago, Oldtech said: On this type of linkage the pull rod - the one operated by pulling back on the shift lever(selector rod) has to toggle the lever on the transmission all the way when the shifter is pulled back. Check to see if this is happening. (Needs 2 people) It also needs to come all the way forward when the lever is in the 2-3 position. What would you do if lever on the trans. is not going all the way? Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 I should also say that there is no 2-3 position on this trans. It's a four speed with three positions: low range, high range, and reverse. And of course neutral. I am fearing now that I may need to pull the trans. as the problem might be internal. Link to comment Share on other sites More sharing options...
Oldtech Posted August 25 Share Posted August 25 Ok. I was thinking standard, but I think that it still applies. There must be an adjustment at the front of the long rod. where the spring is. Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 There is and I've adjusted it, but I don't really know what I'm doing. This car needs a good 1950s era DeSoto or Chrysler dealership to take it to, since I'm no pro, just a total amateur. But those dealships are hard to find!!! The shop manual says nothing about gearshift adjustments, but the MTSC booklets and filmstrips do mention the subject in a 1949 filmstrip on MyMopar.com. They demonstrate on a 3 speed manual, but it is almost the same as the M-6 trans. It says to remove all slack from the selector rod and tighten the nut. I don't have any idea what remove all slack means! So I've tightened the nut and backed the nut off with no results. Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 After loosening the control rod nut, I am able to get into some gears now. I even started the engine and now, it shifts into reverse perfectly with no grinding. I also got it into high range, but it was a hard shift. But I can't get it into low range now. So this makes me think it may not be some internal trans. problem, but just a linkage problem. I will have to continue to tinker with it until I can find the answer. All I know now is when I tighten the control rod nut everything freezes up and I can't shift gears. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 25 Share Posted August 25 The book cautions that it is possible to adjust so you get low but not reverse. This seems to be what happened. As you have adjusted according to the book several times, I suspect you have a worn linkage or worn bushings that are causing the problem. Have been thru this before, replaced bushings or grommets as necessary, in some cases built up worn shifter parts by brazing and filing to shape, removing all slop and the car shifted like a dream. 3 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 25 Author Share Posted August 25 I did replace the control rod lever bushing, but not the bell crank bushing. I'm also not sure about my clutch free play. see video Link to comment Share on other sites More sharing options...
keiser31 Posted August 25 Share Posted August 25 (edited) I believe you need to readjust the clutch pedal to match the plane of the brake pedal. The one inch of "free play" should be the movement of the pedal BEFORE the linkage starts to move. Edited August 25 by keiser31 (see edit history) 2 Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 26 Share Posted August 26 (edited) I'm not sure what you mean by first. The Fluid Drive system does not have a "first". You have a reverse in the usual position and you have Low and High range in the usual 2nd - 3d position. The usual first gear position has nothing. Edited August 26 by Rusty_OToole (see edit history) Link to comment Share on other sites More sharing options...
marcapra Posted August 26 Author Share Posted August 26 When I say first, I mean 1st and 2nd or Low range. That's when you shift the stick up, but not pulling the lever toward you, which would be reverse. Link to comment Share on other sites More sharing options...
c49er Posted August 26 Share Posted August 26 Your double nut adjustment is wrong at top of the shift rod next to the steering column. Back em off a turn at a time just till it shifts into low range...road test... recheck at a stop a couple times. 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 26 Author Share Posted August 26 I think you are referring to the Selector rod with the nut and the lock nut. Yes, I have fooled around with that setting, but didn't really know what I was doing. The book just says to take out the slack and back off a half turn. Thanks for the tip.. Marc. Link to comment Share on other sites More sharing options...
c49er Posted August 26 Share Posted August 26 (edited) I just fixed that same common issue on my 48 Chrysler. Edited August 26 by c49er (see edit history) Link to comment Share on other sites More sharing options...
Rusty_OToole Posted August 26 Share Posted August 26 There is a general rule for adjusting shift linkage, not sure if it applies to your car. There is a detent when the lever on the trans is in the Low position. Slack off the adjustment, go under the car and put the lever in the Low position. Put the shift lever in the car in the Low position. Now tighten up the adjustment in that position. 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 26 Author Share Posted August 26 (edited) Sounds good. That would be easy for me since I took the floor out. I've been adjusting the Selector nut all morning experimenting by screwing it out and in. It definitely changes the feel of the stick. But the situation hasn't really changed. I now can shift to reverse and high with the engine off. Still can't shift into low. One thing that has been bugging me is I can't adjust the stick to be horizontal in neutral. When I loosen the control rod nut and slide the stick to a horizontal position, after I tighten the nut, neutral goes back up above horizontal. I think that is part of the problem. Since neutral is above horizontal, there is not enough space to get it into low. Edited August 26 by marcapra (see edit history) Link to comment Share on other sites More sharing options...
marcapra Posted August 27 Author Share Posted August 27 (edited) After playing around with the adjustments for a few hours, I am now able to shift the trans into low, high, and reverse. Unlike before, now the low has the longer throw of the stick and high has a short throw from neutral. I am also able to shift to reverse, so I am making a lot of progress. And this is with the engine running too. I would like refine the adjustment so the throws for low and high range are equal. I've learned that there is a subtle relationship between the control rod position and the selector rod nut. It has to be right, or you will have shifting problems. Edited August 27 by marcapra (see edit history) 1 Link to comment Share on other sites More sharing options...
keiser31 Posted August 27 Share Posted August 27 44 minutes ago, marcapra said: After playing around with the adjustments for a few hours, I am now able to shift the trans into low, high, and reverse. Unlike before, now the low has the longer throw of the stick and high has a short throw from neutral. I am also able to shift to reverse, so I am making a lot of progress. And this is with the engine running too. I would like refine the adjustment so the throws for low and high range are equal. I've learned that there is a subtle relationship between the control rod position and the selector rod nut. It has to be right, or you will have shifting problems. Good news! Link to comment Share on other sites More sharing options...
Oldtech Posted August 27 Share Posted August 27 Re the clutch. the set screws at the bottom are to align the pedals so ther are even with each other and don't bang the floorboard when you take your foot off them. so reset it even with the brake. Free play is that "floppiness" that you refer to, There is supposed to be one inch of floppy before you feel it working the clutch. This is so the throwout bearing isn't riding on the fingers and spinning all the time. Hope this helps. It is likely easier to feel with your hand than a foot. 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 27 Author Share Posted August 27 That's good to know, but that 1 inch of floppiness makes it hard to get the pedals even. I tried to get the clutch pedal even with the brake using the screw, but this is as close as I could get it. Do I need to do an over center spring adjustment to raise the pedal? Link to comment Share on other sites More sharing options...
keiser31 Posted August 27 Share Posted August 27 (edited) Googling "1948 De Soto interior photo", I see the pedals are supposed to be on an even plane. The inch of free play should occur BEFORE pressure on the linkage starts to move it. Edited August 27 by keiser31 (see edit history) 2 Link to comment Share on other sites More sharing options...
JACK M Posted August 27 Share Posted August 27 I think you have it working like it should. Shifting, and the one-inch free play. I suggest a spring to pull the pedal play up away from the T/O bearing and call it done. 1 Link to comment Share on other sites More sharing options...
c49er Posted August 27 Share Posted August 27 (edited) If....your clutch over center spring adjustment was done 100% correct ...(I assume you down loaded the template of the factory Miller tool).. ....then you adjust clutch pedal stop bolt adjusting the pedal arm to stop 1/4" from the underside of installed floor boards. Make same adjustment on the brake pedal so both pedals are equal height. Then properly adjust clutch fork push rod to provide 1" of free play at top of the clutch pedal movement. The brake pedal needs 1/4" to 3/8" of free play. Clutch Pedal should positively and easily return to full up and back against stop bolt. I lightly use the toe of my foot my foot to carefully feel that proper 1" of free play. It is critical for proper over center spring adjustment to obtain OE factory clutch and linkage feel and operation. Note: The lower over center spring bracket cannot be bent but exactly 90 degree's other wise your adjustments are wrong. Edited August 27 by c49er (see edit history) 3 Link to comment Share on other sites More sharing options...
marcapra Posted August 27 Author Share Posted August 27 Thank you C-49er! Excellent pics of the details. I am lucky enough to have the overcenter spring Miller tool. I'm looking for it now to double check my over-center spring adjustment. Link to comment Share on other sites More sharing options...
c49er Posted August 28 Share Posted August 28 I now remember you do have that rare tool! Link to comment Share on other sites More sharing options...
marcapra Posted August 28 Author Share Posted August 28 I also have the the 49-52 overcenter spring adjustment tool. It has a little chain with a sharp marker on it. Link to comment Share on other sites More sharing options...
c49er Posted August 28 Share Posted August 28 I have and use that 49-52 tool too. I have many many old factory Miller service tools I use on the 30's thru mid 50's MoPars... Some of the smaller ones... 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 28 Author Share Posted August 28 With tools like that, are you a pro mechanic? Link to comment Share on other sites More sharing options...
c49er Posted August 28 Share Posted August 28 Retired several years ago. 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 28 Author Share Posted August 28 Just want to thank you for the expert advice you have given me over my many amateur problems I've had with my 48 DeSoto! 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 30 Author Share Posted August 30 Uh oh! I'm back with the original problem again. I was showing a friend how my car was running and shifting with the rear axle on jack stands. And my friend said after I shifted into reverse, "hey you're not in reverse!". "Yes, I am. I pulled the lever toward me and shifted up." My friend answered "but your wheels are still going forward!" So that's my problem now. I can shift the lever into the reverse position, but I am still in low. I fiddled with the control rod nut and the selector nut, but could not get the transmission in reverse. And I have no idea what I'm doing wrong. I've turned the selector nut in and out, but it doesn't seem to make a difference. Link to comment Share on other sites More sharing options...
61polara Posted August 30 Share Posted August 30 I had this problem on my 1950 Chrysler. The problem was in the gearshift leaver just below the steering wheel. At the top of the shift column, there is an olite bearing. The bearing was dry and not letting the shift leaver actually move back far enough to get into reverse, even though you thought it was. Spray some penetrating oil in there and start working the gearshift leaver forward and backwards in the neutral position. This may be your only remaining problem. 2 Link to comment Share on other sites More sharing options...
marcapra Posted August 30 Author Share Posted August 30 Thanks I will try that! Marc. Link to comment Share on other sites More sharing options...
marcapra Posted August 31 Author Share Posted August 31 worked for a couple hours on the shift linkage with zero progress. I tightened the selector rod nut and the gear shift slid into reverse just fine with the engine off. But with the engine running there was a loud scary grinding when I tried to shift into reverse, so I backed off immediately. It's also touchy about going into low and even high. I'm thinking maybe I should disconnect the rods and see if I can shift the trans. at the trans manually just to see if it will go into all three positions. I'm at the point now where I'm beginning to doubt I can fix this problem. I'd like to tow it to a mechanic who could fix it, if I knew of someone who could fix it. There is a guy who works on old cars, but he's about 70 miles away. If I can't find someone closer, I might have to tow it there. Link to comment Share on other sites More sharing options...
c49er Posted August 31 Share Posted August 31 Clutch is not disengaging if grinding into non syncro reverse gear. Forward speed gears 1st/3rd are syncro'd... So you can kinda force the gear shifter and get into the forward gears with no grinding...with a slightly dragging clutch. You have a noise in the clutch FD area and a clutch that's not fully dis-engaging. Put that on the imediate to do list! 1 Link to comment Share on other sites More sharing options...
marcapra Posted August 31 Author Share Posted August 31 So I may have put too much free play into the clutch pedal. that would not disengage the clutch. So I will adjust the clutch rod in a little more. Thanks for the details on grinding problem. Link to comment Share on other sites More sharing options...
marcapra Posted August 31 Author Share Posted August 31 I did, and C49er, you gave me some golden advice. I had adjusted the clutch pedal to have too much free play and that was causing the problem. And I thought it was all in my linkage! But it was the clutch not letting me shift. I just turned the clutch rod nut in quite a few turns and that fixed everything! The stick shift now goes into all three positions, low, high, and reverse, beautifully, and I do have reverse again meaning the wheels are going backwards! Only a pro could give me this advice, so I'm really happy. You've restored my faith in antique Chrysler products. Thank you very much! Marc. 3 1 Link to comment Share on other sites More sharing options...
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