37-50 transmission

[sly37]

 I just swapped in a transmission I purchased recently and found that it slips out of third gear while going down the road. It doesn't pop out in applying throttle or letting off, just kinda works its way out. Also I noticed the trans to bellhousing gasket wasnt installed. My trans guy isn't familiar with these but thought the 3rd gear may be loose on the shaft. Any ideas? Trans I removed worked well in third.
         D Schroeder

[Steve Passmore]

Thats usually a selector or the indent springs worn. I have to ask, why swap out one that was working?

[sly37]

1st and second gears were shot. Couldn't find others. Ran into this one so bought it. If anybody is familiar this is the coupe used in raiders of the lost ark. Original condition other then paint.

[harvey b]

If you still have your old tranny,you might be able to combine the parts from each of them to make 1 good one?.it is a job for the pros,as special tools are needed to remove some of the shafts?.It may be tough to find someone brave enough to tackle it too .There are some service procedures in the shop manual for them.On my 37 It did not have the gasket for about 6 years,i did not find amuch difference with it or without it?,i do have a leak around the shifter base,but that is not what you have.Many of the sellers sell the gaskets in sets of 3,the big one between the bellhousing is wrong,as the 37 has a hole in it for the rod to pass through,it is a 37 only feature,i made my own when I did mine,not that hard with gasket paper,with the tranny removed you usually can see the old outline where it used to be.Not sure if I still have a copy of it here or not,but will look and see. Harvey

[sly37]

Appreciate the info. I can remove the top while in the car. May swap that with the other see what happens. Do the springs as well. Been driving it around alot this last week and the fix it list is growing and growing.

[Steve Passmore]

Appreciate the info. I can remove the top while in the car. May swap that with the other see what happens. Do the springs as well.

I think your wrong there as the 37 is a bottom loader, there is no top cover and considerable dismantling has to take place to get at the spring and selectors as Harvey has just said.

[Jay Friedman]

Although I've never worked on a 37 floor shift (bottom loader) Cad transmission, I've worked quite a bit on 41-53 column shift (top loader) types, which are practically the same except for the shifter mechanism.  I agree with what Harvey B wrote except for his contention that working on one of these transmissions "is a job for the pros, as special tools are needed to remove some of the shafts".  In my experience I've only needed 2 special tools and they are not very unusual:

1. a metal or wooden shaft 7 1/8 inches long and for a 37 transmission 15/16 in diameter which is used to remove and replace the countershaft.  You use it as a drift to tap the countershaft in and out in such a way that it holds the needle bearings surrounding it in place.  You can make it out of wood, aluminum or any other metal.  If you are switching parts from one transmission to another, I think you could use the countershaft of the donor transmission for this purpose; ie. the one not going back into the car;

2. A special pliers which is used to remove the heavy snap rings on the front input shaft bearing and the second gear.  It is KD Tool 2534 and can be ordered for about $25 from MyToolStore.com (800-347-5096).  You have to grind down the tips so that it fits in the snap ring grooves 

(There is also a special tool to replace the shifter shafts on column shift types which, of course, you won't need.)

In my opinion if you have reasonable skills you should be able to remove and replace the input shaft, the countershaft, the synchronizer and related parts, which are the only components I think you'll have to work on for the problem you have.  (You don't need to touch the reverse idler gear or its shaft.)  Two words of caution: 1. Note well the exact placement of the spacers at either end of the countershaft as you take it apart; 2. Make sure you install the gasket Harvey B mentions between the front face of the transmission and the bell housing after cutting a hole for the shaft that sticks into the bell housing (which only is true of 37 transmissions); 3. put gasket sealant on all bolts going into holes that are not blind.

Several CLCers have written up the procedures for working on the column shift versions of these transmissions.  If you let me know your snail mail address, I'll send you photocopies.  Also,  the Cadillac shop manuals I'm familiar with (1941 and 49) are pretty good too, so the 37 shop manual should help too if you have a copy. 

[Steve Passmore]

I'm afraid the 37 box is nothing like that Jay, and Harvey is correct, the 37 has the strangest pins that hold the selector forks to the shafts and special tools are needed that actually screw onto these pins to extract them and another to drive them back in. One of the tools has to work up through the filler hole to pull one of the pins. Nothing comes out the box until they are removed. Not a job to attempt while in situ.

[Jay Friedman]

I stand corrected.  Sorry about that, guys.

[sly37]

The transmission has been my biggest headache for the 15 years I've owned it. At least I have two now. Thanks for the input this forum has been in invaluable. One of my favorite sayings.....why reinvent the wheel when somebody has already done it. Can't seem to get the pic right side up...but that's my old lasalle.

[harry s]

There is a special tool for those pins Steve mentioned. It is a Snap On Stud Remover CJS 700. There are also detailed pictures and directions in the shop manual to disassemble and re assemble the trans.    Harry

[Tom Beaver]

Misalignment between the transmission and the crankshaft will also cause the transmission to slip out of 3 rd gear on light throttle or deceleration.  Check the crankshaft to bell housing alignment to verify that any run out is within tolerance.  Check that the transmission front bearing seats into the bell housing properly when you install it.  Make sure the front gasket is the proper thickness and that any gasket sealer used doesn't preclude the transmission from mating properly with the bell housing also that the mounting bolts don't interfere with the alignment.  You can draw the transmission up to the bell housing with the mounting bolts without the transmission front bearing seating properly with the bell housing and then you will play hell trying to figure what went wrong.  Been there done that.

Tom Beaver

[sly37]

That sounds the easiest so far. Ill check that out. I have a slight vibration I've never felt in anything before. Could be it.

[Steve Passmore]

There is a special tool for those pins Steve mentioned. It is a Snap On Stud Remover CJS 700. There are also detailed pictures and directions in the shop manual to disassemble and re assemble the trans.    Harry

Is that available as a single item Harry?  When you search for CJS 700 there only seems to be a complete expensive kit available. I would like to get hold of the correct extractor.

[harry s]

Steve, I was able to get a smaller set of four that included the right size for this application. I bought mine a number of years ago from one of the Snap On guys.  The full set is definitely expensive.     Harry

[Classic]

I recently had occasion to contact the Snap-On home office about a 60 year old broken box end wrench (which I inherited already broken).  I called to ask if their lifetime warranty still applied.  I was astonished when they said 'yes'.  They immediately sent me a new $60 wrench and didn't even want the old one back!  With that kind of superb customer service, maybe someone could call and ask them if you could buy just the one tool from the set.  If they would require a minimum order, I'd buy one.

PS:  With regard to the broken wrench, I first contacted the local Snap-On retailer and he was of no help at all.  That's why I called the home office.

[Steve Passmore]

[quote  With that kind of superb customer service, maybe someone could call and ask them if you could buy just the one tool from the set.  If they would require a minimum order, I'd buy one.

Well I cant do anything from here in England but if anyone can get any joy from Snap-on I would be happy to buy one.