Jump to content

51 Chrys. with m/6 trans acting up


Lou Earle

Recommended Posts

Friend on mine got a beautiful 4 door 51 Chrysler Windsor 4 door. very pristine western car.

Has one problem- the trans will not shift into hight(4th gear??) except after 2 or 3 miles running then ill not stay there- downshifts back to 3rd when let off gas.

I am betting wrong fluid in the trans- Motor's manual calls for 10 weight oil and I think some probably put grease in the thing.

Anyone got any ideas before he starts t have the local transmission guy go to work on it?

Lou

Link to comment
Share on other sites

Sounds like a bad governor on the M6, but there is a Troubleshooting guide at the Imperial site with some specific steps to go through to diagnose the problems.

I would check all the wires and connections on the carb and the transmission before anything.

M6_FluidCoupler_Clutch_1.jpg

The rear Can with two contacts is the Solenoid, and the other can is the Governor. The one on top is the Ignition Interuptor Switch. You can also see the filler bolt on the Fluid Coupling. (3:00 position)

Link to comment
Share on other sites

I would recommend getting a reprint of the shop manual and following their troubleshooting proceedure.

But, it wouldn't hurt to drain the tranny and refill with SAE 10 motor oil, then drive it... also make sure the engine idle speed is set between 450 and 550 RPM. If someone did fill it with gear-lube, best to drain it, fill with kerosene, drive the car slowly around the block ( or run on jack-stands), drain again, then fill with SAE 10.

If it still hesitates to up-shift, and when it does, keeps dropping-out of 4th, I would next pull the access panel from the passenger-side of the tranny hump, and disconnect the wires from the solenoid ( round "can", on the right-rear of the tranny), tape the ends of each wire with e-tape, then drive the car again.

If it now upshifts and stays in 4th, this indicates that the tranny's internals are working, and that the shifting problem is somewhere in the wiring/electrical controls ( back to the shop manual ).

I wouldn't bother taking it to the local tranny shop unless they have someone there who's older than Methusaleh and actually WORKED on Chrysler semi-autos back in the day...

These are NOTHING like any automatic tranny made since 1955. They are "self-shifting" manual gearboxes (sliding-gear) and must be understood on their own terms. It took me several years and many frustrated hours under my '48 New Yorker to get this concept through my thick head.

Good luck with it !

Frank McMullen

Link to comment
Share on other sites

I had a '51 DeSoto that had an unusual shifting problem. It made a large clunk when it upshifted to 4th unless you let it shift at 10mph. Went through every test in the book and then some including experimenting with different types and weights of oil. I finally sold the car to a guy who said he had a blown Hemi to put in it.

Interestingly different weights and types of oil made no difference in the shifting!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use