tranny issues

[48chrysler]

i have a 48 new yorker spitfire 8....i received it through my grandfather's passing...it sat in a heated building for 35+ years...i got it running and driving...all new wheel cylinders and rebuilt the water pump my self...it has the fluidrive transmission. and i cant get it to shift into the higher gears so it maxes out at about 30 mph....any ideas...i don't want to dump a whole bunch of money into it..i'm afraid that replacing solenoids will just be a costly adventure that might not fix my problem ..will any other transmissions fit...what would you guys do

thanks

Seth

[BobT-47P15]

I going to presume you checked the fluid levels in that transmission. ?

[PatS....]

Usually if you go through the wiring to check that all the connections are clean and tight, no broken wires, good grounds you should be OK, also as mentioned, fluid level and the correct fluid...different for the fluid coupling and for the transmission...is important.

Those M5's (which is what you have) and the next generation M6 are actually very simple and virtually bulletproof.

You could also take the top off the governor (the one with 4 screws) and spray some carb cleaner in there and then some white lithium grease so it will spin freely.

Also, the Imperial Club website has some troubleshooting guides from Chrysler posted online to walk you through the testing of these.

James Douglas has also done some in depth research into the best modern fluid to use in the fluid coupling...check out his post on that.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=14473

Edited June 4, 2009 by PatS....

[Tom Skinner]

Dear 48Chrysler,

If the engine is idling to high - say over 500 rpm

it will not upshift. Of course the Fluid must be full as well

because the pressure in that tranny has to be over 40psi

to shift smoothly also.

So if its racing (the motor) turn it back some and it will shift.

Tom

[Jim Yergin]

Dear 48Chrysler,

If the engine is idling to high - say over 500 rpm

it will not upshift. Of course the Fluid must be full as well

because the pressure in that tranny has to be over 40psi

to shift smoothly also.

So if its racing (the motor) turn it back some and it will shift.

Tom

Tom,

Do you happen to know if the same is true for the Borg Warn overdrive? If the idle is too high will it not shift into overdrive when you let up on the gas?

Jim Yergin

[Young Ed]

Jim I dont see how the idle would have anything to do with the OD since its not supposed to go to OD under 35MPH.

[Dodgeb4ya]

If your hydraulically operated transmission (M-5) won't even try to upshift and yet the car will pull away from a complete stop ok and accelerate well, it's one of two things basically- no transmission oil pressure caused by low fluid level of 10W oil in the transmission-check the square fluid level plug on the pass. side of the trans 1/2 way up-forward part of the case.

Second reason is the Oil Pressure control solenoid is causing the oil pressure to be bled off back into the case to keep the trans in downshift position- caused by possible wiring issue- 6 volts constantly being fed to the solenoid preventing oil pressure buildup for upshifts.

Quickest test to see if the transmission itself mechanically is good, you need to to prevent all 6 Volt power to the transmission to cause it to have to upshift as soon as you get going- do this by removing the fuse in the 5 terminal transmission relay on the drivers side inner fender, if trans is now upshifting smoothly and imediately it it means you have an electrical issue to deal with-wiring/solenoid/relay ect-not an internal trans issue. Also the transmission will take more time to downshift at a stop with the clutch pedal pushed in because you have no voltage to the solenoid preventing the dumping of oil pressure for a automatic downshifts. Remember that if you were to have no wiring hooked up on a M-5 or 6 trans they will upshift imediately after letting off the gas- and they will not downshift W/ floored gas pedal at road speed and also you will have to wait at a complete stop W/ clutch pedal in to wait for the delayed (slow bleed down) of oil pressure to let the direct speed blocker ring/sleeve pull out of high range. If it upshifts by removing the fuse thats a good thing- trans is ok so now check all the wiring 1st, usually it's in need of repair or complete replacement. You can buy that harniss new from "Rhode Island Wiring". Next step to clean /check the solenoid/interupter sw./ carb kick down sw./governer and relay. Use the factory books or Imperial website to guide you.

Another BIG problem that is common on these transmissions is wear of the main drive pinion (input shaft) and mating blocker ring and sleeve-these will sometimes if worn bad enough cause a loud scary bang upon upshifts and or rarely no upshift at all but will at least make some grinding noise on an attempted upshift.

You need to get the factory shop manual or a Motors repair manual for complete operation info to help you in fixing/maintaining this car. Solenoids and governers rarely fail. I have several of these cars and have worked on lots of them for people over the years so I have seen most all the trouble issues they can have- both 6 and 8 cylinders.

Good luck!

Bob

[Tom Skinner]

Jim,

I don't know about Borg Warn overdrives.

Just M6 Fluid Drives in 1948 Chrysler Royals (have had 2 such cars) for the last 35 years.

As for all that changing out wire harnesses stuff Dodge4ya is talking about

I would opt for changing out that 3-1/2 Pints of 10wt oil in the tranny

and setting my Idle down and going for a test drive before spending a grand on wiring. Of course checking the fuse etc is prudent and running some diagnostic checks (electrical) if the couple of things I mention above didn't help.

All in all great advice has been given above, but by all means keep it simple.

One doesn't need a tranny overhaul or wiring overhaul to get their tranny to upshift.

In his book "A Chrysler Chronicle" Dave Floyd describes how he mixes a little

kerosene (say 1 pint to the 2-1/2 pints of 10wt oil) into the tranny.

Then drive say 10-20 miles, dump it and add back straight 10wt oil.

In this way Dave Floyd rinsed the gunk out of his Fluid Drive Tranny.

It then shifted real smooth. Of course cleaning the Filter will tell alot about the health of this transmission also. The Plug is magnetized and will attract loose fillings or burs that might tell of possible problems inside without taking it apart alot can be done to correct these tranny's they are all but bullet proof as said above.

Tom

[Dodgeb4ya]

Yes the filter probably should be removed to see whats in it-probably not a lot. It's just a tube screen and usually just a few tiny bits of brass and sliver filings are all I have found. At this stage I wouldn't waste time running kerosene through it-just make sure it's full of 10 weight or even 20W at this point just to see if the trans will shift and if so then change it out later. Idle @ 5-600 RPM-it will upshift at even 700 rpm. See if it will now upshift. If not pull the fuse-if now upshifting do the transmission electrical diagnosis work.

I did not say Buy a $1000.00 complete car electrical harniss as you refer to Tom. (As for all that changing out wire harnesses stuff Dodge4ya is talking about) Nice statement! I meant for some who doesn't know how to fix a tatered/frayed transmission harniss they are available for about a $130.00! And it is simple to install. I agree do the simple stuff 1st. If the engine compartment has ugly cloth wiring it needs to be fixed to make the car reliable and safe to drive too. I have done several show car rewire's on these C38/9 Chryslers. Sounds like Seth wants to do the car right and not spend a fortune on it- thats a good plan. I'm just offering hopefully some good help!

Bob

[greg g]

are you selecting the correct range, the trans has two sets of gears, is it shifting and them topping out at 30? You may have it in low range. Driving gears are in the same position that 3rd is in on a three on a tree.