Michigan 55B questions?

[chipped tooth]

Hi guys, New member here!

I picked up myself an Michigan 55B loader a while back and have a few questions.

Pretty sure it's an 1977 model going by the serial #

V378 Cummins.

First off everything seems to work pretty good except the transmission.

Reverse gears seem to grab better than forward gears.

All 3 speeds work both directions but 3rd is almost as if it's non existent for a minute or two when cold, it's better warm.
Reverse 3rd seems to grab sooner.

Fluid is a mixture of 10wt and Dexron atf.
It is full and the drain screen was spotless when I checked it.

Also 1st and 2nd fwd don't seem to "grab" like in reverse.

It still spins the tires and with it locked down the drive shaft from converter to transmission doesn't turn unless the tires spin.

Is there a regulator or such what could cause the forward to reverse differences? Clutch plates worn?

Also the loader sat for a few years before I purchased it.
There was many mud dobber nested all over, on holes under hood you name it!

Where is the crankcase vent?
I can't seem to find it and have been using a race car breather in place of the fill cap.

Thanks in advance anyone who has some insight on my issues!

 

[chipped tooth]

Couple pics of my old girl!

 

[chipped tooth]

I removed the decoupler valve and piston assembly that kicks trans out of gear upon left brake application.
It was spotless, valve and piston assembly. but according to parts schematic there seems to be an thin disc missing?

Anyone know what that could be? Drawing is sorta poor to actually tell.

Doesn't make sense because a disc would keep the valve from returning maybe .060

 

[chipped tooth]

Little update on the 55.

Since we have a bunch of snow recently I've had a chance to work the old girl...

I changed transmission fluid to ATF type F little trick Mopar racers used to positive up the 727 shifts.

Well not sure if there was an actual problem but she's good as new now!

Possibly the original fill was something other than 10w?!

 

[steve wherley]

make sure you are check trans oil running . It will be 2 gals low if checking shut off

 

[chipped tooth]

Definitely! When I first bought it the trans fluid was probably 2-3 gallons over full, the original owner probably filled it cold and 1 of the tranny cooler lines had an slow leak so he might have added extra, all is good now!

 

[Mike Van]

Is type F thinner?

 

[chipped tooth]

I don't believe the viscosity of Dexron vs type F is any different.
type F has friction modifiers to make the clutches slip less.
old Ford's didn't have the automatic transmission thing figured out to good so a special grippier fluid was used.

I know the manual only specifies Dexron for my loader but I have used type F in numerous race cars and sometimes even lack luster shifting GM and Mopar transmission to sorta crutch a little more time out of them. I can't imagine there's anything special about my loaders transmission that type F could hurt.

It was a performance tip back in the day for the Mopar and GM guy's!

 

[Mike Van]

Thanks for that info -

 

[Ryan151]

Hello, Ive got a 55b and I am pretty knowledgeable with the transmissions and just about everything on these little guys. I read you changed your oil and its working better now which is good. when I first got my 55b it was a dog turns out all the problem was is it was missing 1 spring in the regulator valve on the torque converter. Even so I would recommend you do a complete system pressure test just to make sure you don't have a possible forward clutch pack issue. I can walk you through how to do that if you like

 

[chipped tooth]

That would be great Ryan!

It's been working excellent lately so it probably wouldn't be till summer before I could tackle the pressure check job.

1 steering cylinder started to drip a little so once the weather is nice I'll set some time aside to work on the old girl.

The transmission always worked fine it was just the delayed 3rd gear fwd stall/shift that seems a bit slower in fwd than reverse.

Old girl sure is handy! Glad I decided to pick her up!!

 

[Ryan151]

yeah I love my 55b

 

[AndyT]

I'm new here too, and I just picked up a 55b as well. I don't have any of the component manuals. I was wondering if you could post the test pressures for the tranny, mine seems a little sluggish.