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Gyromatic problem


Alexander

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Hi guys

First, a quick thanks to all who helped with my DOT 5 brake fluid conversion. All went well- the car stops great and has no leaks!

Now that the brakes work I took the car for a drive. I seem to have a problem with the gyromatic shifting. between shifts the gears grind untill i fully release the acclartor and the rpms match to what they want.

is this normal? I cant imaging driving around like this.

Your thoughts would be greatly appreciated.

Thanks

Alex

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I tried again just to make sure I am doing it right. I bring the car up to speed then let go of the throttle all the way. The transmission grinds for about 1-seconds then the gears shift.

The engine drops to idle correctly and quickly (450 rpm)

I don't even know where to start, is it mechanical, electrical, hydraulic?

Thank you

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I'm talking about the oil,10 wt., in the transmission not in the fluid drive which has its own fluid.

Sometimes 90 wt. has been put in the transmission and that will effict the shifting. The three speed uses 90 wt. and the giromatic uses 10 wt.

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Hot idle speed has to be correct-not too fast. Trans has to pump up (10W.)oil - pressure 35-40 psi.If you were to disconnect wiring off of the transmission solenoid and the governer and drive the car and now it quickly upshifts properly the problem is electrical. Take off all of the trans wiring on a fluid drive (Gyromatic) car and they should imediately upshift- almost instantly! The transmission will not downshift until you come to a complete stop and wait a few seconds till the oil pressure drops and lets the direct speed blocker ring and sleeve retract into low range. If it still grinds on upshift problem is inside of the trans-possibly blocker ring/sleeve ect. This is a quick way to decide if the problem is an electrical or transmission mechanical (internal) problem.

Bob

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Great information!!!

I did not know that the trans will shift with all the electrical disconnected.

when you say the car will shift quickly with all the eclectic disconnected, do you mean it will happen early (say 5 mph)? or does it mean there will not be a delay during the shifting process.

Thank you,

Alex

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With the wiring disconnected the oil pump control valve does not work at all. So the oil pump builds up 35-40 lbs of oil pressure imediately which means that the direct speed sleeve and blocker will attempt to upshift into high range with no delay, 5-15 MPH as soon as you let up on the the throttle. These hydraulically operated 2 range transmissions need the electrical controls to make the transmission shift up and down at the correct speeds. With out them it (trans) will want to upshift as soon as the car gets going and WILL NOT downshift until the car comes to a complete stop with the clutch pushed in. Oil pressure has to drop to zero lbs. so direct speed sleeve can pull back out of high range with no load on the input shaft. A worn input shaft and sleeve/blocker ring assembly can cause the problem you are describing-grinding, banging delayed upshifts . Also low oil pressure.

Bob

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Im with Dodgeb4ya----sounds like a worn Blocker ring,which is a common prob with these trannys. Later ones used a redesigned Blocker ring which lasted longer. The rings purpose is to syncronize the speed of the mainshaft with the input shaft so the shift can be accomplished. Hate to say it,but if thats what it is-- they are a bit difficult to replace for a person who hasnt been into one before. First job is finding one. The manual tells how to replace it step by step tho, and a few swear words and a lot of beer and it can be done. I redid my first one three times before I got it right. But then the next guy might find it easier.

Frank M.

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Over the years I`ve realized to fix this transmission to be 100% sure of a "proper " fix if it is the bolcker ring problem the input shaft/updated-steel and brass blocker ring and clutch sleeve should all be replaced but--- try to find the input shaft new! After many,many years of swap meets and searching through auctions and old dealerships I finally found a new one! Now it`s in a glass case for display only even though I could use it!!! Oh well.

Chrysler parts division sold a kit with the updated blocker ring and sleeve package as a kit. Your old input shaft needs to be carefully looked at. The 12 teeth at the end get worn out - rounded off because of the upshift grinding or just high mileage. Check it carefully if you determine this ends up being your source of the problem.

Good luck, Bob

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And here I thought I was in for a struggle, getting ready to rebuild my 3 speed/OD. Sounds like care and feeding of the Gyro-matic is truly a labor of love!

Think I'll go hug my 3 speed.

This thread is one of those that should be in the tech tips.

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Thank you Frank & Bob

looking at the parts book, I cant seem to figure out which one is the blocker ring and or "sleve clutch??". Is it 21-10-96?

would you happen to have the part number for the replacement kit that includes the sleeve?

I guess I don't have much of a choice. If I find the parts I will attempt the repair.

Perhaps I should just look for another trans? But I guess what are the chances the next one will be good.

I have a used manual 3 speed in the garage, any chance that will work on a 51 coronet with fluid drive?

Thanks guys!

Alex

post-188-13585345939203_thumb.jpg

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Is this what i need? to fix my issue?

new old stock MOPAR transmission syncro blocking or stop ring. It is made of brass, and is just over 1.5 inches inside diameter, and the outside diameter is about 2-7/16 including the nubs. Not sure of the exact year or part number, but it says should fit 1940's or 1950's

Thanks

Alex

post-188-13585345942397_thumb.jpg

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That is a 12 tooth ring and that is correct for the 1946-1953 M-5 an M6 transmissions. You really should get the ring and sleeve package # 1311177.

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Forgot to mention the steel and brass ring is a late-better designed Mopar replacement part #1488930. Make sure of the problem before you purchase these parts unless you would just like to have them on hand!

Bob

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