VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Grind coffee not gears!!

Hello All,Jay here with my current challenge! When I got my 31 AE Coach 5 yeas ago I drained the tran fluid (if that is what that stuff was),flushed out the tran,opened the lid,got everything all cleaned out,filled with proper amt of 600w as instructed....Now,what happened next puzzles me still! When tran is filled to proper level you CANNOT shift,up or down without grinding!! Tried double clutching,shifting real slow,wiggling that shifter to "slide er in" ----you name it I tried it!! Noticed as the fluid leaked out (before I fixed leak) the less oil in tran,the better it shifts!! Actually,when it has about 1/4 normal oil level it shifts best!!Clutch seems to be disengaging fully,I do know there are no sync,so why does it shift so much better when it is nearly EMPTY?? Am I using wrong weight oil? Have been practicing 5 yrs. now and still no improvement.....Any thoughts my friends??? THANKS FOR ALL INPUT!

Find a friend with a similar non-synchro vehicle and have him take a try at it. You need to determine whether you need to make an adjustment with your car or the driver.

Thanks Steve6,I am probably O.K on the drivin&shifting end as I have driven stick for the last 50 years including several cars from the 30's,40's and 50's. Like I said before,it seems to have something to do with the level of the oil in the transmission case. Several of the guys in our local car clubs have also driven the car and have the experience as I....But thanks anyway!

The specs. call for 600W. However, drain the transmission and refill with a lighter weight oil and see if that makes a difference.

Thanks J-Dog---I was going to give that a try,but,not before checking with the guys that are in the know,first! Got a good weight I should go to ? Does it matter,det. or nondet.? Gotta be lighter than 90w,correct? Thanks again to all!!

I would try 90 weight, which is about as light as you should go.

Driving stick and driving UNSYNCRONIZED stick is two different worlds. As far as I know,in the case of Chev. all cars after 32 were synchronized. I don't doubt your experience with stick driving, but your problem defies logic as the heavier oil should help to syncronize the speed of the gears being shifted. Is it more of a problem upshifting or downshifting or equal in both? Has it always been that way? I have to agree that its a strange problem. I worked in the trucking industry for 41 years and you would not believe the number of drivers with 20-30 years or more experience that had to be retrained due to changes in the powertrains. When peak torque goes from 2000 rpm to 1200rpm the shift points change dramatically. Many drivers complained about lack of power and certain hills that they had to drop down to third gear to climb at 20mph and then rode with our service manager who climbed the same hill (with an equal load) in 8th gear at 55mph. While the lighter oil may help to alleviate the problem it will not correct it.

Thanks again Steve6--I had the same thoughts on the weightof the oil as you did but had to check with this great crew of mentors!! I do understand the difference between sync vs. non sync.Always more difficult to downshift with no sync has been my experience with this car as well as many I had in the past as trying to find that sweet spot of allowing gears to get to equal rpms to mesh smoothly.
If we eliminate the drivers ability to shift properly,why would the gears mesh more smoothly with the oil low by 3/4 of proper level ? That is my bigest quandry Steve.
One would think that with the proper oil level and proper weight oil,the trans would mesh BETTER,not worse as the oil would help to slow the gears to the same speed so as to mesh together more smoothly.Hope my train of thought here makes some sorta sense . The question is why it shifts so well when it is almost empty vs.filled to proper level.Thanks Steve6

Hello jay32249,
Your current challenge does seem puzzling. To better understand your post, there are some questions that need answering. Before you fixed your transmission oil leak, was it and were you shifting ok? If yes, something changed after your repair. If no, the shifting problem was not affected by any servicing. Your answer should guide you toward resolving the problem. Besides having a friend test drive your Coach, you should test drive their non-sync geared vehicle. This troubleshoots the operator and the Coach separately. The findings should guide you toward resolving the problem. Another mechanical check to be made is if the clutch system in your Coach is actually fully disengaging or not. In an open and safe area, try starting your engine with the clutch pedal to the floor and the transmission in gear. Does the Coach start and remain stationary or does it want to move? If there are no issues with the clutch system or driver operating error, then suspect issues within the transmission and/or shifter mechanism. I hope you resolve the issue and let us know what you find.

Thanks Harry,All are good ideas and will run down the whole list of ideas from all.
Have driven other vehicles with no syncro,not a AE Coach cause I do not know anyone that has one,some shift good for me,some a bit grumpier if you will! All in all I believe it to be a mechanical problem,the clutch,throwout,etc. was going to be the next direction to be honest.Thank you for those ideas,Jay

During the war years, and due to steel shortages, GM contracted with some Amish woodworkers (who would not go overseas) to make transmission replacement gears out of hardwood blocks (maple or walnut). While the gears worked excellent, the owners found sometimes grinding on shifting due to the wood gears being bouyant in the tranny. They found if they lowered the water level in the tranny (oil was also short in that period so water was used as a lubricant)then the gears no longer floated and the grinding problem went away. Just a suggestion!

Two major revelations all in the same day.

I did not know that.

Hey Gunsmoke---that is some really wild stuff !! How strange is that ! Nope,no wooden gears here though ..LOL

That is hilarious! Of course the wooden gears would float in the water. Steel gears would just sink to the bottom.