Transmission Problems are continuing.

[brian6622]

Transmission Problems are continuing.

For two seasons I have had transmission problems with my atomic 4 engine.

It appears to have happened when the transmission was in resverse and it was revved high and reverse stopped working.

THe people at Moyer have been very helpful but here is thesituation now and the steps and the results of those steps to fix the problem this year.

WHen we started out before doing any tinkering we had no reverse, although when in neutrall the prop turns ever so slowly in reverse as if a clutch was almost totally pushed in. Forward worked fine.

STEP ONE: REVERSE tightened one notch
FORWARD left as it was
RESULT: Seems that forward and reverse are overlapping, and engine stalls out in forward, some power in reverse

STEP TWO: REVERSE left as is
FORWARD back off two notches
RESULT: Minimal Forward, same reverse

STEP THREE: REVERSE left as is
FORWARD tighten one notch
RESULT: Forward works but stall out immediately becasue of forward/reverse overlap

STEP FOUR: REVERSE back off two notches
FORWARD tighten one notch
RESULT: Forward OK, but no reverse

There is no linkage probelm since arm on transmissionwill not go back any further even with linkage disconnected.

This problem is driving me nuts. It seems to have been going on forever.

I am looking for the following:

1) to understand what is wrong.
2) to find a local person in (Midland area) Central Ontario, Canada who can fix it if it is fixable
3) to know if I have missed trying anything
4) if none of the above what are my options

[Al Schober]

Brian,
You say no linkage problem. I'm not so sure. I've had my share of both (sometimes it seems like more).
I recommend you disconnect your linkage and try shifting using just the lever on the outside of the transmission. I'd even try this with the engine off so you can watch things inside the case. I'd look for things that don't seem 'right' - lost motion at one of the connections. Bad throw out bearing, loose or missing keys, excessive clearances - any of these are possible causes of lost motion inside the transmission. Look particularly for parts that don't move right away when the mating part moves. Once this checks out, I'd move on to the shift linkage.
Does the range of travel of the linkage agree with what the transmission needs? Your linkage may have more than adequate travel in the forward direction, resulting is a loss of travel in the reverse direction. In particular, check the cable for freedom of motion (time for new cable?). Also, check that both ends of the JACKET of the cable are secure. The shifter end of the jacket is usually well secured to the shifter, but the transmission end is often a weak point. On my boat, the transmission end was secured to a block, but the block had come loose from the hull.
These transmissions do work properly. Yours doesn't. Your challenge is to find out why.

[hanleyclifford]

A clue in your post that the reverse stopped working after an over revving event. Could you have damaged the clutch material inside the band? Reverse is obtained by stopping the drum and forcing power thru the planetary gears. How about some pictures of the inside of that box?

[JOHN COOKSON]

A clue in your post that the reverse stopped working after an over revving event. Could you have damaged the clutch material inside the band? Reverse is obtained by stopping the drum and forcing power thru the planetary gears. How about some pictures of the inside of that box?

6622
Welcome to the forum. I'm sure the experts here will be able to help with the trany problem.
It was also my first impression that something was marginal with the clutch and the over revving did it in.
Questions: Can you find a true neutral where the prop was not turning after reverse went out? And did you have a true neutral before the reverse went out?
Is there anything else that changed transmission wise when neutral stopped working?

TRUE GRIT

[Mo]

Few years back I had a problem setting up a transmission and it was caused by lack of power from the engine. The valves were seized and although it sounded OK at idle, and would rev up in neutral, the engine would stall in forward and had very little reverse. It's a little different from you situation, however, it might be a good idea to Compression Check the engine. If you have stuck valves, stalling in forward is very common. Once you set up the gear box to try and run in that situation everything else will be off...I've done that and once the engine was fixed had to go back and set up the tranny again. It took a while to figure it out though.

EDIT: If you do a compression check use a gauge. The thumb test indicated there was compression and was very misleading...it was a gauge, after a few days of unsuccessful attempts to resolve the issue, that identified the problem.

[edwardc]

The fact that you can stall the engine with a reverse/forward overlap indicates that the reverse friction band has plenty of grip and is working fine.

In forward, the whole planetary gear assembly is bypassed, and the entire assembly rotates as a single unit. Since this works, it would seem to indicate a failure somewhere in the planetary gears themselves.