Reversing gear video

[Don Moyer]

Here's a clip from our reversing gear video, to give you some idea of the style and content. This video describes the operating concept of the reversing gear, as well as instructions for adjustment and maintenance, and is available in both DVD and VHS formats.

Don

[txsailorboy]

Any still pictures/drawings/web site/etc available that show how the Brake Band Reversing Bar, MMI #161 (OXX Paragon Reversing Gear) connects to the Reversing Gear Brake Band, MMI #253? Same concerning how the Spring connects. I'm in the process of putting it all back together, and I can't remember how it fits. I knew I should have taken better notes.
Emmett

[Don Moyer]

Emmett,

If you have a copy of our MMI Service and Overhaul Manual, Chapter 6 has pictures showing how the reversing bar is configured. I don't know of any other place where good still pictures exist of this assembly. Basically, the end of the bar with the connecting hook installs into the top of the shifting yoke, and the end of the bar with a ramp slides between the roller in the end of the adjusting bolt and the large ear of the brake band.

Don

[ne57301]

This is a silly question and it's probably answered in many places but..

In the 'Forward Mode Adjusting Procedure' in Chapter 6 of the Overhaul Manual, in step 6 it says turning the adjusting collar clockwise will tighten the clutch. Clockwise as you face which direction? I will be looking at the 'transmission' in the same direction as the picture in Fig 7. Will I rotate the adjusting collar to the right or left as seen in that picture to tighten Forward Mode.

And is this the right adjustment if my engine "slips out of gear" when I give it too much throttle? If I just back off the throttle it re-engages and I can accelerate again but it slips out at about 1500-1600 rpm.

Thanks,
Randy

[Mark S]

Clockwise as if you were behind the engine looking forward at the reversing gear. In the video clip, you would be standing at Don's right looking at the shaft end of the reversing gear. Adjusting the collar by turning it clockwise should reduce and ultimately eliminate all slipping. It's a trial and error process. Let us know how you make out.

Mark S

[ne57301]

Thanks Mark. I'll check back after I dig into it. I think I must have been cutting it close before but I had to put a new shifter cable on and it probably is ever so slightly different than the old one. I'll go through Don's full procedure including adjusting the reversing gear.

[Don Moyer]

A one-notch adjustment should take care of your slippage, and be careful to get the tip of the retaining screw into the notch before you tighten it or you will risk breaking out a small piece of the pressure plate.

Don

[RobH2]

I adjusted my Forward and Reverse today as reverse was not engaging. It was a lot easier than I feared it might be but Don's video, like all of them, was excellent and demystifying.

My shifter is (has always been) pretty hard to engage into "forward" so I changed it by one cog and it felt much better. Great I thought. I adjusted the "reverse" one turn of that nut to the next flat and now reverse is great.

My issue is that my engine never got over 1200RPM underway, clean bottom and prop etc. It's just he way it's been since I bought it 14 years ago. With the new "forward" adjustment, I'd get up to about 1000RPM and it would slip out and the RPM would runaway. So I took back that one cog I gave it and decided that I'd just have to live with the very firm engagement on the lever.

Here's my issue, with forward engaged (now back to the original gear cog) and prop pushing, I'm now getting 1800RPM underway. Since I've never been able to get more than 1200RPM it made me wonder if something could be slipping and subsequently overheating? If it's in forward and the prop is driving, is it "in" or "out" with nothing inbetween? Can something slip when engaged if not properly adjusted? I just can't figure out why I'd now have 600 extra RPM since I set it back to the original setting.

[Dave Neptune]

Rob, that is perplexing to say the least. As the reversing gear uses "wet clutches" any slippage when under power will cause over revving of the engine and not a controlled steady RPM issuing power to the prop. Just a note it does take far more force than anticipated to engage the lock in forward on these transmissions.

Was anything cleaned like the prop? Was the engine adjusted in any other way like a tune up at the same time?

Dave Neptune

[RobH2]

My engaging the transmission has always been really firm, like you say, harder than anticipated. But, it's the only Atomic 4 i've ever driven so I have nothing to compare to. Mine might be absolutely normal. But, I'm used to it, it's been the same for 14 years since I bought it.

I did to a tuneup, but checked the RPM afterwards to see if I gained anything. I might have gained 500RPM or so but it really was close to where it's always been on my RPM meter. So, nothing odd there.

But, after that tuneup, literally two days later, I checked the RPM again before doing the transmission adjustment and it was the same. Then, after the transmission tune up and then, "tune back down", I see the RPM change. That's what had me wondering if it could still be engaged and pushing, but also slipping. I have a friend with a Westerbeke who has has a lot of transmission slippage and overheating.

I know our transmissions are different and from reading all of you guys forum posts, I assumend that either it's "in" in forward or "out" and can't be inbetween and slipping. I think that's what I'm hearing, that in 'forward', it can't slip. I ran it for an hour yesterday under full power and everything was fine, just much higher in RPM than ever before.

[Sam]

I have a similar boat 1966 Morgan 34 with original A4, owned for 46 yrs. A few years back I had some variable slippage problems sometimes after a long run. One of the causes i believe was that I used some 10w-30 synthetic blend oil during a mid season oil change - perhaps too much lubricity in a warm engine for the reversing gear plates, went back to regular oil. 2nd cause was some surface rust on the cable near the pin end prior to the shift handle. 3rd this helped the cable sheath to slip occasionally in the hold down clamp - had the pre drilled holes for it so I added a second "U" clamp and tightened the first. I too also thought it was the adjustment ring and the one notch adjustment did increase effort required to engage the shift lever. Steps 1,2 & 3 solved issue.

[Dave Neptune]

Rob, when shifting do you feel the shifter "clicking" NOTICABLY into the "detent"? There is a definite click once engaged.

Dave Neptune

[RobH2]

Dave, yes, I do. You can feel it drop in and set. If I gave it a name it would be "soft clunk."

Sam, interesting. I use 30W consistently. I think you are mainly talking about "reversing" right? I know it can slip as it's pressure plates. Have you had slipping in forward? Again, I don't think this can happen if I'm understanding the system more. Once those gears lock in, it's like it's one piece of metal from the drive shaft to the propshaft. Don talks about it some.

[Sam]

I had intermitent slippage in forward and reverse but usually after a long run ie motoring to the yard for haul out etc - needed high rpm just to move slowly. I switched back to regular oil and made sure cable could not slip in clamp. I tested did not need the extra ring adjustment and set it back to the initial setting - still has a nice detent "feel" and not too much shift lever force needed. Sometimes we make things too complicated.

[edwardc]

When you put collar adjustment back to where it was, is it possible you got the set screw on top of a tooth instead of in the notch, allowing it to loosen?

[RobH2]

No Edward, the screw in between teeth. Don warns over and over how not doing so can cause a big cracking issue.

So here's a debrief to try to keep this thread on topic and less confusing:

1. I adjusted my forward and reversing settings as reverse was not engaging.
2. After adjustment, forward would slip out but reverse was perfect.
3. Reset forward to original teeth setting. (I had marked them prior)
4. Now I have 500-600 extra RPM. Yes, odd indeed.
5. Have determined it's not slipping and artifically showing better engine rev because of poor engagement.
6. One thing I did between the forward adjustment and then setting it back was to rev the engine pretty high and just read the rpms while in neutral. I was a litte afraid of throwing a rod or harming my old engine but I did run it at about 2200 rpm for about 30-seconds with my fingers crossed. Some of you may say, "why the hell did you do that?" Regardless, it's done and nothing blew up...lol...
7. Per #4 above, after that rev up test was when I set the forward back to the original settings.
8. Theory...could it be I knocked some carbon or something off inside the engine and now it has better power output? The "only" abnormal thing I did was to rev it up to 2200. Nothing else I did should be able to increase the same rpms I've had for 13-years.

So, all seems to be well. Reverse is working perfectly, Forward is firm, but maybe a little less firm to engage than it was, even as it's set back to its original adjustment.

Maybe someone can tell me if I accidentally cleaned the inside of my engine by running it as such high rpms, thus, giving me 500-600 new rpms and about 1.25 more kts at full throttle.

[Dave Neptune]

Yes it is possible to clean the cylinders out a bit BUT that also indicates something is amiss with the carb fuel mixture or you got the C-advance working again.

How do the plugs look? Also give a twist of the rotor under the cap to be sure it is moving freely.

Can't really think of much else to cause that sort of change.

Dave Neptune

[RobH2]

Part of what's kind of buried in this long thread is that in the midst of this, I installed a new Indigo Ignition system the day before the transmission adjustments. So, new plugs (old not fouled), wires, cap, infrared rotor, coil and microprocessor controller.
http://www.atomic4.com/ignition.html

Some might argue, "there you go, new ignition, better rpms." But, I did my rpm tests after that new ignition and it was the same. The engine just starts instantaneously now instead of turning over a few times. The new ignition did not affect my rpms.

So, I guess I'm leaning on "something in the engine got knocked off" for now. Anyway, I'm glad to have the rpms so no complaint there. It's just an enigma how I got them.