Reverse Gear Installation, Part 4 - Resolution?

I'm getting far to experienced with pulling this unit off and reinstalling it!

Seems the basic problem was factory assembly of the unit. Way too much black RTV, and perhaps a lack of gaskets. 0.004" clearance between the side plates and the arm, and everything jammed up with black RTV.

The arm that drops the reverse gear was never free to move easily even when new in the box. With the torquing down of installation, it squeezed even more RTV out and essentially locked the arm up against the side plates.

Soooo, I cleaned everything up, used thin paper gaskets to increase arm clearance, and put it all back together.

At which point the arm moved freely and engagement and disengagement was smooth and easy. All was wonderful.

Not quite. Now the blasted thing wouldn't completely disengage from reverse. It would leave the gear hanging just knocking against the rearward transmission gear.

The problem was the external engagement lever on the shaft. It's pinned with a roll pin, and clamp bolted. The subtle problem is the roll pin hole in the shaft is not tight, so the lever arm can be rotated a bit on the shaft.

Once I realized that and adjusted it to its most rearward position, and locked it down (again), all was good.

I have not been out on a ride with it yet. It's cold and raining, and will continue to be this way for a few more days. But I do have great hopes. Sitting on the jack, it works superbly now. Very easy to move and engage or disengage. What was a ham fisted operation before, right from the start, is now a two finger thing.

It does crash mightily when engaging. I see why some folk recommend engaging 1st gear to stop the sprockets from spinning, engaging reverse, and then disengaging 1st.

It's stupid fast in reverse. 12 mph at idle, according to the speedometer. Just a wee bit below 2nd gear ratio. Stupid fast. But, manageable with clutch slippage.

It's a little spooky with regards to accidental engagement. The only thing holding the gear up is the roll pin sitting in the gate. It's shown in this picture.

If that pin falls out or breaks, or that gate tooth wears away, the arm will drop, the gear engage, and some sort of horrible thing will happen.

None the less, backing the bike out of the shed and across the soft grass was delightfully easy with the reverse. I still have great hopes for wonderfullness, and do anticipate being quite happy with having a reverse gear.

It looks like they have OK engineering but iffy manufacturing. I'm not real sure about that roll pin. Dunno. Maybe a solid piece or add an extra spring to hold it there or something. Maybe it's not an issue.

Hopefully you got all the problems worked out. They can't be selling very many of those things. I'd provide them some feedback on what they screwed up.

Weather played nice last night, so I got to spend some quality time riding and playing with the reverse. All went well. Yippee!

Most importantly, it's now easily actuated and easily used.

I have been in touch with the company, and while they were initially nice and concerned, once they realized they didn't have a warranty claim to deal with, they seem to have "hung up" on me.

What would I do differently with this reverse if I were to engineer it?

1. Lower the ratio by changing the sprockets. I don't know that one could get it down low enough to make me happy, but there is certainly enough room to lower the ratio a fair bit. Trying to work the bike backwards against a load (sunk in the mud or uphill) is darn hard because you're trying to do it in a 2nd gear ratio. You've got to rev the engine up a lot higher than you should, and slip the clutch, while trying to duck walk backwards. Not good.

2. I'd design a more secure way to hold the shifter lever on the shaft so it doesn't slip. Fine splining would probably suffice.

3. I'd create a secondary retainment for holding the engagement gear away. Something as simple as a hole in the arm with a spring and ball dropping into a matching dimple, or double lock. Though honestly, the existing system does seem to work perfectly adequately at the task.

I like that pack the gears with rtv as lube, lifetime fill. Also not a fan or roll pin, wonder if you can pull it out and replace with a stud, having that sucker pop into reverse while riding doesn't sound good. Good luck.

I'd get rid of the split pin and use a coil spring pin or a stud. you could add a spring ball detent if you get slop at a later date.

In reply to Dr. Hess:

I disagree, this is E36 M3ackular engineering. I mean look at the whole of the posts, wrong bolt sizes, washers, half threaded gear, and the coup de grace is this roll pin used to pivot the reverse gear. No engineer worth their salt should rely on a roll pin that experiences friction in a pivoting application to keep the reverse gear from engaging at speed. I wish that you would include the manufacturer's information in these posts to warn others of the deathtrap they await.

In reply to eebasist:

Well, I'm not going to disagree with your assessment, eebasist. I still think that their general engineering idea was sound, but the implementation suspect. Wrong size bolts and washers and the roll pin are primarily a manufacturing problem. The rest maybe worse than just manufacturing. The proof is in how it holds up and functions after the repairs.

Personally, I get my wife to push me back if I'm in a place that bad. And I do the same for her. I suppose that's "manual" reverse.

So, FT, any more feedback?

Not really. Haven't had a chance to ride it all that much in the past few weeks. Weather and being a bit busy.

I should clarify that the unit does not pivot on a roll pin. Top two pictures above show the very solid sized shaft the mechanism pivots on. The roll pin is only going up and down a notched track, to hold it in neutral (disengaged), or to sorta hold it in gear (actually, the power direction on the gears does this).

Company support may or may not exist. They still have never replied to me regarding the problems or clarification of their use of a gasket of the lack there of. I did post a writeup on their facebook page that they eventually replied to, stating only that they thought I'd worked everything out and was happy. So I suspect if you push hard enough, they will provide some sort of support. Probably best done over the phone or face to face.

I ride solo most of the time. No one there to shove my bike backwards. Almost all the time, it's a non-issue. But on those times that it matters, it really does matter. Sorta like having 4wd in a truck because while you hardly ever actually need it, when you do it's the only thing to have.