LST2 two speed jumping the hump on the shaft?

[olds97_lss]

I just installed a set of LST2 tires on my aftershock with 20mm adapters. I was running +3 pinion/gear flip with standard MT tires without issue. I was looking to get larger wheels/tires to make landings a bit softer by adding some ground clearance.

Anyway, I dropped down to a +1 CB, installed the tires, adjusted my two speed a bit to compensate and took it out for a run. Seemed ok for the first half tank or so. I was adjusting the two speed so it would engage later, as it was, I overdid it and it was hitting second in about 5 feet. Once I got the two speed close to where I wanted it, I was jamming around pretty hard in grass/off grass to pavement just to feel it out a bit. Required a bit of tune adjustment (LRP28S3) and once I got the engine dialed in, I was fairly happy with the results. Although, I may step down to a standard CB.

Anyway, once I had it dialed in pretty good, I noticed a really bad lurching once it hit second gear. It would make a pop-pop sound, but lurch pretty bad until I let off the gas.

My first thought was a blown diff. So, I pulled it in, grabbed the rear bumper and gently applied throttle on pavement until there was quite a bit of strain and the tires were spinning on the ground. Didn't notice either the front or rear getting weird or any popping. I was pretty aggressive with this due to if it is a blown diff, I'd rather have it shell out now so I can replace it rather than not know what it is.

Then once I was content that it didn't seem to be a diff, I drove it around a bit more and it would pop-pop and lurch once it was in second gear.

So, anyone have a diagnosis? I'm wondering if the two speed shoes are hopping over the hump on the shaft they run on.

Here are a few photo's of my two speed:

It appears that the roller has hopped the hump as there are track marks on the high side of the shaft. Although, I'm not sure if this is a sign of something else or what.

If this doesn't seem plausible, let me know what you think it may be.
If it is this, would a new pair of shoes fix it or do I have to drop the dough on a new 2-speed hub as well?

 

[AxialLST]

I am not sure how the 2 speed rollers inside the clutch itself are held into the clutch, but do the rollers themselves look worn? Looking at the pictures, the contacting surface of the rollers inside the clutch look shiny, which may be a sign of metal wear. It sounds to me like when the clutch expands for 2nd gear the rollers lose enough contact to slip around the hub (as indicated by the track marks on the hub). Maybe the pins that hold the rollers inside the clutch have worn through the clutch material that holds them, allowing them to shift outwards at speed? But from looking at the pictures, the hub still looks fine with minimal wear. I would just go with the new shoes and see what it does from there.



Edit: And after looking at the pictures a little harder the surface of the 2 spd hub where the rollers would be does look a little rounded compared to the rest of the hub, so maybe its ther combination of that and the rollers being a little loose?

-AxialLST

 

[AxialLST]

Here is where I mean by the worn edge.

-AxialLST

 

[olds97_lss]

Yeah, I get what your saying. I decided to try and bastardize it for the time being and took out the little rollers, then put a thin layer of cardboard under them and popped them back in. This raised the rollers a bit to where they were dragging ever so slightly on the outer ring.

I took it out and ran it for about 3/4 tank, and it appears the problem went away and a new one cropped up... thought my LRP died on me in a catastrophic way. Was running at about 1/4 throttle, then it just died, hard. My gut said busted con-rod... my head said "OH NO!!! NOT MY BABY!!!"... pulled the starter, it appeared to not be grabbing. Combined with how it died, I was certain the con-rod snapped.

Turns out, the back plate screws all came loose and the OWB jammed the crank which stalled it (or the massive air leak did it). Then when I pulled the starter, it was spinning nothing but the bearing.

Tore it down, cleaned it up/out, polished the sleeve up a bit and put it all back together. There was a bit of debris in there from the crank banging the OWB, but not a lot, so I cleaned the entire thing out really well prior to putting it back together.

Hopefully will be able to give it a run next weekend, but I believe I'm busy.

If nothing else, let this be a warning to all of you! Do at least an engine tear down prior to running every season to make sure everything is clean, sealed and tight.

 

[AxialLST]

Ill keep my fingers crossed for you, theres not much that gives you that sinking stomach feeling quite like an engine dying like that.


-AxialLST