Transmission slippage

[tvanvran]

Just got back from an hour ride on my 1994 Aspencade trike. About halfway through the ride, in 4 gear and it felt like it tried to slip out of gear. It did it again once I shifted into OD. Did that a total of 4 times during the ride. In looking back over the last year this has happened before. I just thought I didn’t quite get it into gear. Never has it been this regular. Clutch?

[thebruce]

If it's a slip and not a grind, then it's the clutch.

Is there a possibility you changed the oil type before this started? Lots of oils will cause clutch slippage.

It probably happens in a high gear when the motor is pulling the hardest, right?

Short of something simple like oil type or a sticky clutch master/slave or collapsed clutch hose you are looking at a bit of surgery to correct this.

Maybe try bleeding the clutch system... can't hurt. I'm not sure just how tough the clutches are in these. Mine has 267k km on it and it grabs hard... not sure if original or not.

[AZgl1800]

first,
let's assume that it is an oil issue, drain the oil and filter.

just for the sake of proving the oil was the issue, please get some Rotella T6 in 5w40 and run that for a 100 plus miles, more would be better.

that oil does not have any Friction Modifiers, and it has been very successful with solving some transmission issues,
for me, and several folks who have asked me, and used it, and commented back, that it solved their problem.

this is a cheap "fix" if it works. it sells for $18 to $20 at Walmart, that's for a 1 gallon jug.

I have owned two 1500s, a 94SE which had a 4th gear popping out problem.
on that one, I switched to Delo 400 in 15w40..... it stayed in gear better, IF,
I made a point of pressing to be sure it was in 4th gear, and then Backing OFF the throttle to ensure that it engaged solid. rode it a lot of miles w/o doing anything else.
that bike ended up smashed by a Semi truck about 15,000 miles later.

had a '98SE, don't recall the oil I used in it, but I had switched to Rotella by the time I bought that one.
It stayed in gear very well, and did not slip.

[newday777]

Just got back from an hour ride on my 1994 Aspencade trike. About halfway through the ride, in 4 gear and it felt like it tried to slip out of gear. It did it again once I shifted into OD. Did that a total of 4 times during the ride. In looking back over the last year this has happened before. I just thought I didn’t quite get it into gear. Never has it been this regular. Clutch?

Did it pop out of 4th into false neutral or into 3rd gear? Same with 5th gear?

Are you lifting you foot high enough to get the second snick into gear? Or are you lazy shifting?

Do you have the heel/toe shifter on the bike? If so are you leaving your foot on the shifter between gears?

Is there a box of rocks sounds coming from the motor while idling or sitting stopped in gear?

[newday777]

You asked if it could be the clutch.
Have you kept the clutch fluid(Dot4) flushed and bled yearly(2 years max per service manual)?
Is the clutch master cylinder Dot4 fluid grey or red/brown colored? It should be clear to slight yellow tint.

If not kept flushed regularly the slave cylinder get crud in it and doesn't operate the clutch properly.

The clutch plates are very stout in these wings and generally never need replacement in 300,00-500,000 miles.....

[tvanvran]

The transmission will slip in the higher gears and the engine revs as though it slips out of gear. I back off the throttle and it goes back into that gear. No grinding or any other sounds. I have not changed and bled the transmission lines so that could be an issue. An I suppose to be using Rotella T6 5w40 diesel oil?

[newday777]

The transmission will slip in the higher gears and the engine revs as though it slips out of gear. I back off the throttle and it goes back into that gear. No grinding or any other sounds. I have not changed and bled the transmission lines so that could be an issue. An I suppose to be using Rotella T6 5w40 diesel oil?

Clutch slipping and popping out of gear are 2 separate things and needs to be determined what you have.
Popping out of gear and back in will have a slight jerk feeling going into gear.
Answer all the questions above.....

[AZgl1800]

The transmission will slip in the higher gears and the engine revs as though it slips out of gear. I back off the throttle and it goes back into that gear. No grinding or any other sounds. I have not changed and bled the transmission lines so that could be an issue. An I suppose to be using Rotella T6 5w40 diesel oil?

the Rotella T6 will help flush out the clutch plates, so yes, it will help if you use it at least once or twice.
I use it all the time, with excellent results.

[bellboy40]

I think you need to take the cover off the clutch master cylinder and check for a clogged return port. Down at the bottom of the master cylinder is a small cover over the return hole. Just pop that cover off and take a small wire, single wire from a wire brush or a guitar string, and poke it down in there to clear the port.
If that return is clogged up, it would cause your clutch to slip.

[newday777]

I think you need to take the cover off the clutch master cylinder and check for a clogged return port. Down at the bottom of the master cylinder is a small cover over the return hole. Just pop that cover off and take a small wire, single wire from a wire brush or a guitar string, and poke it down in there to clear the port.
If that return is clogged up, it would cause your clutch to slip.

Yes, that is true. The return ports get clogged with hardened gunk from lack of proper, regular(24,000 miles max) flush and bleeds.

[tvanvran]

As of right now I drained the oil and replaced with Rotella. The reservoir was down a bit so I filled with fresh and have been running with no slippages. I will bleed the lines this winter. Thanks to everyone who helped.

[newday777]

As of right now I drained the oil and replaced with Rotella. The reservoir was down a bit so I filled with fresh and have been running with no slippages. I will bleed the lines this winter. Thanks to everyone who helped.

So what was actually happening??? Slipping clutch or popping out of gear?
What oil did you have in it before??