I once took a primary cover off of a triumph, 650. The owner had filled it to the top. Then one of the 3 pressure plate nuts was wound all the way in warping the 💩oughta the pressure plate. Good times! Smitty
I had this same problem on a 2000 RM125 dirt bike. Dogs and slots looked just like that and it popped out of 2nd. Those rounded dogs and especially the rounded slots will cause an issue. I'm sure you had the right countershaft endplay, but I'll bet the shift fork is flexing enough to let 5he countershaft 3rd to move. That backcut only holds the gears together under load. I guess my point is if the gears were damaged from someone else's bad setup, replace them
There’s a lot going on with the XL 4-speed! First of all, from what I can see from your video, you didn’t verify or duplicate the concern. With an XL 4-speed, the first thing I’d look at with a transmission that jumps in and out of the same gear is the shift cam plate and the little “top hat” rollers on the shift forks. Next is the plunger and spring that indexes the cam plate in gear. Considering the distance that the gears must move in order for this to happen, something must be loose, worn or bent. If the back angle is acceptable, the countershaft end play, shift fork play in the cam plate, shift fork play in the gear are things to consider. If the transmission jumps from low to neutral or second, that’s a different problem. In your video you didn’t demonstrate the “mechanical engagement” when shifting on the bench. The benchmark for mechanical engagement on these transmissions is 50%. Anything less than that and the transmission may not shift fully into gear, allowing it to jump back to neutral. Excessive CS endplay may also aggravate this when shifting into low. If the transmission jumps out of low gear and back to neutral, then “short shifting” or short mechanical engagement is likely contributing to that. FWIW, the spacing on this transmission appears to favor low gear, which would help to minimize jumping out of low, but a properly setup XL 4-speed would be setup to favor 2nd on the 1-2 shift. Before making changes you may want to confirm the proper endplay of both shafts, put it back together and make an attempt to verify the issue. Good luck, sir.
Interesting problem... What I am wondering is did 2nd or 3rd gear pop out also? Or did he just stay in 1st... I am not very well versed in fluid dynamics/hydraulics, but it is easy to see that concave cut in 3rd gear (that mates to 1st) would make for any fluid pressure to pop the 2 gears apart... BUT that is a guess.. My first thought was on the shifter plate, was it wore down between neutral and 1st... I am sure you could see that instantly, it was just blocked in the video. MY thought is reduce the oil and take it for a spin, shifting in all gears.. sure a new 1st and 3rd gear would be nice, but as you shown the wear is not where the gears actually mate up.. that is why I wondered if this occurred in 2nd or 3rd also. Also on the first gear there seems to be a cut out and a hole in the gear, which I assume is getting oil down to the bushing/shaft. So we know that it is designed for oil splash to lube that area... Just not a flood of oil. Haha!!! Now make sure to show us how to prevent that oil sump problem!!! This is the GOOD content, because how many of us have seen a transmission full of oil before and the effects. Not me.
There will be too much resistance in the gearbox with too much oil. The synchronization between the gear changes also becomes worse as the oil slows down the gears in the gear change.
What I can't see , is what is the actual end play in the layshaft and although this may be a PITA , I've removed the entire mainshaft + gears and bearing to allow me to get into the transmission and check the end float on the layshaft low gear . The slight rounding of the engagement dogs on that low gear has never been a problem for me . I worked (as a mechanic) at a dealership when those Iron head Sportsters were new .
Hey Greg! My thought is the transmission is so full of oil, that the first gear dogs are hydro liking into the pockets of the 2nd gear. Cause is too much oil!
I can't claim personal experience in this, but I think enemyilaf and tinman 7130 are on the right trail. Gears that are completely submerged in heavy oil will be negatively affected if they are designed to run in a splash environment. Since there is not any real wear or damage to the gears or the rest of the transmission I would blame the owner and his unlimited supply of oil. You might advise the owner that when he finds the oil low to remove the oil level screw/bolt in the cover (if that engine has one) to check if it is over filled in the future.
Having rebuilt many transmissions, I would change the low gear and third, the rounded edges. always cause problems. I don't believe it's the oil level.
The excessive chain case / transmission oil is a problem no mater what. Did the customer think it was supposed to be filled up to chain inspection plug? Is that oil transfer valve / breather valve in the LH case dicked with and no longer fluttering? Or is that a newer motor with the breather fitting and hose on top of the transmission housing in the RH case half? Is the low-third gear shift fork hat, (roller) missing? any burrs, cracks or hammer marcks in the shifter cam plate? I cannot tell the exact year of that bike but as you know if its a '75 - '76 every component of shift linkage is suspect especially under that sprocket cover. Double check the shifter pawls and the shifter pawl springs too, and the shifter cam pawl and its spring also. The first gear dogs look O.K. to me, the third gear dog pockets look O.K. too; is that first gear bushing in good shape? lastly, is the owner riding around with his foot on top of or wedged into the shift lever rubber?
I think I would try running it with proper oil level before spending any money. People need to be aware that when main oil is low that they need to remove the level plug on the primary before just adding oil to the tank. That oil has to go somewhere. Lol
As another shop that does a ton of ironheads, Gary, I think this is a multi-faceted issue. Too much fluid is going to cause an insane amount of friction and aeration which increases a lot of effort in a shift, whether it's a 4-speed like this or a 5 speed from a newer Sportster. Another question I'm asking myself, is this countershaft taking the single or dual shims on the low gear, as we know it changed. Usually a healthy bench test of these stacks tells the tale and as we can see you're right on the money on spacing.
I wonder if the clutch was the problem. Maybe it was slipping and grabbing because it was submerged in oil. The owner thought it was jumping in and out of first gear, if it was jumping out of first gear wouldn’t it hit neutral?
If this were my bike and I was doing the work, I would put a new 1st gear on and fill with the correct amount and weight of oil. I would also want to know if this happened prior to the rebuild or after. As an aside, I have a model A which were known to slip out of gear which was attributed to excessive clearances.
Overfilling would slow movement and cause resistant. Was it actually popping out of gear or was it that full engagement wasn't achieved so of course it would come out of gear when power was applied .
Kinda crazy and might not be same cause but when I got a new at a dealership in 02 a , xl883c , foward controls, w/3 miles on it , within 150miles bike would jerk/pop outta 1st intermittently between 0 - 15 m.p.h. if i offed throttle would continue into gear. Took back to dealer, said everything was in spec , inspected all clutch and trans , they had it couple months and 3 mechanics said everything checked out ok to spec. ? One mechanic said microscopic burr 's , they replaced shifter shaft slider ?and some gears their conclusion bur not letting gear in place so popped out or got hung up ? , was fixed under warranty. But when my warranty expired shortly after it all started again . Surprise ya but if ya know its gonna happen just dealt with it . Never found out the cause or got exact answer ? Over 95k miles same problem figure ill fix when i overhaul motor. Or when ? Let us know what ta find . I've had pawl springs brake and stick in gear on fxe and a shifter shaft ball end brazing slip on 61 xlch but that left me stuck in gear also ? Dang sorry im no help , but a couple stories take care
I would ask him how he got 50 miles on it with it slipping out. Was this a problem right away or did it happen after sitting for a time? My guess would be the excess fluid, but that is just a guess.
Improper oil level does not sound like a warranty issue to me. Not everyone is versed with ironheads. Thus don't understand what it takes to keep one operating properly.
All you can do is try and eliminate issues,until you find it,start with the simple most obvious issues first. How much mileage do you put on these bikes before hand over. Maybe you need to do a bit more proof riding with customers before hand over.. Start with the obvious simple things first
Interesting ; I will invoke the spirit of old CAMPY of New Orleans 😇 !
The giveaway here is the cracked crank case. You have a thrust and alignment problem......I would put money on it.
Yep 👍
I once took a primary cover off of a triumph, 650. The owner had filled it to the top. Then one of the 3 pressure plate nuts was wound all the way in warping the 💩oughta the pressure plate. Good times! Smitty
I had this same problem on a 2000 RM125 dirt bike. Dogs and slots looked just like that and it popped out of 2nd. Those rounded dogs and especially the rounded slots will cause an issue. I'm sure you had the right countershaft endplay, but I'll bet the shift fork is flexing enough to let 5he countershaft 3rd to move. That backcut only holds the gears together under load. I guess my point is if the gears were damaged from someone else's bad setup, replace them
Good luck with achieving the 200.000 ...
There’s a lot going on with the XL 4-speed!
First of all, from what I can see from your video, you didn’t verify or duplicate the concern.
With an XL 4-speed, the first thing I’d look at with a transmission that jumps in and out of the same gear is the shift cam plate and the little “top hat” rollers on the shift forks. Next is the plunger and spring that indexes the cam plate in gear.
Considering the distance that the gears must move in order for this to happen, something must be loose, worn or bent.
If the back angle is acceptable, the countershaft end play, shift fork play in the cam plate, shift fork play in the gear are things to consider.
If the transmission jumps from low to neutral or second, that’s a different problem.
In your video you didn’t demonstrate the “mechanical engagement” when shifting on the bench. The benchmark for mechanical engagement on these transmissions is 50%. Anything less than that and the transmission may not shift fully into gear, allowing it to jump back to neutral. Excessive CS endplay may also aggravate this when shifting into low.
If the transmission jumps out of low gear and back to neutral, then “short shifting” or short mechanical engagement is likely contributing to that.
FWIW, the spacing on this transmission appears to favor low gear, which would help to minimize jumping out of low, but a properly setup XL 4-speed would be setup to favor 2nd on the 1-2 shift.
Before making changes you may want to confirm the proper endplay of both shafts, put it back together and make an attempt to verify the issue.
Good luck, sir.
Interesting problem... What I am wondering is did 2nd or 3rd gear pop out also? Or did he just stay in 1st... I am not very well versed in fluid dynamics/hydraulics, but it is easy to see that concave cut in 3rd gear (that mates to 1st) would make for any fluid pressure to pop the 2 gears apart... BUT that is a guess.. My first thought was on the shifter plate, was it wore down between neutral and 1st... I am sure you could see that instantly, it was just blocked in the video. MY thought is reduce the oil and take it for a spin, shifting in all gears.. sure a new 1st and 3rd gear would be nice, but as you shown the wear is not where the gears actually mate up.. that is why I wondered if this occurred in 2nd or 3rd also. Also on the first gear there seems to be a cut out and a hole in the gear, which I assume is getting oil down to the bushing/shaft. So we know that it is designed for oil splash to lube that area... Just not a flood of oil. Haha!!! Now make sure to show us how to prevent that oil sump problem!!! This is the GOOD content, because how many of us have seen a transmission full of oil before and the effects. Not me.
There will be too much resistance in the gearbox with too much oil. The synchronization between the gear changes also becomes worse as the oil slows down the gears in the gear change.
What I can't see , is what is the actual end play in the layshaft and although this may be a PITA , I've removed the entire mainshaft + gears and bearing to allow me to get into the transmission and check the end float on the layshaft low gear . The slight rounding of the engagement dogs on that low gear has never been a problem for me . I worked (as a mechanic) at a dealership when those Iron head Sportsters were new .
👌👍👍👍👍👍👍👍
Hey Greg! My thought is the transmission is so full of oil, that the first gear dogs are hydro liking into the pockets of the 2nd gear. Cause is too much oil!
Fluid couplings are real. Can you lapp the check ball in the oil pump to make it stop wet sumping?
The clutch dog ears on first gear are shot, looks like the rest has had some abuse too.
I can't claim personal experience in this, but I think enemyilaf and tinman 7130 are on the right trail. Gears that are completely submerged in heavy oil will be negatively affected if they are designed to run in a splash environment. Since there is not any real wear or damage to the gears or the rest of the transmission I would blame the owner and his unlimited supply of oil. You might advise the owner that when he finds the oil low to remove the oil level screw/bolt in the cover (if that engine has one) to check if it is over filled in the future.
Having rebuilt many transmissions, I would change the low gear and third, the rounded edges. always cause problems. I don't believe it's the oil level.
The excessive chain case / transmission oil is a problem no mater what. Did the customer think it was supposed to be filled up to chain inspection plug? Is that oil transfer valve / breather valve in the LH case dicked with and no longer fluttering? Or is that a newer motor with the breather fitting and hose on top of the transmission housing in the RH case half? Is the low-third gear shift fork hat, (roller) missing? any burrs, cracks or hammer marcks in the shifter cam plate? I cannot tell the exact year of that bike but as you know if its a '75 - '76 every component of shift linkage is suspect especially under that sprocket cover. Double check the shifter pawls and the shifter pawl springs too, and the shifter cam pawl and its spring also. The first gear dogs look O.K. to me, the third gear dog pockets look O.K. too; is that first gear bushing in good shape? lastly, is the owner riding around with his foot on top of or wedged into the shift lever rubber?
I think I would try running it with proper oil level before spending any money. People need to be aware that when main oil is low that they need to remove the level plug on the primary before just adding oil to the tank. That oil has to go somewhere. Lol
As another shop that does a ton of ironheads, Gary, I think this is a multi-faceted issue. Too much fluid is going to cause an insane amount of friction and aeration which increases a lot of effort in a shift, whether it's a 4-speed like this or a 5 speed from a newer Sportster. Another question I'm asking myself, is this countershaft taking the single or dual shims on the low gear, as we know it changed. Usually a healthy bench test of these stacks tells the tale and as we can see you're right on the money on spacing.
I wonder if the clutch was the problem. Maybe it was slipping and grabbing because it was submerged in oil. The owner thought it was jumping in and out of first gear, if it was jumping out of first gear wouldn’t it hit neutral?
If this were my bike and I was doing the work, I would put a new 1st gear on and fill with the correct amount and weight of oil. I would also want to know if this happened prior to the rebuild or after.
As an aside, I have a model A which were known to slip out of gear which was attributed to excessive clearances.
Overfilling would slow movement and cause resistant. Was it actually popping out of gear or was it that full engagement wasn't achieved so of course it would come out of gear when power was applied .
Kinda crazy and might not be same cause but when I got a new at a dealership in 02 a , xl883c , foward controls, w/3 miles on it , within 150miles bike would jerk/pop outta 1st intermittently between 0 - 15 m.p.h. if i offed throttle would continue into gear. Took back to dealer, said everything was in spec , inspected all clutch and trans , they had it couple months and 3 mechanics said everything checked out ok to spec. ? One mechanic said microscopic burr 's , they replaced shifter shaft slider ?and some gears their conclusion bur not letting gear in place so popped out or got hung up ? , was fixed under warranty. But when my warranty expired shortly after it all started again . Surprise ya but if ya know its gonna happen just dealt with it . Never found out the cause or got exact answer ? Over 95k miles same problem figure ill fix when i overhaul motor. Or when ? Let us know what ta find . I've had pawl springs brake and stick in gear on fxe and a shifter shaft ball end brazing slip on 61 xlch but that left me stuck in gear also ? Dang sorry im no help , but a couple stories take care
I would ask him how he got 50 miles on it with it slipping out. Was this a problem right away or did it happen after sitting for a time? My guess would be the excess fluid, but that is just a guess.
Improper oil level does not sound like a warranty issue to me. Not everyone is versed with ironheads. Thus don't understand what it takes to keep one operating properly.
✌😎✌
🤔
All you can do is try and eliminate issues,until you find it,start with the simple most obvious issues first.
How much mileage do you put on these bikes before hand over.
Maybe you need to do a bit more proof riding with customers before hand over..
Start with the obvious simple things first
Two bad gears caused by too much fluid ? Sounds reasonable. Lol
Try it again with proper amount of oil than check that off your list of possibilities
Microscopic burrs ?
My answer is…. Operator Error