Hi folks. Finally got into the gearbox, remarkably good shape. This is the basket case early '74 850. Gears are not pitted on the mating faces, kicker pawl looks very good, turns freely, want to measure the end play in the layshaft. So, what to do? The outer cover bobby pin looks like it should be replaced, already has an MK3 breather by PO, will replace oil seals since it is apart and likely originals in place, put in a new gasket. Three questions, and I did read a lot in archives. 1) Anything that needs to be repalced just because it is open, and it is good practice? 2) Regarding bushes, can one measure them to determine if they are worn out? Or should a guy just replace them, or leave them be? 3) seems like the original bearings are prone to grenading with bad results (I am city dweller, for freeway riding will be the norm) so sounds like they should be replaced. I will be a conservative rider, but i will get on it now and again. I do live in Arizona, so no cold weather worries, but hot weather (like 118F = 48C) is not uncommon, does that matter? Using the Hemmings video, manual, and parts list, Old Britts writeup, and the collective knowledge of the Access Norton Borg (OK that was nerdy) to make an informed decision. Thanks in advance, everyone here is very helpful. I will try to get some gearbox photos up for the group.
Gearbox Rebuild
- Thread starter rwalker28
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Tough luck I'm still up peeking in just now.
The most seasoned gearbox builders a decade ago told me there is no reason for the gear box gaskets so i've left them out which eliminated lay shaft shim issues. Not many left in my camp on this so you call.
Al the venders carry the upgrade lay shaft roller bearing plus the couple other bearings. When gear box all nice and tight its got to be the sweetest thoughtless manual there is. IIRC the big main shaft one has a rubber seal on just the outside, either comes that way or must remove one of the seals. Oil can still seep out the sleeve bush/main shaft seam, but heck not much oil can even get in there to leak out so no seal available to cover this.
Buy two pawl clothes pin springs and seal one up from oxygen for long term but eventual show stopping need.
Definitely go with all new bushes for peace of mind baseline whizing in close freeway traffic that any wide slide or toss off means road kill. Realize the bushes - about all of em will need custom reaming to fit each shaft and cog. Buy 2 first gear bushes as they are the first to go. Realize that when in 1st 2nd 3rd the sleeve shaft bushes sling the lube right out of there so the longer you remain in lower gears the faster first gear and sleeve bushes get ground up. Main source of clutch wobble i've had were the lube straved sleeve bushes ground up. The factory only put two in there so they tend to migrate to center and not support the shaft as well, so tradition is to place a 3rd used one as middle spacer. Once I realized this area was above oil level and slinging out what might seep in the thin bush/shaft fit, I spiral oil grooved all three and filled with Dextron II ATF. ATF not really needed unless red lining with sport bikes below 4th ok. I have not put ATF in my factory Combat as didn't have much ATF left, just gear oil because ole Peel got the ATF but didn't turn bushes to ceramic no mo.
Don't lug no Commando please its the absolute worse thing for them, but so is spiking to red line. Oil wedges ain't surfing till like 2000 rpm. Commandos are happy all day long at 5000 and really smooth out nice but go to jail fast. Act a bit aggressive short of police notice as makes traffic conscious or unconscious a bit scared of ya to get as close as otherwise or plain miss seeing ya.
Don't sweat sitting idling in traffic as can't over heat that way but low charging can stall ya and prevent easy restart. Almost all headlights are un-noticed candle light dim yellow to oncoming, only hi beam can be seen a ways, so compromise to juggle watts with traffic with speed. Freeways charge plenty for hi beam constant on and its good to annoy drivers a bit.
Run that bugger up the gears brisky but 4th is only good to down to about 30 with low throttle or wear tear increases.
ohh yeah, the kicker o-ring groove is a tad too deep to compress ring well. I tried a layer of Al foil in bottom then light grease parts, put a swipe of RTV around the groove and o-ring then slapped it together to cure over night. Seems to work as good as a machined seal I had done to prior cover. ie: no drips but mist weeps out on longish hot rides.
Ah the clover leafs... Snorts echoing off the barriers... Beware of tire wide diagonal junction seams...
The most seasoned gearbox builders a decade ago told me there is no reason for the gear box gaskets so i've left them out which eliminated lay shaft shim issues. Not many left in my camp on this so you call.
Al the venders carry the upgrade lay shaft roller bearing plus the couple other bearings. When gear box all nice and tight its got to be the sweetest thoughtless manual there is. IIRC the big main shaft one has a rubber seal on just the outside, either comes that way or must remove one of the seals. Oil can still seep out the sleeve bush/main shaft seam, but heck not much oil can even get in there to leak out so no seal available to cover this.
Buy two pawl clothes pin springs and seal one up from oxygen for long term but eventual show stopping need.
Definitely go with all new bushes for peace of mind baseline whizing in close freeway traffic that any wide slide or toss off means road kill. Realize the bushes - about all of em will need custom reaming to fit each shaft and cog. Buy 2 first gear bushes as they are the first to go. Realize that when in 1st 2nd 3rd the sleeve shaft bushes sling the lube right out of there so the longer you remain in lower gears the faster first gear and sleeve bushes get ground up. Main source of clutch wobble i've had were the lube straved sleeve bushes ground up. The factory only put two in there so they tend to migrate to center and not support the shaft as well, so tradition is to place a 3rd used one as middle spacer. Once I realized this area was above oil level and slinging out what might seep in the thin bush/shaft fit, I spiral oil grooved all three and filled with Dextron II ATF. ATF not really needed unless red lining with sport bikes below 4th ok. I have not put ATF in my factory Combat as didn't have much ATF left, just gear oil because ole Peel got the ATF but didn't turn bushes to ceramic no mo.
Don't lug no Commando please its the absolute worse thing for them, but so is spiking to red line. Oil wedges ain't surfing till like 2000 rpm. Commandos are happy all day long at 5000 and really smooth out nice but go to jail fast. Act a bit aggressive short of police notice as makes traffic conscious or unconscious a bit scared of ya to get as close as otherwise or plain miss seeing ya.
Don't sweat sitting idling in traffic as can't over heat that way but low charging can stall ya and prevent easy restart. Almost all headlights are un-noticed candle light dim yellow to oncoming, only hi beam can be seen a ways, so compromise to juggle watts with traffic with speed. Freeways charge plenty for hi beam constant on and its good to annoy drivers a bit.
Run that bugger up the gears brisky but 4th is only good to down to about 30 with low throttle or wear tear increases.
ohh yeah, the kicker o-ring groove is a tad too deep to compress ring well. I tried a layer of Al foil in bottom then light grease parts, put a swipe of RTV around the groove and o-ring then slapped it together to cure over night. Seems to work as good as a machined seal I had done to prior cover. ie: no drips but mist weeps out on longish hot rides.
Ah the clover leafs... Snorts echoing off the barriers... Beware of tire wide diagonal junction seams...
Just another idea for the kickstart O ring: try using a 25mm id x 4mm section ring. It worked a treat in my 70 model, without the need for silicone.
In fact, the only oil leak my bike had after the rebuild i did long ago was a slight weep from the kickstart. I put up with it for a long time before finally fixing it. I couldn't seem to find a thicker section ring in the imperial range.
Martin
In fact, the only oil leak my bike had after the rebuild i did long ago was a slight weep from the kickstart. I put up with it for a long time before finally fixing it. I couldn't seem to find a thicker section ring in the imperial range.
Martin
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Thanx for this shop gem part, will keep eye out for one in hardware, till next reason to open up outer cover, like notes not park here dripping oil.
Don't know if matters of not but I also oil grooved the big ole bush kicker ride on. Its the hardest one to suck out or cut out, but least likely to need renewing.
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Well I've been re-updated following other posts to remember last set of bushes I ordered, but not yet installed in Peel's deal - provide 2 Two Longer sleeve shaft bushes so no need to slip in a used 3rd bush as locator spacer on shorter factory pair of bushes. I used a ball end grinder wheel with enough slips to ugh, feather the oil feed a bit beyond the crooked 360' spiral shallow groove. Give some thought to the direction of the bush shear spin for direction of spiral to maybe help some oil into the area, as all the other factors, location above oil level, sling outward with only thin film access back in make if dry out fast and Hot. On the outside bush at main shaft there is no oil sealing provision at all so I stopped the groove just short of breaking through a freer path of oil out the gearbox into the chain or down into clutch plates. That there is little of no need of sealing this direct bush seam leak exposure to outside is proof there is so little oil reaching it in the first place. Bad ju ju to race about long in lower gears as Manx racers found out too. I did not groove the thin 1st cog bush but always have a spare as that's the 1st to go at least twice as fast as the others.
I know better now than hold my factory Trixie in low gears long, even maxing out once or less severe low gear times hanging with elite sports bikes, so don't worry without ATF in her gear box, but Peel was another animal that mostly contested in 2nd up 90 mph to embarrass the balloon tires and made me think of tricks that worked a while after prior let downs. I asked long seasoned Nortoneers before i tried the above to find it was known solutions used well prior.
I know better now than hold my factory Trixie in low gears long, even maxing out once or less severe low gear times hanging with elite sports bikes, so don't worry without ATF in her gear box, but Peel was another animal that mostly contested in 2nd up 90 mph to embarrass the balloon tires and made me think of tricks that worked a while after prior let downs. I asked long seasoned Nortoneers before i tried the above to find it was known solutions used well prior.
I was looking at how all this fits together, and found the shifter forks were not easily sliding the full travel of the selector fork spindle. So I put the spindle up against a straight edge, and it was bent. Looks to be bent in about the middle, only a few mils off, but the shifter fork guides are long, and a fairly tight fit. Can just barely by hand push the fork the whole travel of the spindle. Does not seem to be a good idea to put this back together with the shifter forks possibly binding on the spindle. Ordered a new spindle. Seems like an odd bit to get bent, anyone have a thought about this, this bring to mind anything else I need to look at? I need to get the cam plate out of a look, see if the shifter fork guide pegs causes some damage to the cam plate.
So check my logic based on you experience, for direction of spirals inside bushings. If bushing turns clockwise, viewed from gear face next to lower gear, then spiral should run counter clockwise. This allows open end of spiral to scoop up oil and force it down path of spiral by a combination of more oil being scooped up by open end, and inertia and friction of oil which will slow its speed compared to gear speed and further force the oil through the bush spiral.
The opposite orientation with the spiral in same direction as gear wheel moves will prevent oil from being scooped up by open end of spiral and also force any oil in the spiral out the open end.
Make sense? Is this the way you cut you spirals, Hobot?
The opposite orientation with the spiral in same direction as gear wheel moves will prevent oil from being scooped up by open end of spiral and also force any oil in the spiral out the open end.
Make sense? Is this the way you cut you spirals, Hobot?
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HOT Dog airedale, you done did my thinking for me, cool! Its been too long thank you since last inside so forget the rotations of main and sleeve shaft. You even rationalized the fluid physics factors for me to envision. I really was hung up on this till hands on working it out myself - as a further idea was which angle to bore holes straight through the sleeve gear and bushes, similar to other bushes burt with a bias to pump outer oil film in or somewhat resisting the fling out. Of course I don't know which of these oiling methods is better or even works, ugh or if both present they self defeat worse than left alone. If you ain't really checked direction then I'll have to double check anyway, ugh. Back ofmy mind says "no oil can get in once spun up good" so better to just try to keep in what was there w/o extra escape vents and hope for a faster refill once out of lower gears or stopped.
Picked up some Redline Assembly Lube at the local speed shop, boy they are not what they used to be...is this stuff ok for gearbox rebuild? I plan run it in and change out the gearbox fluid quickly. Gearbox might sit awhile before my project is done (like a few months at least.) Any other thoughts? I am going to use it to rebush and install the new bearings. Sorry for the unending questions, this is the first time I have done this...
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Oh yes sir its very good practice to run in a transmission a few hundred mils then switch to the good stuff. Its standard practice among some long time Brit Iron builders and I saw rather dirty dark oil come out on my 1st early change. Redline is famous top of the line products so should last a long time. I learned every inherent weakness on Ms Peel which got abused in lower gears but I rarely press my stock Combat in lower gears so its held up sweetly on plain gear lube 8000+ miles.
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