Should this shaft have end movement if I pull it by hand?

[McCabe-Thiele (Ted)]

This afternoon I bolted the crankcase halves together, I now have the primary drive shaft in place.

I then noticed that if I pull on the gear shaft shown in the picture below  - where the clutch fits it moves out a bit is this normal - will the play be taken up when I assemble the clutch or is there something wrong with the gear shaft before I fitted it?

As much as I do not want to have to take the crankcase halves apart again it just feels suspicious.

.This shaft here where the clutch fits question by Macabe Thiele, on Flickr

[Nurse Julie]

Not sure how it can move from side to side Ted 🤔 (if I'm remembering correctly.). The inside of the bearing is attached to the shaft, so there should be no movement there and the outside of the bearing should be clamped between the top and bottom cases. Where exactly is the movement?

[McCabe-Thiele (Ted)]

It's what you would normally call end float - grip the shaft it will pull out a little - if its out it will push back in the same amount if you get my drift. Difficult to measure I'll have a go at trying to get a figure. The bearing is solid as it's secured by the half circlips thingy. I've measured it with my caliper end part it's  around 0.75mm.

[McCabe-Thiele (Ted)]

It's what you would normally call end float - grip the shaft it will pull out a little - if its out it will push back in the same amount if you get my drift. Difficult to measure I'll have a go at trying to get a figure. The bearing is solid as it's secured by the half circlips thingy. I've measured it with my caliper end part it's  around 0.75mm.

[K2-K6]

I've not as much local knowledge on the 400, but conceptually you'd not generally have a gearbox shaft "pinched" across the geabox casing to nil tolerance.  Ordinarily it'll need end float and or expansion room to avoid axial loading of the bearings at maximum heat cycle.

This one looks like it's pinched by the clutch assembly to sit tight on that main bearing to give alignment to the primary drive as priority and leave the tolerance inside the box between the visible bearing and it's opposite number on the same shaft.

The clutch is also subjecting that shaft to thrust load when clutch is operated by the lever, which would make it intolerable if it moved.

The bearing you can see is equivalent to the thrust bearing on a car crankshaft and should have virtually nil play with clutch assembly tightened.

[McCabe-Thiele (Ted)]

Thanks K2-K6 I'm following your logic that there would be some clearance for the reasons you have given - I'm a little paranoid I guess. I have a partial memory that when I replaced the clutch the shaft had some end movement already. Ted

[McCabe-Thiele (Ted)]

I'd just stop pulling things by hand Ted, you'll go blind.

lol Oj good one mate tha't really made me chuckle,

tbh Oddjob I've been well stressed about fitting the crank case halves together so I'm probably seeing things that aren't there - it's been a real groundhog day but now I am where I was on the 1st June but there is no sticking conrod - that's progress in my book.
 
I was going to do the crankcase bolting up yesterday but like many peaking with my hay fever has gone on to irritate my Angina / breathlessness in the mornings so I just took an extra 20 mg Isosorbide mononitrate tablet today to help keep me calm!

My more rational side is saying what's the worse that can happen if there is a bit of extra end float in the dam shaft - it ain't life changing that's for sure. It probably crunched gears before I bought it - onward & upward.

As an added bonus I'm getting much better at applying a thin layer of Hondabond in the process - it made all the difference putting it on my rubber gloved finger then smearing onto the upper casing amazing what a different technique can do.

Yes still talking about Hondabond Oddjob before you comment !!

[K2-K6]

You could always get someone else to pull the shafts by hand if not feeling up to it  but that's probably onto a whole new forum   

[McCabe-Thiele (Ted)]

I am now seriously considering taking the casing apart again before I continue any further.

I can see the end small gear on the left hand side of the shaft in question through the side gap near where the oil pump fits.
I can get my finger on this gear and feel it move from side to side along the shaft when I pull & push on the shaft from the other end.
Clearly this is movement on the shaft of the gear as if there has a shim missing.
I have not dismantled this shaft.


All it will cost me is time seperating the casing & getting off the Hondabond again it just seems too much movement.
Any further opinions / observations  before I have another Groundhog Day ?

[royhall]

Probably a silly question but you did put the half moon bearing retainers back in. I'm sure you did, just covering the obvious.

[McCabe-Thiele (Ted)]

Probably a silly question but you did put the half moon bearing retainers back in. I'm sure you did, just covering the obvious.

Yes on both bearings also where the stud locates on the smaller bearingd were in place correctly. Before I split the casing I'm going  to look at a spare casing I have that has the main gear clusters to see how it compares but more importantly if everything is in its place how can I alter the movement. It will give me a better understanding of the gearbox & how it works. I do not know if Honda make different end gear spacers on production.

[McCabe-Thiele (Ted)]

Okay I have checked the gear clusters on my 'spare' casing - there is no movement discearnable on the shaft in question as per NJ's hint.
 
So it's Groundhog Day again (day 3) as soon as I can summon up the enthusiasm during this current heat wave!

I knew this project woud be challenging but come on Honda not this early in the rebuild please.........!

[McCabe-Thiele (Ted)]

I have this morning grasped the nettle and started Groundhog Day 3 before the mid-day sun saps my energy.

Good news is everything was seated & in place as it should have been - 98% of the Hondabond has been removed with thinners from the two crankcase surfaces with relative ease. Only downside is some runs on my painted cases - easily fixed.

The rear countershaft / output shaft is all as it shoud be with naff all lateral movement between the end bearings.

The mainshaft however definetely has quite a lot of lateral movement between the end bearings most noticeable between the small end gear (second gear) at the needle roller end. The spacer is in place but clearly something is not right to me it's just a lot of travel. Unlike the output shaft I have not taken this unit apart.

When I find my feeler gauges I will measure it and post here again.

[McCabe-Thiele (Ted)]

Okay if I insert 40 tho" feeler gauges into the gap between the end spacer & second gear its then like I think it should be imho.

40 tho" is 1.016 mm that sounds far too much

Not sure where to start but I guess the two end bearings are places where wear is most likely. DS tell me the bearings are colour coded & difficult to find I hope the guy in parts was confused with mains bearings!

There is no obvious wear on the large mainshaft bearing inner race or contact wear where it sits against the fixed mainshaft gear. The needle roller unit at the other end looks normal the 20mm thrust washer that sits between the needle roller & second gear does not show excessive wear - you can tell which way round the washer was (is) as there is a rotary mark where it has been against the gear but the wear is very slight - certainly nowhere near enough to explain the lateral movement.

The only thing that I can see that would alter the end float as it's one shaft is the thrust washer at the small end unless the large main end bearing is made to different thickness to allow for crank case widths when they are machined?

Any advice welcome at this point.

[McCabe-Thiele (Ted)]

First thing that I have found out is that there is a slight ovalation of the slot where the locking pin sits in the roller bearing outer casing.

My thoughts are to firstly get a new pin if they are available together with the needle roler bearing plus replace the thrust washer anyway.

I have rotated the bearing to get a picture of the location hole -  it does not show up the elongation that well tbh.