End plate fitting

[dickie]

Just about to start building a gearbox and came across this.

Is it really necessary? Does it do more harm than good?

I really like the idea of making sure things are done properly but I'm nervous about giving the end-plate so much play that it does nothing of any use. I also think AF know an awful lot more than me about these things, so I'm inclined to accept their word on the matter; but that's just not my way.

Take a look and see what you think please.

https://www.youtube.com/watch?v=oidS7kxkBck&t=41s

[dscscotty]

this was due to issues around new uni casings, however I regularly take a little off the cluster to allow it to fit easier through the bearing

[Storkfoot]

It is definitely food for thought. I suspect we have all struggled with very tight fitting endplates that exert side pressure on bearings but I would be a little concerned that if you drill the holes to 8mm, you are very much relying on the dowels

I would be interested in what engineers make of it.

[dickie]

It is definitely food for thought. I suspect we have all struggled with very tight fitting endplates that exert side pressure on bearings but I would be a little concerned that if you drill the holes to 8mm, you are very much relying on the dowels

I would be interested in what engineers make of it.

The studs/nuts only take load through the friction they apply to the face of the plate, so, within reason, you can drill the holes as large as you like and they will do the same job.

The dowels however are a different matter. By drilling the holes larger, they now only take load in one direction. This direction depends on the new drilling that you do. That said, the dowels role is to ensure correct location, not to take load.

So, I think this is a sound idea.

Thanks for the inspiration storkfoot.

Scotty, the cluster slides nicely into bearing, but it's an AF 4 close ratio box, so I suspect it's already manufactured or adjusted to meet this spec.

[Warkton Tornado No.1]

To put my own reaction into context, I have built dozens of gearboxes into cases but have never had to resort to modifying the dowel hole size or position. That's not to say it will never happen, but even the "matched" SIL cases & endplates are not something that I have allowed to dictate they be kept as a pair when striving to achieve an optimum set up. Perhaps there are far worse SIL cases that have not come my way, but I have had no misgivings about mixing Eibar, Innocenti & SIL cases & endplates, though I avoid the SIL endplates in any case as they are so rough & the raceway tolerances are questionable. Fortunately, I appear to have accrued many spare Innocenti endplates over the years which are my first choice for the reasons given.

My belief is that the original tooling from Innocenti to create cases passed on to SIL has been knocked about & fudged up, but this is only evidential for the brake pivot position(s) in particular.

So my comment about the video in the matter of endplate fixing is that it is sound engineering practice SHOULD it be necessary. From all accounts, as far as relocating the dowel hole positions, the UNI cases may make this modification essential. If I were doing the modification I would be very careful to achieve perpendicularity of the oversize dowel holes & be looking to ream the holes tight in the case. Ideally the dowels would be the hollow, tapped extractable type too. I think that the importance of OEM quality studs, nuts & washers should be stressed. The Mickey Mouse replacements that some well respected dealers supply are not to be trusted as they are neither rolled thread high tensile studs or hardened half-height nuts & washers.

Interesting that the importance of the dowels are stressed in the video as they are quite rightly the location elements & also in shear. I completely agree with the functionality. Just as the hubs centralise the rims & are in shear. Pity then that rather contradicts what was being said about aftermarket wheel rims that do not rely on that principle.

Whilst I'm @ it, I may as well be hung for a sheep as a lamb......

As I understand it, the new double row rear hub bearing places the hub in an offset position. That is a compromise that I personally would avoid. IMO they are better than the potential life threatening rear hub bearings with a plastic cage marketed as "Innocenti" but there are good rear hub bearings about that still embrace the OEM criteria so I can see no reason to change, regardless of power & torque.

TBH I know that some aftermarket rims also cause offset, but I reason that if used as pairs, the positive safety aspects outweigh the negative (as long as the rim locates snugly on the hub!)

[Fast n Furious]

If the endplate is original to the casing then there's rarely a problem with endplate bearing alignment.
A doner endplate can however become a real pain to mate satisfactorily.
All too often (usually with some spanish stuff I find), the centre distance from the mainshaft to the layshaft can prove to be the problem and no amount of shuffling the endplate position can compensate for this anomily.

[Warkton Tornado No.1]

With gearbox fitting & endeavouring to achieve the best result, I have had to resort to swapping out endplates, loose gears & cluster, shims (of course, though my stock includes 'in between' sizes created by cleaning up worn shims on a surface grinder) & swapping of the bearing insert.

The actual two axis location of the layshaft bearing in the endplate is determined by the dowel positions which are the datums.

With a comparison in an Inspection Department where I used to work, the variations between Innocenti & Eibar endplate dowel holes to layshaft hole was so small as to be insignificant. If the layshaft journals in the case & endplate are line bored in assembly, or were, I find it difficult to equate the test results I got with the claim that there is much variation between Innocenti cases. I'd be surprised that Eibar 'cases vary much too.

Such a test is by no means exhaustive or conclusive because it could only be performed on what I had to hand @ that time, many years ago. Sneaking a 'case into work was not practicable.......

SIL endplates were not so common place as to be included, but as mentioned previously, I avoid them & can't recall ever using them. Not even the ones that came with SIL cases that have been used.

I do not doubt that other's have experienced issues, though.

However, if the topic of discussion intimates that the new Uni cases have managed to establish a manufacturing capability even worse than SIL, then they really should be 100% inspected & corrected prior to release for independent approval. Only then should they go on sale IMHO.

Whilst many of us are more than capable of the engineering modifications required, many of us really aren't, so bodges will occur.

Ideally any significant errors should be eliminated @ source & I can't imagine that the machinery involved will not be programmable to conform with the criteria that must exist in the form of a drawing. In fact, if I were commissioning the supply of a batch of such an item I would demand access to the drawing or relevant toleranced dimensions to reject any that didn't comply. Currently, it appears that none of the 'cases are fit for purpose & anybody purchasing them are subject to yet more fettling