Complete cheesehead screw/nut set for the 1947-49 roadgoing type Norton Upright gearbox - as fitted to SV/OHV/SOHC roadgoing models.  Consists of 4 main cheesheads, 2 smaller 'inspection cover' type cheeseheads and botton stud spring washer and 5/16" BSC nut - all CNC'd by ourselves in stainless steel to the original Norton patterns. 

Backgroung Information:  This was the 2nd type of roadgoing Norton (upright type) gearbox Norton fitted after WWII, the first type in 1946-47 looked visibly very similar, but used a round inspecton cover for the clutch worm.

This type, introduced in 1947, was changed to provide a larger inspection cover for easier access to the clutch worm - the inspection cover having a distinctive egg shaped cover - and using smaller cheesehead screws than other Norton gearbox's - exclusive to this model of gearbox, which was only offered for 2 - 3 years, before the introducton of the 'Laydown' gearbox.

This item includes all the front fittings for the external upright cover for this gearbox, and all are the same pattern as the original items - consisting of 4 0.250" Cheesehead screws (which have the correct dimensions and 'flat type' cheesehead style as originals) 1 x 5/16" hex nut and spring washer (fitted at the bottom of the gearbox - rather than the longer pre-war type blind nuts, which would foul the exhaust pipe on post-war models) and the 2 x smaller Norton Inspection cover cheesehead screws (which again, are copied from original items.

Price is for 8 items in total

Please note - unfortunately, in my collection of original parts, I do not have an original egg shaped inspection cover any more - but the screws are of the original pattern.  I have also included another photograph of this type of gearbox, so you can see what the cover looks like, and confirm if it is this type of gearbox you have.

We also produce the blind nuts in stainless steel for the pre-war type Norton gearbox cover (and postwar Manx), as well as complete Cheesehead Screw Sets for the 1950 onwards 'Laydown' gearbox cover

These are the two small screws used on the egg shape 'Norton' Clutch Worm adjuster inspection panel on 1947-50 type Norton Upright gearoboxs. They are CNC'd in stainless steel using an original Norton screw as a pattern

This type of inspection cover was only fitted for small period of two years and the screw used was smaller than other Norton cheesehead screws - so they are hard to find.  These are bar turned stainless steel with the correct thread and Norton gearbox head profile (which at this period was slightly  flatter than corresponding engine timing cover screws.  Price is per Pair of screws.

Note: we also sell a complete gearbox cover cheesehead screw set for this type of gearbox - Item 0995, which includes this pair of screws in that set, if you wish to upgrade your entire cover to stainless steel, and looks very pretty

(By the way - for the Item listing photograph shown here, although I have the correct main uprgight gearbox cover of the 47-50 type, I no longer have one of the egg shape inspection cover, so the screws are shown located where they would normally be - however, we have also included another reference photo of a similar type cover with inspection cover fitted - so you can confirm if yours is of this type.

Complete cheesehead and cover bolt set for Norton Laydown type gearoboxs, as fitted to all roadgoing Norton models and DOHC Manx Nortons from 1950-56. 

This set consists of 7 main gearbox cover cheesehead cover screws, 2 clutch worm inspection cover screws (which are slightly shorter), 3 of the distinctive Norton 'blind' type lower hex nuts (these were the same type as fitted pre-war Norton gearbox covers - they continued to be used on Laydown gearbox's under the kickstart boss) - with the correct Norton type spring washer and finally, the distinctive fine thread filler level plug (which has distinctive pattern with fine thread, almost no chamfer at end of thread, where it contacts rear of filler area, square head and screwdriver slot of b and washer and the correct Norton type square slotted Filler Level Plug. 

All are CNC manufactured by us from stainless steel bar stock and for each of them - orgiinal Norton bolts and screws were used as patterns.

For the cheesehead screws - we have used original Norton gearbox screws (from another complete and unmolested Norton Laydown gearbox, which has been in our family workshop spares collection unstripped since the 1960's!).  The cheesehead screws fitted to gearbox's at this time have a slightly flatter head shape than the Norton SOHC and OHV/SV engine cheeseheads screws used at the same time - and we have copied that style exactly.

Likewise, the Oil Filler plug (which is actually a finer and wider thread than BSC - although on first glance it looks like BSC) is copied from an original item - including the flat finish to the end of the thread.  These are also made from stainless steel bar stock, but we mill the square head and screwdriver slot - so they also look very pretty (originals are nearly always chewed!).

Finally the blind nuts are the correct 'Norton' pattern, which were the same BSC design as used on earlier pre-gearbox's.  It is important to fit the correct thin-width spring washer in the recess before fitting the nut - otherwise the head of the nut 'bottoms out' on the casting.  

As well as being functional, and correctly emulating original patterns, these gearbox cover sets are CNC manufactured in stainless steel and as you can see in the photographs - really look nice and improve the finish of your gearbox.

Background note: When manufacturing our engine cheesehead screw sets, we supply them with special red fibre washers behind them, which was original fitment on engines.  For Norton gearbox's the Spare Parts list did not mention fibre washers, and on gearboxs I have stripped I have never seen them fitted.  Not sure why this was, but because of that, we do not supply the gearbox cheesehead screws with fibre washers.  If you do want to fit them (and there is no reason why they cannot be fitted) - we sell them seperately - Item 0097

This is the distinctive oil level filler plug as fitted to all Laydown Norton Gearbox's (under and to the left of the kickstart boss) from 1951-56.  As per the original it has the correct extra fine thread, square head, with screwdriver slot.  Ours are CNC machined in Stainless Steel and also look vgery pretty.

As you can from the photogrpahs, I have shown pictures of the original Norton Gearbox laydown outer cover, that shows where this oil level plug resided - and as its name suggests, it is there to give owners an indication when the main gearbox casing had been filled with oil to the correct level.  You would first drain out old oil from the main gearbox sump plug, and once having replaced that you would unscrew this distinctive plug and then place new gearbox oil via the oval shaped clutch worm inspection cover.  Once the correct oil level had been reached, oil would flow along a special oilway at the back of the inner gearbox shell into an area behind the oil level plug.  Once any excess had drained, the plug was replaced and you knew the oil level was correct.

I have seen 3 versions of this plug - one with just a square head (which is actually very difficult and fiddly to remove, because few owners have a spanner to fit the square head and resort to a large adjustable that hits and scratch's the gearbox cover), and then the type with a screwdriver slot parallel to the outer square, and finally the most common type you see here - where the screwdriver slot is diaganally across the square - which is the best type (and I assume the type that Norton themselves quickly settled on).  This allows for a screwdriver to be used to loosen the plug, while also offering a longer screwdriver slot length than the type where the slot is parallel with the square. 

We replicate this type exactly as per original - but we CNC machine these from stainless steel and as well as the fine thread and flat rear face, we also perform two milling operations - we mill the square head, then mill the screwdriver slot at 45 degrees to the square in stainless steel.  So as well as being very practical (particularly as most originals are now badly chewed) they also look very pretty and do not rust. (this is not the cheapest of fasteners, but the time taken to perform two milling ops as well as the turning reflect this).

Background Information:

This particular screwplug is particularly unusual in that it has an extra fine thread (often mistaken for 3/8" BSC - but it is actually finer and a bigger diameter than BSC - so dont attempt to fit a BSC bolt by mistake!).  However, it also has a particularly flat end to the threaded section, with almost no thread chamfer - where it locates into the gearbox filler area (see accompanying photographs). 

The original 1955 Norton Spare Parts List also lists a washer for this plug (Part No 13833), but does not include a picture.  I vaguely remember stripping one of these gearbox's many years ago and finding a small piece of brown gasket paper fitted to the end of this flat threaded area - which would make sense . . . but it was so long ago I cannot be sure, so I will leave you to decide if you want to fit one.  

Final point - if you are considering buying this plug, but also considering changing any other screws on the outer gearbox cover - then please look instead at Item 0996 - as that kit contains all the cover cheesehead screws, bottom blind nuts and this filler plug within that kit.  Also, If you really want the type without the screwdriver slot (i.e. because you have a special square spanner, we did make a handful without the slot - drop us a note when ordering, if you want one of this type instead)

This listing is for the camplate plunger and camplate plunger spring that was fitted into the brass plunger bush on all upright Norton gearbox Positive Stop Mechanisms.  Original plungers often have a worn and flattened head, which can affect the effectiveness of gear changing.  The same plunger was also fitted to the Norton Laydown Manx Norton gearbox.  Price is for Plunger and Spring 

These plungers are CNC manufactured then case hardened in EN32B to the same dimensions as the original item - and the plunger head has the same profile as an unworn original item (i.e. a rounded point).  They come fitted with a spring, which again has been replicated by our specialist UK spring manufacturing company from an original Norton spring.

Background:

These plungers are fitted into the brass hex plunger holder, as shown in the accompanying photographs.  It is normal to find that original plungers have had their head worn to some extent or another - and often, they are completely 'smeared' flat (as per the accompanyning comparison photo, that shows our plunger alongside an original worn example).  When they get that worn, it is easy to understand that the 'positive stop' mechanism is likely to be less effective and no longer 'positive' in operation!.

Replacing with this plunger should restore some of that positive gearchange operation if your original plunger is worn.

These plungers have been CNC manufactured from EN19T (a very hard steel) to the original dimensions, and include the correct hole drilled 'off centre' to the plunger point, which was to stop the plunger 'hydraulic locking' when pushed into the plunger body.  Likewise we have also had the spring manufactured to the same dimensions and gauge as an original spring.   We also sell the spring seperately (Item 1011) if multiple springs are required, but this item includes both the plunger and spring.  They should both be assembled with grease and ensure they slide back and forth smoothly in your original brass plunger holder.

It is worth noting that in writing the CNC programs and setup for this plunger - we looked at many original Norton gearbox plungers and found a selection of (different!) springs fitted to them.  As this plunger and spring was manufactured for many years this is not surprising - and I am sure subsequent owners may have also fitted different springs.  When making these, we used an original spring - but also ensured that the plunger and spring together resulted in the plunger sticking out of the body to what we believe was the definitive length (to ensure it gives enough purchase against the indent in the positive selector plate.

Note:  As at time of this listing (May 2021), we are not intending to make the original brass plunger holder shown in the photos, as we are working on the theory that most people will just be replacing the plunger in their original gearbox.  However, if your brass plunger body is badly worn, or is missing (i.e. you are building a gearbox from parts) - then email us on sales@racingvincent.co.uk and we may consider making a batch

This listing is for the camplate plunger spring that was fitted into the brass plunger bush on all upright Norton gearbox Positive Stop Mechanisms.  An original plungers spring was used as the pattern, which has a strong poundage for its size, providing the correct original strength to the plunger.  Price is Each

We have had this spring made, using an original Norton A2/352 spring as the pattern, by our specialist UK spring maker.

We had this spring made as part of manufacuturing replacement plungers (A2/350), and also offer this spring along with the pllunger as a pair in Item 1010.  However, if your plunger is not worn, but you are missing the spring (or just suspect yours is not the original item or is worn), this spring is offered here on its own.

It should be noted, that as part of having this spring manufacutred, I looked at many original positive stop plungers and did find different springs fitted to the multiple originals we have in our possession.  However, most have similar strengths and this spring is based on a version that I found in multiple original gearbox's (most of which have been in our possesion since the 1960's), so I have every reason to believe the template spring from which these are copied are original Norton springs in unworn condition.

This is the shim fitted behind the selector fork and rear mount plate on both Upright and Laydown gearboxs from 1930's to late 1950's.

I am told by someone in the know that it is very important to have this shim fitted to ensure a smooth gear selection.  What I do know is that in the majority of gearbox's I have stripped down have this shim missing! - so it is worth checking yours to check if fitted.

The pattern for ours was taken from a genuine and unmolested upright 1940's Manx Norton gearbox.  It was fitted to all types of Norton upright gearbox (i.e. 1931'ish onwards) and laydown gearbox, up until the introduction of the AMC style gearbox.

In the first photograph, the mechanism on the left is a typical (1930's-40's) upright gearbox selector mechanism with the shim fitted, while the mechanism on the right is from a 1950's laydown gearbox with shim fitted.

See also item 0852 for similar (non-standard?) front pawl shim  

Set of 3 different thickness shim washers to fit Norton Upright/Laydown gearbox mainshaft or the layshaft of racing gearbox's.  Useful if you have endplay or your gears are not fully in line. 

Set of 3 in following sizes: 0.030”/0.018”/ 0.012" (metric equivalent: 0.5mm/0.3mm/0.2mm).  

Comes protected in Duck Oil to prevent rusting

Update Feb 20: Now available in packs of 3 sizes: 0.030”/0.018”/ 0.012",  (metric equivalent: 0.5mm/0.3mm/0.2mm)  

Background Information:

It is not unusual to have some play or drag on a Norton clutch. This is often caused by a worn thrustwasher (which we also sell - see Item 0641) or sometimes just because a gear has become worn or assembled from parts of different years.

Therefore these shims can be a useful addition to take up small amounts of endplay. To measure endplay on most Norton gearbox's - check the outer cover with bearings fitted - often the bearings will be flush with the casing gasket face (but if not use a digital depth gauge to measure the + or - difference and make a note of this).  Then on the main gearbox casting, with gears fitted and pushed up against the opposite wall fully, place a ruler across the casting - and check if there is a gap between the ruler and first gear shoulder of the mainshaft.  If there is, and the gap (with any +/-  difference of the outer bearing against front casting taken into account) is 20 thou or more, then this shim can be used to take up end float.  Please note - you should always carefully check rotation of the shaft when tightening up the gearbox end nuts - if the shaft rotation tightens as the nuts are tightening, you may have negative clearance - in which case stripdown and find out what is causing it.

Note: always check the other gears for faults first, and particularly look to see if the bronze thrust washer that fits on the mainshaft up against the sleeve gear is not excessively worn - as this can also result in excessive end float - see the information given in Item 641's listing and replace this thrustwasher first.

Final note - This shim will also fit the layshaft endcover end on racing (i.e. M30 or Manx gearbox's, where no kickstarter is fitted) - to achieve a similar purpose if excessive float or uneven gear meshing exists.

Single shim washer to fit Norton Upright/Laydown gearbox mainshaft or the layshaft of racing gearbox's.  Useful if you have endplay or your gears are not fully in line. 

Update Feb 20: Now available in 3 sizes: 0.030”/0.018”/ 0.012",  (metric equivalent: 0.5mm/0.3mm/0.2mm)  - please state which size you require when placing online order.  Now also available as a set of 3 shims - Item 0405S.

Background Information:

It is not unusual to have some play or drag on a Norton clutch. This is often caused by a worn thrustwasher (which we also sell - see Item 0641) or sometimes just because a gear has become worn or assembled from parts of different years.

Therefore these shims can be a useful addition to take up small amounts of endplay. To measure endplay on most Norton gearbox's - check the outer cover with bearings fitted - often the bearings will be flush with the casing gasket face (but if not use a digital depth gauge to measure the + or - difference and make a note of this).  Then on the main gearbox casting, with gears fitted and pushed up against the opposite wall fully, place a ruler across the casting - and check if there is a gap between the ruler and first gear shoulder of the mainshaft.  If there is, and the gap (with any +/-  difference of the outer bearing against front casting taken into account) is 20 thou or more, then this shim can be used to take up end float.  Please note - you should always carefully check rotation of the shaft when tightening up the gearbox end nuts - if the shaft rotation tightens as the nuts are tightening, you may have negative clearance - in which case stripdown and find out what is causing it.

Note: always check the other gears for faults first, and particularly look to see if the bronze thrust washer that fits on the mainshaft up against the sleeve gear is not excessively worn - as this can also result in excessive end float - see the information given in Item 641's listing and replace this thrustwasher first.

Final note - This shim will also fit the layshaft endcover end on racing (i.e. M30 or Manx gearbox's, where no kickstarter is fitted) - to achieve a similar purpose if excessive float or uneven gear meshing exists.

This spring is is the main positive stop return spring that fits in the gearbox selector mechanism pawl, and it is the wear of this spring over years of use that causes it to eventually causes it to lose it's tension - which then results in changing gear becoming more haphazard and less direct.

We manufacture these springs to the original Norton dimensions. 

Price is each

As always, this spring was copied from an original pattern in very good condition. Fitting it is a relatively simple exercise - remove the end cover to reveal the selector mechanism, then undo the two nuts holding the Return Spring Cover Plate, which allows the removal and replacement of the old spring. This spring fits both upright pre-war gearbox's, post-war upright gearbox's and laydown pre-AMC Norton gearbox's.

A simple fix if not already done, that can greatly improve positive gearchanges

And if you whole positive stop mechanism is slopping about in its housing - you might want to check if the bushes are worn - we also sell these which will improve it more, as will fitting new clevis pins on upright gearbox types.

Norton Upright and Laydown Gearbox's - Background Information

You will notice that previously a customer has rated this Item, and as part of 'Rating' he has asked the question if this spring will also fit the Norton Laydown type gearbox's? - as if you look in the 1955 Spare Parts catalog, you will see that the similar spring fitted to the later Laydown gearbox's is listed as 'D12/410', rather than the 'A12'/410'  part number here (which comes from the 1948 catalog - when they were still using Upright type gearboxs).

Well - I can tell you that to my knowledge they fit and work fine - but I cannot be 100% sure that they werent modified from this style at some point in the evolution of the later Norton Laydown Gearbox - as I have stripped original Laydown gearbox's (that I know have not been touched in my families possesion since the late 60's/early 70's) and found springs both the same as this spring, but also with a slight kink in the springs ends, half way along their length.  The last two photographs show an original Laydown type gearbox selector pawl with one of our springs loosely fitted over the spring area (but not fully fitted in the photo - they normally have both tangs fitted between the pins).   in one of those photographs, two springs are shown next to the selector - both these spring types were taken from original Laydown gearbox's, one being the same as ours, the other having a slight kink.  So yes - it seems they were fitted like this (although it is difficult to be definitive if that was a later modification or not) - but may later have been modified  to have a slight kink (maybe to ease the 'centre point' of the tension on the spring?).  I would be interested to hear if anyone knows more about this, and may instroduce the kinked type as shown in the photo at a later date.