Gear Dimension Changes by Color Code | ||||||
Brown → Black denotes ranges starting with the smallest and increasing in size to largest dimension. | ||||||
Brown | Blue | Red | White | Green | Yellow | Black |
.000 - .001 | .001 - .002 | .002 - .003 | .003 - .004 | .004 - .005 | .005 - .006 | .006 - .007 |
Brown ← Black denotes ranges starting with the largest and decreasing in size to smallest dimension. | ||||||
Brown | Blue | Red | White | Green | Yellow | Black |
.000 - .001 | .001 - .002 | .002 - .003 | .003 - .004 | .004 - .005 | .005 - .006 | .006 - .007 |
Gears Manufactured with Multiple Dimensions including Ranges | ||||||
1954 → 1985 | ||||||
Pinion | 54-76 (24011-37) | Range Brown ← Black - 1.2681-1.2611 | ||||
77 (24015-74) | ||||||
78-85 (seven part #s-74) (Standard 24059-74 - Green 1.2641-1.2631) 2) Replacement for 77 models | Range Brown ← Black - 1.2681-1.2611 | |||||
1957 → 1979 | ||||||
Idler | (25576-57) | Range Brown ← Black 3.0223-3.0153 | ||||
1959 → 1979 | ||||||
Rear Exhaust | (25504-59) | Range Brown → Black 1.8893-1.8963 | ||||
Front Intake | (25501-59) | Range Brown → Black 1.8893-1.8963 | ||||
1971 → 1979 | ||||||
Rear Intake Inner | (25485-71) | Range Brown ← Black 1.8953-1.8883 | ||||
Rear Intake Outer | Range Brown → Black 2.3902-2.3972 | |||||
Front Exhaust Inner | (25503-71) | Range Brown ← Black 1.8953-1.8883 | ||||
Front Exhaust Outer | Range Brown → Black 2.3902-2.3972 | |||||
1980 → 1985 3) | ||||||
Front Intake | (seven part #s-80) | Range Brown → Black 1.8893-1.8963 | ||||
Rear Exhaust | (seven part #s-80) | Range Brown → Black 1.8893-1.8963 | ||||
Late 1984-1985 4) | ||||||
Front Exhaust | (seven part #s-84) | Range Brown - Black |
68 Gearcsae Cover 6) |
78 Cam Bearings 7) |
There is no relationship between the timing of the cams and the position of the crankshaft timing mark in the hole. Just line up the cam marks and the pinion gear mark and you are done. 8)
Use some clothes pins to hold the lifters out of the way 9) |
* . . . Gearcase Cover Removal
Compatibility
1957-1985 pinion gears have 18 teeth and splines to match the splined pinion shaft.
1957-1976 pinion gears have 4 splines.
1977-1985 pinion gears have 6 splines.
Part# | Year Models |
24011-37 | 1954-1976 KH / XL / XLH / XLCH |
24059-74 | 1977-1978 XLH / XLCH |
24055-74 (brown) | 1979-1985 XL / XLCH / XLS / XLX |
24056-74 (blue) | |
24057-74 (Red) | |
24058-74 (white) | |
24059-74 (green) | |
24060-74 (yellow) | |
24061-74 (black) |
Click on any pic below to enlarge:
1957-1976 Pinion Gear. 18) | |
1977-1985 Pinion Shaft Timing Mark 19) |
These are OD measurements of 3 OEM pinion shafts as measured by needspeed (.7844“, .7840” and .7840“). 22)
Comments by Dr Dick;
Installing a tight gear: If you tap the gear on the shaft you are tapping on your flywheel assembly in a direction not supported by anything. NOT recommended.
You should utilize the 5/16”-24 left hand threads tapped in the pinion shaft to counteract installing force (press it in).
The 1957-1976 pinion gear needs to be a tight fit and was a factory press fit. However, it's a common problem to find them loose on a used engine. 23)
The trick in selecting the right fit part during assembly. The gear is supposed to be “size for size” with the major diameter of the shaft splines.
The “press” actually is between the sides of 1 male shaft spline and it's matching female spline in gear.
There is 1 bigger spline so the gear can index for cam timing. The press spline is the one opposite the bigger one.
The bad news is the shaft wears before the gear. The XL gear is beefier where the pump drive gear hits the back of the pinion gear.
It's beefier because HD also had these failures.
However, leaving the gear loose makes you 1 of 80% of Ironhead riders. Worse side effect is non stop “tappet noise”.
It can be heard even just pushing the motor over with kicker.
It's usually not “destructive” problem to leave it as is and you can't use an adhesive to “glue” the pinion gear on.
(1) - A loose gear doesn't mess with breather timing too much. A correctly positioned gear sits .312“ above the gasket surface. 24)
The cover bushing face sits .312” below gasket surface. So the gear clears the bushing by 1 gasket thickness.
A loose gear rides on the bushing face. There is virtually little breather timing difference between the tight position and the loose one.
A shim between gears can make up for the loose position. This shim mustn't self destruct and get caught in cam train.
(2) - A loose gear will make a valve tapping type noise. No mechanical problems, just a tad noisy. Looser = noisier.
(3) - The gear press isn't diametrical. Its lateral. When loose both gear and shaft wear.
When a loose gear is removed you will see the wear on shaft spline flanks.
25)
4) Bikes using stock valve springs can use a 45“ flat head gear to regain some fit.
I have done this many times. Probably 50 times.
These gears are OEM WWII surplus (-29 pn). Many times marketed as XL but they are not the real XL gear. The real xl gears have been obsolete for decades.
Warning: I also had two 45” gear failures. Both big bore strokers. Both heavy springs and cams. Both bikes ridden extremely hard.
Both gears very tightly fitted to unworn shafts. Broken pinion gears make a serious mess of your motor. $$$$
Worst case scenario, you will be looking at new cylinders, pistons, heads, valves, guides, pushrods, cams and cam cover. You don't wanna go there.
I suggest never to use the 45“ gears on unworn shafts. Or with cams that require heavy springs.
The 79-85 pinion gear is a slip fit and slides up on a timing mark on the pinion shaft and corresponding to a timing mark on the pinion gear.
These must line up. 26)
When installing the tappets, the valve may be recessed in the head a bit. 28)
You can gently lever up on the pushrod to allow it to pop in the tappet cup.
Just be sure you have some free play remaining once it is in the cup and before clearance is adjusted.
An open end wrench will work, or carefully with a pair of smooth sided needle nose pliers.
You just need to overcome some valve spring pressure.