GEAR 2ND TR2-early 6 ON MAINSHAFT

2nd Gear with 33 teeth used on all cars TR2-6 up to approximately 1972. The length of the bore (1.565” diameter) of the gear is approximately 1.160”

This gear has 3 oil holes from the bore to the teeth and 8 of the dog teeth are larger than the rest.

105629 was originally mated with brass bush 129939 but can advantageously be mated with the 2 piece steel bush 129939X.

Consider second hand original part 105629SH. Please be sure which you have before ordering.

This part appears on the following Triumph Catalogue Plates

Car Type	Plate	Plate Title	Plate No.	Triumph Part Description	No per Unit
TR2	L	GEARBOX: MAINSHAFT, CONSTANT PINION SHAFT, COUNTERSHAFT AND REVERSE GEAR.	L21	Gear, 2nd speed	1
TR3	L	GEARBOX: MAINSHAFT, CONSTANT PINION SHAFT, COUNTERSHAFT AND REVERSE GEAR.	L21	Gear, 2nd speed	1
TR4	M	GEARBOX: MAINSHAFT, CONSTANT PINION SHAFT, COUNTERSHAFT AND REVERSE GEAR.	M21	Gear, 2nd speed	1
TR4A	Q	GEARBOX: MAINSHAFT, CONSTANT PINION SHAFT, COUNTERSHAFT AND REVERSE GEAR.	Q21	Gear, 2nd speed	1
TR250	P	GEARBOX: Internal	P20	Gear, 2nd speed	1
TR5	N	GEARBOX: MAINSHAFT, CONSTANT PINION SHAFT, COUNTERSHAFT AND REVERSE GEAR	N20	Gear, 2nd speed	1
TR6CP	AA	GEARBOX: Internal	AA20	GEAR, 2nd speed Fitted up to Gearbox No. CD20281	1
TR6CC	AA	GEARBOX: Internal	AA20	GEAR, 2nd speed Fitted up to Gearbox No. CD20281	1

Q: TR4-6 second and third gears have excessive end-float on the mainshaft. Second gear bush is too short allowing excessive movement over the mainshaft.

A:

There are two combinations of second gear bush and gear. What can happen over time is that the gearbox can be rebuilt with "early" and "late" specification mixed. It is often thought that the later specification must be stronger and Triumph must have made the changes for that reason, technically this is so, but we have found that the dog teeth on the late specification fail much more quickly than the early type did, although the bush part doesn't.

What often occurs is a late specification bush UKC956 and gear TKC454 are mated with the early thrust washers in the range 129941-2-3-4, when what is needed is thrust washers in the range UKC958-9-60-61

The late specification bush is shorter and the bore of the gear is correspondingly short, but the thrust washers are that much thicker, by around .080", which does make the 2nd gear thrust washers less likely to break.

We recommend fitting the early specification gear 105629 plus uprated steel bush 129939X (which is 1 x 153237+1 x 153239 sold as a kit). These must be used with thrust washers 129941-2-3-4. Also we have available a specially made thicker version of 153239 (originally approximately 0.123" thick), which we stock as 153239A (0.126" thick) which may be required to achieve the correct end float, measured using a new circlip 055707.

When correctly fitted to the mainshaft, if (say) 153237 is clamped against the 2nd gear thrust washer, using 153239, it should have 0.003" end float, irrespective of the total end float of the whole cluster on the mainshaft, which we suggest should be 0.004"endfloat. The same end float applies to TKC454 on UKC956, against thrust washers UKC958-9-60-61.

An alternative would be to fit TKC454 gear, UKC956 bush, with thrust washer UKC958-61. More often than not UKC959 is needed. If the gearbox has TKC454 fitted, carefully inspect the dog teeth, and if they are chipped and rounded, throw it away.

If you measure the length of the BORE of the gear, 105629 is approximately 1.375" and UKC956 is approximately 1.187", so it will be hard to mix them up. This measurement can be done with a steel rule for the purposes of establishing which gear you have.

All the thrust washer dimensions are shown on our website against individual part numbers.

Part No.	Description and Comments	Price	Add to Cart
TKC454 CLICK FOR MORE INFO	2ND SPEED GEAR Revington TR information: Gear second speed 33 teeth used on TR6 cars from approximately 1972. The length of the bore (1.565” diameter) of the gear is approximately 1.160”. This gear is used with bush UKC956 and thrust washers... READ MORE	£150.71 Ex VAT @ 20% £125.59	Available to order
TKC454SH CLICK FOR MORE INFO	Second Hand GEAR SECOND SPEED Revington TR information: Second Hand 2nd speed Gear second speed 33 teeth used on TR6 cars from approximately 1972. The length of the bore (1.565” diameter) of the gear is approximately 1.160”. This gear is used with... READ MORE	£91.36 Ex VAT @ 20% £76.13
153237 CLICK FOR MORE INFO	2ND GEAR BUSH	£70.10 Ex VAT @ 20% £58.42
UKC956 CLICK FOR MORE INFO	BUSH 2ND SPEED TR6 STEEL Revington TR information: Bush second speed used with gear TKC454 and thrust washers UKC958-61 This part might need to be worked a little to get a sliding fit to the mainshaft. This is the best fit part we can... READ MORE	£40.58 Ex VAT @ 20% £33.82
129939X CLICK FOR MORE INFO	BUSH UPRATED 2 PIECE This item has been superceded by 129939-SE - see below
129939-SE	BUSH SECOND GEAR UPRATED STEEL	£84.25 Ex VAT @ 20% £70.21	Available to order
105629SH CLICK FOR MORE INFO	Second Hand GEAR SECOND SPEED Revington TR information: Second Hand 2nd Gear with 33 teeth used on all cars TR2-6 up to approximately 1972. The length of the bore (1.565” diameter) of the gear is approximately 1.160” This gear has 3 oil holes from... READ MORE	£116.66 Ex VAT @ 20% £97.22
153239 CLICK FOR MORE INFO	WASHER THRUST STAG Revington TR information: This washer is an original Stag thickness spacer washer between 2nd and 3rd gears. 153239A is +0.005"	£34.85 Ex VAT @ 20% £29.04

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