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Triumph TR3 - Noise from gearbox

Hello.

I am interesting in buying a TR3A, whose gearbox makes a continuous “clicking” noise when driving on first or reverse.
What is the cause of this? A gear that is engaged both in first and reverse I suppose. However, I cannot identify such a part in the exploded drawings of the gearbox.
Is it risky for the gearbox to drive in these conditions? Would it very complicated to fix?

Thanks in advance for your help.

Jesus
Jesus Benajes

It sounds like the problem lies with the straight cut spur gears for
1. the 1st/reverse idler gear (Item 51 on page 6 of Sect.E of the big "S-T Service Instruction Manual" or it may be
2. the lay-shaft and countershaft (Items 41 & 40). If it is these you will also need to change the needle bearings (Item 46 - there are 48 that come in one kit).

Because you mention only a "clicking" sound, you may have lost the corner of a gear tooth off any of these gears. If you don't rev the engine too fast while reversing or starting off in 1st gear, the gearbox may last another year or two.

I would drain the oil and get all the metal bits out now. Also I would put in a magnetic drain plug so all the steel bits will do no further dammage as they will cling to the magnet.

If the 1st and reverse start to "growl" like "hunnng-huuung-huung . . . . with the "growl" going faster as you go faster, then you have to change the parts detailed above.

These parts are still available but all are quite expensive. It should be done by a gearbox specialist, preferably one who has done TR gearboxes before. If you can't find such a person, find a talented gearbox technician who can read English and you make photo-copies of all of Sect. E for him and he can read how to do it properly. If you are doing it, or having it done, it would be wise to also change all the ball bearings, seals as well as the synchro rings. The synchro rings must be of the right axial thickness, measuring 0.445" from the flat front face to the smaller tags extending axially backwards. I can explain this more later when you decide what you want to do.

Don Elliott, Original Owner, 1958 TR3A, Montreal, Canada
http://members.rogers.com/sharetwo/images/don%20elliott%20del/elliott.htm

Don Elliott

Jesus-As Don mentioned, the problem is probably a tooth missing from the cluster gear, which is very common on the 3 synchro gear boxes. If the cluster gears are being reproduced they would cost more than replacing the trans. with the later and stronger all synchro ones used on TR4-6 cars. Good used non-overdrive trans. sell for around $200, but shipping might be brutal.
Berry Price
BTP Price

This thread was discussed on 12/09/2004

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