Upgrading TR2 non overdrive gearbox to overdrive

[MMARSHALL]

I want to add overdrive to my standard non overdrive gearbox on my 1955 TR2. Does anyone have any experience of this? Any advice gratefully received.

[Lebro]

Not that simple. You will need to take the box apart, take all the gears off the mainshaft, then re-assemble them on an "overdrive" mainshaft, this is shorter than the non O/D version. You then re-assemble the gearbox, & add the O/D to the back end using an adaptor plate between the two.

 

All of this is open to lots of problems, My advice would be to locate another box which has O/D already.

 

Bob.

[TR 2100]

Not that simple. You will need to take the box apart, take all the gears off the mainshaft, then re-assemble them on an "overdrive" mainshaft, this is shorter than the non O/D version. You then re-assemble the gearbox, & add the O/D to the back end using an adaptor plate between the two.

 

All of this is open to lots of problems, My advice would be to locate another box which has O/D already.

 

Bob.

 

Or - give your gearbox and an overdrive unit to a specialist.

 

Special tools and specialist knowledge are required, especially

in the area of upgrades necessary to overcome some design

shortcomings.

 

AlanR

[Don H.]

 

Or - give your gearbox and an overdrive unit to a specialist...

 

This is what I did when Mark Macy and his crew added an overdrive given to me by a friend to the original TSF-full-synchro 'box in my car.

[pfenlon]

Peter Cox is "the knowledge here" great workmanship at a fair price.

[foster461]

The chances are that your gearbox is ready for a refresh anyway so give it to one of the specialists and have them add the overdrive. It wont be cheap but it will be a great addition to the driving experience.

 

In addition to the switch and the wiring loom and relay you may also have to make a new hole in the dashboard for the switch.

 

Stan

[Lebro]

The chances are that your gearbox is ready for a refresh anyway so give it to one of the specialists and have them add the overdrive. It wont be cheap but it will be a great addition to the driving experience.

 

In addition to the switch and the wiring loom and relay you may also have to make a new hole in the dashboard for the switch.

 

Stan

The hole in the metal of the dash should already be there, just need to find it, & cut the vinyl to match.

 

Bob.

[foster461]

The hole in the metal of the dash should already be there, just need to find it, & cut the vinyl to match.

 

Bob.

 

That is a detail worth poking at Bob. My 1960 LHD post 60K non-OD TR3A did not have a hole, I had to drill one.

 

Stan

[Don H.]

 

That is a detail worth poking at Bob. My 1960 LHD post 60K non-OD TR3A did not have a hole, I had to drill one.

 

Stan

 

My dash did have a hole; it was in use by the windscreen washer pump. This accessory was noted on my BMIHT build certificate, so I assume the hole was put there by the factory. There really aren't any rules for how the cars were put together -- they were more interested in sales than any sort of future discussions about what might be found on the cars!

[foster461]

Exhibit B, sans hole.

 

[Lebro]

Hmm seems some were & some were not.

 

Bob.

[PhilExe]

I am doing this modification on my 3A right now. After a lot of researching and looking around for an overdrive unit I eventually bought a complete refurbished overdrive gearbox from a chap in Ryslip Middlesex (David 07831304319 only contactable by phone) who just does old gearbox refurbs swapped by non overdrive box. I went and met him and swapped the units he does it from a workshop at his home said he has been doing then for 50 years and does seem to be well set up. Am still in the process of reinstalling the new box so have yet to test it but initial impressions of the new box are very positive its appears its been done properly. Expect to pay around £1,500.00 for the exchanged unit.

 

You'll need an A type overdrive or rear mounting adaption for a J type which just adds more cost.

 

Re-installing the box is not easy I've struggled with that it needs very careful and precise alignment, that's this weekend little job.

 

On the subject of switch position my dash did have a spare hole but its position clashed with the indicator switch so I simply purchased a 14mm hole cutter from Screwfix which did the job very easily.

 

Phil

[rhino_mac]

I am doing this modification on my 3A right now. After a lot of researching and looking around for an overdrive unit I eventually bought a complete refurbished overdrive gearbox from a chap in Ryslip Middlesex (David 07831304319 only contactable by phone) who just does old gearbox refurbs swapped by non overdrive box.

 

I bought my gearbox from David. Lovely chap who works out of a little workshop attached to his house and just does Triumph gearboxes. He used to race Norton motorcycles!

 

I bought a complete 3 synchro gearbox from him - no exchange needed. He has a reconditioned 4 synchro unit on Ebay at the moment: http://www.ebay.co.uk/itm/TRIUMPH-OVERDRIVE-TR-2-3-4-5-6-A-RECONDITIONED-GEARBOX-ATYPE-OVERDRIVE-22-/322307196526?hash=item4b0b01866e:g:7r8AAOSwEK9ULFq-although I do see he has a £120 surcharge if you don't exchange.

 

My gearbox worked faultlessly (although the solenoid needed replacing) and it is lovely going through the gears. Overdrive engages instantly. He gave me a six month warranty on the box (although this was just an email note).

 

He discounted the box slightly for me if I collected from him and didn't use Paypal so well worth having a chat with him.

[RogerH]

Hi Phil,

there have been a couple of gearbox installation posts somewhere on here recently.

Maybe helpful to you to get that box in. manhandling and alignment are the two major problems.

 

Jack under the sump - to raise / lower.

Jack under the GB to help align

Keep the GB in gear so by turning the output flange the input shaft can rotate and help engage in the clutch.

 

Apart from that - easy.

 

Roger