Overdrive Rebuild

[Darren Groves]

Well I knew it was coming, I have been nursing my gearbox for a couple of years now and it's finally had enough. Was always a slightly crunchy affair, but now non existent. I have collected a few NOS spares to do this job, but whilst it's out of the car I should get the OD sorted as well. 

 

Are OD rebuilds for specialist only or should I tackle myself?

[Pete Lewis]

if you have the manual then its easy DIY.

 

there is little to go wrong and you make well strip it down and find nothing alarming  you will need ti make a drag to remove the punp and piston , this can be upgrades to a higher capacity pump.

 

fitting the balls and one way clutch  can tease the mind , and read the bit about the timing etched marks on the planet gears need to align .

 

when dropping the od back on the gearbox lever the two plates on the piston  side this replicates opening the clutch cone and allows all the splines inside to align easy,  otherwise the book says stick long screwdriver down into the black hole and twiddle to align them ...thats a right faf   and doesnt work well

 

two good levers and whiz its on.

 

Pete

[rogerguzzi]

Hello Darren

                   I made one out of several for my spitfire about 4 to 5 years ago,as Pete says its not rocket science.

 

Have a read of this link.

 

http://www.buckeyetriumphs.org/

 

I must admit I fininshed up with a 28% J type(a bit overgeared but nice when cruising on motorways)And I have a very slight whine but that is probably due to being a mix of parts that have worn in to different parts(can only hear it when the hood is up)and it has covered about 15,000 miles now.

 

I found it worth getting a pressure guage to set the pressure as you dont want the high pressure of the TR's and big saloons

 

Roger

[Darren Groves]

On the Canley's Classics website it says to 'Never remove the adaptor plate from the gearbox' but doesn't say why: http://www.canleyclassics.com/technical-archive/the-d-type-overdrive/

 

Had a quick look inside the gearbox today, found the remains of the needle roller bearing floating around in the oil....

[dougbgt6]

 I stripped my gearbox down because it kept getting stuck in gear, I found tiny bits of needle roller. It's amazing how well it runs without bearings!

[Pete Lewis]

to remove the OD you dont need to remove the adaptor plate, if you strip the gearbox you obviously have too

 

they say dont as it stops the lay spindle exiting and you drop a thrust or the  reverse spacer etc from dropping out the big hole in the GB case.

 

 if you strip a Dtype on refitting the planets read the book  there are small etched or dot mark on the planet teeth you have to align so all three  with the carrier this is best running postion  for the gears to take the same load  or you invoke a lot of vibration

 

Pete

[Darren Groves]

Thanks Pete, if that's the reason then it'll have to come off as it's the gearbox that's really poorly.

 

OD generally works, very infrequent slip, slightly lazy change sometimes and just the hint of vibration. Finances may have to dictate revisiting the OD at a later date.

 

Curiosity is bound to get the better of me though, so it'll probably end up stripped and reassembled at least.

 

Darren