My Gearbox Rebuild

[Kpas]

A few months ago I was out driving my S2 Elan when I was greeted with a god awful crunching noise and a lack of drive in the first 3 gears.

I managed to limp the car back to the garage in 4th gear (was a short distance away).

It turned out of be a pretty terminal gearbox failure with the input shaft having lost all its teeth.
https://www.dropbox.com/s/8oxfc6unzmefl ... 3.jpg?dl=0
https://www.dropbox.com/s/f4lri16n98dow ... 7.jpg?dl=0

Like any good repair this is where my gearbox rebuild progressed to
https://www.dropbox.com/s/koak0swnx2pii ... 9.jpg?dl=0
https://www.dropbox.com/s/1q2be4e6wmxgz ... 0.jpg?dl=0

Nothing like a bit of scope creep! The thought process was while I've got the engine and gearbox out I should paint the engine bay..... and while I'm painting the engine bay I should paint the rest of the car.

I was lucky enough to have access to Richard Mann who helped with the fiberglass repairs. He also provided the space to rent for storage of the car and it's disassembled bits, as well as a location to paint it.

I use the car frequently, and at the outset wanted to just do a quick and easy respray over a 3 week period whilst my better half and our little one were away...... I ended up a fair bit more involved than that with the bodywork taking about 3 months with a whole bunch of life distractions getting in the way.

As we progressed with the fiberglass repairs, and the body prep the cars shape got better and better. Richard worked through some dodgy repairs on the bonnet (a hole which had been bogged up) which was the worst fitting panel.
https://www.dropbox.com/s/73ewuvexgr3f1 ... 2.jpg?dl=0

The high fill and blocking back process took a few iterations before I landed on the final shape with enough primer still on the car.
https://www.dropbox.com/s/xfmsjo92g1mcx ... 1.jpg?dl=0
https://www.dropbox.com/s/1ge2aqhyfk2p7 ... 6.jpg?dl=0
https://www.dropbox.com/s/2qimv1adm18l0 ... 8.jpg?dl=0

And last weekend I managed to finally get some paint onto the car.
https://www.dropbox.com/s/oriv36ysl032l ... 9.jpg?dl=0
https://www.dropbox.com/s/oriv36ysl032l ... 9.jpg?dl=0
https://www.dropbox.com/s/v32qcjisb7ef1 ... 7.jpg?dl=0
https://www.dropbox.com/s/v32qcjisb7ef1 ... 7.jpg?dl=0
https://www.dropbox.com/s/fmr3kka3d48kw ... 3.jpg?dl=0

Now to build that gearbox.....

[types26/36]

Wow! ......never seen that! .........that?s some serious gearbox issues.
Is that a close ratio box (2.5) first gear, semi C/R (2.9) first gear or the wide spaced (3.5) first gear?
Have you worked out what caused the g/box problem? ....
Nice spray job

[The Veg]

?WOW!

[SENC]

Thanks for making me feel better about my scope creep!!!

That is quite the gearbox damage - any warning? Any root cause?

[Kpas]

The gearset fitted to the car turned out to be a standard cortina ratio, so one upside is that I didn't destroy a rare gearset.

There was no warning signs unfortunately. Rohan came past to cast an eye over thr remains, his determination was fatigue failure of the teeth on the input shaft.

[mark030358]

Love the colour!
Nice work

[geni]

hua!
Very beautiful painting, it has charm! his reference?
could I know the positioning = relays fixing measure in the left front wheel arch!
The rims with these 3x pins to maintain the central hubcap chrome are type car?

[2cams70]

The gearset fitted to the car turned out to be a standard cortina ratio, so one upside is that I didn't destroy a rare gearset.

There was no warning signs unfortunately. Rohan came past to cast an eye over thr remains, his determination was fatigue failure of the teeth on the input shaft.

Very unusual for teeth to strip like that with an engine in standard tune. Did you check to see whether something might have come adrift inside the box and jammed in between the gears? The primary gear on the countershaft sits lowest in the gearbox and hence is the most likely gear to pick up any debris that may be lying at the bottom. Once something hard gets stuck between the gears it doesn't take long before it's bye bye gearbox. Not saying it's what has happened in this case but nevertheless it is a possibility,

[rgh0]

The gearset fitted to the car turned out to be a standard cortina ratio, so one upside is that I didn't destroy a rare gearset.

There was no warning signs unfortunately. Rohan came past to cast an eye over thr remains, his determination was fatigue failure of the teeth on the input shaft.

Very unusual for teeth to strip like that with an engine in standard tune. Did you check to see whether something might have come adrift inside the box and jammed in between the gears? The primary gear on the countershaft sits lowest in the gearbox and hence is the most likely gear to pick up any debris that may be lying at the bottom. Once something hard gets stuck between the gears it doesn't take long before it's bye bye gearbox. Not saying it's what has happened in this case but nevertheless it is a possibility,

The failure was very clearly a fatigue failure of the teeth with most of the failed teeth showing fatigue cracking before failure. The Cortina gears may have done a few hundred thousand miles before being put into the Elan so its not surprising after 50 years. Most Elan boxes will have done a lot less miles.

cheers
Rohan

[Quart Meg Miles]

The failure was very clearly a fatigue failure of the teeth with most of the failed teeth showing fatigue cracking before failure. The Cortina gears may have done a few hundred thousand miles before being put into the Elan so its not surprising after 50 years. Most Elan boxes will have done a lot less miles.

cheers
Rohan

Oh dear, my speedo just passed 80,000 for the third time...

[Kpas]

Some progress happening. It's nice to be putting bits back onto the car again!

Though it was a bit of a two steps forward one step back.

I pulled all the masking off which has made it loom like a car again, two steps forward.

I'd pulled out the steering column bushes as part of the strip down. In the process of installing the new ones I've damaged the column.... one step back. Silly silly boy.

[Kpas]

Ok so I've been a bit lazy with the updates, but that's not due to a lack of progress.

The car is 98% back together now and is a real joy with the correct gearset in it. I'm quite surprised at how much of a difference it has made, but I guess you don't know what you don't know.

I'll have to wait until the car has seen a bit of sun over the Aussie summer as the paint is still quite soft. The badges and other fittings will also have to wait as I won't polish the csr until after summer.

But all in all, I'm very happy with the results.

[davidj]

This is the layshaft from a triumph gearbox fitted in a kit car I built 30 odd years ago. Similar failure....

[davidj]

Fantastic restoration by the way.

[SENC]

beautiful!