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Gearbox question / 4th gear / main shaft

PostPosted: Sun Dec 18, 2016 11:47 am
by el-saturn
good morning everybody! my main gear (4) has a bit of a chewed up "running surface" at the very front (where it's engaged during gear change) and wonder how much wear is normal. if i change it can i switch WITHOUT pulling the entire unit and as i see it, i'd have to remove all of the rails etc...!!!?????? hope to hear that yours are also worn and still work?! sandy (engine is already out) 4982 with a 701 block: not correct!

Re: Gearbox question / 4th gear / main shaft

PostPosted: Sun Dec 18, 2016 2:33 pm
by Lyn7
Hi Sandy, just gave an answer in the other post! :D Sorry, but, to get the first motion shaft out you will have to completely strip the box. Not as onerous as it seems. :wink:
Lyn.

Re: Gearbox question / 4th gear / main shaft

PostPosted: Tue Dec 20, 2016 3:01 pm
by Elan45
But even if you pull it down to replace the input shaft, good luck finding a replacement. They are made of unobtainium! I'd replace the bearing in the back of the crankshaft, grease it, and hope for the best.

Note: this bearing only operates when you have the clutch pedal depressed. Do Not sit for long periods with the clutch in. No long traffic lights w/o going to neutral and clutch out.W/ proper care, your shaft and bearing will last a long time.

Roger

Re: Gearbox question / 4th gear / main shaft

PostPosted: Tue Dec 20, 2016 4:25 pm
by el-saturn
tx roger - this is identical to/for all of the 2000e main gears and therefore easy to find or not? sandy

Re: Gearbox question / 4th gear / main shaft

PostPosted: Tue Dec 20, 2016 8:05 pm
by Chancer
Even significant wear wont be a problem subject to a couple of caveats.

As has been said it only handles any relative motion if you are at a standstill with the engine running, car in gear and clutch depressed, mots of the time the engine will only be idling at this point, try to avoid high revs and prolonged standstills in gear.

As you have damage to the shaft I would recommend fitting a bush rather than the needle roller bearing next time the box is out assuming that you have the right bore in the crankshaft, a bush will be more tolerant although I'm sure you will have no problems with the needle roller bearing.

Tip, to remove the bush or bearing fill the bore with grease and hammer in a first motion shaft or clutch alignment tool with a hide mallet, hydraulic pressure will push the bearing out and probably spatter your face with grease so wear glasses.

Finally I have removed many a gearbox and found that the crankshaft spigot bush had never ever been fitted and in only one case had it caused gearbox problems despite the extra axial loads in the intermediate gears caused by the input shaft being able to oscillate around the fornt bearing, again it was only Noisy when clutch in gear at a standstill.

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 12:14 am
by 2cams70
That input shaft is the same as the one used in a 1967 onwards (MkII) GT or 1600E Cortina. It is the same whether it is out of the 2000E 3 rail gearbox or the later single rail box with aluminium extension housing.

Probably difficult to source in the US - more likely available from the UK.

Usually what happens is someone takes a box out of a car and leaves it lying around without protecting the input shaft with some grease which then rusts leading to a situation similar to yours.

Maybe it's possible to have it turned down and sleeved if it's really bad??

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 8:34 am
by rgh0
2cams70 wrote:.......

Maybe it's possible to have it turned down and sleeved if it's really bad??



Certainly possible to spray weld and grind back to size or to turn down and fit a sleeve to bring it back to size.

cheers
Rohan

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 3:04 pm
by Elan45
Sandy,

No they are not all the same. Close ratio vs semi-close vs wide ratio (non-GT Cortina etc) have different tooth count. Also different is normal bushed vs needle bearing type and even 2 styles of attaching ball bearing onto shaft. Be careful.

Roger

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 3:19 pm
by el-saturn
currently ill stick to the grease solution and a bit of scotch brite and some 600! sandy ..... tc in hybernation!

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 4:57 pm
by jimj
No wonder you`re currently ill. Avoid the grease and try a wire brush and disinfectant.
Jim

Re: Gearbox question / 4th gear / main shaft

PostPosted: Wed Dec 21, 2016 5:34 pm
by el-saturn
----------------------------- this is the difference a couple of minutes of finger-grease make - i suppose there's nothing to worry about sandy

Re: Gearbox question / 4th gear / main shaft

PostPosted: Thu Dec 22, 2016 5:08 am
by 2cams70
[No they are not all the same. Close ratio vs semi-close vs wide ratio (non-GT Cortina etc) have different tooth count. Also different is normal bushed vs needle bearing type and even 2 styles of attaching ball bearing onto shaft. Be carefu]

It has to be out of a later Mk11 (67-70) GT/1600E Cortina. Not a Mk1 (63-67) Cortina. The Mk1's were fitted with 2.54:1 1st gear ratio boxes (early Lotus models only, or the unique Australian GT500 model Bathurst winner!) or 3.54:1 first gear ratio boxes for everything else (later Lotus, all GT as well as all cooking models).

The Elan just followed whatever Ford had going in it's parts lists for their models that had the Lotus engine at the same time.

Re: Gearbox question / 4th gear / main shaft

PostPosted: Thu Dec 22, 2016 11:15 am
by gjz30075
The semi close has a 2:97.1 first gear, I believe.