Gearbox wear checking

[miked]

I have a question. I am wanting to make up a spare gearbox.

When re building a 2000E 3 - rail gear box there are end float tolerances for the gears in the manual. When wear has taken place: Is it on the shoulder of the gears or the shoulder of the shaft or the snap rings.

Or a combination of all of them. If I am making sense, I am looking at getting back a little bit more inside the max tolerance and wondering if new snap rings make a difference or is it down to the the kit on the shaft and the main shaft.

I know you can have things like winding out of 3rd gear on the overrun with play.

Mike

[KevJ+2]

Mike, I noticed the other day that someone has put a 2000e gearbox rebuild on YouTube in six parts.
I didn't actually watch as I've just rebuilt mine and I'm too scared to see something I've forgotten
Might be worth a look.
http://www.youtube.com/watch?v=GcOdtYcVNzs
Kev.

[miked]

Kev,

Thanks very much for that, what a stroke of luck. I am looking forward to watching all 6 parts. My home PC is very old and kept breaking up on the sound but from the bit I saw it looks great. Hopefully he is not just replacing stacks of parts and explains about checking wear and effects.
New Laptop coming next week . I will report back.

Mike

[Hawksfield]

Kev

It will require quite a few parts to complete the rebuild it is painfully slow after six parts he has only got the gears on the main shaft. however it will be a very useful video if he lists the description of each video when it is complete.

I look forward to it

[KevJ+2]

It's a shame really because it seems a great idea to show a complete rebuild. When I saw the first opening shot, I thought it a shame it was already dismantled, surely half the job is to show the stripdown! So yes it must be a bit slow going to watch six episodes with a built up mainshaft as the result. Still, as I write this, it has to be better than watching dancing on b*****y ice
Kev.

[miked]

I just watched all six. The guy is helpful in doing this. Yep I agree it would be good for people to see the strip down if you have not had one to bits before.
Nothing there about wear other than visual, no checking with feeler gauges for end float.

Things I did notice not covered, that I thought were meant to be important, was that the synchro' springs tag ends going in the same blocker bar and the free ends then in opposing directions. Saying that he must asssume we read the manual as he was following it.
Also I have been careful that the inner hub and outer sleeve are marked (if the etch/paint, can not be seen) so they go onto the shaft, as they came off, as I am sure I read that they are matched to the shaft. Hence etch and paint marks. Therefore going back together they all slide easier? Was this not his problem by saying the fit was universal and struggling a little to put it together. Sweet pot comment.

I know it is easy to comment. Interesting to see the lay shaft bit.

Mike


.

[miked]

http://www.bing.com/videos/search?q=how ... 5689F98B76

I just found video above and learn't a bit more about synchro' rings. Whilst not Elan, the principles are the same.
Also found labelled diagram which helps.

Mike

[miked]

This is good.

http://www.lotuselan.net/wiki/Gearbox_(Transmission)_-_Fault_Finding

I also learnt that the actual gear sides that spin against the side location of the main shaft collar do wear giving more end float clearance. The thing that has surprised me most was the wear on the synchroniser hubs and sleeves. When I opened a box that was mint these were a very nice fit. On another they were a very sloppy fit. On the sloppy fit one the blocker rings were also very worn and seated deeply and did not do that clutch type grip when turned and pushed like the guy shows in the previous video clip. Using a semi close gear ratio set from a snap ring type main shaft (that had caged needle roller damage on it) I used a lock nut type main shaft. I used the rear bearing carrier and 1st gear spacer from the later snap ring box as the lubrication on the rear of the 1st gear matches it. On the lock nut shaft type first gear there are lube slots on the back of the gear and a plane spacer. I saw no other difference and it went together nicely with new mains, lay and roller bearings etc.
I saw the etching that matches the synchroniser hubs and sleeve together and to the shaft and can understand that from new they have a matching position. However it would appear when they have done some miles (and worn) they are more forgiving and don?t feel any different if moved from the etched position.

Mike

[KevJ+2]

Mike, although I can't access the wiki link for some reason, I'm glad to hear about the etched marks not being so important when a bit worn. I took my mainshaft apart but could'nt find any. I was a bit worried about this so hope it's all ok
The gearbox seems all good now it's assembled and I can select all the gears but it has a bit of resistance on what I think is a full lay gear rotation. I can only think this is due to the layshaft being assembled in a different position to its very slightly worn original one. Now someone is going to say this is bad and I'm not going to be able to sleep for a while
On the subject of synchro rings, I paid ?90 cash (sent by post) to a very well known Lotus person for the 3rd/4th rings. These, I was told, are like rocking horse droppings and the two I got were from his private stock (hence the cash payment) and weren't even unused
So if you see some good ones, grab them while you can.
All the best,
Kev.

[Craven]

Hi,
My understanding of the fit of synchroniser hubs to main shaft is that when manufactured the hub to mainshaft is an interference fit and is pressed on. This would make sense as you appreciate the whole of the transmitted power is carried by the hub/shaft splines. In theory then it should be necessary to remove and fit the hubs using a press, I?ll quickly add I?ve never found a used box that needed this.
Interesting subject the 3 rail gearbox lots of subtle differences over the years.
Ron.

[miked]

Hi Kev,

Hope yours is OK. I am only learning and there must be guys on here who are expert at this. I bought a few Anglia boxes and Mexico ones to get bits out of so have semi-close (2.97 1st gear) stuff. As Ron say?s quite a few variations over the years. I just opened an old Anglia one and it has that 1st gear sleeved business. The Dave Bean Cat is also a good source of info' on the variations.

Yep I was paranoid about those etch marks. They are clear on some but not on others. It is hard to mark up before you split with them being so hard and then cleaning things. I have gathered a few lay shafts so have compared (measured) them and used the best. Could find no difference between some and a new one. The thing I have noticed it that opening up old boxes, some are mint and must have been pulled out early while others are worn and must have had a hard life. External condition has no bearing on this.

Not sure about lay shaft, you would think that if you?re main case holes are not worn that a new one just puts you back in the exact right position. Talking to others is seems the only proof in the pudding is in the eating. I too share your reservations about this. Not that big a deal to pull a motor when you get over the disappointment. When I chased that click noise, on pull off, I had had the motor out and replaced the clutch to find I still had it. Found it on the second try, It was the broken up needle roller between 1st motion and main shafts.

Hi Ron, yes I too get the synchro? hubs on and off the shafts without the need for a press. Whilst a good fit ,not that tight. One thing that amuses me is the fact about the etching and fit is when you can buy a new main shaft and news hubs. They must just go one were they let with no markings. So that kind of tells you. With respect to Ford I believe the manufacturing process and Quality control was the best and perhaps under appreciated. All the guys from the period who drove these cars (inc me as a very young chap ) will wax about nothing quite like it until this box came a long. We are spoilt with modern cars.

Interesting stuff playing about with these.

Mike .

[Craven]

Hi,
Miked & Kev+2
Re marking on hubs, just had a quick look at some NEW unfitted hubs, and yes these are marked as pairs.
I believe that after the pair was pressed onto the mainshaft their position was then marked.
Kev, were the layshaft thrust washers in good order, are you sure they are both located in the slots OK.
May help Ron.

[AHM]

Also found labelled diagram which helps.

But is the early diagram and doesn't show the input shaft bearing 'Dust' shield.

[miked]

Yep, it has that sleeved first gear too.

Is that the metal insert cover thing that covers the ball bearing on the front side! The thing I prised out as I was afraid it would restrict lubrication? There was none on the old bearing. If so I am confused as there is an oil seal infront of this. How can you get dust in there past this seal. Mike

[miked]

Few more observations after some more tinkering:

I have found a few boxes with the needle roller cage in bits now (3 out of 7) over the last 5 years. I think I see the reason. I opened a low mileage Cortina box yesterday and the rear lock nut was loose. When I examined the edge of the roller it has end thrust wear from the main shaft. It would have gone through the side of the cage and released the rollers. In the bin with it. Sides are about 32 thou thick, just peeled the thin worn bit off with pliers with hardley any effort.

I also notice that the 3rd/4th selector hubs are more worn and loose than the 1st/2nd gear ones. I knew that this always seems the case with the actual selector forks for 3rd/4th. Seen a lot of worn one and better 1st/2nd one. Maybe not a trend with the small sample!

Can only assume then we do more changing between 3rd and 4th.

I have found that the 3rd/4th gear selector on a really nice low mileage box got stiff when pushed on the shaft away from the etch mark. With the inner and outer etch mark lined up but in a random position on the main shaft it seems to make the sliding action stiffer. Distortion? When built up with the springs and blocker bars it is very hard to move. Before separated it moved well. I am going to have another go at it and see of I can see the etch on the shaft etc. My fault really I should have marked it. It is the first one I have come across that is so unworn and unforgiving. We live and learn.
Update; Found it, done it worked. Now moves better.

Thought I post as a record as I may forget and can look back in a few years time.

Mike