2000E semi close 1st gear welding itself to mainshaft

[TrevorJones]

Hi folks
Last year following a two year restoration I had a first gear weld itself to the main shaft after only a few miles running in. The box is an early version (without sleeve under 1st) rebuilt with new bearings, layshaft, syncro springs, millers oil, etc, everything else looked good with end floats within tolerance. The first gear and main shaft was scrap, and the box rebuilt with spare parts I had available and Redline MT90 oil this time.
This box has lasted about a 1000 miles most of which on track days and then last weekend at Pembrey Circuit Wales the box let go again, inconveniently at 8000 RPM in second going for third on the exit of a bend. Having stripped down the box, first gear had welded itself to the main shaft whilst still in second the destruction of the lay gear, first and second gear sets are total.

Is this common on standard 2000E boxes when in use at hi RPM and 160BHP?

[rgh0]

The later standard box in my 68 S4 lasted about 10 years and 20,000 miles of racing plus 15 years before racing of enthusiastic road use with that sort of HP and rpm and more. it failed when the second gear teeth failed from fatigue.

For the last 20 years of racing I have used a Quaiffe straight cut synchro gear set with just one rebuild when the layshaft shaft spun in the casing. I have always used MTL not MT90 . MT90 is thicker than the Ford original viscosity specification that MTL meets.

Welding a gear onto the shaft suggests lack of lubrication between the shaft and gear for some reason. I presume Ford added the sleeve to the later gear box design for a reason also.

cheers
Rohan

[Craven]

Hi,
My time line of gearbox evolution seems different, the sleeve was fitted to EARLY generation of the Ford Anglia 4 speed all syncho box, I don?t think it ever appeared in the ? 2000E ? gear set.
Two points that may be of interest, not shown on exploded views of gears is a SNAP RING holding the 1st 2nd syncho hub in place, not been missed out by any chance? The other, a later modification made to the oil pickup arrangement of oil feed to rear bearing this may have also improved general oil lubrication at that end of the main shaft. This modification is found in gearboxes using a snap ring to retain rear bearing NOT a large nut, also usually has a PLASTIC speedo drive.
FWIW
Ron.

[Chancer]

There should not be any power transmitted through the bearing clearance of the gear on the mainshaft, as usual words are failing me, suffice to say that its either locked to the mainshaft in 1st gear hence no movement between the two or it is free to rotate in the other 3 gears, the greatest differential speed between the gear and shaft is at V-max in direct top gear.

I think its either a lack of lubrication, a surface finish/hardness problem or combination of both.

Are the mainshaft and first gear both Ford original parts? - If so then my gut feel would be the o?l that you have been using.

[patrics]

Hi Trevor
I had exactly the same problem last year or year before.
Personally I wouldn't waist any money rebuilding an early gearbox, save the money and buy new.
I sold two 2.5 first gear boxes for good money which paid for a new 3J Driveline gearbox - Should have done that first time around.

Regards
Steve

[TrevorJones]

The later standard box in my 68 S4 lasted about 10 years and 20,000 miles of racing plus 15 years before racing of enthusiastic road use with that sort of HP and rpm and more. it failed when the second gear teeth failed from fatigue.

For the last 20 years of racing I have used a Quaiffe straight cut synchro gear set with just one rebuild when the layshaft shaft spun in the casing. I have always used MTL not MT90 . MT90 is thicker than the Ford original viscosity specification that MTL meets.

Welding a gear onto the shaft suggests lack of lubrication between the shaft and gear for some reason. I presume Ford added the sleeve to the later gear box design for a reason also.

cheers
Rohan

Hi Rohan, Ron, Chancer, Steve

Agree the issue is oil related at the first gear end of the shaft, Now that I have forced the old gear off the shaft the nose of the gear has been so hot that it has formed over the synchro ring and has tried to weld itself to the synchro hub, the rear of the gear shows pickup as does the spacer bearing surface and finally the mainshaft was simply friction welded to the gear. The 2nd gear shows no signs of overheating against the synchro hub?

I have had the car for 43 years and most of them running the same tune of engine & original gearbox in daily use for about half of that without gear issues. These issues only started when I changed over to Millers fully synthetic oil then Redline MT90 and giving the old girl a real thrashing at Castle Combe and Pembrey trying to test the car for a seasons racing.

I have a spare gearbox for my +2 elan that I am rebuilding (very log term project) but don't want to commit this to the same fate as the previous two boxes on the track. I agree with Steve that a new driveline or Quaife straight cut synchro would be a better way to go and save time.

I have also decided to hold the body on with Velco instead of bolts which will greatly improve gearbox changing time!!!!

Thanks for the help guys.

Trevor Jones
S3 Elan GTS 1967
+2 Elan 68

[Chancer]

Not being able to see the parts and just going from your description could it be that the heat and friction were between the synchro ring and the tapered face on the 1st gear? A selector problem or tolerancing error on reproduction synchro rings or a shifter plate anomoly could push the syncro ring against the gear.

I dont understand the bit about the gear welding itself to the synchro hub, there is either clearance between then or the synchro teeth are engaged, do you mean the synchro ring, you arent using steel ones by any chance? I know Quaife once made steel ones for the T9 box but they had to be regularly lapped and I thought it was dreadfull engineering and saw some friction welding between the parts.

My hypothesis does not explain the gear welding to the shaft though, if it got heated by friction from the synchro ring the running clearance on the shaft would increase.

[patrics]

Hi Trevor,
My problems started when I changed oils - it was good - quiet, changed gear really well then I changed to Redline and it only lasted a few laps of practice at Donington. Just my opinion but I wouldn't bother trying to make these boxes work just not worth the expense - every time you don't finish a race because of mechanical problems is something like ?500 to enter and then the expense to fix it

Regards
Steve

[TrevorJones]

Chancer

caution - please ensure you have had your tea before viewing the gear photos.

Please see photos attached. The gear bearing surface on the ring side has been in heavy contact with the synchro hub at some point during the failure. Whether this occurred first and the heat destroyed the lubrication of the gear to shaft is a possibility. The 1st / 2nd synchro snap ring was in place with no evident hub float and the welded gear had a 0.030" gap to the thrust spacer ring (after the incident 0.010" after build).
Some how the lubrication beaks down in the first gear bulk ring area allowing the faces to overheat and this must get transmitted to the shaft with consequent loss of oil lub and finally friction welding occurs.

2000E First gear & synhro hub

2000E First gear & synhro hub

I'm starting to look at the Quaife and Driveline 2.5 straight cut synchro gear set with new hubs anyone have any good advice on the suitability of either box for occasional road, track day and hopefully racing in 2018 and what oil should I use???

[Chancer]

Been years, nay d?cades since my hands were regularly dirty with these gearboxes so this has given my failing memory a work out, how i wish I could just walk out to my garage and play with a box to satisfy my curiosity but I'm in the wrong country.

I think, and you will know better having done a couple of rebullds recently, that in a correctly assembled and toleranced 2000e box the synchro cones have some end float, when the hub is correctly engaged in the neutral position (neutral, 3rd or 4th gear engaged) they can move laterally and come into contact with the tapered face on the corresponding gear but the o?l film would hold them off, when the gear is engaged the synchro shifter blocks push the ring against the gear shearing through the o?l film, when the speed of ring and gear are synchronised the engagement teeth on the gear and hub align and the gear is engaged.

when you assembled the box did you check that the synchro rings, especially 1st gear were free to move backwards and forwards, that is had some lateral end float? was the synchro ring a remanufactured part? if it was too thick or too much meat on the taper it could have been in permanant engagement (rubbing) which is supposed to break down the o?l film to allow the synchro to work, my money is on that being the cause with a lubrication failure second.

Editted, are there not 2 different synchro rings in the gearbox or am I getting confused with different box types, in either case you may have the wrong one fitted, again I cant go out to the garage and look through my spares to see.

[Chancer]

I have just recalled how i would test a second hand box or one that I had just rebuilt, it needs 3 hands so you have to use your knee on the gearlever.

With the box in neutral and a front prop yoke pushed in the tail extension grip it with one hand and rotate the input shaft with the other, there should be no resistance, then while turnng prop yoke (easier to grip) and holding the input shaft still put pressure on the gearlever pushing it towards each gear, you should feel the frictional resistance of the baulk ring and when the gear engages it will turn no more, disengage the gear and there should be no resistance.

with the top cover open you can see the synchro rings being pushed forwards as you feel the friction and you should see and feel when they release.

I'm convinced now that yours was dragging, it can build up a huge amount of heat, enough to oxidise the o?l film.

[TrevorJones]

Chancer

I believe you may be correct about there being a a difference between 1/2 and 3/4 bulk rings on the earlier version of the box which i will check tomorrow in case I used the wrong ones for first gear set. When I had finished building the box i measured the gaps and first had a 0.010" float which is about right according to the manual.

Thanks for the test routine which I will also try out on the +2 box which I finished building last week.

Oddly I did notice that the 4th gear bulk ring appeared to stick on when going back down the box which I put down to needing a bit more oil. I hope the bulk rings never got mixed up at some point in the past when rebuilding the S3 box! If the 1/2 bulk rings are thicker than the 3/4 bulk rings then that might explain the tightness of the +2 elan 4th gear ring and if the 3/4 ring got into the S3 first gear position then it may not have been building up the hydraulic engagement allowing the faces to rub almost constantly.

Trevor

[Craven]

Hi,
You can?t mix 1st/2nd and 3rd /4th rings they are different diameters, from your pics the bulk/synchro ring looks correct for an early box, but they will be different to the ones in your +2 box. Can?t recall but I think there is some guidance given in the workshop manual on ? float ? of the bulk rings.
I read somewhere that these low friction oils are unsuitable for a synchro box as the rings need a certain level of grip/friction in order to work correctly.
Ron.

[promotor]

Looks like a bit of a headache!

How did you get first gear off the shaft - had the gear un-welded itself after the issue, or did you press it off?

Do you have a gear-case-facing-side photo of the cast steel (rear) bearing carrier?

[Chancer]

The measurement is not end float per se but how far the taper engages, how much meat is left on the grooved mating surface of tha baulk ring, when pushed against the gear the outer flange with the baulk teeth should not touch the shoulder on the gear but be spaced off by 10 thou plus.

What is important in the case of your box is that it can move backwards away from the gear, only a little, probably about 1/32" from memory but it must not be pushed into contact.

Knowing that most after-market manufacturers know nothing about tol?rances or how a part is designed to function I am asking the question for the 3rd time and in bold this time (forgive me) WAS THE BAULK RING AN AFTERMARKET PART?