Gearbox replacement

[PhilExe]

Have been trying to re-install a gerarbox into my TR3a but try as I might the primary shaft will not locate onto the clutch splines and push home. I can get it close within about an inch of the engine but the splines will not line up. The gearbox and casing look externally to align and I've checked that the clutch does actually go on the end of the primary shaft although it is a very tight fit.

 

Does anyone have any wise words which might help.

 

Phil B

[Steve R]

Phil

I used loads of words when I fitted mine! not many of them wise, but they worked,.... eventually, I did read that putting exhaust manifold studs in the bell housing helps line it up. and be careful when raising the rear of the engine that you don't put strain on the exhaust or top rad hose. And of course put it in gear so that you can turn the output shaft to engage the splines.

Good Luck

Steve

Edited October 31, 2016 by Steve R

[Rob Salisbury]

Put 2 or 3 long studs in the backplate, temporarily, for the bell housing to ride on, have the rear of the gearbox supported independently but able to move forwards, select a gear so that you can "feel" the primary shaft move over the splines of the clutch plate as you rotate it by hand, from underneath, by eye, keep the bell-housing and the backplate parallel as they are brought together, give the box a bit of a shake, keep trying and suddenly the two will click together as if they were supposed to be like that!!

Cheers Rob

[RogerH]

Hi Phil,

welcome to the forum - what a start.

 

I have success by putting a crocodile jack under the sump and an electrc scissor jack under the GB

 

This will allow the engine and GB to align spot on.

Have you got the GB engaged in a gear as you need to rotate the GB output shaft so that the input rotates.

 

After that it is easy

 

Roger

[Lebro]

IT's never easy

 

Bob.

[BlueTR3A-5EKT]

Put 2 or 3 long studs in the backplate, temporarily, for the bell housing to ride on, have the rear of the gearbox supported independently but able to move forwards, select a gear so that you can "feel" the primary shaft move over the splines of the clutch plate as you rotate it by hand, from underneath, by eye, keep the bell-housing and the backplate parallel as they are brought together, give the box a bit of a shake, keep trying and suddenly the two will click together as if they were supposed to be like that!!

Cheers Rob

+ 1 on the long studs.

 

Have you got the gearbox in gear so you can rotate the the input shaft very slightly from the rear drive flange - that might help.

[Paul Down]

I have always had a problem lining the gearbox up so the last time I tried a new approach. The box was supported within the car on a home made stand ( thanks to another Forum member ? for this advice). The engine was supported on a trolley jack.

 

The input shaft was aligned near enough with the clutch plate and then a spirit level was placed on the gearbox and adjusted with an appropriate size drill bit to give a level reading. The same arrangement was then transferred to the engine and its height adjusted with the trolley jack so that the bubble again registered level.

 

 

 

 

 

 

 

 

 

 

 

 

A sharp push on the gearbox and it seated instantly. My reasoning being that if the angle of approach for the input shaft is in line with the clutch plate then at least one variable is ruled out.

 

Perhaps lucky but I shall repeat next time if the box is out.

[PhilExe]

Thank you all verry much for all the above very wisewords i will go try a new and crack this.

 

Phil

[Lebro]

Interesting approach, may try that next time.

(there is always a next time. )

 

Bob.

[Graham Harris]

That spirit level arrangement is a good idea as i have found in the past until you get engine and dox in line they will not engage . Defiantly filed away for future reference.

 

Graham

[billy l]

Have you had the clutch off? if so have you centralised/ aligned the centre plate? cheers, Bill.

Edited November 1, 2016 by billy l