HELP PLEASE! - Problem refitting greabox-HELP PLEASE!

[Farid]

PLEASE HELP!

I had to take the gearbox off of my TR3A, since my starter has broken, and several pieces had fallen inside the bell-housing. While it took literary 5 minutes to take the gear box out of the car (after taking the cover off the gear box out, of course), I spent 3 hour today trying to put the gearbox back, but without success. The problem is that I have had hell of a time to put the gear portion of the so-called first-motion shaft into the clutch centre hole.

 

FYI, I have also taken the transmission shaft off of the car, so I could easily maneuver the gearbox into the clutch. I have also tried to bring the engine up and down by small increments trying to line up. I have a ¾” gap now between the bell-housing surface and the engine wall. Needless to say that I have ripped of my elbows and arms in several places!

There has to be a trick for doing this, otherwise, mechanic shops should charge one thousands of dollars for the installation.

PLEASE HELP!

Thank you very much

Farid

[littlejim]

Farid,

I suffered the same experience about 4 times when sorting out my cluch problem. With the body off it slid in up to the hilt no problems.(MInes a 4A)

Each time, once the body was on, it was a pain. (I guess you have aligned the clutch properly with an alignment tool or such.)

 

I had to then have a (mobile) jack under the engine, and another on under the gearbox, then oversize bolts through every available hole including the starter holes. Then gradually pull the gearbox in with the longer bolts, experimenting with different heights on each jack to make sure I wasn't bending anything with the force..

Eventually it pulled in to where the proper bolts would pull it in to the snugged up position. But it was frustrating after the ease with which it had gone in with body off.

By the time I sorted the clutch I was getting the hang of getting it in.

Edited August 21, 2011 by littlejim

[Bob Smith]

Farid,

It is not easy but you need to have the vehicle as high up as possible and having properly aligned the clutch with a tool remove the rear engine mounting. I used a fixed jack under the sump and a trolley jack under the bell housing get the two parts more or less aligned then used over long bolts to pull the gearbox onto the back of the engine. Unless the mating flange on the gearbox is exactly square to the back of the engine it wont go together. I measured the distance between the two parts before tightening. Then slowly tighten the bolts using shorter ones as necesary until the gearbox slides on. It really is one of the more awkward jobs on these vehicles but it can be done. Good luck!

[Dave Larnder]

Farid

 

The clutch alignment tool is a MUST. It is a very cheap component you can buy from the likes of Moss for a few £'ss.

You need to insert this to align the plate which you could have accidentally moved out of line when you removed the gearbox. Also put the gearbox in 4th gear so that when you turn the driving flange either way only a few millimeters, the first shaft will revolve slowly as well so when you are ready to push home that last 3/4", the splines will line up, you should feel it kick in, just keep the revolving movement turning minimally, it is something your wife could do for you while you are pushing the box inwards.

Good Luck

Dave

[ianc]

You do not mention any dismantling of the clutch, so, being undisturbed, the clutch's driven plate should be centered correctly. However, if the clutch has been dismantled, you will need to centre the position of the splines or you will never get the gearbox to re-engage - for this, a special tool (Churchill 20S.72) or a spare constant pinion shaft is required.

 

That leaves two possibilities for misalignment as far as the splines on the clutch's driven plate and the gearbox's constant pinion (input) shaft are concerned:

1. rotationally: select top gear and, with the gearbox aligned correctly (see 2), gently rotate the output shaft of the gearbox whilst pushing the gearbox into the clutch

2. vertically: there cannot be any significant angular or height difference if the gearbox's input shaft is to enter the splines of the clutch's driven plate. It may help if the rear of the engine is raised slightly in order to effect initial engagement. How? With a piece of timber under the rear end of the sump, use a screw jack to lift the rear end of the engine - but be careful! As soon as engagement starts, use a couple of bolts to prevent the gearbox sliding back out! As the gearbox slides into engagement, you may need then to lower the rear of the engine slightly so that the gearbox bell housing clears the bulkhead.

 

The job is easier if two people are involved, but even then, it is hard work. Good luck!

 

Ian Cornish

[Farid]

Dear friends:

Thank you very kindly for your suggestions.

I had done almost all, but using the clutch alignment tool. I have one jack under a piece of wood under the read part of the swamp, and another one just behind the bell-housing under the gear box for alignment.

I never touched the clutch; so why should it get out of adjustment, hence the need for the alignment tool?

I have come to the following collusion: considering the fact that there is only ¾” final gap, and the spline portion on the gearbox shaft is longer than 3”, I am concluding that the spline is engaged in the clutch, but perhaps the throw-out bearing is stuck and does not permit the final ¾” travel of the shaft into the clutch?!

I read two other threads in different forums, and apparently the idea of using a couple of longer bolts for the initial alignment is very helpful.

BTW Dave, my wife was suffering with me the entire 3 hour long ordeal!

Today, I am going to take the gearbox out again, and check that the throw-out bearing is sitting properly. Then I am going to use the longer bolt idea and sweat like a pig again!

I will keep you posted; meanwhile if any other hint or remedy pops into your mind, please do not hesitate to share it.

Cheers (and wish me luck).

BTW, I am near the end of the rope and very close to replace my baby with a convertible Lexus!

Thank again folks!

Farid

[RogerH]

Hi Farid,

if you didn't disturb the clutch then it should still be in alignment.

However have you looked to see if the bronze bearing on the pilot of the drive shaft has been drawn out of the crank and is blocking its entry.

Not sure if this is possible but we are clutching at straws.

 

Roger

[Guest ntc]

Unless it is in true line you will not get it in and I would never use bolts to pull it together there should be no need

[vivdownunder]

Try using two long bolts with the heads cut off as guides. Screw them into the block at 3 o'clock.

 

Offer up the gearbox on the guides. Use the top gear engaged method to align the input shaft to the clutch plate.

 

Push the gearbox in to where the input shaft engages the crankshaft spiggot.

 

Check from the engine bay that the two faces are parallel.

 

Push the gearbox home from the tailshaft end.

 

Oh, and a little trick - some input shafts have a small taper around the front of the input shaft, some don't. Grind a slightly larger taper and it will pop straight into the spiggot.

 

Viv.

[Farid]

Dave was right (although it did not make sense to me first!). I just got the gearbox out again, and although I had never touched the clutch, its pigot (the centre hole) had gotten misaligned. I believe that was caused by the turning and twisting the gearbox when taking it out, since at that time, I had not the transmission shaft out (since the shop manual did not say to do so).

Now, I have to go find a clutch centering tool. I wonder if they are standard, and I can buy it from a usual auto store, otherwise, I have to wait two weeks to get it mailed!

Again, thank you all, and I will keep you posted.

Regards,

Farid

[Guest ntc]

http://www.rimmerbros.co.uk/Item--i-RX1389

 

You can also use a simple socket set I am sure you can work it out good luck

[RogerH]

Hi Farid,

do as Neil suggested and use some sockets to get the right combination or turn it out of wood.

 

Roger

[Lord Flashart]

I hate this job on a TR. Always a PITA. I use a couple of sockets to align the clutch then fight with the 'box for about four hours. When you've sweated and bled enough it usually just clicks and slots home! I'd rather rebuild the engine than refit a gearbox!!

 

Stay with it though mate. It will go in eventually. When it does, you'll wonder why it was so hard!

 

Paul

Edited August 21, 2011 by Lord Flashart

[Ashley James]

I don't want to depress you further, but if the clutch friction plate has moved, I'd take it out and make sure the boss hasn't got bent in all the wrenching about. If it has, buy another or it will kidder like hell.

 

TBH if you carefully line everything up and the gearbox is on a trolley so you can slide it in easily, it should go in pretty easily. Put it in top gear so that you can wiggle the splined shaft to help it in.

 

I'm ashamed to admit I've rarely if ever used an alignment tool, I do it by eye or with a socket extension or similar.

 

Ash

Edited August 21, 2011 by Ashley James

[Farid]

Thank you all for your suggestions and sympathy!

 

One last question before I go; do I need to loosen any bolts on the clutch unit to make sure the ribed hole is centred with respect to the clutch? Obviously, I am a novice!

 

Cheers again,

 

Farid

[RogerH]

Hi Farid,

the pressure plate needs to be slackened (6 bolts)in order to slide the friction plate into the correct place.

 

Best of luck.

 

Roger

[Farid]

Roger:

Thanks a mil;lion for the quick reply.

Farid

[Rodbr]

Farid,

IMHO I have to agree with Ash on this issue of examining the clutch driven plate. You have to slacken the bolts in any case to re-align the plate. You have to ask yourself why did it go out of true in the first place as it was in place before you removed the box? The driven plate should not move around if you pulled the gearbox straight out and off, unless your pressure plate is very weak. But and this is the rub, perhaps you let it drop slightly and bent the spline hence when you look at it, it appears out of line.

If you decide to remove it please MARK it so you do not put it back the wrong why round, it is possible, don't ask.

 

The good thing about inspecting the plate is that you can see the condition, also check you have not chipped the spigot bush and check it for wear. Take the positives and it will give satisfaction in the long run, as against ripping the centre out of the plate and likely needing to replace much more, or at best take the box back out again.

You could also try a series of different size pipes inside each other to align the clutch.

 

All the best of luck

Rod

[randall977]

I've been in your position (literally) several times. Once it went in in 30 seconds but normally it took an hour of VERY frustrating manovring. I jacked the engine up slightly which helped and just rotated the output while rotating the gearbox in at the same time (and pushing the box towards the engine). First of all the geabox shaft should rest into the inner hole which should leave the box around 1" from the block, then it's a case of getting the flange to line up...which can take ages, however when it does it's a wonderful feeling!

[Guest ntc]

I would check for play on the gearbox input shaft

[Dave Larnder]

http://www.rimmerbros.co.uk/Item--i-RX1389

 

You can also use a simple socket set I am sure you can work it out good luck

 

 

Farid

Thats the tool and at £6.00, Do you really want to struggle some more again , when the tool will get it absolutely spot on so easily, I got mine from Moss.

Dave

[John McIver]

The last time I removed a TR3 gearbox was some 46 years ago to replace the cluster and first sliding gear. The job was done in a week-end with the assistance of my father and I don't recall any significant grief in the replacement procedure. However, I do remember thinking that if I had to do it again at some stage, I would remove the engine/gearbox as a unit. The gearbox with overdrive is quite a heavy component to refit and there is not a lot of room to work in as most of us know. Add 46 years to 23 and at 69 I'm probably not going to do another, but if the need occurs it will be apron off and both out together. I would much rather work from above than below at this stage of life.

[RogerH]

Hi John,

I did exactly that a couple of months ago.

I fitted the engine, all nice and tidy. Then came to the G/B. I used a hoist to lift it apprx into position. Then using the usual scissor jacks

and lumps of wood spent an hour getting nowhere.

 

Out with the box. Out with the engine. Fit box to engine. Fit whole lot to car.

Less than on hour to remove the whole lot and refit.

 

The car is a TR4 - much the same as the TR3.

 

Roger

[Dave Larnder]

The last time I removed a TR3 gearbox was some 46 years ago to replace the cluster and first sliding gear. The job was done in a week-end with the assistance of my father and I don't recall any significant grief in the replacement procedure. However, I do remember thinking that if I had to do it again at some stage, I would remove the engine/gearbox as a unit. The gearbox with overdrive is quite a heavy component to refit and there is not a lot of room to work in as most of us know. Add 46 years to 23 and at 69 I'm probably not going to do another, but if the need occurs it will be apron off and both out together. I would much rather work from above than below at this stage of life.

 

 

Hi John

I lost third gear in my TR3A last year going to Classic Le Mans, so I took the g/b out from the top, after having removed both doors, using an engine hoist and two trolley jacks and wood packing under the rear of the engine. I did it on my own, and I'm 72, but it took a friend to help to get it back in and he's 74

I had lifted the whole car 13" above the ground and mounted it on steel scaffold planks, that made the under work easier. I think I would still prefer to do it that way as opposed to taking the apron off,- never done that! can't the engine + g/b come out without taking the apron off? as I said I have never had to do that so I don't know, but putting the apron on when I rebuilt the car was something else so I would avoid that if I could.

Dave

[foster461]

Unless it is in true line you will not get it in and I would never use bolts to pull it together there should be no need

 

 

If you are on your own the long bolts are handy to help you get the two aligned and the mating surfaces parallel. That is half the battle. I agree that trying to pull the two together with the bolts is a bad idea. If the box doesnt slide in on its own that has to be fixed otherwise something is going to bend or crack, probably the gearbox bellhousing.

 

Stan