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Melmac

T9/N input shaft movement

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Hi,

I was going to change the sump seal on the GT6 because it was getting a little messy again. It is not unknown that it leaks a little on the front edge on theese engines.
The sump is so close to the steering rack, and especially the rack clamp on one side, that we had to lift the engine slightly to be able to disassemble the rack.
We unloaded the engine mounts (but not the gearbox mounts) and then it was enough to lift a few centimeters for finally be able to take out the sump.

When we lowered the engine again my dad tried (for some reason) to rotate the crank with a socket wrench and it went well. Half a turn! Then it stopped. Same thing the other way. The gearbox was in neutral.

Then we decided to get the engine out and when it was done it was easy to rotate the crank. I turned the input shaft to the gearbox (Ford type N, Sierra 2.8 V6) and it went nice and smoothly. However, I felt that it was possible to move the shaft a little laterally, maybe a few mm. Isn't there bearings that whould make it impossible to do that?

Can we have broken something in the gearbox when we lifted the engine that is only noticed when the gearbox and engine are connected? It doesn't seem likely since the bellhousing and the gearbox mounts should have taken all the strenght, not the things inside.

Anyone have an idea before we pull out the gearbox too?
 
 

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Can't explain what was stopping your engine from turning while it was in the car......

Seems most unlikely that lifting the engine caused a problem between engine an gearbox - as you say, the bell housing is there and strong enough to keep everything where it should be.

As regards the lateral movement in the T9 input shaft, a little here is considered normal - remember that the nose of this shaft should be supported by the oilite bush in the back of the crankshaft when the gearbox and engine are fitted together.  More than a few mm could indicate a problem with  wear in the front main gearbox bearing or the mainshaft tip bearing - but this is a Ford gearbox, not feeble Triumph rubbish!

One thing though - are you sure that the gearbox input shaft is actually long enough to reach the bush in the back of the crankshaft.  People with T9 conversions on GT6s have had problem with this.  The T9s with the 4 cylinder input shafts are shorter and do not reach the bush.  Your 2.8 V6 version should be ok, but worth checking.

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Thanks Nick,

I bought the T9-kit from Frontline after the second breakdown of the Triumph box, and it have only done 25-30 miles so far. The bearings in the 2.8 version are supposed to be quite strong (and new) so if there is a problem with them after such short time there must be an even bigger problem somewere else. Strange thing I didn't notice anything the last time I drove it before it ended up in the garage for the subaru conversion.

Well, it's easy to pull the box out now, with the engine out of the way, so that's what I have to do. I will come back here with some answers (I hope) in case someone else encounters the same problem.

By the way, the shaft fits perfectly in the bush.

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Can I double check this?

When lifted, the engine would partially turn then stop.

When seperated, the gearbox rotates smoothly with a little movement (I have just renewed the front bearing and the rollers between input shaft and mainshaft on my 2.8 T9 box, most stuff s the same as the std box, just a few differences. Anyway, there is still a couple of mm play on my tip!)

And also the engine now rotates freely.

Sounds like something jamming up within the bellhousing? That is where I would be investigating. There is a nice opening for the clutch fork that should let you have some sort of look inside, but hopefully there will be a witness mark where the jamming too place. 

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The 2.8 T9s come in two forms.  Early ones have the same bearings as all the others and the later ones had uprated layshaft bearings, shown by an additional boss on the front face of the gearbox casing below the input shaft.

Don't feel the gearbox has any blame in this.

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3 hours ago, zetecspit said:

Can I double check this?

When lifted, the engine would partially turn then stop.

When seperated, the gearbox rotates smoothly with a little movement (I have just renewed the front bearing and the rollers between input shaft and mainshaft on my 2.8 T9 box, most stuff s the same as the std box, just a few differences. Anyway, there is still a couple of mm play on my tip!)

And also the engine now rotates freely.

Sounds like something jamming up within the bellhousing? That is where I would be investigating. There is a nice opening for the clutch fork that should let you have some sort of look inside, but hopefully there will be a witness mark where the jamming too place. 

We didn't try to rotate it "in the air" if that's what you mean. It was in the normal angle when we did that.

Funny, while I am writing this I got an email from Frontline. I asked them a few days ago about this but when I didn't recieve any answer I went in here to my favourite Triumphplace on the net. I quote "Re the front input shaft, there is always play of around 2 – 4mm in them. Although there is a bearing at the front, it allows a little movement, hence needing to run the spigot bush in the crank"

Yes, I agree about the bellhousing. Engine works fine > gearbox works fine = something in between is messing things up.

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1 hour ago, RedRooster said:

Whats your crank end float?

I will check in the weekend. And the little spigot bush looks fine.

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When i fitted the T9 to the AH the Frontline spigot bush didn't fit properly so had to get a new one made up, i remember not getting the best after service back up from Frontline way back then.

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I did a T9 conversion several years ago.
Before undertaking this I researched conversions on the internet and found a blog from a Spitfire owner who had experienced spigot bearing problems...

He had a brass type spigot bearing break up after a few hundred miles. Unfortunately he found out the hard way that
the clearance on these against the shaft has to be quite large 
and it is necessary to steep overnight in engine oil before fitting.

It may be over the top, but I have pondered getting the crankshaft machined to take a Ford roller bearing spigot?

 

 

Ian.

 

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The issue with the T9 conversion is being sure that a reasonable amount of the input shaft is actually reaching and engaging with the bush.

My W58 conversion also struggled with this (the input shaft is short) meaning the spigot bearing had to sit in the flywheel. Initially I used an oilite bush machined to suit but second time around I got the flywheel machined to take the small ball race that Toyota chose.

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15 hours ago, Nick Jones said:

The issue with the T9 conversion is being sure that a reasonable amount of the input shaft is actually reaching and engaging with the bush.

My W58 conversion also struggled with this (the input shaft is short) meaning the spigot bearing had to sit in the flywheel. Initially I used an oilite bush machined to suit but second time around I got the flywheel machined to take the small ball race that Toyota chose.

I also have the brass spigot bush in the flywheel. I don't remember if it came with the kit or we had it made. Isn't it difficult to get the input shaft in the ball race when mounting the gearbox?

Flywheel.jpg

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19 minutes ago, JohnD said:

I thought the original was bronze, not brass.

John

It's possible but nearly nothing in this engine is original. I'm not sure about the material of this hybrid between Triumph and Ford, but it has that "yellowish" brass colour.

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Bush needs to be bronze or oilite.  Brass would be short-lived.

6 hours ago, Melmac said:

Isn't it difficult to get the input shaft in the ball race when mounting the gearbox?

No, the input shaft spigot is a sliding fit in the inner race of the bearing.  As with the plain bushing, provided everything is correctly aligned, it just slots on.

 P1120407s.jpg

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54 minutes ago, Nick Jones said:

Bush needs to be bronze or oilite.  Brass would be short-lived.

No, the input shaft spigot is a sliding fit in the inner race of the bearing.  As with the plain bushing, provided everything is correctly aligned, it just slots on.

 P1120407s.jpg

Ah, I googled oilite (never heard about it) and some of them has that brass colour. Thanks, now I know.

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