Aligning Centurion engine to gearbox

[Malcolm Towrie]

I'm struggling with how to align our Meteor engine to the gearbox. The manual specifies using quite an elaborate tool. The tool has a flange that bolts to the crankshaft oil seal housing face. A 2.500" round bar has a tight sliding fit in the bore of the flange hub and extends out to close to the gearbox flange, where there's another tight sliding fit flange that two dial indicators are mounted on to take face and periphery TIR measurements on the stationary gearbox input flange as the sliding fit flange is rotated.

We don't have this tool, and I can see making one will stretch my limited machining skills.

First of all, I have to make a flange that slips on the crankcase studs precisely enough to keep the 2.501" hole in the flange hub dead concentric to the crankshaft. Then I need to make the slip fit flange at the grarbox end of the shaft so that is it is also concentric to the crankshaft within a couple of thou.

Then I have to get the face and periphery runout reading within 0.010" by shimming and moving the engine mount frame, which is achievable.

Then amazingly, I just scribe around the mounting faces on the engine frame so I can replace the engine to those scribe marks after installing the clutch. But replacing the engine using scribe marks has got to be at least plus or minus 0.020" error.

I see the clutch output flange is mounted on a self aligning ball bearing so the clutch can handle some misalignment. But how much?

Has anybody been through this process?

Malcolm

[Mike Cecil]

Malcolm,

Have you emailed John Blackwell at Pucka? They have been through the process installing the new engine in 005.

Mike

[Malcolm Towrie]

No, i haven't, Mike. I'll try that.
Malcolm

[Lauren Child]

I’ve not been on for a while, but we’ve done it at Duxford. Alas I was out on the day at a family do, but if you’re stuck I’ll ask the question. I’m fairly sure they used a magnetically attached feeler gauge in place of the big version in the book.

[Malcolm Towrie]

I think we have it figured out, Lauren. We're using the shaft from a old clutch installed between the engine and the gearbox. And using magnetic based dial indicators or maybe a laser alignment tool if I can borrow one to measure runouts at gearbox and engine ends.
The photo shows the shaft mounted to the gearbox. We don't have the engine in yet.

Malcolm

[Lauren Child]

I asked the question today, and apparently we managed to borrow the special tool from a friend.

I guess that means we still have a 50/50 and ask the audience left for when the project restarts, but it looks like you’ve got it sorted anyway. I’d love to know how you get on

TTFN
Lauren

[Malcolm Towrie]

To close the loop here, I got the engine and gearbox aligned. Using the shaft from an old beaten-up clutch we had worked well. If you don't have an old shaft, seems to me you'd have to make something similar, which is quite a machining challenge.

I got really lucky. The runout readings taken with the dial indicator on the gearbox flange face and the crankcase face (see photos) indicated the engine was sitting about 1/4" low, relative to the gearbox. I made shims out of 3/16" plate and installed them under all four engine mounts. That brought the total indicated runout down from 0.060" to 0.020". Another 0.075" under each mount brought the TIR down to 0.008", which is within spec.

I was dreading this job, but it turned out to be simpler than I thought. I suspect that is due to the factory ensuring that the gearbox mounts and the engine mounts are parallel and that simply shimming up and down will correct misalignment.

I also suspect this spec is far too conservative for those of us running Centurions today. We're more likely to do 3 miles a year rather than 3000. So wearing out clutch, crankshaft, and gearbox components is pretty unlikely.

Malcolm

[David Herbert]

Well done Malcolm !
That is not a job that I would have looked forward to. Now you get to install the world's heaviest clutch !

David

[Robin Craig]

Good old fashioned engineering not requiring a USB stick or an I phone. Great to see such work going on by such skilled dedicated people. Thank you for sharing your work Malcolm

[Malcolm Towrie]

Originally Posted by David Herbert

Well done Malcolm !
That is not a job that I would have looked forward to. Now you get to install the world's heaviest clutch !

David

Thanks, guys. Luck's been with me lately - I've also been finding parts that I thought I would have to fabricate, including one exhaust pipe from the manifold to the hull penetration.
The one part I can't find, despite seeing photos of it in this very tank, is the voltage regulator for the main engine-mounted generator. (I've no immediate plans to install the auxiliary Morris engine powered generator, although I think we'll have to if we get the turret traverse working.)
We have a few deuce-and-a-half's in the boneyard so I hope I can find a suitable regulator there. They're 28 volt, approximately 40 amp rated, so close enough.

David, the clutch in a T-55 is a beast too, but I think you're right, this one has it beat. In fact, that's my new worry, can I get it in without having to remove the engine or gearbox? The manual doesn't help - in the clutch removal section it says, remove the engine. In the replacement section, it says replace the gearbox. A bit confusing.

I can install and remove the bare clutch shaft I used for alignment easily by sliding the engine forward a few inches (I have the starter removed at the front and the fan drive pulleys and tensioners removed at the back) but the complete 450 lb. clutch might not be so cooperative.

By the way, that exhaust pipe I mentioned above - where it passes through the hull, it's a loose fit sealed by 2 piston rings! I thought that was a clever idea. It allows for thermal expansion and hull flex and still maintains a decent seal. And the old piston rings I removed from a Staghound engine recently were a good fit!

Malcolm

[MikeV]

Malcolm
And His guys are doing a great job I am Lucky to be a member of the same museum. Can't wait to see this tank roll out of the MVCC.

[45jim]

We found it easier to move the engine forward to replace the clutch. We marked the location of the engine on the mounts and cut some wood for positive reference between the engine and gearbox. It was a bear to lift out and replace the clutch but once installed it proved relatively easy to re-align the engine to transmission. The wood was used as a rough check as we were moving things into place and final alignment came from the reference marks we made during disassembly. We did have the element of experience as we had two old RCEME Cent guys assisting. I believe that while the suggested tolerances exist, the design is far more forgiving and while adhering to the suggested tolerances provides the maximum clutch and seal life a slight error will not affect its life as a parade vehicle.

As a side note, when a Centurion had sat for a period of time it is important to preserve the clutch during initial start up. Centurions stored outside often suffered from seized track pins, stuck brake shoes and there is always the possibility of a stuck clutch disc. We were told to warm the engine with the transmission in neutral clutch engaged. Once warm, a couple of light applications of steering tiller (while still in neutral) is applied to each side, not enough to effect a turn but to put some stress on the track and clutch. Once this was done and the brakes were known to be free only then was it moved forward or back to free everything up. Wonky track link got a smart smack with a sledge.

The Strathcona's stored their Centurions in Wainwright Alberta and they sat for up to 9 months a year (several months below -30C) with only a skeleton maintenance crew. All the training was done in a 3 month window from spring to early summer so every time the unit went up to train there was caution in how the tanks were brought out hibernation.

[Malcolm Towrie]

45jim, I need to talk to you about this! I'll send a PM.
We've tried to drop the clutch in from the gearbox side (with the gearbox installed) but no go.

We are going to try rotating the engine 45 degrees in the hull to see if there is enough room to get the clutch in from the engine side, but it seems a faint hope. Now you are saying it can be done. I'll be in touch.

Thanks for the info on the risks of long term storage. Right now we have very frozen tracks from being a gate guard for decades, so I am certainly concerned about the first movement under power.

Malcolm

[jdmcm]

We suffered a frozen clutch in our Centurion this year, and it was a real bugger to break free, finally followed Rick from the UK's advice and gave it a good shot with the steam cleaner as it was running, clutch depressed, worked like a charm. This winter she is coming inside!

[Malcolm Towrie]

Do you mean ice frozen or rusted frozen, John?

Malcolm

[Malcolm Towrie]

An update: I finally have the clutch installed in the Centurion, or at least in place.

We were held up tracking down a lip seal for the clutch, the one that seals to the crankshaft. It's installed in a crankcase cover that's part of the clutch assembly. You can see it in the first photo. The original seal was 4 15/16" outside diameter. Despite Garlock and Timken making a large selection of inch-size seals (and probably others), they are a bit limited on the 1/16" increments, especially in the larger sizes. So we bought a 5" OD seal and bored the cover out to suit.

With the clutch finally assembled, I then struggled to get it installed with the engine and the transmission in place, the engine loosely, but the transmission fully installed.

What did the trick was supporting the engine in the hull with the gantry crane at a 45 degree angle to the centreline, and unbolting the left-hand fan so it could be pushed back towards the transmission. I then dropped the clutch in beside the engine and finagled it into place.

That was the last major hurdle to getting the tank moving (I hope).

Malcolm

[MikeV]

So I have a question for Malcom Do we know the history of Our centurion Tank? Since the B.C. Tanks is a little out on their history?

[jdmcm]

Hi Malcolm

good to see you have it installed! I am so jealous of how clean that engine bay is...our frozen clutch occured from what we think was moisture rusting the plates together, so we used a Centurion clutch hold down device (a stick) fired her up and then we used a steam cleaner to loosen the plates, worked very well. Now after we run it up to temp, especially on typical Vancouver days, we use the stick to hold the clutch down for a day or two to ensure the plates are free from moisture, so far so good, but as soon as we get brave enough to bring her inside that is the plan...

[Malcolm Towrie]

Originally Posted by MikeV

So I have a question for Malcom Do we know the history of Our centurion Tank? Since the B.C. Tanks is a little out on their history?

Mike, this is a great thread on Canadian Centurions in general and ours specifically.

Malcolm

http://www.mapleleafup.net/forums/sh...ferrerid=11288

[Malcolm Towrie]

John, interesting that the steam cleaner worked so well. I would never have thought it would. Was it a large industrial type cleaner? Do you think it was just the heating effect or was it blasting dirt and debris out?

Malcolm

[Malcolm Towrie]

Another update:
The engine is back where it should be and bolted down.

The clutch linkage is connected up and the pedal travel set to spec. I realized we were missing a spring on the linkage that pulls the pedal right back up to its stop so the release bearing isn't dragging on the clutch fingers.

The fan belt tensioners are back on and the fan belts installed. The belts came in nice matched sets with the rebuilt engine, so they're 45 years old, but in great condition.

The starter's installed and connected. I gave the engine a quick test crank from the driver's push button. I was tempted to put it in gear and see if I could move the tank but common sense prevailed.

Malcolm

[Malcolm Towrie]

Update: the Centurion is running, neutral steering, and moving. Still a long way to go, but it's a big step for us!


https://youtu.be/j-oCNXBoAH8

Malcolm

[Peter Duggan]

Malcolm,

Congratulations !!! That is a major milestone, I hope that your celebration is just as memorable.

Peter

[Mike Cecil]

Excellent Malcolm: it has come a long way since I first saw it.

Mike

[Malcolm Towrie]

Thanks, guys. It was very special getting this old girl running and mobile again after decades of neglect.

It got me wondering how many running Centurions there are out there.
John has one out in BC; I know of at least one in the US, but probably more; Australians love their Cents so there's must be a few running there; Bovington has at least one, maybe more.

So maybe ten running Centurions in the world?

Malcolm

[45jim]

Malcolm,

When I was with the Strathcona's (when they were still posted to Calgary) we restored one of our monument Centurions to running and driving condition for our Regimental 100th anniversary in 2000. It was the last running Centurion with the Regiment and spent its last days in the indoor miniature range for training before finally becoming a monument. We actually had the Centurion running and driving for our Regimental Reunion parade in 1995. It is still running strong up in Edmonton with the other vehicles from the Strathcona historical vehicle troop. We were very lucky in that we had some outside sponsorship and two excellent retired RCEME mechanics who guided us through the work (and to be honest did the majority of the work). I was trying to remember exactly how we did the clutch change but it was so long ago and I have no photos to refer to and I have lost contact with our RCEME colleagues. Here's a photo of the 1995 Reunion line up with yours truly in front of the Centurion as I was driving it for the roll past.
.

[Mike Cecil]

Nice pic!

Malcolm, I can think of eight runners in Oz without any effort, so there are probably more in Oz I'm not aware of.

Four with Tim Wood in Qld (MBT Dozer, DTV, Bridgelayer, ARV): https://tankride.com.au/
One at Mt Oberon NSW.
Two in Victoria (Mk2, upgraded to Mk3, then Mk5, now fitted with a fuel trailer;and a Mk5/1 with a fantastic operational service history)
One at Parramatta (1/15 RNSW Lancers Museum).
One owned by the 1st Armd Regt Assoc and housed at the Army Tank Museum (169005).

All of which are regularly run.

There are two in the AWM collection that are capable of running, but not sure when they were last run. One, 169110, was driven from ANZAC Hall onto the low loader in 2005(or about that time), and the other (169108) was driven onto the low loader at Bowna, NSW, when purchased circa 2002.

Mike

[jdmcm]

Malcolm

Congratulations! I have followed this tank since it first was featured on "Tank Overhaul", can't even remember the year but at least 2005-09? So awesome that you have it up and running!

As for running Centurions in BC, there is mine (Mk5-ish??) and my pal Mark who has an ex-Australian Mk5/1 (might have recently sold that?)

45Jim...is that Centurion in Edmonton still a runner? I wish they would bring that down to Spruce Meadows rather than all the damn leopards!

As for Australia Cam Stone has a runner at South Gypsland Tank Adventures, and Rob Lowden has one at his incredible museum at Cairns. Did Tim Vibert sell that awesome ARV? Any idea where that ended up?

John

[Lynn Eades]

Speaking of running Centurions,there is a privately owned one in the South Island of New Zealand. It belongs to a gold miner on the west coast. He also has a Crusader. I believe both are runners.

[Malcolm Towrie]

So that works out to be 13 (maybe going on 20?).

2 in BC, Canada
1 in the US ( there's gotta be more)
6 (at least) in Australia
1 in England (again, likely more)
1 in Ontario Canada
1 in Alberta Canada
1 in NZ

So the club isn't as exclusive as I thought it was.

I have another question: I backed off the large track tensioning nuts on both sides since the tracks had been severely overtightened for some reason. Neither idler moved back to loosen the track. They were stuck. After reversing and neutral steering, the left hand one snapped back, simultaneously extruding a ton of grease (I think it was hydrolocked with grease), so I can see sag in that track now. But the right hand one is stuck despite some subsequent reversing and steering in the display bay.
The manual says reversing the tank should pull it back.
We may have to wait for the mud hole outside to freeze so we can take it outside and drive it for a bit to see if this frees it up.

Any suggestions on getting the track tensioner to release?

I'm going to try some heat.

Malcolm