Lister with a wobble

[Cockie]

I have a Lister D to restore, but when running has a bit of wobble in the fly wheel and shaft. There's a bit of noise going on that sounds like it's coming from the bottom end. Does this indicate a bent shaft, or could it be a bearing issue. Just want to know what to look for as I'm stripping it down. I do intend to replace all parts that could be worn out, but don't want to replace the bearing only to find the shaft is bent.
Thanks in advance,

Cockie

[cobbadog]

Sounds like a bent shaft. Remove the spark plug and set up something to act as a dial indicator on the shaft and rotate the flywheel to see if the shaft is bent. If it i bent you will need to strip it and straighten it up. Best for a professional to do this as it does need to be true, not close enough. If the shaft is not bent then check the flywheel in the same way but I feel it is the shaft.
You do not want to run it as described it can turn out to be dangerous if it lets go. Thankfully these are a popular engine and if the shaft is bent you could possibly pick up a spare from a wreck.

[dieselspanner]

Once you've got it stripped, check the crankshaft. You don't need anything special to do a fast and dirty check.

A couple of axle stands will do, if you can tack weld a two pieces of 2"angle iron to them, to act as vee blocks, so much the better. If all you have is some 4" x 2" timber(2" x 4" lumber for the cousins!) a wooden cradle will do for a one off.

Support the outside ends of the crankshaft then rotate it and watch the inside ends of the shaft, it should all run concentrically. a stiff wire in a block of wood will easily show 0.020" (20") - 0.5mm to the naked eye.

Search the forum, 'cos somewhere there's a post from 38ac - Butch - on straightening crankshafts with a bottle jack and the lintel of the barn door, failing that you'll need professional help.

Check the bearing surfaces for roundness, a cheap vernier from Ebay will get you close. The OD should be the same at all points.

Easy, a couple of hours work on a sunny evening!

Cheers
Stef

[ajaffa1]

Hi Cockie, a Lister D is a very robust engine, it would take a very substantial impact or other event to bend the crankshaft. I suspect bearing/crankshaft wear or a loose flywheel. let us know how you get on and what you find.

Bob

[Cockie]

Thanks to all replies, much appreciated. I will be stripping her down over the next few months.

Cockie

[BruceM]

I was the guy doing the crank straightening on a CS clone via barn, beam and bottle jack about 4 years ago. The freight hauler must have slammed down the pallet and both flywheels were bent downward ever so slightly (around 20 mils as I recall vaguely). It's easy to be brave when the seller is Gary at DES; he said sure, give it a go, you're covered.  We were able to get runout to about .002 inches.  Normal is <= 5 mils, I think.

Glad to pitch in on that farm style straightening method if that is the diagnosis and the crank is otherwise salvageable, Cockie.  You need an overhead beam on a very heavy structure and a post between it and the case bearing support. Then crank up the end of the shaft via bottle jack. You have to flex it the other way about as much as the error, and keep checking the runout with dial gauge. 

Good luck with your D, pictures are appreciated by all.

[Cockie]

Thanks Bruce M, I'll give it a go. I have a modern steel frame shed, but I should be able to cobble something together to brace it down, while I jack the wobble out.

[ajaffa1]

Hi Cockie, if you don`t have access to a hydraulic press or a stone barn you could easily achieve the same by digging a hole in the ground approximately 2 feet square and 2 foot deep. Brace two sides of it with timber or steel and then use your jack to straighten things, You would be amazed at how much force it takes to shift 4 square feet of dirt!

Bob

[cobbadog]

0.002" run out is a great result but it sure would need to be far less than 5mm as that is nearly a 1/4". Or did you mean 0.5mm?