Changing the rear (pulley end) crankshaft oil seal (DG)

[airheadboxer]

I’m trying to change the rear (pulley end) crankshaft oil seal on my DG engine and am having a problem removing it.

Have I missed a tool or technique for doing this please?

The Haynes manual simply says prise it out, and a few engine rebuild threads I’ve been through don’t mention removing it (I suppose if you’re splitting the cases it’s not an issue). I’ve seen a video where the guy just puts a screwdriver in, flicks his wrist and out it comes – but that was on the workbench and maybe my wrist is too limp! I've tried searching on this site but haven't had any luck - I'm happy to be proved wrong and take the stick

I’ve removed the silencer and heat shield so I’ve got a bit of room but the water pump and pipes are still in place. I’ve tried using a hook to pull/yank it and I’ve tried using a screwdriver but without success (not a lot of room, but maybe I’ve not done it correctly). I’m worried I’m going to do some damage if I start yanking or prising too hard in ignorance.

On eBay there is a kit which includes a two-legged puller type of tool, is that worth trying? (not entirely happy as it looks like it would use the crankshaft to pull against?).
Also on eBay is a tool that looks like a two sided ice pick - but is there enough room for that to work?

I’d really appreciate some thoughts on this.
Thanks, Brian

[Aidan]

Also on eBay is a tool that looks like a two sided ice pick

with the exhaust shield and exhaust off there should be enough room to use of the this type of seal puller, be sure to tidy up any burr made on the case and clean the surface where the seal sat and lube the new seal with oil before fitting, I'd grease the bore as well and put a little grease in the lips of the seal
is the pulley seal surface ok ? If it scored or pitted it should be possible to repair using a speedi sleeve

[airheadboxer]

Aidan - many thanks for your comments.

I’ve tried again today to remove the seal but still no luck.

Your comment about the amount of room for the twin headed tool made me check with a ruler and it would be tight, so I’ve ordered this – it has an adjustable head so it may give me a little more scope to position it: (E D I T - before you rush out and buy one please see my comments about my experience of this tool in a later post)



The speedi sleeve suggestion was an interesting one, but the crank pulley is being replaced with a brand new one so any groove from the old seal won't be an issue.

I know it's a trivial task in the scheme of things, but I'll try to update this thread with how I get on in case anyone else has a similar experience in the future.

Brian

[Aidan]

nice find, I wasn't aware of adjustable version for tight spots

[airheadboxer]

Just an update on how I’m getting on.

Well, my new adjustable head oil seal puller (see earlier photo) arrived and broke the first time I used it. It’s a good idea, but poorly engineered.

What seems to have happened it that as I put some effort into it (not a lot as just trying it out) the head tries to rotate about its pivot, this in turn forces the sprung loaded locking pin to try to rotate as well. The locking pin isn’t braced in any meaningful way and tries to rotate about its fixing. As mine did this the locking pin also seems to have twisted and got itself wedged between the head and the handle/shaft causing the handle/shaft to part and bow.

This photo shows the end result and the bow in the handle/shaft. There is no riveting or fixing between the head and the handle so the two halves that make up the handle can spring apart easily. And it stays that way.

DSCF1648.JPG

This photo is of the head end and the resulting gap that the locking pin tries to go into now if you try to use it following the initial problem.

DSCF1649.JPG

And this is as close as I can get to show the locking pin rotated - the spring you can see should be straight, not bowed as seen. The chrome knob is the pivot point

DSCF1647.JPG

Maybe I’ve been unlucky. Maybe, but personally I won’t be buying another one. [/size]

[Aidan]

can you drill through the two pieces of the handle close to the spring and bolt the two halves together to make it more rigid and keep it all together ? was it simply spot contact welded together badly and thus has sprung the weld ?

[itchyfeet]

I just use a large screwdriver and brute force, you can punch the seal with a pin punch or screwdriver too to distort it as you can see which helps to break the seal to the block



and fitting new...

[Aidan]

Paul's in the room

[airheadboxer]

can you drill through the two pieces of the handle close to the spring and bolt the two halves together to make it more rigid and keep it all together ? was it simply spot contact welded together badly and thus has sprung the weld ?

Hi Aidan, thanks for the suggestion, and that's what I've gone off and done this afternoon. There were no component or weld failures, it just seems down to poor design. I checked on line (eBay) and all the adjustable head seal pullers are this same model, so modifying the one I've got makes sense.

These are the bits that make up the sliding locking mechanism.


The pin on the right is the slider knob thread, which I’ve had to drill it out from the back. Apart from the slider knob not being shown that is all the bits that make up the locking mechanism and probably explains why it rotates in sympathy with the head under pressure.

This is the result of my bolting up.


The sliding locking bits have been removed and replaced by the long bolt (after some drilling and filing of the teeth). This bolt locks the head in place but isn’t as convenient as the slider, but I’m hoping to get a wing nut to make moving the head quicker. The big bolt is big because the existing hole was big and is to keep the wider section in shape. There’s also a couple of spacer washers in there. The smaller bolt half way along the handle is to keep that part together.

It was still raining when I finished it, but I hope to try it out tomorrow.
Brian

[airheadboxer]

I just use a large screwdriver and brute force, you can punch the seal with a pin punch or screwdriver too to distort it as you can see which helps to break the seal to the block

Thanks itchyfeet. I'm hoping the repaired seal tool works and allows me to use much more (brute) force as you mention.

The idea of distorting the seal outer makes a lot of sense. And I like your wooden insertion tool, I should be able to replicate that.

Thanks again. Brian.

[airheadboxer]

Done it!!! It's out.

I followed itchyfeet’s suggestion to deform the lip of the seal and then using the now strengthened extractor it finally came out, but it still took a lot of effort.

I deformed (prised outwards) about ¼ of the lip edge circumference between the 12 and 3 o’clock position and used the extractor in the 7 – 8 o’clock position where there is more room underneath.

It might have been a little easier if I had deformed more of the lip than I did.

Now to put the new seal in.

[Aidan]

nice work
patience pays off