Engine Rebuild Mileage?

Hi Guys, 
My Haflinger smokes a little. It's enough to stain the number plate and make the spark plags black. The speedo shows about 31000 miles. Is this about the mileage something normally needs rebuilding?
It's a1962 civilian model.


  • Haf engines are pretty strong, but they get given a hard life. You might just get away with a top end rebuild, Maybe not even a rebore - Actually, that might make your life very difficult as pistons are not the most plentiful in all the oversize sizes!
    I am not sure there is a "normal" rebuild mileage point for Haflingers as they could have spent a lot of time idling as opposed to travelling running up the odometer.
    Does it smoke once it is warmed up - how badly? Do you see a blue cloud / Haze went just driving along - time for new rings. Just smoke when you start it up, but then clears? Time for new Valve guides (Maybe valves).

  • Hi HaffOnTheDowns,

    I also have a 1962 civilian Haf; I used to live near Caterham in the North Downs, but now live a little further south in mid-Sussex. Where are you based? Julian
  • Hi Julian, I'm near the point Berkshire meets Wiltshire and Oxfordshire. "Didcot" sort of.
  • Hi John, It's a haze you can smell if you are in a car behind me. A black sooty patch forms on the back of the vehicle. The spark plugs are sooty black I'm tempted to fit plugs that get hotter, to burn off the soot.
    I think it's oil not rich mixture, because I'm using just under 20mpg on super unleaded.
  • Sounds like new rings / bore hone - If you can source the correct size pistons and rings, then a rebore.

    There used to be many years ago, a tube of paste you could buy that claimed to seal bores and stop that sort of oil haze - I am sure all it did was gum up the rings and the expansion gap - That would reduce the oil haze for a while, but likely do more damage long term. I never used the stuff, but I know it existed.

    Hotter plugs only if you can't source new rings. Treating the symptoms is not a cure.

  • Also I tried adjusting the mixture screw on the single choke webber but it seems to make no difference. Is it just for the mixture at idle ?
  • I did a compression test yesterday. The right cylinder gave 120psi and the left I couldn't be sure I got the pipe sealed onto the hole but it gave 105psi. That's pretty good and these were with the engine cold. I'm a bit puzzled because if anything the 120psi seems too high I thought the haflinger's compression ratio was supposed to be down near 7.5:1 so that would suggest a target of (14.7 x 6) - 14.7 = 95.6 as an absolute highest. My tester is brand new so I'm thinking that it's working properly, maybe I just don't get what's going on.
  • Well if the rings are okay, then the only other source for oil in the exhaust would be via the valve guides.
    I would get a bottle of ToolStation's engine flush, get the engine hot, stick that in the oil and run it as per instructions. Do an oil and filter change and see what happens.
  • Since the last post I've noticed I may have to get into the clutch housing as oil is leaking fairly badly from the drain hole. I'm guessing at what's in there that I could replace to fix this. 
  • Oil in clutch housing can only come from two places. Crankshaft oil seal and main gearbox oil seal. So when you take the engine off, you will see a dribble mark from one or both sides!

    Until you get there you won't know.

  • Are both those seals replaceable from the clutch housing side?
    While poking around under there to see how things come apart I've found another oil dipstick I didn't know about, it's on top of the gearbox, but I had thought the gearbox and rear diff share the same oil level plug on the LH side of the vehicle?
  • One of the earlier gearboxes then. Later ones do not have that dipstick. I would still measure the amount of oil in the Diff / Gearbox by using the side level fill hole on the left hand side of the Diff / Gearbox. 

    I haven't actually had to replace the oil seals on either the crankshaft end or the gearbox side myself as both the gearbox and the engine required major work so I paid for the work. Looking at the exploded parts book, it looks like the oil seals are the last item before the outside world which means you should be able to replace them with out having to dismantle either side more than being able to see them. You would probably wreck them taking the out as i think you would have to drill a couple of holes in them 180 from each other, put a screw in each hole and pull on the screws. You might have to heat each case a bit to get them to come out, but it should be possible. One word of warning though, the flywheel nut is on very, very tight and you should make a holding tool out of  something which can give you a lot of leverage to hold the flywheel still whilst you apply equally large amount of leverage to the nut!!

  • Out of interest, in case I chicken out of doing it myself, who did you pay to do the engine-gearbox work and are there places the Haflinger community uses (or avoids)?  I'm in the south but I could always get it transported a fair distance. 
  • The way things are going in the world just now I can see myself driving the Haff all summer +autumn and taking on the oily clutch and oily portals in the winter.
  • Have you posted some pictures of the progress? Sound like a plan, Clutch unless it is slipping should be fine to use. Portals can be attacked one at time so could be spread out during use if they don't leak to much.
    Just remember to check the oil levels frequently as there is not much oil in theses things so every little bit that drips out could make a difference.

  • Good point <span>:smile:</span> -)
  • Just wondering how long it takes to do the oil seals in one portal? Bear in mind that I've never done one before :-)
  • First off, it depends on where they are leaking or if you are just going to renew all the oils seals / gaskets / bearings.
    Plan on taking a couple of days to do the first one - after that you you will know how fast or slow you work!

    Fronts will take longer that the backs obviously. I would start at the back if you have never done this sort of work before as they are straightforward.
    Make sure you have all the bits you need or you will have to wait for that bit you don't have with everything in pieces!
    1. Wheel off
    2. Hub off
    3. Brake shoes off
    4. Handbrake cable disconnect, remove lever  
    5. Drain oil
    6. Undo 4 nuts on back plate
    7. Undo hub flange nut at back of back plate - make note of all shims /oil seal (and order of things)
    8. Undo nuts around the edge of back plate and remove handbrake spring
    9. Pull front part of hub from back plate.
    10 Clean
    11 Replace bearings if that's what you are doing.
    12 Re-assemble in reverse order of this list.
    13 Flange bearing play is governed by the shims being put in from the back of the back plate and "squashed" when you put the small square plate back on.
    The workshop manual has a description of how you do this, but basically you make a short piece of wood which will fix to the wheel studs and stick out, I think, about 10 to 15 cm to one side upon which you can hang a 1 kg weight. If you have the correct tension on the bearing, the weight will stay still, but move if you touch it lightly!

    Fronts are more complicated as you have to deal with the swivel pins (King pins) and the CV joint. There is all this info on thehaflinger.com forum.

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