[ROVERNET - UK] Starter & DeDion tube

Fletcher gofanu at usachoice.net
Tue Aug 8 06:17:10 BST 2006


>3.) When cranking the car, the starter motor will
>engage properly and crank the engine fine-- however,
>if the engine begins to fire, but does not catch, the
>starter motor drops out of engagement and revs freely.
> I have to wait for the starter motor to come to a
>complete stop and then try cranking again. Is this a
>gummy Bendix drive? Something else? Normal for this
Not a result of gummy drive or missing teeth, This is usually a result 
of very low compression on one cylinder, and I have found that Rovers 
with a dead hole are especially prone to this. Normally a cylinder 
fires, and the next cylinder resists turning as it comes up on 
compression stroke. If a cylinder fires but the next cylinder has low 
compression, the engine spins freely and kicks the drive out. Do a 
compression test before anything else. If the car has been sitting, it 
may have a stuck open valve which if you are very lucky you might free, 
if you can figure out how to get penetrating oil to the valve stems 
Generally that means pulling manifolds, but I have had sucess with 
squirting a lot in the bad cylinder, then cranking the engine to blow 
the PO up around the guides.Then let it sit overnight and try again. You 
may be able to see a stuck valve through the plug hole with a good 
light, You can positively determine if a valve is stuck by checking 
valve clearances - if one has way too much clearance, that valve is 
stuck. If you have this, call back for further dodges. If all valve 
clearances are close to spec but a cyl has no comp,. then you have a 
burned valve or worse.

The axleshafts are fixed length, but the DeDion tube is not. Once the 
axles are unbolted, the entire rear susp on either side can be moved far 
enough to drop the halfshaft. Be careful about your jackstands, as the 
trailing arm/hub etc has to move sideways a bit If the stands are under 
the suspension, the car will have poor lateral location on the stands 
once the halfshafts are unbolted, so it is recommended to have stands 
under the base unit.

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