ALH wrist pin to rod bushing clearance

Hi All,

The Bentley does not say anything about this. Does anyone know what the factory specs and wear limits are on the wrist pin to rod bushing (small end connecting rod) clearance? I gather that in general it is around 0.8mil (0.02mm) but that is not TDI specific. I measured mine at 0.047mm and it seems too much. Thanks!

Greg

if the piston feels rattly on the wrist pin, I would replace the bushings.

That's how I look at it too. However, the new bushings are "ream to fit", i.e., they have to be machined to fit with the pins. Thus I need the factory clearances. My Mercedes Diesel (1985 300SD) manual says: 0.7 to 1.2 mil; (actually 0.018m to 0.029mm).
So, will I be wrong to ask the machine shop to fit them 0.8mil ?

that I do not know. pm user Franko6 thats an o not a ZERO. he might know the spec you are looking for.

Wrist pin clearance

The wrist pin clearance is .0004 INCHES they need to be honed to fit. We go on the basis that a reemer will not give the surface finish that a stone will nor do you have the control with a reamer that you have with a hone. The pin should just fit in the bushing. The rod bushing must not be warm from the machining process when the pin is fit. We soak our rods in solvent to reduce temp between honing strokes.

How many miles on those wrist pins/bushings?

~200k
The machine shop to which I took the rods seemed to be on top. They are using a Sunnen machine and they told me that their manual says 0.0003 to 0.0005 for floating pins.
Thanks A1 for the peace of mind!