Rocker Arm Assembly: Service and Repair

Removing and installing rocker arm bearing bracket

Preceding work:
- Camshaft oil pipe removed.





- Rotate crankshaft or camshaft until the camshaft base circles are resting on the rocker arms.
- Unscrew bolts (13) (15 Nm).
- Remove camshaft bearing cap (12); see note. Use a plastic-headed hammer to detach tight camshaft bearing caps. Pay attention to dowel sleeves.

Caution! Pay attention to ball sockets (8); re-install at the same point. Replace M8x70 bolts (12) by M8x73 10.9 bolts

Special Tools:

Note:



The camshaft runs in 7 bearing points in the cylinder head and is bolted with 6 bearing brackets.
The front bearing bracket has two bearing points and two retaining lugs.
The retaining lugs are designed to fix the thrust washer of the camshaft.




The numbered bearing brackets are each centered with 2 dowel sleeves at the cylinder head and bolted with 4 M8x70 bolt+washer assys, as of 06/1990 with M8x73 10.9 bolt+washer assys.
When performing repairs, always use M8x73 10.9 bolt+washer units.
The bearing brackets are machined bolted to the cylinder head.
Camshaft with oversized bearing journals (+0.5 mm) are used for camshaft bearings with 0.5 mm oversize (eg. reconditioned engine).




Modification of thread layout on camshaft bearing brackets
The distance between oil pipe and rocker arm has been enlarged as of 1011985 as a result of the modified thread layout, size (A), at the camshaft bearing brackets.
Size A = 45.5 mm, was 44 mm.

Distance Between Oil Pipe And Rocker Arm, Production Breakpoint: 10/1985:

Bolts for camshaft bearing caps at cylinder head
M8x73 10.9 (previously M8x70) bolts+washers are used.
This avoids shearing of the securing thread in the cylinder head.

M8x73 10.9 Bolt+washer, Production Breakpoint: 06/1990: