Spar bearing blocks

[N5442C]

My mechanic is doing my annual and showed me 2 Spar bearing blocks that were recently removed from a cessna 180(sky diving plane). The condition of them was quite alarming. Severe corrosion in the location of the smaller bolts holes (layers of flaking metal). The accociated bolts on my 170a have rusty heads and I would have to believe my spar bearing blocks could be in the same condition as the C-180. These normally would not be inspected unless the wing was removed. Has anyone had any problems with the bearing blocks?
EC

[GAHorn]

The bearing blocks (PN 0411129, pgs 40, 41, Fig. 21, 170B IPC. $52.53 each, two req'd, from http://www.cessnaparts.com/ ) are notorious for intergranular corrosion, especially in airplanes that lived outdoors for very long (like most of these 170's did.) I've got photos of my airplane being restored in which the blocks resembled exploded wood.
Some mechanics feel that if your wing attach bolts can be easily removed and reinstalled that is a valid check of the blocks. I wouldn't accept that tho'. If yours are suspect, budget for about 8 hours of labor to inspect them. If you find them disintegrated, you'll sure be glad you looked. If yours are fine, then you'll have piece of mind.

[jon s blocker]

I have recently replaced the blocks in my '53 model, and they were BAD! If you check the parts manual, you will find not only the number that Gahorn listed but another one as well. The front blocks are different than the back blocks! The other set of blocks were listed in the $90 range, but I don't have my parts catalogue in front of me to give you the correct number. check your parts catalogue and make sure you get the right blocks. I'm sure that there are several aircraft out there with corrosion in the blocks, but it is a little hard to determine on some unless you look closely. Good luck.
Jon

[GAHorn]

The parts I listed earlier are the front spar carry through blocks. The rear blocks are: 0512122 (List Price: $ 131.00) sold by Hill @ $ 111.35