Replace a damaged Dana 18 rear output shaft housing questiob

[Jim chapman]

I need to replace a damaged Dana 18 rear output shaft housing. Will I need to adjust the shim pack to maintain proper shaft end play when I install a replacement rear output shaft housing?

[Rus Curtis]

Jim,
Welcome! 

In a perfect world, I'd guess that yes, just put it on with the same shims and it will be exactly the same.  But.  The Service Manual (SM) states, par K-22. Transfer Case Overhaul, that you have to check the end movement of the main shaft because this determines the adjustment of the tapered roller bearings. Tolerance is .004" - .008" end play.

That procedure is for rebuilding your own original parts.  So, the logical conclusion is, knowing this isn't a perfect world, you should be checking that end play and you may need to adjust the shims. 

Planning on this and then being pleasantly surprised it's within tolerance is best.  But, even if you need to adjust the shims, it will help you avoid repeat maintenance after the installation.

[duffer]

As indicated, yes, you need to check the end play.  Even if it was correctly set on the prior installation, any wear on the tapered roller bearings may require a thicker shim pack.