Published data on the emission of charged particles following nuclear muon capture are extremely limited. In addition to its interest as a probe of the nuclear response, these data are important for the design of some current searches for lepton flavor violation. This work presents momentum spectra of protons and deuterons following $mu^{-}$ capture in aluminum. It is the first measurement of a muon capture process performed with a tracking spectrometer. A precision of better than 10% over the momentum range of 100--190 MeV/c for protons is obtained; for deuterons of 145--250 MeV/c the precision is better than 20%. The observed partial yield of protons with emission momenta above 80 MeV/c (kinetic energy 3.4 MeV) is $0.0322pm0.0007(text{stat})pm0.0022(text{syst})$ per capture, and for deuterons above 130 MeV/c (4.5 MeV) it is $0.0122pm0.0009(text{stat})pm0.0006(text{syst})$. Extrapolating to total yields gives $0.045pm0.001(text{stat})pm0.003(text{syst}) pm 0.001(text{extrapolation})$ per capture for protons and $0.018pm0.001(text{stat})pm0.001(text{syst})pm 0.002(text{extrapolation})$ for deuterons, which are the most precise measurements of these quantities to date.
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