Cummins/Onan — Generator Alignment for DFT Generating Plants
Installation
From a Cummins/Onan operator's manual covering: 250DFT-57R8, 300DFT-4R8, 300DFT-4XR8, 300DFT-5DR8, 300DFT-6DR8, 300DFT-7XR8, 300DFT-9XR8. Check it applies to your exact model before use.
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Procedure
- Set plant on its mounting foundation.
- Remove two mounting bolts securing generator support to skid base. Remove shims.
- Secure skid base to mounting foundation.
- Measure clearance from top surfaces of skid base to both mounting surfaces of generator support.
- Add clearance and weight correction figure to determine total shims required.
- Use mounting bolts as jackscrews to increase clearance and place shims.
- Lower generator to rest on shims. Total clearance must equal base-to-support clearance plus weight correction.
- Remove jackscrew bolts and install as mounting bolts. Secure and lock.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Laminated shim has .002" increment
- Use shims as thick as possible
Source: Cummins/Onan operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.