The oil is actually from the transmission. This was a common issue that Isuzu had to deal with while these were under warranty.
To fix it:
- Remove the single bolt holding the speedometer gear housing, and gently pry it loose. Do NOT pry against the tab where the bolt-hole is. It will break off. Or, just tug on the speedometer cable itself, if you can grip it well enough.
- Once the speedometer gear housing is removed, pull the gear itself out. Then remove the cable, which is secured by a threaded collar.
Attachment:
speedo_gear3.jpg [ 506.07 KiB | Viewed 7654 times ]
- (This is where my memory comes up short) Inside that housing, there's a sleeve, holding an o-ring in. That all needs to come out, so the o-ring can be replaced.
- Source another o-ring from your local hardware store, and you may want to get a few of various sizes/thicknesses, just to be safe.
- Replace the o-ring and the sleeve, re-insert the gear, and make sure it turns without much effort. It should be tight enough to make contact, but that's about it. Too tight, and it might cause wear on the plastic gear.
- Put the gear housing back into/on the transmission. Make sure it is fully seated before putting the bold in!. If you try to tighten the bolt before the gear housing is seated, you WILL break off the mounting tab (don't ask how I know this). Re-attach the cable.
Hope that helps.
Jack
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'83 Isuzu P'up Diesel LS - Original Owner
JoeIsuzu@IsuzuPup.comIsuzuPup.com