Swapping 1st Generation Isuzu Trooper Auto Locking Hubs for WARN Manual Hubs

I upgraded to manual locking hubs after wanting to do it for several years.  Now, “upgrading” to something that makes you get out of your car to use 4 wheel drive seems a little crazy to most people, but I see it as an upgrade since they are considered stronger than the stock automatic hubs and there is no question if they fully engaged or if something is wrong.  Listening for the “click” and not being sure you heard it is a little unnerving.  Also, I am only engaging 4-high and 4-low when I am going somewhere off road, so getting out and turning the hubs isn’t that big of a deal.

Stock photo of the new hubs


If you would like the service manual, it goes into detail disassembly, service, and reassmbly of the stock auto hubs and the Aisin/Asco manual hubs:


Before installing the hubs there are several choices of what brand to get.  The OEM hubs are made by Aisin (or Asco and I have read that Aisin bought Asco) and it seems that they are considered the best.  The other two brands are Superwinch and Warn and then there a few other brands that are significantly cheaper, AVM , Rugged Ridge, and another brand that is on eBay that looks like Aisin but without a brand name.  Since Aisin are hard to find, I didn’t want to buy a random brand, and Superwinch seemed cheaper, I went with WARN 61385 hubs.

The only downside is that I bought them on eBay and the seller shipped the original box without any tape and the hubs fell out in transit.  After some emailing they finally shipped me a replacement set, but when it came the box only contained the hubs, but no gaskets or bolts.  Maybe that is normal or maybe they didn’t include it in the box.  Either way I needed those parts and got the WARN 61693 Service Kit that has the missing parts.

The Warn hubs didn’t come with the hardware or gaskets, so I ordered them separately
The instructions


Blocking the rear wheel before jacking up the front
Break the lugs free
Jack up the tire (not shown is also using a jack stand in case the jack fails)
Remove the lug nuts
And pull the tire off
Remove the six bolts holding the hub on
This reveals the hub assembly inside
Remove the snap ring holding the auto hub to the axle shaft
And the hub assembly should come off revealing the inner cam that needs to be pulled off as well or may come out with the hub
Clean up the inside if you need to


Take the new hub body and put the gasket on and then place it over the axle shaft
Install the six new bolts that came with the kit and torque them down to 25-38 ft-lbs
Install the new spacer over the axle shaft and the new snap ring to hold it in place
After making sure the dial is on 4×2 and not 4×4, line up the gasket on the new cap
Make sure the roll pin is in the correct cutout of the gasket
And make sure the roll pin aligns with one of the three cutouts on the hub as well
Tighten the six allen bolts to hold the cap in place, 45-50 in-lbs (not ft-lbs!)
The hub is now installed!
Rotate the hub and make sure that the axle doesn’t move when in 4×2, change it to 4×4 and make sure it locks everything up
Reinstall the tire and test it out!

2 Comments on “Swapping 1st Generation Isuzu Trooper Auto Locking Hubs for WARN Manual Hubs

  1. I also have a 91 and have heard that switching to manual hubs will improve the gas mileage by about %25. I’ve experienced occasional “funkyness” with engagement and disengagement of the hubs and thought about switching but was not sure. Your article clarifies the job immensely! THANKS MUCH

    • Unfortunately my mileage has stayed pretty constant since doing this upgrade, but the more solid engagement is worth it to me.

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