Tech: Replacing Auto Hubs with Rebuilt Aisin Manual Hubs
December 11, 2000
|Why Replace Those "Convenient" Auto Hubs?|
The pros and cons of auto hubs are well documented in the annals of off-road literature. All I can say is that I was tired of...
|About the Author:
Jay Riggs lives in St. Paul Minnesota, and drives an 89 4 door V6 Montero. Among his extensive list of mods, Jay has installed an ARB bullbar, larger coils, KYB's, etc. Check out his rig in our Mitsubishi Reader's Rides
|The auto hub, before the cover is removed|
So I decided to replace the auto hubs on my 1989 4dr Montero with manual hubs. After a bit of research, I found my only two options were to buy a set of new Superwinch hubs or find a set of used Aisin hubs. The excellent reputation of the Aisin hubs and the hope that I could find a set for less than half the price of the Superwinch justified a trip to the junkyard. I had success on my second junkyard expedition and the donor vehicle was a 1986 2-door Montero. And the price was right - $50 for the set.
|The Donor Hubs|
When I pulled the hubs off the donor Montero I noticed a lot of gunk, but no obvious cracks or unacceptable flaws. Once on the workbench, I pulled the hubs apart and started the thorough cleaning process.
|The Rebuild: "We Have the Technology..."|
|On the Bench|
The rebuild went smoothly except for two things: (1) I lost the small ball bearing in one of the dial mechanisms (I think it went down the floor drain, but I will never know) and (2) the brass bushing in the freewheeling hub ring of one of the hubs was extremely worn (sorry, but I do not have pictures of what it looked like when I got it). I found a replacement ball bearing at a local hobby store. Sorting out the worn freewheeling hub ring took me a bit longer.
My first thought was to find a source of new replacement parts for the worn hub ring, so I sent a quick email to Eric Johnson. He informed me new rebuild parts were not available. My only option was to find a donor hub. Eric also mentioned that since the Toys and Mitsu's have the same bolt pattern, the Toyota Aisin hub might fit. In the meantime I installed the manual hubs with the worn hub ring on my Montero thinking I would fix it soon enough. Yup, there's some subtle foreshadowing going on here . . .
The auto hub removal and manual hub installation is very simple. Just unscrew the auto hub cap, remove the axle clip, and unbolt the hub.
|Removing the allen-head bolts of the auto hubs||The rebuilt Aisin is ready for locking action||The Aisin looks as OEM as the Autos did.|
Manual hub installation is the reverse except you have six more bolts for the dial face. I reused the dial face gasket and used silicon gasket for the housing. Don't forget to use locktight on all the bolts.
|The Rest of the Rebuild...|
|A Toyota hub, with a donor hub ring.|
After about one month of commuting and about two off-road day-trips I finally got back to addressing the worn hub ring. Since I knew there were tons of Toyota manual hubs out there and there weren't any more Mitsubishi manual hubs at the yards I frequent, I decided to look for a Toyota hub. It took me about 10 minutes at my favorite junkyard to find a hub in the bed of an 1986 Toyota pickup. Price? $20 including a replacement headlight washer nozzle I accidentally knocked off while pushing a fallen tree out of my way (I love my bull bar!).
Back on the workbench, I compared the Toyota hub with the Aisin hubs off my Montero. Right away it was apparent the housings were different. Pulling the hubs apart, I found that the inner hubs were different, but the freewheeling hub rings were the same! Life does have its good moments. The outer parts of the hub, including the springs and dial mechanism appear to be interchangable. Refer to the images below - Toyota parts are on the left and Montero parts are on the right. As noted in Eric Johnson's article, there are different versions of the Toyota Aisin hubs, so my comparison only applies to the 1986 pickup's hubs.
|The Toyota hub's outer diameter is the same||From this angle, one can see the Toy's is taller||The inner hub rings are not interchangeable|
After inspecting the worn hub ring out of my Montero Aisin hub, I realized it had gotten a lot worse and I had narrowly avoided a potentially serious mechanical failure.
|The Montero hub ring is the upper right|
The Toyota hub ring fit perfectly and after a quick rebuild and repack, the Mitstoy Aisin hub was put back on the Montero.
Other than the worn hub ring (which I never should have installed in the first place) that is now replaced, the manual hubs work flawlessly. It inspires a lot of confidence to know that the front hubs will stay locked once engaged. Without hesitation, I am very pleased with the swap. My total cost is $70, which is still not bad considering new Superwinch hubs now run about $112 from JC Whitney. Plus I have a few replacement parts and a new knowledge of hub. Now where's the nearest snow bank?
Editor's Note: Jay has since heard that the Samurai outer hub ring will also fit: the faces appear interchangeable, so he is going to find one, and compare it to the Mitsu and Toyota hubs, to make sure. All Toyota manual hubs are interchangeable/identical from 86-95 on all Toyota trucks and 4runners.
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