72 FJ40 Birfields

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Dec 9, 2007
Grand Rapids, MI
I think I all ready know the answer to the questions I am going to ask, as I have read the FAQ, just looking for some confirmation. My hubs will not work with mini truck birfields, because they are coarse spline? Am I correct? Will mini truck hubs work on my knuckles, I have knuckles up front from a FJ60 or 62 with disc brakes, so when I do upgrade to longfields (I am saving for them), what will I have to do to make everything work? What would be the best fix? For the time being I would like to buy some coarse spline birfield so I can continue to drive the 40 around this summer. I will be able to afford the longfields this fall. Thank you for all input.
get the 30 spline Longfields and a set of hubs to match. I have the 30 splines with Warn premium hubs. I have beat the snot out of them and never had a problem. One note. Bobby's lifetime warranty does not cover damage from broken hub gears damaging the splines. When I can afford it I would like to go to the aisan hubs with the longfield hub gears. Last time I checked he only made them for the Aisan hubs. Unless they were swapped the birf's are coarse spline for sure, What did you do with the hubs / birf's you had on your 40 to start with? If you need a set of course spline hubs I think I have a set in my parts box I'd let go cheap. I think the hubs should bolt right up.If not I'm sure I wiil be corrected very quickly. What year did the 60 series knuckles come off of?
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Yes you will need new hubs to run the mini bf they will work with your 60 knuckle but you might have to clearance the axle housing alittle to get them to fit in there search disc brake install. Mini,60 and standard longs are the same size bf
Alright! Just took it apart, I have the aisin lock out and it is fine spline. The ball was in a few pieces. The inner shaft is longer than a mini truck? I'm going to use the inner shaft with a mini birfield. Going to the store to get more paper towels and some brake clean. Any suggestions please post as I will check back in before cleaning the mess and doing the rebuild. So does this mean all I will need for the longfields is the set of inner and outer, 30 spline? Thanks.
As stated above, make sure you order the hub gears from Bobby so you never have any warranty issues.

I will, I love to do things right the first time, it is less money and better. It is nice to know that a mini truck will work, my brother has a bunch for spares. He runs longfields, meaning I have some spares until I run longfields. Thanks for all the help and advice.

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