Axle swap

[Nitro]

I have a September 74 fj40 and planning to do an axle swap with a 78 fj55. I read that people are using a mini truck brake master cylinder and proportional valve for this swap. Is the differential flange bolt pattern that the drive line bolts to the same on the 74 to the 78? Also, are there any tricks or wish I would have done things differently people would like to share with me?

Thanks for any help

 

[inkpot]

Howdy! I would use the master and booster from the FJ55 if you can get it. It is the same as FJ40 parts. JOhn

 

[FF LC FREAK]

Is the differential flange bolt pattern that the drive line bolts to the same on the 74 to the 78?

Maybe. But if it doesn't, you have lots of options. The simplest would be to just swap the pinion flange from you 74 onto the new third if the spline count is the same. That way, your drive line would be the same. Or, you could swap the entire third from your 74 into the 78 housing if the spline count is different. Or, you could get the driveline from the 78 and use half of it on your 74. Or, you could get a new pinion flange from someone like Cruiser Outfitters - Cruiser Outfitters. Like I said, you have lots of options.

If you are interested, you can go here - Cruiser Outfitters - to see which flange you might need.

Good luck!

 

[zuluzeugma]

78 is the first year for fine spline so you won't be able to just swap flanges. You're going to have to take the third from your old axle and swap it in or buy a triple drilled flange.

 

[Poser]

I have a September 74 fj40 and planning to do an axle swap with a 78 fj55.

Is the differential flange bolt pattern that the drive line bolts to the same on the 74 to the 78?

Welcome.



Yes.



A September of 1974 truck, provided no one has changed anything on the axles previous to you picking up the truck, will have a companion flange on the differential that is compatible with the 1978 drive shaft components, meaning, other than the fine vs. coarse spline pinion, the bolt pattern where the drive shaft attaches will be identical and work just fine.

 

[Poser]

Maybe. But if it doesn't, you have lots of options. The simplest would be to just swap the pinion flange from you 74 onto the new third if the spline count is the same. That way, your drive line would be the same. Or, you could swap the entire third from your 74 into the 78 housing if the spline count is different. Or, you could get the driveline from the 78 and use half of it on your 74. Or, you could get a new pinion flange from someone like Cruiser Outfitters - Cruiser Outfitters. Like I said, you have lots of options.

If you are interested, you can go here - Cruiser Outfitters - to see which flange you might need.

Good luck!

78 is the first year for fine spline so you won't be able to just swap flanges. You're going to have to take the third from your old axle and swap it in or buy a triple drilled flange.

Provided the companion flange on the front axle and the drive shaft has not been changed out prior to his ownership, there is no reason to change the companion flange on the differential as they have the same pattern. Spline count of the pinion does not matter in this instance.


Companion flange bolt patterns changed when Toyota changed from a three-speed transmission to the four-speed in 1974. (yes, there are three speed 1974 trucks that have the larger u-joint/bolt pattern, vs. the smaller three-speed bolt pattern flange, but even if he had that combination as late as September, it would still have the larger pattern companion flange that would be compatible with the 1978 differential companion flange)

 

[Nitro]

Wow, thanks for all of the posts. My friend has the extra 78 fj55 with 100k on it that has huge rust holes everywhere in the body. That is where I'm getting the drive train from. My plan is to pull the axles out and go threw them, put arbs in, rear disc brake conversion, power coat, and install. Have my fingers xed.

Has anyone put a 78 brake master cylinder/booster in an old fj? Or should I go though the hassle with the mini truck master cylinder?


1974 sept fj40
1992 Prado (70 series)
2005 Prius

 

[Poser]

Has anyone put a 78 brake master cylinder/booster in an old fj?

As inkpot stated, the booster/master will bolt up just fine.



If you have the whole 55 to take parts from, then you can get the brake lines that run across the firewall, along with the divider block that is bolted to the passenger side frame rail, and any other associated parts in the front brake line circuit, as they are not going to be the same between the drum brake 55 and one that had disc brakes in it from the factory.


Good luck!

-Steve

 

[Josie'sLandCruiser]

Hi All:

Hey Steve, this fella has a 1974 FJ40, not a '55. The donor front axle comes from a '78 FJ55 however.

Regards,

Alan

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[QUOTE=Poser;321591


If you have the whole 55 to take parts from, then you can get the brake lines that run across the firewall, along with the divider block that is bolted to the passenger side frame rail, and any other associated parts in the front brake line circuit, as they are not going to be the same between the drum brake 55 and one that had disc brakes in it from the factory.

 

[Josie'sLandCruiser]

Hi All:

I have a 11/74 FJ40, running a '78 BJ40 front disc brake axle.

IMHO, you have two routes to choose from with this project:

1) Remove the disc brake front axle assembly from the '78 FJ55, completely re-build it, then swap it into your '74 FJ40;

or

2) Strip all the disc brake bits (essentially, everything from the knuckles outwards) from the '78 frontend and swap them onto the stripped, bare '74 front axle tube, re-building the axle assembly in the process.

Option #1 allows you to do the re-build on the work bench, while option #2 saves you the trouble of removing the old front axle from the leaf springs, etc.

YMMV, of course!

Good luck with the project!

Alan
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I have a September 74 fj40 and planning to do an axle swap with a 78 fj55.