Swapping front axle from drums to disc (1 Viewer)

[AZkick-n40]

I just bought a '78 FJ45 that has drum front brakes. The guy I bought it from said that he has a complete front axle from a late '70s FJ40 that should bolt right on that had factory disc brakes and wants $250 for it.

Is that a good deal?

Does that decrease the value of the truck since it was not what it originally came with? (anyone know if the '78s in other parts of the world came with discs?)

Anything else that I should know before I do this, assuming it is a good deal and worth doing? Gears?

My goal with this truck is to keep it stock but to also have it functional.

Thanks!

 

[nuclearlemon]

yllalso nee proportioning valve (by master) and to remove check valve in master for front circuit.because you're sticking with toyota, i don't think it decreases value.

 

[AZkick-n40]

I need a proportioning valve for front discs only?

Is that something I buy from SOR or MAF? Or is there a stock Toyota one?

Does the price seem OK?

 

[Chef]

$250 is a fair price for a complete with diff, rotors, calipers front end.

Actually, I believe you need to *remove* the residual valve from the front barke circuit. It's there to hold a coupla psi of brake pressur on the shoes and keep them from withdrawing a distance away from the drums and leave you with spongey late to engage brakes. Disc brake pads float on the rotor til you step on the pedal and don't need this.

Is your 78 a dual or single circuit master cylinder?

Edit: sorry Ige, I think we're saying the same thing about residual valve. Proportioning valve: Helps set pressure bias between front and rear I've done some 40's that needed one, and some that didn't as much. Kinda depends on the vehicle and wheelbase. My guess is that a lwb 45 might not need a prop valve...As mine is in boxes, I have no direct experience with that yet...

 

[AZkick-n40]

My '78 is a dual circuit master cylinder. I know that I have to remove the residual valves for my 40 and makes sense I would have to remove for the 45. So 1 circuit runs the rear and the other runs the front. Correct? Therefore, I would only remove the residual valve for the front. Also correct?

 

[Steve-O]

My '78 is a dual circuit master cylinder. I know that I have to remove the residual valves for my 40 and makes sense I would have to remove for the 45. So 1 circuit runs the rear and the other runs the front. Correct? Therefore, I would only remove the residual valve for the front. Also correct?

You are correct about both. The front circuit is for the front brakes, so remove that check valve only. In my opinion $250 for a complete front axle is a good deal. Keep in mind that you will probably replace or rebuild some of those parts on it. Did you get that cruiser from Australia, oddly enough they didnt come with disc brakes until 1980 down there. Make sure the axle you are getting is not a 79, they had a different gear ratio.

Steve

 

[AZkick-n40]

Steve-O,

No the truck is from Costa Rica.

Any years that would be preferable for the gears?

Can I transfer my gears from my existing axle to another?

Can you tell that I am a neophyte mechanic?

 

[Chef]

81 on (?, I think) had 3.73 gears, 80 and older had 4.11 gears...or at least this is my recollection of when that change took place.

Diff's will swap between housings with one caveat...67(? again, my memory is not that great) and earlier had smaller studs holding the diffs on. This can be worked around, but is actually work

Steve-O from MAF-always nice to see vendors in the forums, welcome! MAF sells very nice knuckle and wheel bearing/gasket/seal sets at good prices...all oem Koyo stuff last time I bought from them.

 

[Steve-O]

81 on (?, I think) had 3.73 gears, 80 and older had 4.11 gears...or at least this is my recollection of when that change took place.

Diff's will swap between housings with one caveat...67(? again, my memory is not that great) and earlier had smaller studs holding the diffs on. This can be worked around, but is actually work

Steve-O from MAF-always nice to see vendors in the forums, welcome! MAF sells very nice knuckle and wheel bearing/gasket/seal sets at good prices...all oem Koyo stuff last time I bought from them.

Thank you, I'm happy to be here! You were close about the gear ratios. Toyota switched to 3.73 in 79 instead of the 4.11. 1968 is when Toyota switched from course spline side gears to fine spline. So technically you can swap diffs all the way back to the begining of the FJ40, but you will need to change the side gears.

AZkick-n40 - For any easy swap (if you wanted to buy a whole new axle), I would use a 9/75 to 12/78 FJ40 front axle. The gears ratios are the same for the diff, and it has disc brakes. If you wanted to swap your diff out, you can use an axle from 9/75 to 9/83 FJ40. You can use an FJ60 axle, but it is wider than the 40, which you will have to modify. You can also do a mini-truck knuckle swap, swap the 40 knuckles, or purchase our disc brake conversion kit. Hope this helps!

Steve

 

[Chef]

Steve, I believe this not to be the case. The early cruisers had smaller diff mounting studs on the axle housing. They will not work on later model housings without drilling the holes larger.
Later diffs can be made to work in earlier housings by drilling out the holes on the housing, and then drilling and tapping for larger mounting studs. At least that's what I think

At any rate, I believe there were smaller and larger mounting studs...

Thank you, I'm happy to be here! You were close about the gear ratios. Toyota switched to 3.73 in 79 instead of the 4.11. 1968 is when Toyota switched from course spline side gears to fine spline. So technically you can swap diffs all the way back to the begining of the FJ40, but you will need to change the side gears.


Steve

 

[AZkick-n40]

Awesome - thanks to all of you who replied!

 

[Radd Cruisers]

Also to mention that the BJ45s ran the 4:11s right through 79 and up.

Rob

Thank you, I'm happy to be here! You were close about the gear ratios. Toyota switched to 3.73 in 79 instead of the 4.11. 1968 is when Toyota switched from course spline side gears to fine spline. So technically you can swap diffs all the way back to the begining of the FJ40, but you will need to change the side gears.


Steve

 

[Cryptic]

I imagine its just like the canadian spec late 70's FJ45's. Keep any good brake hardware from the front for spares. The shoes are wider than 40's use and are very pricey. The drums themselves are also bigger and cast with cooling fins. Backing plates are different but are interchangeable front or rear with the full floater. The rest of the axle hardware would swap right into the disc axle so keep it around as well. Same 4.10 gears, same fine spline shafts, same birfeilds. When you find out how much it costs to overhaul the drum brakes you will appreciate the disc swap from that angle alone.

 

[bad_religion_au]

You are correct about both. The front circuit is for the front brakes, so remove that check valve only. In my opinion $250 for a complete front axle is a good deal. Keep in mind that you will probably replace or rebuild some of those parts on it. Did you get that cruiser from Australia, oddly enough they didnt come with disc brakes until 1980 down there. Make sure the axle you are getting is not a 79, they had a different gear ratio.

Steve

australia never really got the 3.70:1 ratio...

 

[Steve-O]

australia never really got the 3.70:1 ratio...

I was referring to the U.S. spec axles. But I did not know that, thank you.

So where are you looking to purchase the axle from AZ? Are you in Arizona? I think a u.s. spec axle would be easier to come by. And considering you are really only looking for disc brakes, I dont know how we got onto this whole gear ratio hooha. The easiest swap for you, is 9/75 to 79. Unless you want to only swap the knuckles, then you have more years to work with.

Thank you everyone for following up on my incomplete global gear ratio specifications!


Steve

 

[bad_religion_au]

sorry i got lost in the US - non us spec discussion above.

but the gear ratio was brought up because someone said not to get XXX year axles

 

[45Kevin]

I have a 78 and recently swaped a disc front end from a JDM 1982 fj43 I think it was. Crushers actually didi most of the work with me fetching bolts and tools from the pit when he dropped them. We reused my gears and and my axels/birfields. The new ones were too short to use with locking hubs. I gues the 43 had non-unlocking hubs. I think I paid $200cdn without the gears. I have yet to touch my master cylinder valve and have not noticed any change in the braking. It took us 3-4 hrs with an experienced mechanic and a well tooled shop.

 

[AZkick-n40]

So can I continue to use my existing axle so long as I change from the knuckles out? Then I wouldn't need to buy the whole axle?

 

[bad_religion_au]

yes

you can use 60 series or mini truck (hilux) knuckles as well, then you get vented rotors

but you probably need to use the cv's that are meant for those knuckles, as the freewheeling hub is different.... there are writeups for it in the tech section.

 

[AZkick-n40]

Did Toyota make different front axles for US, Canada, Austrialia, and South America? Or would a 1978 axle be the same regardless of where the truck was originally sold?

I have a line on some disc brakes (no axle) from another person that came out of a '75 FJ40 - what is the chance it will fit my Costa Rica '78 FJ45?

Hate to get stuck w/ something that I can't use.