Early 75 brake upgrades + widetrack

[dogbreath_48]

I'm looking at upgrading the brakes and increasing the track on my HJ75 troopy. Did a bit of searching but couldn't come up with many answers spescific to an early 75.


1. I understand V6 4runner calipers are a direct bolt on.
a) Do i need to replace the discs?
b) Are all V6 'runner calipers the same?
c) Could i run 15" rims
d) Will my standard master cyl be adequate? --->

2. Is there a bigger master cylinder i can bolt on? If so;
a) Will it work with my booster? If not what booster can bolt on?
b) Will it work ok with drums on the rear --->

3. How could i get discs on the back? I'd want to keep my diff center+ cw/p (locked and recently rebuilt) and do it with as little trouble as possible. Not really interested in upgrading the std axle, would rather go wider.
a) Did 60s come with disc rears?
b) Is the diff offset on a 60 axle suitable?
c) What is involved in getting a 60 rear under a 75 (don't want to change spring position etc)
d) What would be involved in disc-ing a 60 or 75 axle?

4. I had a feeling IFS lux spindles could be used on the front for a 50mm track increase?
a) What parts need to be swapped?
b) Would the big 'runner calipers still fit?

Sorry for all the questions i'm just trying to save all the fucking around i'd have if i went into this blind. Lets make this thread bible worthy!

Cheers,

-Stu

[dow50r]

Stu
So many questions.....the end result will depend on the requirement you set. Did you know that around 1992, the hzj75 went 4wdisc, and from 1990 the hzj75 had bigger front callipers (thesame as 1990+ lux) so a straight forward fix is to fit later front callipers and rear disc diff and you have discs...then you can modify this diff by bolting 80 series handbrake/hub to the 75 diff...straight on and 30mm per side wider.
An 80 series master and booster would be the easiest way of getting a better pedal if you use larger v6 runner callipers...the v6 runner or surf calliper has thesame 4x45mm piston as 80 series, so using that master booster is like keeping it a std upgrade...You dont need to change the front discs, id suggest the front track is a little wider than rear top begin with...so maybe wider rims (40 series offset) would do up front...yes you can run 15's with v64runner calipers, if you get early 80 rear discs, you can also run 15's up back....but later than 92 rear discs are bigger, and better, and a slight skim to the calliper fits the 15's no problem.
This all begs the question.....why not get an 78/9 front diff with coils for the front of your troupy?? coils from the factory
Andrew

[dow50r]

More...if you run ifs front hubs, you have to space the disc and that means engineers...the v6 calls bolt straight on to your disc and where the std ones came from, so much better they flatten out the leafs under braking.std 1990+ hilux callipers fit aswell, with 4x35mm pistons and can be used with std master/boster. std 79 series front diff has bigger c/v's bigger brakes, smaller diff but coil suspension. You can run 80 series brakes on them for 6 studs. I suggest you put that rear diff up front, and get a disc rear from a later 75...60 series is wider diff, wider spring perches, need repositioning, and only drum. Nothing wrong with drums either....get the new callipers on and a 80 master/booster and you will be cheering

[dow50r]

PPS you have detroits both ends, the rear centre will fit in a 75 disc rear end diff housing...straight in

[dogbreath_48]

Thanks, i knew you'd be able to help

So the best setup, short of a 79 front axle (too much work at this stage - maybe one day) would be the V6 'runner calipers up front, 80 series master+booster, later 75 rear with late 80s hubs/brakes.

-Is the 80 master/booster a bolt on affair?
-How dodgy is spacing the front calipers to suit IFS spindles? Apart from the legal technicalities should i be worried about doing this? (using well made spacers/quality bolts etc)
-Could i use the 80 master and 'runner calipers but keep the standard drums (as an interim measure)
-Will the complete rear diff assembly (the whole pinion/crown/housing etc) bolt into the later 75 rear, or just the Detroit center?? I've only recently had the whole thing rebuilt and don't want to have to do it again.

Also, has anyone done a transfer-mounted-disc (or drum i suppose) handbrake mod on a 75? If so where/how did you mount the caliper?

Thanks,

-Stu

[dow50r]

Stu
your centre will fit in the disc rear end housing complete...it has a handbrake incorperated, when you get 80 hubs, they fit straight on too, diff bolts up to springs, handbtrake cable might be different...no big deal, they r on ebay cheap,
front spacers will be more than new deep offset rims...if you get 4 of them, you wont need 80 rear hubs either...

[dogbreath_48]

your centre will fit in the disc rear end housing complete...

I've had conflicting advice from the local wrecker Think i trust your word more though. Just not sure if we're having confusion with my terminology will check it out thoroughly before buying anyway...

Any word on the bolt-on-ability of the 80s booster/master? Will the std alternator be adequate for the 80 booster?

Also could i use the 80 master + 4runner calipers but retain the drums on the rear for the time being? I need a new master at the moment, but don't have the cash to upgrade the rear straight away.

[dow50r]

I once had 5.29's in an 80, which ment a 75 series centre had to go in the 80 housing with 7/37 gears....i also once helped a guy at Appin with a snapped pinion shaft in his 1995 troupy....it turned out being a old 4.11 from a 60 series down there, and 4.1 up front per std....they retro straight in
You can put the 80 booster straight in, with a small mod to the bit that bolts to the pedal, it needs lengthening.....easy job....
You can run drums back there, some 80's had drums...i used 4wdisc master on my drum rear 60 ok...
With the 4 runner callipers you will need the 80 master and booster...if u put the 80 master on your booster, the pedal effotrt will be increased.
Andrew

[dogbreath_48]

I once had 5.29's in an 80, which ment a 75 series centre had to go in the 80 housing with 7/37 gears....i also once helped a guy at Appin with a snapped pinion shaft in his 1995 troupy....it turned out being a old 4.11 from a 60 series down there, and 4.1 up front per std....they retro straight in
You can put the 80 booster straight in, with a small mod to the bit that bolts to the pedal, it needs lengthening.....easy job....
You can run drums back there, some 80's had drums...i used 4wdisc master on my drum rear 60 ok...
With the 4 runner callipers you will need the 80 master and booster...if u put the 80 master on your booster, the pedal effotrt will be increased.
Andrew

Thanks for all the help. Now i'm excited - will let you know how it goes...or stops...

[midi73]

Thanks, i knew you'd be able to help


-How dodgy is spacing the front calipers to suit IFS spindles? Apart from the legal technicalities should i be worried about doing this? (using well made spacers/quality bolts etc)

You dont space the calipers, you space the rotors using which look like wheel spacers made by marks adapters.
This is them.

[dogbreath_48]

You dont space the calipers, you space the rotors using which look like wheel spacers made by marks adapters.

Yep worked that out - bit dopey of me