75 on 80 Chassis

[horndog]

I have searched and only found that it have been done before but no specific details are given.
I want to put my cab and running gear from my hzj75 onto a 80 chassis. Will the gearbox and engine bolt straight in and will the diffs also go in. All the diffs and box and transfer have all been done up and the engine is being rebuilt now for a turbo so i don't want to waste the money i spent on these already.
thanks Mitch

[pinkfloyddsotm]

i think new cab mounts will be needed

[horndog]

i realize that but thanks pinkfloyddsotm.
more interested in knowing about the drive line

[Thommo 73]

with money you can make anything fit.


but i dont see the point if your going to use your diffs.

[horndog]

ill only use my diff centres not the housings

and i want to get it on the road legally before lifting it so modifying the cross member the transport might not like it that much.

Agreed that money makes anything possible but im a uni student so dont have that much to begin with. o if i can use my box and diff centres that will save alot

[pinkfloyddsotm]

ill only use my diff centres not the housings

and i want to get it on the road legally before lifting it so modifying the cross member the transport might not like it that much.

Agreed that money makes anything possible but im a uni student so dont have that much to begin with. o if i can use my box and diff centres that will save alot

i know of a coiled troopy (milo) on here used 75 diff centres in the 80 diffs, and you can always make a new crossmember to suit. or even buy an x-member off an 80 chassis ?

[skootin]

80ser frt diff is a high pinion not the same as the 75 also the gearbox is very different best to use the 80ser running gear as its the way it was made.
Cab mounts will need to made for the whole cab.......
dont forget the fuel tank...

[84sloth]

yea mate it can be done im in the middle of doing it atm. i havea 91 80 series chassis its suit 15 inch wheels not 16inch. my rear diff centre out of my 75 will fit. also if u have a diesel u should try to get the diesel chassis as im pretty sure the gearbox crossmember is further back on the petrol. the cab mounts are pretty close the rear mounts are with 10mm. the central ones need to come forward and out 50mm and the front ones come outwards 70mm eitherside. also u need 80 series 1hz engine mounts for your engine as the chassis width is narrower on the 80

[hulsty]

80ser frt diff is a high pinion not the same as the 75 also the gearbox is very different best to use the 80ser running gear as its the way it was made.
Cab mounts will need to made for the whole cab.......
dont forget the fuel tank...

hzj75 centre will fit the 80 housings front and rear. hzj/fzj has a high pinion front diff. Unless it is a really early hzj75 which may have a low pinion front diff

[horndog]

thanks 84sloth, will be looking for an early model chassis as well cause i don't want to change my wheels over to 16inch rims. How did u go with the steering, did you use the 80 box or 75?

Thanks Hulsty, mine is a 91 and has a high pinion front diff so that should go in.

[thrashlux]

hi guys which box are you using?

the h55 or the H151?

the diffs will fit if from late 75 to 80

pre 92 are the small brakes trucks

you can use the late chassis with the big brakes on 15'' wheels if you swap the rear housing to and early one
this will give you the benefit of much better braking

the cross member location for the gearbox is the same for diesel and petrol
the difference is between auto and manual auto is further back

you need to use the 80 series steer box and make a new steer shaft from fire wall to the steer box
80 series and 75 series steer boxes turn opposite directions

any more q,s shot away

i put a 1980 lux on the 80 series chassis even harder!!!!! trust me

cheers

jonathan

[Ice]

doing a similar conversion atm

hzj75 cab onto an 93 model petrol 80 chassis

slightly different motor and box though

1uz with 2uz bellhousing and auto

shall put up some pics as it progresses

[horndog]

thanks thrashlux
Its the h55 box I'm pretty sure, as long as the mount is fairly close i should be able to modify the crossmember to make up the difference.
yeah my main concern is the box n transfer as i have spent a few thousand on these n don't wanna use different ones.

Your lux looks the goods mate, done well with it

[thrashlux]

thanks thrashlux
Its the h55 box I'm pretty sure, as long as the mount is fairly close i should be able to modify the crossmember to make up the difference.
yeah my main concern is the box n transfer as i have spent a few thousand on these n don't wanna use different ones.

Your lux looks the goods mate, done well with it

Thank mate

the best thing to do is get the tape out and work out if you want a manual or auto chassis

i used the center of the front wheel as the datum point

basically how i did it was put the wheel in the right spot of the wheel arch then worked out where the engine and trany had to sit relative to the body

and mounted the engine and tranny to the chasis in the right spot

its a bit of a juggling act

if at all posible the first question i would be asking is the guys who have done the 75 series cab swap is did they use the 80 series front engine mounts and the wheels could still be in the right place in the arches with the motor located in the engine bay correctly

if this is the case you will want a manual chasis

i made a new crossmember mouting i have a r150 with a splt case transfer and a 2jz twin turbo supra engine
also a good trick is to get hold of a early split case with the transbrake and swap the bits over that way you get 2 hand brakes and one that works after you have been in the mud and slosh
80 series hand brakes dont last well in these conditions

cheers

jonathan

[thrashlux]

doing a similar conversion atm

hzj75 cab onto an 93 model petrol 80 chassis

slightly different motor and box though

1uz with 2uz bellhousing and auto

shall put up some pics as it progresses

how are you gunna run the 2uz box ?
the ect will not run it? are you going to run a hyro conversion?
its not the problem of bolting them together its the problem of getting it all to run correctly out of limp home mode

i would recomend that you use the 1uz auto box and adapt it to your transfer of choice

or just go manual plenty of options if you go manual

jonathan

[rockcrawler31]

i put the 75x centres into 80x housings then had that grafted to my 75 chassis.

I honestly don't know what would be the easier way to go. complete chassis swap or diff housing and coil conversion.

both can be expensive to get the fabbing done if you don't do it yourself.

the chassis swap will require making all new cab mounts, possible moving the motor to suit where the cab will be over the front axle etc.

a coil conversion won't require new mounts but all new suspension geometry will have to be designed and grafted in.

Either way a bit of work and the best thing you can do is consult engineers FIRST. Or have your fabricator put it into WRITING that he will GUARANTEE that it will pass roadworthy

[thrashlux]

i put the 75x centres into 80x housings then had that grafted to my 75 chassis.

I honestly don't know what would be the easier way to go. complete chassis swap or diff housing and coil conversion.

both can be expensive to get the fabbing done if you don't do it yourself.

the chassis swap will require making all new cab mounts, possible moving the motor to suit where the cab will be over the front axle etc.

a coil conversion won't require new mounts but all new suspension geometry will have to be designed and grafted in.

Either way a bit of work and the best thing you can do is consult engineers FIRST. Or have your fabricator put it into WRITING that he will GUARANTEE that it will pass roadworthy

as far as legality goes the cab swap is more favorable (cab substitution)
this way far less welding of suspension mounts and things also steering and suspension geometry is all factory set (much less for the engineer to freak out about)

this way he only has to certify for the mounting of the cab and engine mounting if any
these are less likely to cause a serious accident if they were to fail
ie if a cab drops at one corner then the car will not roll or veer off the road
or if one engine mount breaks it will just sit down at one corner and hit on the body or chassis making a lot of noise

but loose a diff mounting and the whole axle skews sideways on the highway and crosses into oncoming traffic that is a little more serious

its about arse covering an rightly so

thats why i did mine the way i did

my last truck was a reaxled truck with coils but more of a night mare to get through

jonathan

[horndog]

yeah thats why Im looking at the cab swap
I have talked to the transport department in queensland and they told me i had to inform them exactly what modifications i intend to do n they will give me the go ahead if they aprove. the way the bloke was talking he recommended the cab swap as it had been done many times before and would be easier to pass

[Ice]

doing a similar conversion atm

hzj75 cab onto an 93 model petrol 80 chassis

slightly different motor and box though

1uz with 2uz bellhousing and auto

shall put up some pics as it progresses

how are you gunna run the 2uz box ?
the ect will not run it? are you going to run a hyro conversion?
its not the problem of bolting them together its the problem of getting it all to run correctly out of limp home mode

i would recomend that you use the 1uz auto box and adapt it to your transfer of choice

or just go manual plenty of options if you go manual

jonathan

Jonathan im not using the 2uz box using an early non electronic box from a turbo 80, Manual no thanks...

[thrashlux]

sweet dude that will work fine man

i misunderstood

i thought you said 2uz bellhousing and auto gearbox as in both from the 2uz

yeah no problem with what you are doing running the hydro box

good luck with it


its just i do a lot of wiring and some of the things people do
like bolt stuff into a car and expect it to work just because it bolted together
then they have gone that far down that path they are screwed

but you are not like that at all
just set the alarm bells off did not want to see some one get burned

cheers

jonathan

[Evil 73]

My old FJ73 onto an 80 series chassi, running supercharged 5 litre, t700 auto and gq transfer, all driveline has been lifted to porvide a flat belly.

Modded 80 diffs front and rear, standard 3 link front and "A" frame rear.

[84sloth]

hey mate im using my engine and box that comes out of my 94 hzj75. are u fellas sure that the front diff out of my 75 will fit the 80 front. i could of sworn that the 80 high pinion is a 8' centre like a dirty hilux has. the 75 high pinion front looks massive compared to thatt

[thrashlux]

hey mate im using my engine and box that comes out of my 94 hzj75. are u fellas sure that the front diff out of my 75 will fit the 80 front. i could of sworn that the 80 high pinion is a 8' centre like a dirty hilux has. the 75 high pinion front looks massive compared to thatt

they are the same the one in your truck is the same size as a hilux

have swapped them myself before to change ratios in an 80

toyota dont make a bigger high pinion
if they did everyone would want one

it may look bigger in the 75 because the wheels are closer together

[nastytroll]

I will proberly sell the 80 I have, pm me if your interested, it would suit a conversion easy.

[horndog]

Hey 84sloth
Have u mounted your gearbox yet on the cross member and what does that do for your drive shaft lengths?
Any pics would be awesome

[84sloth]

nah i havent mounted anything yet just measurements and thats 1 thing i have forgotten to do. i have both 75 and 80 driveshafts to work with. i know the crossmember on the petrol 80 if further back. ive the diesel so hopefully not to many probs. does anybody know how much longer/short the 75 box is compared to the 80 one?

[horndog]

I had a look at my mates 80 the other day n its about 200mm further back i think give or take a bit, it surprised me how much longer the 80 box is.
on the 75 the mount is at the front of the box whilst its ruffly at the back of the 80 if i remember correctly which makes it worse.

I didn't measure the drive shafts but the wheelbase is 3 inchs shorter than the 75

[land8079]

A mate of mine did it him self in his shed and got it all leagl.
P.M. me if you want his phone no as i know he would be only to happy to fill ya in on all the little issues

[GO79]

85-89/90 in the 7x series were the last of the big front diffs so pretty much any hzj will have the high pinion hzj come out in 90