80 Vs 75 diffs

[rockcrawler31]

hey there guru's

i currently have 91 model 75 series diffs under my chassis, and when i have the suspension swapped to coils it's a perfect opportunity to swap axles if its an advantage.

So these are the considerations -
Will my RD23 front locker fit 80 series axles (and which year models)
What are the best year model 80 series axles and why
What is the exact track gain over 75x diffs
Are there any disadvantages to choosing 80 diffs over 75's

My current diff is a standard 91 model 75 series diff with what seems to be a high pinion diff. is this the same diff that is in the 80x trucks that everyone seems to think is a grenade? Chromoly cv's are available for both of these so that's not really a drama, but how do the stock cv's compare?

The diff swap shouldn't be too much of a drama legally, i spoke to DOT and they are more concerned with the coil conversion. How will 80x diff brakes go with a 75x master cylinder and booster?

[midi73]

From my research doing a coil conversion is easy where as altering track is not easy. That is why when i go coils on my midi I am doing a whole chassis swap to an 80 series chassis, so I can legally go wider track.

[Z()LTAN]

legally

Dude none of that is legal...

LOL

[known 2]

80's front is no grenade. u've been listening to nissan people.

plenty og big powered 80's on 35's have no woreis and u'll allways do a cv 1st

[midi73]

legally

Dude none of that is legal...

LOL

Rubbish. I have already looked into getting my midi put onto an 80 chassis. and it can be fully engineered. Whats more I know people who have done it.
Anyway, what do you think I am talking about? taking drugs?
Lol.
Cheers.

[dogbreath_48]

hey there guru's

i currently have 91 model 75 series diffs under my chassis, and when i have the suspension swapped to coils it's a perfect opportunity to swap axles if its an advantage.

So these are the considerations -
Will my RD23 front locker fit 80 series axles (and which year models)
What are the best year model 80 series axles and why
What is the exact track gain over 75x diffs
Are there any disadvantages to choosing 80 diffs over 75's

My current diff is a standard 91 model 75 series diff with what seems to be a high pinion diff. is this the same diff that is in the 80x trucks that everyone seems to think is a grenade? Chromoly cv's are available for both of these so that's not really a drama, but how do the stock cv's compare?

The diff swap shouldn't be too much of a drama legally, i spoke to DOT and they are more concerned with the coil conversion. How will 80x diff brakes go with a 75x master cylinder and booster?

If yours is the high pinion front, the locker should fit into the 80 diff.
80's run larger/stronger CV's than 75's AFAIK (though the hi-pinion axle might have identical CV's ????)
An 80 series master cylinder and booster will bolt into the 75, with only a very minor mod (extension) of the actuator rod required. Even the pipes line up.

That's all i know. One day i'd like coils and 80 diffs under my 75 - so you do it 1st and iron out all the problems for me

-Stu

[rockcrawler31]

excellent

i was having a chat to the DOT modifications office ( i actually found a chap who was real helpful and knew his shite), and he said that the coil swap is what they would be concerned about as it changes the handling dynamics of the vehicle most. As far as he's concerned the axle swap would be easy as the track width would not be altered for that axle, it's an axle from a similar make truck with similar braking performance etc.

i might swap the centres between the diffs if i can, that way i can buy diffs without centres, and save the hassle of swapping the diff carriers/lockers.

MILO

[rockcrawler31]

excellent

i was having a chat to the DOT modifications office ( i actually found a chap who was real helpful and knew his shite), and he said that the coil swap is what they would be concerned about as it changes the handling dynamics of the vehicle most. As far as he's concerned the axle swap would be easy as the track width would not be altered for that axle, it's an axle from a similar make truck with similar braking performance etc.

i might swap the centres between the diffs if i can, that way i can buy diffs without centres, and save the hassle of swapping the diff carriers/lockers.

MILO

[bj on roids]

excellent

i was having a chat to the DOT modifications office ( i actually found a chap who was real helpful and knew his shite), and he said that the coil swap is what they would be concerned about as it changes the handling dynamics of the vehicle most. As far as he's concerned the axle swap would be easy as the track width would not be altered for that axle, it's an axle from a similar make truck with similar braking performance etc.

i might swap the centres between the diffs if i can, that way i can buy diffs without centres, and save the hassle of swapping the diff carriers/lockers.

MILO

yes the centres will swap over if you're 75 series is pre 1998 (on the rear) and the front will swap no matter what.

your 75s is probs about 55"wms to wms, whereas your 80s is around 63"wms to wms.

[bj on roids]

From my research doing a coil conversion is easy where as altering track is not easy. That is why when i go coils on my midi I am doing a whole chassis swap to an 80 series chassis, so I can legally go wider track.

talk to all the engineers before doing anything, brad on here knows hiw stuff when it comes to that, i think he calls himself offroadvw or something