RT40 Corona Diff Choices....?

[RT40Corona4AGTE]

Hi all,

As some of you know I am currently building an RT40 Corona up. It currently has the stock'o diff and I am afraid it just wont be good enough. I have been told that a ST141 diff could be the way to go? Being a disc-brake rear end I thought it sounded quite good. Do these diff's bolt straight in or are there mods required? shortening, etc?

I am also thinking maybe a G-series hilux diff with disc-brake conversion would be the way to go? As the centre is offset, I beleive (correct me if I am wrong as I am a n00b when it comes to diffs) I only need to shorten one side? I can do all the machining at work, so shortening and welding on mounts, etc wont be a hard feat at all.

I also thought of a Ford 9 inch, but I think that will be way too overkill for my application.

How do I measure my existing RT40 diff so that I can go to the wreckers and start chasing down hilux diffs, etc?

Can anyone point me in some form of direction? Sorry for the several questions, but yes as I have said above, I am a complete n00b when it comes to differentials.

[RT40Corona4AGTE]

anyone?......

[gianttomato]

All overkill for a 2R.

Ah, 4AG turbo...stick with an F or G series. 9" is probably over the top.

[RT40Corona4AGTE]

I was going to say......2R.....pffffftttt!

Think I will go with a G series though.

[RT40Corona4AGTE]

Anyone with info on measuring diffs, etc, etc as per my post above?

[MWP]

Go F series.
Turbo 4AGE shouldnt have enough torque to kill one.

Also G series will be too heavy and kill your unsprung weight ratios (=bad suspension performance).

[M.J.H]

Anyone with info on measuring diffs, etc, etc as per my post above?

If the wheels are still on the car then measure from the center of the tread on one side to the center of the tread on the other side.

if the wheels are off the car then measure from the outer edge of the drum on one side to the outer edge of the drum on the other side.

Will be a 2 person job to be as accurate as possible and write it all down, Don't try to guess or remember cause you will get it wrong at some point.

[MWP]

Drum face to drum face is the best way as wheels can have different offsets making tyre->tyre measurements rather useless.

[grotty100]

Anyone with info on measuring diffs, etc, etc as per my post above?

As pointed out, wheels have different offsets, but here is some interesting info including standard wheel track specs:

http://ourworld.compuserve.com/homep...o/coronprd.htm

Don't know if it will help you much for this topic, but may help you in other ways.
Cheers.
Grotty.

[RT40Corona4AGTE]

thanks guys! +rep for all!

I think I will probably go with the F series....thanks for the information guys. Anyone know who resplines axles and do they need to be re-hardened afterwards?

The rest of the machining/fabrication I should be able to do myself at work, unless somebody knows of a place that does the work cheap.

[grotty100]

Anyone know who resplines axles and do they need to be re-hardened afterwards?

After resplining the axles have to be rehardened. Probably Titanium Nitrided or similar.
Try this mob:

Race Engineering
Wheel Repair Specialists
Custom narrowing and widening for Steel and Alloy wheels plus
gutterscrapes, re-rolling, axle resplining, general milling, mig and tig welding
www.raceengineering.com.au
(07) 3376 6275
(Something here for everyone!)

Don't know how much but give 'em a call.
Cheers.
Grotty.

[RT40Corona4AGTE]

no worries mate, will give them a call tomorrow hoepfully! thanks!

[shoom]

something like a hilux 8" would be fine and can take an amazing amount of punishment, jeff watsons 6 second fj20 sprite runs a tricked up one if you need any verification on their ruggedness. fit a eaton truetrac and you'll have a sweet package that will handle all the abuse that driveline could throw at it, I know a guy who has one in his peripheral port RX2 and its handled 2 years of thrashing including 3rd gear burnouts, drift clutch kicks and helicopters and the LSD is still as tight as the day he got it. good thing is u dont need to run any exotic oils with the truetrac and they corner like a normal open diff / lsd when your driving normally but when you want to give it some herbs they act kind of a spool. There are many different widths of hilux diffs ranging back to the rn10 and varying also between the 2wd or 4wd diffs.