Rear differentials

[Jazkin]

I am in need of help. My 84 Datsun 720 2WD rear differential is gone. Can’t seem to find any third members on my area that would fit my truck. I have seen some 73-80’s Toyota rear axel and I was hoping someone could educate me on Toyota and Nissan rear diff interchangeability. Or better a part number or how to source a third member from

[datzenmike]

Toyota differentials won't fit at all.

 

Find the engine tag on the passenger side inner fender under the hood hinge.

 

 

 

Bottom right HF 38 means H-190 3.889 differential ratio. You probably have the 3.889.

HF 35..... 3.545

HF 37..... 3.70

 

HF 41...... 4.11

HF 43..... 4.375 and so on

 

Avoid 4x4 differentials.

[Draker]

B and r or row52

 

you’re in Washington. They’re out there.. 

Edited November 24, 2021 by Draker

[Madkaw]

5 hours ago, datzenmike said:

Toyota differentials won't fit at all.

 

Find the engine tag on the passenger side inner fender under the hood hinge.

 

 

 

Bottom right HF 38 means H-190 3.889 differential ratio. You probably have the 3.889.

HF 35..... 3.545

HF 37..... 3.70

 

HF 41...... 4.11

HF 43..... 4.375 and so on

 

Avoid 4x4 differentials.

Why avoid 4x4 diffs?

[datzenmike]

Around '81 the went to a larger flange and driveshaft. I tried to swap the flange but the pinion spline is also changed. As I see it a 2wd driveshaft won't fit it. An '80 or maybe an '81 might work but they only came in 4.375 ratio.

[Stoffregen Motorsports]

A complete Toyota 4x4 axle assembly would be a good swap. There are so many aftermarket performance parts available for the Toyota axles. Many gear ratio choices, limited slip, detroit locker, air and electric locker, spool even, plus the upgraded chromoly axle shafts and disc brake kits all make the Toyota very inexpensive to build. Plus, the early 4x4 axles are nearly the same width, with the IFS rear axles a bit wider, and finally, the Tacoma axle which is wider still.

 

 

[thisismatt]

On 11/24/2021 at 11:36 AM, Stoffregen Motorsports said:

A complete Toyota 4x4 axle assembly would be a good swap. There are so many aftermarket performance parts available for the Toyota axles. Many gear ratio choices, limited slip, detroit locker, air and electric locker, spool even, plus the upgraded chromoly axle shafts and disc brake kits all make the Toyota very inexpensive to build. Plus, the early 4x4 axles are nearly the same width, with the IFS rear axles a bit wider, and finally, the Tacoma axle which is wider still.

 

 

I feel like I've asked this before, but what disc brake kits with parking brake are available for the ~79-85 axle? I see one from Little Shop Mfg...

[Stoffregen Motorsports]

The only one I would use is quite expensive. It come from Front Range Offroad and converts to full floating axles with spindles and hubs from a solid front axle and the brake parts are from a late model FJ Cruiser or 4Runner. It also widens your axle six inches, which is perfect for the off-road guy trying to gain some width. Total cost is about $2000 all in.

 

Obviously the above is not great for a minim truck where width is a concern. There are cheap disc brake conversion kits using GM "floating" type calipers, but the misconception there is that they will float with the axle. They weren't designed to float that rapidly and this usually ends with irregular pad wear.

 

There was another company selling a six lug Toyota rear disc kit with parking brake. I think they were called Tacoma Racing, but they may have changed their name. Here's a link to what I think is the new company - https://sosperformance.com/products

 

And here's a screenshot of the items I think would work to convert an old school Toyota rear.

 

 

[Stoffregen Motorsports]

In the past, you could use Supra calipers, but the parking brake mechanism was so dismal, guys stopped using them.

[Stoffregen Motorsports]

The Little Shop MFG kit appears to use a Lincoln caliper...? Or s that an AE86 caliper?

 

https://www.littleshopmfg.com/toyota-79-95-4wd-pickup-rear-disc-brakes-6-lug/

Edited November 27, 2021 by Stoffregen Motorsports

[Stoffregen Motorsports]

Found this too, but it's for 5 lug 7.5" rear axles, and not clear if parking brake is an option.

 

https://www.xcessivemanufacturing.com/truck-axle-caliper-brackets.html

[thisismatt]

3 hours ago, Stoffregen Motorsports said:

The Little Shop MFG kit appears to use a Lincoln caliper...? Or s that an AE86 caliper?

 

https://www.littleshopmfg.com/toyota-79-95-4wd-pickup-rear-disc-brakes-6-lug/

 

No idea. What is it about this particular axle's runout that makes them not great for disc brakes?

[bottomwatcher]

Wilwood 120-12070-BK Black Caliper Mount (MC4 L/H .810 Rotor) https://www.amazon.com/dp/B011B3Y9K6/ref=cm_sw_r_awdo_navT_g_ZGT6DBH5R5BWYK43SK73

What about something like this for a rear parking brake?

[thisismatt]

7 hours ago, Stoffregen Motorsports said:

The Little Shop MFG kit appears to use a Lincoln caliper...? Or s that an AE86 caliper?

 

https://www.littleshopmfg.com/toyota-79-95-4wd-pickup-rear-disc-brakes-6-lug/

 

Looks like it is the same ol' Eldorado, Seville, Riviera caliper...

[Stoffregen Motorsports]

16 hours ago, bottomwatcher said:

Wilwood 120-12070-BK Black Caliper Mount (MC4 L/H .810 Rotor) https://www.amazon.com/dp/B011B3Y9K6/ref=cm_sw_r_awdo_navT_g_ZGT6DBH5R5BWYK43SK73

What about something like this for a rear parking brake?

Yes, those work, but who wants two calipers per side on their rear axle?

[Stoffregen Motorsports]

15 hours ago, thisismatt said:

 

Looks like it is the same ol' Eldorado, Seville, Riviera caliper...

El Dorado...That's what I was thinking.