Truer Track vs OEM Torsen LSD and other G series questions

[TheStitt]

Hi

I like the driveability I have with a True track, now im changing diffs and would like to know are there any strengh differences between the Truetrack and the OEM JZA70 torsen LSD.


and with G series do you need spacers for the crown wheel to get either of these centres into a Live axle housing

thanks for any info Stitt

[BigWorm]

There seems to be, the JZA70 torsens don't get a very good rap.
Compared side by side the JZA70 one has big viewing holes around the housing whereas the Truetracs have a 'solid' housing.

[SillyCarS]

you can tell if you need a spacer by measuring the offset of the ring gear, there is a thread that jase (smokey) started and has link to other g series build threads

sorry i cant comment on the strength tho, but as soon as i do some 'product testing' i'll be sure to post evidence

[JustCallMeOrlando]

I'm with BigWorm, I've heard of the JZA70 Torsens failing, but never a Truetrac.

[TheStitt]

I asked this on Supra forums and a few people had heard of failures of the OEM ones

and these two posts are enough for me.

I'll stay ture track

thanks guys

[cambelt]

You cant sucessfully put a IRS toyota torsen into a live axel toyota diff even with the spacer as the live axel axels cant support the torsen side gears . The IRS side shafts are machined for a nice locating fit into the torsen centre hence locating the torsen side gears .
Dave

[TheStitt]

ah ok good thing I didn't bid on ebay than. Thanks Dave

[assassin10000]

Hi

I like the driveability I have with a True track, now im changing diffs and would like to know are there any strengh differences between the Truetrack and the OEM JZA70 torsen LSD.

Contact detroit via email. IIRC they are stronger than the OEM toyota ones that seem to have problems with breaking under hard use. I know lots of the 4x4 guys use them and they put a ton more load and torque through them than most cars ever will.

40" inch tires (or larger) + 5 psi + rocks w/grip x 5.29 gears + multiple t-cases... Torque loads like a semi truck.

You cant sucessfully put a IRS toyota torsen into a live axel toyota diff even with the spacer as the live axel axels cant support the torsen side gears . The IRS side shafts are machined for a nice locating fit into the torsen centre hence locating the torsen side gears .
Dave

Not true, what your saying just doesn't sound right to me. Unless there is a difference in the spline dia or tooth that prevents the axle from fitting. Or do you mean installing torsen gears into a non-torsen carrier (open 4-pinion type case)?

I slipped my MA46 semi-floating axles into the oem lsd from a ma61 no problems. I've seen plenty of websites/threads/reports of people using irs/ifs lsd's in solid axle's and visa versa.

Examples:
Supra clutch type lsd from a g-series IRS, into a solid axle g-series toyota 3rd member.
http://www.gearinstalls.com/supralsd4.htm
http://www.gearinstalls.com/supralsd2.htm
http://www.gearinstalls.com/supralsd.htm

IMO, as long as the spline count, ring gear dia, and offset are right. And you can source correct carrier bearings it shouldn't be a problem at all.

Andrew

[Robbos_Toyotas]

hey guys

The diff centres OEm need modification to fit a live axle. The place in the centre where the axle bearings sit over needs machining down as the hilux runs smaller axle bearings. I had to have this done when i put a ma70 lsd into my hilux. It isnt cheap either, it cost me $300 odd to get the machining done and new bearings put in. I was led to believe it all "bolted in" but was sadly mistaken....
edit: but it is installed now and has no problem whatsoever. this was in a yn57 hilux....i also put ma70 discs on it too...
Blake

[cambelt]

We all wish if things were as simple as comparing a few dimensions. If internet says it fits it must LOL.
Have a look at the difference betwwen live axel side gears and side gears in a toyota torsen centre. I havent got pics to show so i cant really show it.
Dave

[assassin10000]

Oh yeah, there are issues with getting the right size carrier bearings. Or having to run staggered sizes.

For example to fit the hilux detroit truetrac in the f-series diff you need to get 50mm id carrier bearings versus the 45mm open diff. But it's a matter of sourcing bearings in 'most cases' versus machining the case...


Dave, are you saying the splines are different count/sizes? If so that makes sense.


Andrew

[Robbos_Toyotas]

Oh yeah, there are issues with getting the right size carrier bearings. Or having to run staggered sizes.

For example to fit the hilux detroit truetrac in the f-series diff you need to get 50mm id carrier bearings versus the 45mm open diff. But it's a matter of sourcing bearings in 'most cases' versus machining the case...


Dave, are you saying the splines are different count/sizes? If so that makes sense.


Andrew

all g series are 30 spline axles
f series are either 26 or 28 from memory

[TheStitt]

try 27mm 27 splines

[Youngy]

I recently bought a Supra Torsen LSD for a lot less than a true trac. When the unit arrived it included a 3mm spacer ring for the crownwheel to be spaced correctly and these instructions - which I quote:

Fitting the Torsen LSD to your Hilux\Hiace carrier.
If yours has the smaller side bearings you will need to buy
32010JA1 bearings for the Torsen. If you have the bigger
bearings they willfir the Torsen. If you really want
longer bolts for fitting the crownwheel the size is 11mm
diameter with 1mm pitch which I do not think you will find
at your local nut and bolt shop. That size us used in
other automotive applications.
For example Mitsubishi 4g92 single cam 16 valve 1600cc
motor use that size to hold the flywheel on to the crank.
They are a little long but can be shortened to the size
you want. I have used the stock bolts to hold on my
crownwheel in my V8 hilux and have had no problems.
I discarded the locking tas and used loctite to secure
the bolts.

I am yet to fit the unit into the car at this stage. I can confirm that the spare axles I have fitted right in without any issues.

It appears to be pretty straight forward!

[cambelt]

Ok put both yr pointer fingers down one axel hole and see if the side gear can move up and down .
What I'm trying to say is IRS half shafts locate the torsen side gears central but the live axels cannot which results in the side gears only being held in alignment by the 3 inside Gears . It's hard to explain,
Dave