fireballs gs400

is this the one which needs repairs done every year or so? maintence wise is this too much money in the long run, having the grip and not losing the factory gears. is this a better overall idea than the swap from a supra. is this the same but with stock gears in essence?? very interested, just don't want to get over my head.

SBMGS4

Future:

Thanks for the link...really good info.

garnet92

Jacob - I always intended to get to Austin - never could get my a$$ in gear and haven't had business there. After a full year of sitting in my garage I decided that I didn't want it to still be there a year from now. So, I'll let the money from the LSD pay for 2 new S03s on the rear that have little tread left. That wouldn't have happened if I'd had the LSD on from the beginning! Now watch what happens - I'll have some business reason to go to Austin in the next month or so and I'll be kicking myself.

fireballs gs400

any idea on the questions i asked? just want to jump on this if its something i can fathom

TTurboPimp

iTrader: (12)

For what its worth, I have never heard anything about this piece needing repairs doen periodically, this doesnt even make sense to me.

Its hard to say if it is better than the Supra swap...if you do a search, you will get great reviews on both pieces from those who own them.

It is not the same as the Supra/RMM diffrential. The TRD LSD actually gets installed into the stock diffrential using the stock gears/ gear ratio.

The Supra/RMM is a complete replacement diffrential, and it uses the 3.76 gears.

They are also different types of LSD, Supra/RMM is a Torsen, and the TRD is a clutch type.

hope this helps, but if you do a search you will find alot of good info on this topic.......

This is a pretty good price on the unit.

rominl

iTrader: (4)

yup, everything what he said. i talked to todd at tmegineering today, he said that the clutch technically will wear out over time but unless you do crazy stuff like going to track and drag every day like no tomorrow, otherwise you won't see it wear down at all. of course this is provided the fact that the trd lsd is installed correctly and professionally. coz' it involves putting in the lsd together with the stock gears, everything has to be very precise otherwise things will go downhill very fast (noise, burns, grind, you name it)

it's hard to say which lsd is better, really depends on what you want, what you need, and what you already have

SBMGS4

Also, here's the link to Banana GS' page regarding the differentials.

http://lexusmodz.netfirms.com/GS_DIY/LSD/

garnet92

There are big differences in the two LSDs that we’re talking about here.

The Supra/RMM unit is the complete “pumpkin” and as TTurboPimp said, it includes 3.76 gears. A new one from RMM costs (new “lower” price on their website) $1,450.00. I don’t know the availability or price of a true Supra unit. Installation was quoted to me as $200.00 for a Supra/RMM swap. That swap doesn’t require any lash adjustments, shimming, etc. – it’s a straight swap.

BTW, I quoted that price in the original writeup – which is incorrect. Installation of the TRD unit does require the teardown of the rear end, bolting the TRD unit onto your ring gear, and lash adjustment and (possibly) shimming. It is a more time-intensive job than swapping the Supra/RMM unit. JacobT’s guy (in Austin) quoted $400.00 for installation of the TRD unit, so that probably more accurate. Jacob has had that unit for some time and he’s very happy with the results. His guy indicated that the parts swapped exactly and didn’t need shimming (correct me if that’s wrong, Jacob). My mechanic here wouldn’t warranty the installation without the lash adjustments – which could require shims – and would have required ordering the proper shims from Lexus once he determined the thickness needed. In hindsight, I wish I’d have left the car for a couple of days and had the LSD installed.

The TRD clutch-type unit retains the original gearing and according to the writeup made available to us (thanks SMBGS4) will still send power to the other wheel even when one wheel loses traction. The Torsen differential (Supra/RMM) will be unable to supply any torque to the other set of wheels if one set of wheels loses traction completely. Do a search to verify, but I’ve never seen any recurring problems with either LSD.

I had an opportunity to buy an RMM unit from a guy who wanted to swap back to an original LSD (don’t know why). Jimy at Davenport Motors told me about it. I saw the car up on a lift at Davenport. He was asking $1,000 and Davenport quoted $200.00 to swap them with both cars up on lifts side by side. The guy probably would have gone for $900. but I walked away because of the 3.76 gearing. He eventually sold to someone in California. Back then, there were some concerns voiced here on CL over hitting the rev limiter with the higher gearing but since then there’ve been several guys with the 3.76 gears that don’t seem to have problems – bitkahuna is an example.

I know this is long-winded (nothing new for me) but in the spirit of full disclosure, I want anyone who buys the unit to know what to expect.

BTW, SMBGS4 - that last link to Banana's site doesn't work.

SBMGS4

Garnet:

Thanks for the insight and your feedback..that really helps. You will need to copy and paste the link into the url address window. For some reason, it didn't create a link when I posted it to CL. Sorry...

3dog

iTrader: (1)

i got the rmm 3.76 torsen lsd last month. cost me $200 to get installed. i love it very nice mod.

rominl

iTrader: (4)

awesome writeup there man! i can't agree more on what you said, and it's so objective (even you are selling yours), very much appreciated!

FutureGS400

Yes, this is correct. Due to the way the differentials work internally, they will supply traction differently under different circumstances. In off-roading, there are many different types of locking or limited slip diffs used for different types of driving and with their own advocates. The Torsen type is used in the original Humvee-one of the most formidable off-road vehicles around- with great success. If one wheel is in the air (i.e. zero traction) the solution is simply to apply the brakes to "fool" the diff into sending torque to the wheel with traction. Either LSD seems like it will do the job for our cars though, the main issue will certainly be the difference in gear ratio...