Making an LSD work?

[shortgq]

Hi I recently asked how i found out whether the ford maverick i just bought had a LSD, well yippie it does. My question is how do make the thing work in the scrub, as i've never owned a 4by with an LSd before, and what are their limitations, ie. do both wheels have to touch ground or can one be airbourne etc and it will still drive through.

Thanx

[bazzle]

Both wheels need resistence so either on the ground or with one foot on the brake.

Bazzle

[roadrunner]

Regular servicing with good quality LSD specific oils

[shortgq]

What oil would u suggest??

[bigbluemav]

You can also go to a diff shop and have them "tighten" it up a bit. That makes a good thing better!!!!

[roadrunner]

What oil would u suggest??

Anything that has LSD written on it !

I use Penrite, but pretty much any oil as long as its not $5 dollar cheap stuff. I found in my GQ that every 5000 ks was about the limit before it stopped engaging properly.

[bazzle]

LSD oil or additive to diff oil 85/140.

It will work better with normal oil but will chatter real bad. Lsd additive makes the clutches slip just a little as they pull up.

Bazzle

[Daisy]

Penrite limoslip 140 works wonders on GQ LSD"s

[XterraGuy]

Foot on the brake shouldn't have any effect on the clutch-type LSDs we have. That works on helical/torsen units that have a fixed torque bias, as long as one side has resistance generating torque, the other side gets some based on the bias ratio, except when a tire is completely lifted. A percentage of zero is still zero, but if you set the parking brake or the like, you have something greater than zero to work from. Clutch types have a fixed breakaway torque, period, once there's more than the breakaway torque across the diff, it's gone and won't come back.

Brent

[Dirty Dave]

Apply the right pedal to full postion and then drop the left pedal and don't change the right pedal's postion until the fun is done......ie don't back off and neither will the limo.....don't be soft.

[bazzle]

Foot on brake helps as it loads spinning /unweighted wheel so lsd can get a bit of transfer again. Works with open diffs too.

Nissan H233b and H260 lsds i believe are ramp loading.

Bazzle

[rOd]

Penrite limoslip 140 works wonders on GQ LSD"s

I agree!

Changed mine to that stuff not long ago. Now my rear tyres chirp around corners. More so in mall carparks.

Rod

[bazzle]

Thats because Penrite only use minimal additive. They sell top ups in small sackets to stop the chirp. (so the man told me)

Bazzle

[XterraGuy]

Nissan H233b and H260 lsds i believe are ramp loading.

Wasn't aware of ramp-loading H233 LSDs, just the R200, H190, and H260, but taking a look at the parts diagrams in my European version of FAST I see the Y61 GR does have a ramp-loading H233B.
However, I found something even more interesting: The 89-94 GR (Y60) H233b is available in an electrically-locking rear that ALSO has a ramp-loading LSD inside the case! Now that's something I would love to have. The only other implementations of a lockable LSD that I'm aware of are the Jeep Wrangler Rubicon's factory units and the Tractec/Detroit Electrac aftermarket (D44 and D60 only), both are helical/torsen units.

Brent

[Josh_GQ]

how much does it normally cost to get the lsd tightend?
foot on the brake works wonders, handbrake won't do anything cause its on the shaft.

[XterraGuy]

Ah, that's right, you Patrol guys have a central parking brake setup. Ours are at the drums.

[Leprecaun]

Likewise here Xterra, by applying the handbrake I can force the real LSD to rampl load and if I tap the foot brake I can do the same with the front wheels as well, basic form of locker at the expense of brake pads. Best thing though is to tighten the Lsds up at a shop. Mine got done when I took the rear diff in to be serviced after my airlocker died inside it.

[XterraGuy]

I've already done some tweaking of an LSD that I plan to swap in in a few weeks. In the mid/late 90's the US H233B LSD was de-rated to about half the breakaway torque of the earlier ones (actually the change follows the switch from 31-spline to 33-spline shafts) and I have built my 33-spline unit to the same spec as the 31-spline type by swapping the two non-keyed spring discs at the outer ends of the stack (that only provide compression) with the keyed spring disc and spring plate that were at the end of the 31-spline stack (they engage the case and side gear as well as provide compression). This requires the longer retainer plates to allow for the extra "ears" as well. Pics of the two:





Originally I was going to just stuff an extra pair of discs in the stack to tighten it up but I've heard too many stories of it being too effective and pretty much locking it up and even some failing, and then I discovered what made the older LSDs different and went that route.
I have pretty much made up my mind to crack the LSD open once more before I install it and stick in just one of the old non-keyed spring discs at the end of the stack between the keyed spring plate (w/ the ears) and the diff case to put additional squeeze on the stack. I'd rather find it too tight and have to revert than have the initial "tweak" be so-so and debate going further.

Brent

[big red]

on track 4wd did my GU a few years ago for about 300 bucks drive in drive out.
it ended up shattering a clutch plate a couple of years later and reverted to an open diff.
i did get it tightened a hell of a lot though so a normal tighten should be ok...

i had a normal tighten done on my GQ with no probs.

with the GU it made the front left wheel tuck under when turning right as the rear right lifted up under wind up.
wore the edges off the left front tyre pretty quick...

when new it would wind up on concrete [such as a servo] then the bfg mud tyre would spin and squeel makeing everyone look
with the centipedes the tyre gripped enough to get the lsd to let go.

if you parked on an angle you could use the wind up to reverse clutch start the truck ...that made em look

[bazzle]

Slightly offf topic but worth remembering is a problem you get with a too tight LSD is sideways walk on sideslopes. Have seen vehicles get into a spot of bother. An airlocker is the best choice if your going to drive this stuff.

Bazzle